Version bump

fix latest version value

.buildscript/deploy_snapshot.sh

@@ -0,0 +1,26 @@
+#!/bin/bash
+#
+# Deploy a jar, source jar, and javadoc jar to Sonatype's snapshot repo.
+#
+# Adapted from https://coderwall.com/p/9b_lfq and
+# http://benlimmer.com/2013/12/26/automatically-publish-javadoc-to-gh-pages-with-travis-ci/
+
+SLUG="bluelinelabs/Conductor"
+JDK="oraclejdk8"
+BRANCH="develop"
+
+set -e
+
+if [ "$TRAVIS_REPO_SLUG" != "$SLUG" ]; then
+  echo "Skipping snapshot deployment: wrong repository. Expected '$SLUG' but was '$TRAVIS_REPO_SLUG'."
+elif [ "$TRAVIS_JDK_VERSION" != "$JDK" ]; then
+  echo "Skipping snapshot deployment: wrong JDK. Expected '$JDK' but was '$TRAVIS_JDK_VERSION'."
+elif [ "$TRAVIS_PULL_REQUEST" != "false" ]; then
+  echo "Skipping snapshot deployment: was pull request."
+elif [ "$TRAVIS_BRANCH" != "$BRANCH" ]; then
+  echo "Skipping snapshot deployment: wrong branch. Expected '$BRANCH' but was '$TRAVIS_BRANCH'."
+else
+  echo "Deploying snapshot..."
+  ./gradlew clean uploadArchives
+  echo "Snapshot deployed!"
+fi

.gitignore

@@ -15,7 +15,6 @@ gen-external-apklibs
 # Gradle
 .gradle
 build
-gradle.properties
 
 # Maven
 target

.travis.yml

@@ -3,9 +3,33 @@ language: android
 android:
   components:
     - tools
-    - build-tools-23.0.2
-    - android-23
+    - build-tools-25.0.0
+    - android-25
     - extra-android-m2repository
+  licenses:
+    - '.+'
 
 script:
   - ./gradlew test
+
+jdk:
+  - oraclejdk8
+
+branches:
+  only:
+    - develop
+    - master
+
+after_success:
+  - .buildscript/deploy_snapshot.sh
+
+cache:
+  directories:
+    - $HOME/.gradle
+
+sudo: false
+
+env:
+  global:
+    - secure: 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
+    - secure: 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

README.md

@@ -1,11 +1,11 @@
-[![Travis Build](https://travis-ci.org/bluelinelabs/Conductor.svg)](https://travis-ci.org/bluelinelabs/Conductor) [![Android Arsenal](https://img.shields.io/badge/Android%20Arsenal-Conductor-brightgreen.svg?style=flat)](http://android-arsenal.com/details/1/3361)
+[![Travis Build](https://travis-ci.org/bluelinelabs/Conductor.svg)](https://travis-ci.org/bluelinelabs/Conductor) [![Android Arsenal](https://img.shields.io/badge/Android%20Arsenal-Conductor-brightgreen.svg?style=flat)](http://android-arsenal.com/details/1/3361) [![Javadocs](http://javadoc.io/badge/com.bluelinelabs/conductor.svg)](http://javadoc.io/doc/com.bluelinelabs/conductor)
 
 # Conductor
 
 A small, yet full-featured framework that allows building View-based Android applications. Conductor provides a light-weight wrapper around standard Android Views that does just about everything you'd want:
 
-              |  Conductor
-------|------------------------------
+|           |  Conductor  |
+|-----------|-------------|
 :tada: | Easy integration
 :point_up: | Single Activity apps without using Fragments
 :recycle: | Simple but powerful lifecycle management
@@ -20,19 +20,42 @@ Conductor is architecture-agnostic and does not try to force any design decision
 ## Installation
 
 ```gradle
-compile 'com.bluelinelabs:conductor:1.1.0'
+compile 'com.bluelinelabs:conductor:2.1.3'
 
 // If you want the components that go along with
 // Android's support libraries (currently just a PagerAdapter):
-compile 'com.bluelinelabs:conductor-support:1.1.0'
+compile 'com.bluelinelabs:conductor-support:2.1.3'
 
-// If you want RxJava/RxAndroid lifecycle support:
-compile 'com.bluelinelabs:conductor-rxlifecycle:1.1.0'
+// If you want RxJava lifecycle support:
+compile 'com.bluelinelabs:conductor-rxlifecycle:2.1.3'
+
+// If you want RxJava2 lifecycle support:
+compile 'com.bluelinelabs:conductor-rxlifecycle2:2.1.3'
+```
+
+SNAPSHOT:
+
+```gradle
+compile 'com.bluelinelabs:conductor:2.1.4-SNAPSHOT'
+compile 'com.bluelinelabs:conductor-support:2.1.4-SNAPSHOT'
+compile 'com.bluelinelabs:conductor-rxlifecycle:2.1.4-SNAPSHOT'
+compile 'com.bluelinelabs:conductor-rxlifecycle2:2.1.4-SNAPSHOT'
+```
+
+You also have to add the url to the snapshot repository:
+
+```gradle
+allprojects {
+  repositories {
+    ...
+
+    maven { url "https://oss.sonatype.org/content/repositories/snapshots/" }
+}
 ```
 
 ## Components to Know
 
-              |  Conductor Components
+|             |  Conductor Components |
 ------|------------------------------
 __Controller__ | The Controller is the View wrapper that will give you all of your lifecycle management features. Think of it as a lighter-weight and more predictable Fragment alternative with an easier to manage lifecycle.
 __Router__ | A Router implements navigation and backstack handling for Controllers. Router objects are attached to Activity/containing ViewGroup pairs. Routers do not directly render or push Views to the container ViewGroup, but instead defer this responsibility to the ControllerChangeHandler specified in a given transaction.
@@ -46,7 +69,7 @@ __ControllerTransaction__ | Transactions are used to define data about adding Co
 ```java
 public class MainActivity extends Activity {
 
-    private Router mRouter;
+    private Router router;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -54,17 +77,17 @@ public class MainActivity extends Activity {
 
         setContentView(R.layout.activity_main);
 
-        ViewGroup container = (ViewGroup)findViewById(R.id.controller_container)
+        ViewGroup container = (ViewGroup)findViewById(R.id.controller_container);
 
-        mRouter = Conductor.attachRouter(this, container, savedInstanceState);
-        if (!mRouter.hasRootController()) {
-            mRouter.setRoot(new HomeController());
+        router = Conductor.attachRouter(this, container, savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new HomeController()));
         }
     }
 
     @Override
     public void onBackPressed() {
-        if (!mRouter.handleBack()) {
+        if (!router.handleBack()) {
             super.onBackPressed();
         }
     }
@@ -95,7 +118,7 @@ public class HomeController extends Controller {
 
 The lifecycle of a Controller is significantly simpler to understand than that of a Fragment. A lifecycle diagram is shown below:
 
-![Controller Lifecycle](docs/Controller Lifecycle.jpg)
+![Controller Lifecycle](docs/Controller%20Lifecycle.jpg)
 
 ## Advanced Topics
 
@@ -105,11 +128,11 @@ The lifecycle of a Controller is significantly simpler to understand than that o
 ### Custom Change Handlers
 `ControllerChangeHandler` can be subclassed in order to perform different functions when changing between two `Controllers`. Two convenience `ControllerChangeHandler` subclasses are included to cover most basic needs: `AnimatorChangeHandler`, which will use an `Animator` object to transition between two views, and `TransitionChangeHandler`, which will use Lollipop's `Transition` framework for transitioning between views.
 
-### Child Controllers
-`addChildController` can be called on a `Controller` in order to add nested `Controller`s. Child `Controller`s will receive all lifecycle callbacks that parents get.
+### Child Routers & Controllers
+`getChildRouter` can be called on a `Controller` in order to get a nested `Router` into which child `Controller`s can be pushed. This enables creating advanced layouts, such as Master/Detail.
 
 ### RxJava Lifecycle
-If the RxLifecycle dependency has been added, there is an `RxController` available that can be used along with the standard [RxLifecycle library](https://github.com/trello/RxLifecycle). There is also a `ControllerLifecycleProvider` available if you do not wish to use this subclass. 
+If the RxLifecycle dependency has been added, there is an `RxController` available that can be used along with the standard [RxLifecycle library](https://github.com/trello/RxLifecycle). There is also a `ControllerLifecycleProvider` available if you do not wish to use this subclass.
 
 ## License
 ```

bll-gradle-push.gradle

@@ -1,101 +0,0 @@
-apply plugin: 'com.github.dcendents.android-maven'
-apply plugin: 'com.jfrog.bintray'
-
-group = 'com.bluelinelabs'
-version = rootProject.ext.versionName
-
-task sourcesJar(type: Jar) {
-    from android.sourceSets.main.java.srcDirs
-    classifier = 'sources'
-}
-
-task javadoc(type: Javadoc) {
-    source = android.sourceSets.main.java.srcDirs
-    classpath += project.files(android.getBootClasspath().join(File.pathSeparator))
-    exclude '**/R.java'
-    exclude '**/internal/**'
-    failOnError = false
-}
-
-task javadocJar(type: Jar, dependsOn: javadoc) {
-    classifier = 'javadoc'
-    from javadoc.destinationDir
-}
-
-artifacts {
-    archives javadocJar
-    archives sourcesJar
-}
-
-if (project.hasProperty('pom_name')) {
-    install {
-        repositories.mavenInstaller {
-            pom.project {
-                name pom_name
-                description pom_description
-                url pom_url
-                packaging pom_packaging
-                groupId 'com.bluelinelabs'
-                artifactId project.hasProperty('artifactId') ? project.ext.artifactId : ''
-
-                organization {
-                    name 'BlueLine Labs'
-                    url 'http://bluelinelabs.com'
-                }
-                licenses {
-                    license {
-                        name 'The Apache Software License, Version 2.0'
-                        url 'http://www.apache.org/licenses/LICENSE-2.0.txt'
-                        distribution 'repo'
-                    }
-                }
-                scm {
-                    url pom_url
-                    connection pom_git_connection
-                    developerConnection pom_git_connection
-                }
-                developers {
-                    developer {
-                        id 'erickuck'
-                        name 'Eric Kuck'
-                    }
-                }
-            }
-        }
-    }
-
-    bintray {
-        user = project.hasProperty('bintray_username') ? bintray_username : ''
-        key = project.hasProperty('bintray_api_key') ? bintray_api_key : ''
-        configurations = ['archives']
-
-        dryRun = false
-        publish = false
-
-        pkg {
-            repo = 'bluelinelabs'
-            userOrg = 'bluelinelabs'
-            name = pom_name
-            desc = pom_description
-            websiteUrl = pom_url
-            issueTrackerUrl = pom_issue_tracker_url
-            vcsUrl = pom_url
-            licenses = ['Apache-2.0']
-            labels = pom_labels
-
-            version {
-                name = project.version
-                gpg {
-                    sign = true
-                    passphrase = project.hasProperty('bintray_gpg_passphrase') ? bintray_gpg_passphrase : ''
-                }
-                mavenCentralSync {
-                    sync = false
-                    user = project.hasProperty('maven_central_username') ? maven_central_username : ''
-                    password = project.hasProperty('maven_central_password') ? maven_central_password : ''
-                    close = '1'
-                }
-            }
-        }
-    }
-}

build.gradle

@@ -3,24 +3,15 @@ buildscript {
         jcenter()
     }
     dependencies {
-        classpath 'com.android.tools.build:gradle:1.5.0'
-        classpath 'com.github.dcendents:android-maven-gradle-plugin:1.3'
+        classpath 'com.android.tools.build:gradle:2.3.0'
     }
 }
 
-plugins {
-    id "com.jfrog.bintray" version "1.5"
-}
-
 allprojects {
     repositories {
         jcenter()
-        mavenLocal()
+        mavenCentral()
     }
 }
 
-task wrapper(type: Wrapper) {
-    gradleVersion = '2.10'
-}
-
 apply from: rootProject.file('dependencies.gradle')

conductor-lint/build.gradle

@@ -1,5 +1,8 @@
 apply plugin: 'java'
 
+targetCompatibility = JavaVersion.VERSION_1_7
+sourceCompatibility = JavaVersion.VERSION_1_7
+
 configurations {
     lintChecks
 }
@@ -8,6 +11,9 @@ dependencies {
     compile rootProject.ext.lintapi
     compile rootProject.ext.lintchecks
 
+    testCompile rootProject.ext.lint
+    testCompile rootProject.ext.lintTests
+
     lintChecks files(jar)
 }
 

conductor-lint/src/main/java/com/bluelinelabs/conductor/lint/ControllerChangeHandlerIssueDetector.java

@@ -1,7 +1,6 @@
 package com.bluelinelabs.conductor.lint;
 
-import com.android.annotations.NonNull;
-import com.android.tools.lint.client.api.JavaParser.ResolvedClass;
+import com.android.tools.lint.client.api.JavaEvaluator;
 import com.android.tools.lint.detector.api.Category;
 import com.android.tools.lint.detector.api.Detector;
 import com.android.tools.lint.detector.api.Implementation;
@@ -9,21 +8,13 @@ import com.android.tools.lint.detector.api.Issue;
 import com.android.tools.lint.detector.api.JavaContext;
 import com.android.tools.lint.detector.api.Scope;
 import com.android.tools.lint.detector.api.Severity;
-import com.android.tools.lint.detector.api.Speed;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiMethod;
 
-import java.lang.reflect.Modifier;
 import java.util.Collections;
 import java.util.List;
 
-import lombok.ast.ClassDeclaration;
-import lombok.ast.ConstructorDeclaration;
-import lombok.ast.Node;
-import lombok.ast.NormalTypeBody;
-import lombok.ast.StrictListAccessor;
-import lombok.ast.TypeMember;
-import lombok.ast.VariableDefinition;
-
-public final class ControllerChangeHandlerIssueDetector extends Detector implements Detector.JavaScanner, Detector.ClassScanner {
+public final class ControllerChangeHandlerIssueDetector extends Detector implements Detector.JavaPsiScanner {
 
     public static final Issue ISSUE =
             Issue.create("ValidControllerChangeHandler", "ControllerChangeHandler not instantiatable",
@@ -34,67 +25,45 @@ public final class ControllerChangeHandlerIssueDetector extends Detector impleme
 
     public ControllerChangeHandlerIssueDetector() { }
 
-    @NonNull
-    @Override
-    public Speed getSpeed() {
-        return Speed.FAST;
-    }
-
     @Override
     public List<String> applicableSuperClasses() {
         return Collections.singletonList("com.bluelinelabs.conductor.ControllerChangeHandler");
     }
 
     @Override
-    public void checkClass(@NonNull JavaContext context, ClassDeclaration node,
-                           @NonNull Node declarationOrAnonymous, @NonNull ResolvedClass cls) {
-
-        if (node == null) {
+    public void checkClass(JavaContext context, PsiClass declaration) {
+        final JavaEvaluator evaluator = context.getEvaluator();
+        if (evaluator.isAbstract(declaration)) {
             return;
         }
 
-        final int flags = node.astModifiers().getEffectiveModifierFlags();
-        if ((flags & Modifier.ABSTRACT) != 0) {
+        if (!evaluator.isPublic(declaration)) {
+            String message = String.format("This ControllerChangeHandler class should be public (%1$s)", declaration.getQualifiedName());
+            context.report(ISSUE, declaration, context.getLocation(declaration), message);
             return;
         }
 
-        if ((flags & Modifier.PUBLIC) == 0) {
-            String message = String.format("This ControllerChangeHandler class should be public (%1$s)", cls.getName());
-            context.report(ISSUE, node, context.getLocation(node.astName()), message);
+        if (declaration.getContainingClass() != null && !evaluator.isStatic(declaration)) {
+            String message = String.format("This ControllerChangeHandler inner class should be static (%1$s)", declaration.getQualifiedName());
+            context.report(ISSUE, declaration, context.getLocation(declaration), message);
             return;
         }
 
-        if (cls.getContainingClass() != null && (flags & Modifier.STATIC) == 0) {
-            String message = String.format("This ControllerChangeHandler inner class should be static (%1$s)", cls.getName());
-            context.report(ISSUE, node, context.getLocation(node.astName()), message);
-            return;
-        }
-
-        boolean hasConstructor = false;
         boolean hasDefaultConstructor = false;
-        NormalTypeBody body = node.astBody();
-        if (body != null) {
-            for (TypeMember member : body.astMembers()) {
-                if (member instanceof ConstructorDeclaration) {
-                    hasConstructor = true;
-                    ConstructorDeclaration constructor = (ConstructorDeclaration)member;
-
-                    if (constructor.astModifiers().isPublic()) {
-                        StrictListAccessor<VariableDefinition, ConstructorDeclaration> params = constructor.astParameters();
-                        if (params.isEmpty()) {
-                            hasDefaultConstructor = true;
-                            break;
-                        }
-                    }
+        PsiMethod[] constructors = declaration.getConstructors();
+        for (PsiMethod constructor : constructors) {
+            if (evaluator.isPublic(constructor)) {
+                if (constructor.getParameterList().getParametersCount() == 0) {
+                    hasDefaultConstructor = true;
+                    break;
                 }
             }
         }
 
-        if (hasConstructor && !hasDefaultConstructor) {
+        if (constructors.length > 0 && !hasDefaultConstructor) {
             String message = String.format(
-                    "This ControllerChangeHandler needs to have a public default constructor (`%1$s`)",
-                    cls.getName());
-            context.report(ISSUE, node, context.getLocation(node.astName()), message);
+                    "This ControllerChangeHandler needs to have a public default constructor (`%1$s`)", declaration.getQualifiedName());
+            context.report(ISSUE, declaration, context.getLocation(declaration), message);
         }
     }
 }

conductor-lint/src/main/java/com/bluelinelabs/conductor/lint/ControllerIssueDetector.java

@@ -1,8 +1,7 @@
 package com.bluelinelabs.conductor.lint;
 
 import com.android.SdkConstants;
-import com.android.annotations.NonNull;
-import com.android.tools.lint.client.api.JavaParser.ResolvedClass;
+import com.android.tools.lint.client.api.JavaEvaluator;
 import com.android.tools.lint.detector.api.Category;
 import com.android.tools.lint.detector.api.Detector;
 import com.android.tools.lint.detector.api.Implementation;
@@ -10,21 +9,14 @@ import com.android.tools.lint.detector.api.Issue;
 import com.android.tools.lint.detector.api.JavaContext;
 import com.android.tools.lint.detector.api.Scope;
 import com.android.tools.lint.detector.api.Severity;
-import com.android.tools.lint.detector.api.Speed;
+import com.intellij.psi.PsiClass;
+import com.intellij.psi.PsiMethod;
+import com.intellij.psi.PsiParameter;
 
-import java.lang.reflect.Modifier;
 import java.util.Collections;
 import java.util.List;
 
-import lombok.ast.ClassDeclaration;
-import lombok.ast.ConstructorDeclaration;
-import lombok.ast.Node;
-import lombok.ast.NormalTypeBody;
-import lombok.ast.StrictListAccessor;
-import lombok.ast.TypeMember;
-import lombok.ast.VariableDefinition;
-
-public final class ControllerIssueDetector extends Detector implements Detector.JavaScanner, Detector.ClassScanner {
+public final class ControllerIssueDetector extends Detector implements Detector.JavaPsiScanner {
 
     public static final Issue ISSUE =
             Issue.create("ValidController", "Controller not instantiatable",
@@ -35,74 +27,56 @@ public final class ControllerIssueDetector extends Detector implements Detector.
 
     public ControllerIssueDetector() { }
 
-    @NonNull
-    @Override
-    public Speed getSpeed() {
-        return Speed.FAST;
-    }
-
     @Override
     public List<String> applicableSuperClasses() {
         return Collections.singletonList("com.bluelinelabs.conductor.Controller");
     }
 
     @Override
-    public void checkClass(@NonNull JavaContext context, ClassDeclaration node,
-                           @NonNull Node declarationOrAnonymous, @NonNull ResolvedClass cls) {
-
-        if (node == null) {
+    public void checkClass(JavaContext context, PsiClass declaration) {
+        final JavaEvaluator evaluator = context.getEvaluator();
+        if (evaluator.isAbstract(declaration)) {
             return;
         }
 
-        final int flags = node.astModifiers().getEffectiveModifierFlags();
-        if ((flags & Modifier.ABSTRACT) != 0) {
+        if (!evaluator.isPublic(declaration)) {
+            String message = String.format("This Controller class should be public (%1$s)", declaration.getQualifiedName());
+            context.report(ISSUE, declaration, context.getLocation(declaration), message);
             return;
         }
 
-        if ((flags & Modifier.PUBLIC) == 0) {
-            String message = String.format("This Controller class should be public (%1$s)", cls.getName());
-            context.report(ISSUE, node, context.getLocation(node.astName()), message);
+        if (declaration.getContainingClass() != null && !evaluator.isStatic(declaration)) {
+            String message = String.format("This Controller inner class should be static (%1$s)", declaration.getQualifiedName());
+            context.report(ISSUE, declaration, context.getLocation(declaration), message);
             return;
         }
 
-        if (cls.getContainingClass() != null && (flags & Modifier.STATIC) == 0) {
-            String message = String.format("This Controller inner class should be static (%1$s)", cls.getName());
-            context.report(ISSUE, node, context.getLocation(node.astName()), message);
-            return;
-        }
 
-        boolean hasConstructor = false;
         boolean hasDefaultConstructor = false;
         boolean hasBundleConstructor = false;
-        NormalTypeBody body = node.astBody();
-        if (body != null) {
-            for (TypeMember member : body.astMembers()) {
-                if (member instanceof ConstructorDeclaration) {
-                    hasConstructor = true;
-                    ConstructorDeclaration constructor = (ConstructorDeclaration)member;
+        PsiMethod[] constructors = declaration.getConstructors();
+        for (PsiMethod constructor : constructors) {
+            if (evaluator.isPublic(constructor)) {
+                PsiParameter[] parameters = constructor.getParameterList().getParameters();
 
-                    if (constructor.astModifiers().isPublic()) {
-                        StrictListAccessor<VariableDefinition, ConstructorDeclaration> params = constructor.astParameters();
-                        if (params.isEmpty()) {
-                            hasDefaultConstructor = true;
-                            break;
-                        } else if (params.size() == 1 &&
-                                (params.first().astTypeReference().getTypeName().equals(SdkConstants.CLASS_BUNDLE)) ||
-                                params.first().astTypeReference().getTypeName().equals("Bundle")) {
-                            hasBundleConstructor = true;
-                            break;
-                        }
-                    }
+                if (parameters.length == 0) {
+                    hasDefaultConstructor = true;
+                    break;
+                } else if (parameters.length == 1 &&
+                        parameters[0].getType().equalsToText(SdkConstants.CLASS_BUNDLE) ||
+                        parameters[0].getType().equalsToText("Bundle")) {
+                    hasBundleConstructor = true;
+                    break;
                 }
             }
         }
 
-        if (hasConstructor && !hasDefaultConstructor && !hasBundleConstructor) {
+        if (constructors.length > 0 && !hasDefaultConstructor && !hasBundleConstructor) {
             String message = String.format(
                     "This Controller needs to have either a public default constructor or a" +
                             " public single-argument constructor that takes a Bundle. (`%1$s`)",
-                    cls.getName());
-            context.report(ISSUE, node, context.getLocation(node.astName()), message);
+                    declaration.getQualifiedName());
+            context.report(ISSUE, declaration, context.getLocation(declaration), message);
         }
     }
 }

conductor-lint/src/test/java/com/bluelinelabs/conductor/lint/ControllerChangeHandlerDetectorTest.java

@@ -0,0 +1,96 @@
+package com.bluelinelabs.conductor.lint;
+
+import com.android.tools.lint.checks.infrastructure.LintDetectorTest;
+import com.android.tools.lint.detector.api.Detector;
+import com.android.tools.lint.detector.api.Issue;
+
+import org.intellij.lang.annotations.Language;
+
+import java.util.Collections;
+import java.util.List;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class ControllerChangeHandlerDetectorTest extends LintDetectorTest {
+
+    private static final String NO_WARNINGS = "No warnings.";
+    private static final String CONSTRUCTOR =
+            "src/test/SampleHandler.java:2: Error: This ControllerChangeHandler needs to have a public default constructor (test.SampleHandler) [ValidControllerChangeHandler]\n"
+            + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+            + "^\n"
+            + "1 errors, 0 warnings\n";
+    private static final String PRIVATE_CLASS_ERROR =
+            "src/test/SampleHandler.java:2: Error: This ControllerChangeHandler class should be public (test.SampleHandler) [ValidControllerChangeHandler]\n"
+                    + "private class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                    + "^\n"
+                    + "1 errors, 0 warnings\n";
+
+    public void testWithNoConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(NO_WARNINGS);
+    }
+
+    public void testWithEmptyConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                + "    public SampleHandler() { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(NO_WARNINGS);
+    }
+
+    public void testWithInvalidConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                + "    public SampleHandler(int number) { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(CONSTRUCTOR);
+    }
+
+    public void testWithEmptyAndInvalidConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                + "    public SampleHandler() { }\n"
+                + "    public SampleHandler(int number) { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(NO_WARNINGS);
+    }
+
+    public void testWithPrivateConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                + "    private SampleHandler() { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(CONSTRUCTOR);
+    }
+
+    public void testWithPrivateClass() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "private class SampleHandler extends com.bluelinelabs.conductor.ControllerChangeHandler {\n"
+                + "    public SampleHandler() { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(PRIVATE_CLASS_ERROR);
+    }
+
+    @Override
+    protected Detector getDetector() {
+        return new ControllerChangeHandlerIssueDetector();
+    }
+
+    @Override
+    protected List<Issue> getIssues() {
+        return Collections.singletonList(ControllerChangeHandlerIssueDetector.ISSUE);
+    }
+
+    @Override
+    protected boolean allowCompilationErrors() {
+        return true;
+    }
+}

conductor-lint/src/test/java/com/bluelinelabs/conductor/lint/ControllerDetectorTest.java

@@ -0,0 +1,96 @@
+package com.bluelinelabs.conductor.lint;
+
+import com.android.tools.lint.checks.infrastructure.LintDetectorTest;
+import com.android.tools.lint.detector.api.Detector;
+import com.android.tools.lint.detector.api.Issue;
+
+import org.intellij.lang.annotations.Language;
+
+import java.util.Collections;
+import java.util.List;
+
+import static com.google.common.truth.Truth.assertThat;
+
+public class ControllerDetectorTest extends LintDetectorTest {
+
+    private static final String NO_WARNINGS = "No warnings.";
+    private static final String CONSTRUCTOR_ERROR =
+            "src/test/SampleController.java:2: Error: This Controller needs to have either a public default constructor or a public single-argument constructor that takes a Bundle. (test.SampleController) [ValidController]\n"
+            + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+            + "^\n"
+            + "1 errors, 0 warnings\n";
+    private static final String CLASS_ERROR =
+            "src/test/SampleController.java:2: Error: This Controller class should be public (test.SampleController) [ValidController]\n"
+                    + "private class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                    + "^\n"
+                    + "1 errors, 0 warnings\n";
+
+    public void testWithNoConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(NO_WARNINGS);
+    }
+
+    public void testWithEmptyConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                + "    public SampleController() { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(NO_WARNINGS);
+    }
+
+    public void testWithInvalidConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                + "    public SampleController(int number) { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(CONSTRUCTOR_ERROR);
+    }
+
+    public void testWithEmptyAndInvalidConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                + "    public SampleController() { }\n"
+                + "    public SampleController(int number) { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(NO_WARNINGS);
+    }
+
+    public void testWithPrivateConstructor() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "public class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                + "    private SampleController() { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(CONSTRUCTOR_ERROR);
+    }
+
+    public void testWithPrivateClass() throws Exception {
+        @Language("JAVA") String source = ""
+                + "package test;\n"
+                + "private class SampleController extends com.bluelinelabs.conductor.Controller {\n"
+                + "    public SampleController() { }\n"
+                + "}";
+        assertThat(lintProject(java(source))).isEqualTo(CLASS_ERROR);
+    }
+
+    @Override
+    protected Detector getDetector() {
+        return new ControllerIssueDetector();
+    }
+
+    @Override
+    protected List<Issue> getIssues() {
+        return Collections.singletonList(ControllerIssueDetector.ISSUE);
+    }
+
+    @Override
+    protected boolean allowCompilationErrors() {
+        return true;
+    }
+}

conductor-rxlifecycle/build.gradle

@@ -1,13 +1,12 @@
+apply from: rootProject.file('dependencies.gradle')
+apply from: rootProject.file('gradle-mvn-push.gradle')
+
 apply plugin: 'com.android.library'
 
 android {
     compileSdkVersion rootProject.ext.compileSdkVersion
     buildToolsVersion rootProject.ext.buildToolsVersion
 
-    lintOptions {
-        abortOnError false
-    }
-
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_7
         targetCompatibility JavaVersion.VERSION_1_7
@@ -16,20 +15,18 @@ android {
     defaultConfig {
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode rootProject.ext.versionCode
-        versionName rootProject.ext.versionName
+        versionCode Integer.parseInt(project.VERSION_CODE)
+        versionName project.VERSION_NAME
     }
 }
 
 dependencies {
     compile rootProject.ext.rxJava
-    compile rootProject.ext.rxAndroid
     compile rootProject.ext.rxLifecycle
+    compile rootProject.ext.rxLifecycleAndroid
 
     compile project(':conductor')
 }
 
 ext.artifactId = 'conductor-rxlifecycle'
 
-apply from: rootProject.file('dependencies.gradle')
-apply from: rootProject.file('bll-gradle-push.gradle')

conductor-rxlifecycle/gradle.properties

@@ -0,0 +1,3 @@
+POM_NAME=Conductor RxLifecycle Extensions
+POM_ARTIFACT_ID=conductor-rxlifecycle
+POM_PACKAGING=aar

conductor-rxlifecycle/src/main/java/com/bluelinelabs/conductor/rxlifecycle/ControllerLifecycleProvider.java

@@ -1,38 +0,0 @@
-package com.bluelinelabs.conductor.rxlifecycle;
-
-import android.support.annotation.CheckResult;
-import android.support.annotation.NonNull;
-
-import rx.Observable;
-
-/**
- * Interface used for RxController. Can also be used if writing your own Controller component without subclassing RxController.
- */
-public interface ControllerLifecycleProvider {
-
-    /**
-     * @return An observable that will have all {@link com.bluelinelabs.conductor.Controller} lifecycle events
-     */
-    @NonNull
-    @CheckResult
-    Observable<ControllerEvent> lifecycle();
-
-    /**
-     * Will bind the source until a specific {@link ControllerEvent} occurs.
-     *
-     * @param event The {@link ControllerEvent} that should cause onComplete to be called
-     * @return A {@link rx.Observable.Transformer} that will call onComplete when the event occurs.
-     */
-    @NonNull
-    @CheckResult
-    <T> Observable.Transformer<T, T> bindUntilEvent(@NonNull ControllerEvent event);
-
-    /**
-     * Will bind the source until the next reasonable {@link ControllerEvent} occurs.
-     * @return A {@link rx.Observable.Transformer} that will call onComplete when the event occurs.
-     */
-    @NonNull
-    @CheckResult
-    <T> Observable.Transformer<T, T> bindToLifecycle();
-
-}

conductor-rxlifecycle/src/main/java/com/bluelinelabs/conductor/rxlifecycle/RxController.java

@@ -5,6 +5,8 @@ import android.support.annotation.CheckResult;
 import android.support.annotation.NonNull;
 
 import com.bluelinelabs.conductor.Controller;
+import com.trello.rxlifecycle.LifecycleProvider;
+import com.trello.rxlifecycle.LifecycleTransformer;
 import com.trello.rxlifecycle.RxLifecycle;
 
 import rx.Observable;
@@ -13,9 +15,9 @@ import rx.subjects.BehaviorSubject;
 /**
  * A base {@link Controller} that can be used to expose lifecycle events using RxJava
  */
-public abstract class RxController extends Controller implements ControllerLifecycleProvider {
+public abstract class RxController extends Controller implements LifecycleProvider<ControllerEvent> {
 
-    private final BehaviorSubject<ControllerEvent> mLifecycleSubject;
+    private final BehaviorSubject<ControllerEvent> lifecycleSubject;
 
     public RxController() {
         this(null);
@@ -23,28 +25,28 @@ public abstract class RxController extends Controller implements ControllerLifec
 
     public RxController(Bundle args) {
         super(args);
-        mLifecycleSubject = ControllerLifecycleSubjectHelper.create(this);
+        lifecycleSubject = ControllerLifecycleSubjectHelper.create(this);
     }
 
     @Override
     @NonNull
     @CheckResult
     public final Observable<ControllerEvent> lifecycle() {
-        return mLifecycleSubject.asObservable();
+        return lifecycleSubject.asObservable();
     }
 
     @Override
     @NonNull
     @CheckResult
-    public final <T> Observable.Transformer<T, T> bindUntilEvent(@NonNull ControllerEvent event) {
-        return RxLifecycle.bindUntilEvent(mLifecycleSubject, event);
+    public final <T> LifecycleTransformer<T> bindUntilEvent(@NonNull ControllerEvent event) {
+        return RxLifecycle.bindUntilEvent(lifecycleSubject, event);
     }
 
     @Override
     @NonNull
     @CheckResult
-    public final <T> Observable.Transformer<T, T> bindToLifecycle() {
-        return RxControllerLifecycle.bindController(mLifecycleSubject);
+    public final <T> LifecycleTransformer<T> bindToLifecycle() {
+        return RxControllerLifecycle.bindController(lifecycleSubject);
     }
 
 }

conductor-rxlifecycle/src/main/java/com/bluelinelabs/conductor/rxlifecycle/RxControllerLifecycle.java

@@ -3,6 +3,7 @@ package com.bluelinelabs.conductor.rxlifecycle;
 import android.support.annotation.CheckResult;
 import android.support.annotation.NonNull;
 
+import com.trello.rxlifecycle.LifecycleTransformer;
 import com.trello.rxlifecycle.OutsideLifecycleException;
 import com.trello.rxlifecycle.RxLifecycle;
 
@@ -13,14 +14,14 @@ public class RxControllerLifecycle {
 
     /**
      * Binds the given source to a Controller lifecycle. This is the Controller version of
-     * {@link com.trello.rxlifecycle.RxLifecycle#bindFragment(Observable)}.
+     * {@link com.trello.rxlifecycle.android.RxLifecycleAndroid#bindFragment(Observable)}.
      *
      * @param lifecycle the lifecycle sequence of a Controller
      * @return a reusable {@link Observable.Transformer} that unsubscribes the source during the Controller lifecycle
      */
     @NonNull
     @CheckResult
-    public static <T> Observable.Transformer<T, T> bindController(@NonNull final Observable<ControllerEvent> lifecycle) {
+    public static <T> LifecycleTransformer<T> bindController(@NonNull final Observable<ControllerEvent> lifecycle) {
         return RxLifecycle.bind(lifecycle, CONTROLLER_LIFECYCLE);
     }
 

conductor-rxlifecycle/src/main/java/com/bluelinelabs/conductor/rxlifecycle/RxRestoreViewOnCreateController.java

@@ -0,0 +1,52 @@
+package com.bluelinelabs.conductor.rxlifecycle;
+
+import android.os.Bundle;
+import android.support.annotation.CheckResult;
+import android.support.annotation.NonNull;
+
+import com.bluelinelabs.conductor.RestoreViewOnCreateController;
+import com.trello.rxlifecycle.LifecycleProvider;
+import com.trello.rxlifecycle.LifecycleTransformer;
+import com.trello.rxlifecycle.RxLifecycle;
+
+import rx.Observable;
+import rx.subjects.BehaviorSubject;
+
+/**
+ * A base {@link RestoreViewOnCreateController} that can be used to expose lifecycle events using RxJava
+ */
+public abstract class RxRestoreViewOnCreateController extends RestoreViewOnCreateController implements LifecycleProvider<ControllerEvent> {
+
+    private final BehaviorSubject<ControllerEvent> lifecycleSubject;
+
+    public RxRestoreViewOnCreateController() {
+        this(null);
+    }
+
+    public RxRestoreViewOnCreateController(Bundle args) {
+        super(args);
+        lifecycleSubject = ControllerLifecycleSubjectHelper.create(this);
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final Observable<ControllerEvent> lifecycle() {
+        return lifecycleSubject.asObservable();
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final <T> LifecycleTransformer<T> bindUntilEvent(@NonNull ControllerEvent event) {
+        return RxLifecycle.bindUntilEvent(lifecycleSubject, event);
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final <T> LifecycleTransformer<T> bindToLifecycle() {
+        return RxControllerLifecycle.bindController(lifecycleSubject);
+    }
+
+}

conductor-rxlifecycle2/build.gradle

@@ -0,0 +1,31 @@
+apply from: rootProject.file('dependencies.gradle')
+apply from: rootProject.file('gradle-mvn-push.gradle')
+
+apply plugin: 'com.android.library'
+
+android {
+    compileSdkVersion rootProject.ext.compileSdkVersion
+    buildToolsVersion rootProject.ext.buildToolsVersion
+
+    compileOptions {
+        sourceCompatibility JavaVersion.VERSION_1_7
+        targetCompatibility JavaVersion.VERSION_1_7
+    }
+
+    defaultConfig {
+        minSdkVersion rootProject.ext.minSdkVersion
+        targetSdkVersion rootProject.ext.targetSdkVersion
+        versionCode Integer.parseInt(project.VERSION_CODE)
+        versionName project.VERSION_NAME
+    }
+}
+
+dependencies {
+    compile rootProject.ext.rxJava2
+    compile rootProject.ext.rxLifecycle2
+    compile rootProject.ext.rxLifecycleAndroid2
+
+    compile project(':conductor')
+}
+
+ext.artifactId = 'conductor-rxlifecycle2'

conductor-rxlifecycle2/gradle.properties

@@ -0,0 +1,3 @@
+POM_NAME=Conductor RxLifecycle2 Extensions
+POM_ARTIFACT_ID=conductor-rxlifecycle2
+POM_PACKAGING=aar

conductor-rxlifecycle2/src/main/AndroidManifest.xml

@@ -0,0 +1,4 @@
+<manifest package="com.bluelinelabs.conductor.rxlifecycle2">
+    <application />
+</manifest>
+

conductor-rxlifecycle2/src/main/java/com/bluelinelabs/conductor/rxlifecycle2/ControllerEvent.java

@@ -0,0 +1,12 @@
+package com.bluelinelabs.conductor.rxlifecycle2;
+
+public enum ControllerEvent {
+
+    CREATE,
+    CREATE_VIEW,
+    ATTACH,
+    DETACH,
+    DESTROY_VIEW,
+    DESTROY
+
+}

conductor-rxlifecycle2/src/main/java/com/bluelinelabs/conductor/rxlifecycle2/ControllerLifecycleSubjectHelper.java

@@ -0,0 +1,44 @@
+package com.bluelinelabs.conductor.rxlifecycle2;
+
+import android.support.annotation.NonNull;
+import android.view.View;
+import com.bluelinelabs.conductor.Controller;
+import io.reactivex.subjects.BehaviorSubject;
+
+public class ControllerLifecycleSubjectHelper {
+    private ControllerLifecycleSubjectHelper() {
+    }
+
+    public static BehaviorSubject<ControllerEvent> create(Controller controller){
+        final BehaviorSubject<ControllerEvent> subject = BehaviorSubject.createDefault(ControllerEvent.CREATE);
+
+        controller.addLifecycleListener(new Controller.LifecycleListener() {
+            @Override
+            public void preCreateView(@NonNull Controller controller) {
+                subject.onNext(ControllerEvent.CREATE_VIEW);
+            }
+
+            @Override
+            public void preAttach(@NonNull Controller controller, @NonNull View view) {
+                subject.onNext(ControllerEvent.ATTACH);
+            }
+
+            @Override
+            public void preDetach(@NonNull Controller controller, @NonNull View view) {
+                subject.onNext(ControllerEvent.DETACH);
+            }
+
+            @Override
+            public void preDestroyView(@NonNull Controller controller, @NonNull View view) {
+                subject.onNext(ControllerEvent.DESTROY_VIEW);
+            }
+
+            @Override
+            public void preDestroy(@NonNull Controller controller) {
+                subject.onNext(ControllerEvent.DESTROY);
+            }
+        });
+
+        return subject;
+    }
+}

conductor-rxlifecycle2/src/main/java/com/bluelinelabs/conductor/rxlifecycle2/RxController.java

@@ -0,0 +1,49 @@
+package com.bluelinelabs.conductor.rxlifecycle2;
+
+import android.os.Bundle;
+import android.support.annotation.CheckResult;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import com.bluelinelabs.conductor.Controller;
+import com.trello.rxlifecycle2.LifecycleProvider;
+import com.trello.rxlifecycle2.LifecycleTransformer;
+import com.trello.rxlifecycle2.RxLifecycle;
+import io.reactivex.Observable;
+import io.reactivex.subjects.BehaviorSubject;
+
+/**
+ * A base {@link Controller} that can be used to expose lifecycle events using RxJava
+ */
+public abstract class RxController extends Controller implements LifecycleProvider<ControllerEvent> {
+    private final BehaviorSubject<ControllerEvent> lifecycleSubject;
+
+    public RxController(){
+        this(null);
+    }
+
+    public RxController(@Nullable Bundle args) {
+        super(args);
+        lifecycleSubject = ControllerLifecycleSubjectHelper.create(this);
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final Observable<ControllerEvent> lifecycle() {
+        return lifecycleSubject.hide();
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final <T> LifecycleTransformer<T> bindUntilEvent(@NonNull ControllerEvent event) {
+        return RxLifecycle.bindUntilEvent(lifecycleSubject, event);
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final <T> LifecycleTransformer<T> bindToLifecycle() {
+        return RxControllerLifecycle.bindController(lifecycleSubject);
+    }
+}

conductor-rxlifecycle2/src/main/java/com/bluelinelabs/conductor/rxlifecycle2/RxControllerLifecycle.java

@@ -0,0 +1,41 @@
+package com.bluelinelabs.conductor.rxlifecycle2;
+
+import android.support.annotation.NonNull;
+import com.trello.rxlifecycle2.LifecycleTransformer;
+import com.trello.rxlifecycle2.OutsideLifecycleException;
+import com.trello.rxlifecycle2.RxLifecycle;
+import io.reactivex.Observable;
+import io.reactivex.functions.Function;
+
+public class RxControllerLifecycle {
+
+    /**
+     * Binds the given source to a Controller lifecycle. This is the Controller version of
+     * {@link com.trello.rxlifecycle2.android.RxLifecycleAndroid#bindFragment(Observable)}.
+     *
+     * @param lifecycle the lifecycle sequence of a Controller
+     * @return a reusable {@link io.reactivex.ObservableTransformer} that unsubscribes the source during the Controller lifecycle
+     */
+    public static <T> LifecycleTransformer<T> bindController(@NonNull final Observable<ControllerEvent> lifecycle) {
+        return RxLifecycle.bind(lifecycle, CONTROLLER_LIFECYCLE);
+    }
+
+    private static final Function<ControllerEvent, ControllerEvent> CONTROLLER_LIFECYCLE =
+        new Function<ControllerEvent, ControllerEvent>() {
+            @Override
+            public ControllerEvent apply(ControllerEvent lastEvent) {
+                switch (lastEvent) {
+                    case CREATE:
+                        return ControllerEvent.DESTROY;
+                    case ATTACH:
+                        return ControllerEvent.DETACH;
+                    case CREATE_VIEW:
+                        return ControllerEvent.DESTROY_VIEW;
+                    case DETACH:
+                        return ControllerEvent.DESTROY;
+                    default:
+                        throw new OutsideLifecycleException("Cannot bind to Controller lifecycle when outside of it.");
+                }
+            }
+        };
+}

conductor-rxlifecycle2/src/main/java/com/bluelinelabs/conductor/rxlifecycle2/RxRestoreViewOnCreateController.java

@@ -0,0 +1,45 @@
+package com.bluelinelabs.conductor.rxlifecycle2;
+
+import android.os.Bundle;
+import android.support.annotation.CheckResult;
+import android.support.annotation.NonNull;
+import com.bluelinelabs.conductor.RestoreViewOnCreateController;
+import com.trello.rxlifecycle2.LifecycleProvider;
+import com.trello.rxlifecycle2.LifecycleTransformer;
+import com.trello.rxlifecycle2.RxLifecycle;
+import io.reactivex.Observable;
+import io.reactivex.subjects.BehaviorSubject;
+
+public abstract class RxRestoreViewOnCreateController extends RestoreViewOnCreateController implements LifecycleProvider<ControllerEvent> {
+    private final BehaviorSubject<ControllerEvent> lifecycleSubject;
+
+    public RxRestoreViewOnCreateController() {
+        this(null);
+    }
+
+    public RxRestoreViewOnCreateController(Bundle args) {
+        super(args);
+        lifecycleSubject = ControllerLifecycleSubjectHelper.create(this);
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final Observable<ControllerEvent> lifecycle() {
+        return lifecycleSubject.hide();
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final <T> LifecycleTransformer<T> bindUntilEvent(@NonNull ControllerEvent event) {
+        return RxLifecycle.bindUntilEvent(lifecycleSubject, event);
+    }
+
+    @Override
+    @NonNull
+    @CheckResult
+    public final <T> LifecycleTransformer<T> bindToLifecycle() {
+        return RxControllerLifecycle.bindController(lifecycleSubject);
+    }
+}

conductor-support/build.gradle

@@ -1,13 +1,19 @@
+buildscript {
+    repositories {
+        jcenter()
+    }
+    dependencies {
+        classpath 'de.mobilej.unmock:UnMockPlugin:0.3.6'
+    }
+}
+
 apply plugin: 'com.android.library'
+apply plugin: 'de.mobilej.unmock'
 
 android {
     compileSdkVersion rootProject.ext.compileSdkVersion
     buildToolsVersion rootProject.ext.buildToolsVersion
 
-    lintOptions {
-        abortOnError false
-    }
-
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_7
         targetCompatibility JavaVersion.VERSION_1_7
@@ -16,17 +22,28 @@ android {
     defaultConfig {
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode rootProject.ext.versionCode
-        versionName rootProject.ext.versionName
+        versionCode Integer.parseInt(project.VERSION_CODE)
+        versionName project.VERSION_NAME
     }
 }
 
 dependencies {
+    testCompile rootProject.ext.junit
+    testCompile rootProject.ext.roboelectric
+
     compile rootProject.ext.supportAppCompat
     compile project(':conductor')
 }
 
+unMock {
+    downloadFrom 'https://oss.sonatype.org/content/groups/public/org/robolectric/android-all/4.3_r2-robolectric-0/android-all-4.3_r2-robolectric-0.jar'
+
+    keep "android.os.Bundle"
+    keep "android.os.BaseBundle"
+}
+
 ext.artifactId = 'conductor-support'
 
 apply from: rootProject.file('dependencies.gradle')
-apply from: rootProject.file('bll-gradle-push.gradle')
+apply from: rootProject.file('gradle-mvn-push.gradle')
+

conductor-support/gradle.properties

@@ -0,0 +1,3 @@
+POM_NAME=Conductor Support Extensions
+POM_ARTIFACT_ID=conductor-support
+POM_PACKAGING=aar

conductor-support/src/main/java/com/bluelinelabs/conductor/support/ControllerPagerAdapter.java

@@ -1,50 +1,93 @@
 package com.bluelinelabs.conductor.support;
 
+import android.os.Bundle;
+import android.os.Parcelable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.support.v4.view.PagerAdapter;
+import android.util.SparseArray;
 import android.view.View;
 import android.view.ViewGroup;
 
-import com.bluelinelabs.conductor.ChildControllerTransaction;
 import com.bluelinelabs.conductor.Controller;
+import com.bluelinelabs.conductor.Router;
+import com.bluelinelabs.conductor.RouterTransaction;
 
 /**
+ * @deprecated Use RouterPagerAdapter instead! This implementation was too limited and had too many
+ * gotchas associated with it.
+ *
  * An adapter for ViewPagers that will handle adding and removing Controllers
  */
+@Deprecated
 public abstract class ControllerPagerAdapter extends PagerAdapter {
 
-    private final Controller mHost;
+    private static final String KEY_SAVED_PAGES = "ControllerPagerAdapter.savedStates";
+    private static final String KEY_SAVES_STATE = "ControllerPagerAdapter.savesState";
+    private static final String KEY_VISIBLE_PAGE_IDS_KEYS = "ControllerPagerAdapter.visiblePageIds.keys";
+    private static final String KEY_VISIBLE_PAGE_IDS_VALUES = "ControllerPagerAdapter.visiblePageIds.values";
+
+    private final Controller host;
+    private boolean savesState;
+    private SparseArray<Bundle> savedPages = new SparseArray<>();
+    private SparseArray<String> visiblePageIds = new SparseArray<>();
 
     /**
      * Creates a new ControllerPagerAdapter using the passed host.
      */
-    public ControllerPagerAdapter(Controller host) {
-        mHost = host;
+    public ControllerPagerAdapter(@NonNull Controller host, boolean saveControllerState) {
+        this.host = host;
+        savesState = saveControllerState;
     }
 
     /**
      * Return the Controller associated with a specified position.
      */
+    @NonNull
     public abstract Controller getItem(int position);
 
     @Override
     public Object instantiateItem(ViewGroup container, int position) {
         final String name = makeControllerName(container.getId(), getItemId(position));
 
-        Controller controller = mHost.getChildController(name);
-        if (controller == null) {
-            controller = getItem(position);
+        Router router = host.getChildRouter(container, name);
+        if (savesState && !router.hasRootController()) {
+            Bundle routerSavedState = savedPages.get(position);
 
-            mHost.addChildController(ChildControllerTransaction.builder(controller, container.getId())
-                    .tag(name)
-                    .build());
+            if (routerSavedState != null) {
+                router.restoreInstanceState(routerSavedState);
+            }
         }
 
-        return controller;
+        final Controller controller;
+        if (!router.hasRootController()) {
+            controller = getItem(position);
+            router.setRoot(RouterTransaction.with(controller).tag(name));
+        } else {
+            router.rebindIfNeeded();
+            controller = router.getControllerWithTag(name);
+        }
+
+        if (controller != null) {
+            visiblePageIds.put(position, controller.getInstanceId());
+        }
+
+        return router.getControllerWithTag(name);
     }
 
     @Override
     public void destroyItem(ViewGroup container, int position, Object object) {
-        mHost.removeChildController((Controller)object);
+        Router router = ((Controller)object).getRouter();
+
+        if (savesState) {
+            Bundle savedState = new Bundle();
+            router.saveInstanceState(savedState);
+            savedPages.put(position, savedState);
+        }
+
+        visiblePageIds.remove(position);
+
+        host.removeChildRouter(router);
     }
 
     @Override
@@ -52,6 +95,54 @@ public abstract class ControllerPagerAdapter extends PagerAdapter {
         return ((Controller)object).getView() == view;
     }
 
+    @Override
+    public Parcelable saveState() {
+        Bundle bundle = new Bundle();
+        bundle.putBoolean(KEY_SAVES_STATE, savesState);
+        bundle.putSparseParcelableArray(KEY_SAVED_PAGES, savedPages);
+
+        int[] visiblePageIdsKeys = new int[visiblePageIds.size()];
+        String[] visiblePageIdsValues = new String[visiblePageIds.size()];
+        for (int i = 0; i < visiblePageIds.size(); i++) {
+            visiblePageIdsKeys[i] = visiblePageIds.keyAt(i);
+            visiblePageIdsValues[i] = visiblePageIds.valueAt(i);
+        }
+        bundle.putIntArray(KEY_VISIBLE_PAGE_IDS_KEYS, visiblePageIdsKeys);
+        bundle.putStringArray(KEY_VISIBLE_PAGE_IDS_VALUES, visiblePageIdsValues);
+
+        return bundle;
+    }
+
+    @Override
+    public void restoreState(Parcelable state, ClassLoader loader) {
+        Bundle bundle = (Bundle)state;
+        if (state != null) {
+            savesState = bundle.getBoolean(KEY_SAVES_STATE, false);
+            savedPages = bundle.getSparseParcelableArray(KEY_SAVED_PAGES);
+
+            int[] visiblePageIdsKeys = bundle.getIntArray(KEY_VISIBLE_PAGE_IDS_KEYS);
+            String[] visiblePageIdsValues = bundle.getStringArray(KEY_VISIBLE_PAGE_IDS_VALUES);
+            visiblePageIds = new SparseArray<>(visiblePageIdsKeys.length);
+            for (int i = 0; i < visiblePageIdsKeys.length; i++) {
+                visiblePageIds.put(visiblePageIdsKeys[i], visiblePageIdsValues[i]);
+            }
+        }
+    }
+
+    /**
+     * Returns the already instantiated Controller in the specified position or {@code null} if
+     * this position does not yet have a controller.
+     */
+    @Nullable
+    public Controller getController(int position) {
+        String instanceId = visiblePageIds.get(position);
+        if (instanceId != null) {
+            return host.getRouter().getControllerWithInstanceId(instanceId);
+        } else {
+            return null;
+        }
+    }
+
     public long getItemId(int position) {
         return position;
     }
@@ -60,4 +151,4 @@ public abstract class ControllerPagerAdapter extends PagerAdapter {
         return viewId + ":" + id;
     }
 
-}
+}

conductor-support/src/main/java/com/bluelinelabs/conductor/support/RouterPagerAdapter.java

@@ -0,0 +1,161 @@
+package com.bluelinelabs.conductor.support;
+
+import android.os.Bundle;
+import android.os.Parcelable;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.view.PagerAdapter;
+import android.util.SparseArray;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.Controller;
+import com.bluelinelabs.conductor.Router;
+import com.bluelinelabs.conductor.RouterTransaction;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * An adapter for ViewPagers that uses Routers as pages
+ */
+public abstract class RouterPagerAdapter extends PagerAdapter {
+
+    private static final String KEY_SAVED_PAGES = "RouterPagerAdapter.savedStates";
+    private static final String KEY_MAX_PAGES_TO_STATE_SAVE = "RouterPagerAdapter.maxPagesToStateSave";
+    private static final String KEY_SAVE_PAGE_HISTORY = "RouterPagerAdapter.savedPageHistory";
+
+    private final Controller host;
+    private int maxPagesToStateSave = Integer.MAX_VALUE;
+    private SparseArray<Bundle> savedPages = new SparseArray<>();
+    private SparseArray<Router> visibleRouters = new SparseArray<>();
+    private ArrayList<Integer> savedPageHistory = new ArrayList<>();
+
+    /**
+     * Creates a new RouterPagerAdapter using the passed host.
+     */
+    public RouterPagerAdapter(@NonNull Controller host) {
+        this.host = host;
+    }
+
+    /**
+     * Called when a router is instantiated. Here the router's root should be set if needed.
+     *
+     * @param router   The router used for the page
+     * @param position The page position to be instantiated.
+     */
+    public abstract void configureRouter(@NonNull Router router, int position);
+
+    /**
+     * Sets the maximum number of pages that will have their states saved. When this number is exceeded,
+     * the page that was state saved least recently will have its state removed from the save data.
+     */
+    public void setMaxPagesToStateSave(int maxPagesToStateSave) {
+        if (maxPagesToStateSave < 0) {
+            throw new IllegalArgumentException("Only positive integers may be passed for maxPagesToStateSave.");
+        }
+
+        this.maxPagesToStateSave = maxPagesToStateSave;
+
+        ensurePagesSaved();
+    }
+
+    @Override
+    public Object instantiateItem(ViewGroup container, int position) {
+        final String name = makeRouterName(container.getId(), getItemId(position));
+
+        Router router = host.getChildRouter(container, name);
+        if (!router.hasRootController()) {
+            Bundle routerSavedState = savedPages.get(position);
+
+            if (routerSavedState != null) {
+                router.restoreInstanceState(routerSavedState);
+                savedPages.remove(position);
+            }
+        }
+
+        router.rebindIfNeeded();
+        configureRouter(router, position);
+
+        visibleRouters.put(position, router);
+        return router;
+    }
+
+    @Override
+    public void destroyItem(ViewGroup container, int position, Object object) {
+        Router router = (Router)object;
+
+        Bundle savedState = new Bundle();
+        router.saveInstanceState(savedState);
+        savedPages.put(position, savedState);
+
+        savedPageHistory.remove((Integer)position);
+        savedPageHistory.add(position);
+
+        ensurePagesSaved();
+
+        host.removeChildRouter(router);
+
+        visibleRouters.remove(position);
+    }
+
+    @Override
+    public boolean isViewFromObject(View view, Object object) {
+        Router router = (Router)object;
+        final List<RouterTransaction> backstack = router.getBackstack();
+        for (RouterTransaction transaction : backstack) {
+            if (transaction.controller().getView() == view) {
+                return true;
+            }
+        }
+        return false;
+    }
+
+    @Override
+    public Parcelable saveState() {
+        Bundle bundle = new Bundle();
+        bundle.putSparseParcelableArray(KEY_SAVED_PAGES, savedPages);
+        bundle.putInt(KEY_MAX_PAGES_TO_STATE_SAVE, maxPagesToStateSave);
+        bundle.putIntegerArrayList(KEY_SAVE_PAGE_HISTORY, savedPageHistory);
+        return bundle;
+    }
+
+    @Override
+    public void restoreState(Parcelable state, ClassLoader loader) {
+        Bundle bundle = (Bundle)state;
+        if (state != null) {
+            savedPages = bundle.getSparseParcelableArray(KEY_SAVED_PAGES);
+            maxPagesToStateSave = bundle.getInt(KEY_MAX_PAGES_TO_STATE_SAVE);
+            savedPageHistory = bundle.getIntegerArrayList(KEY_SAVE_PAGE_HISTORY);
+        }
+    }
+
+    /**
+     * Returns the already instantiated Router in the specified position or {@code null} if there
+     * is no router associated with this position.
+     */
+    @Nullable
+    public Router getRouter(int position) {
+        return visibleRouters.get(position);
+    }
+
+    public long getItemId(int position) {
+        return position;
+    }
+
+    SparseArray<Bundle> getSavedPages() {
+        return savedPages;
+    }
+
+    private void ensurePagesSaved() {
+        while (savedPages.size() > maxPagesToStateSave) {
+            int positionToRemove = savedPageHistory.remove(0);
+            savedPages.remove(positionToRemove);
+        }
+    }
+
+    private static String makeRouterName(int viewId, long id) {
+        return viewId + ":" + id;
+    }
+
+}

conductor-support/src/test/java/com/bluelinelabs/conductor/support/StateSaveTests.java

@@ -0,0 +1,113 @@
+package com.bluelinelabs.conductor.support;
+
+import android.app.Activity;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.util.SparseArray;
+import android.widget.FrameLayout;
+
+import com.bluelinelabs.conductor.Conductor;
+import com.bluelinelabs.conductor.Router;
+import com.bluelinelabs.conductor.RouterTransaction;
+import com.bluelinelabs.conductor.support.util.FakePager;
+import com.bluelinelabs.conductor.support.util.TestController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.Robolectric;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+import org.robolectric.util.ActivityController;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class StateSaveTests {
+
+    private FakePager pager;
+    private RouterPagerAdapter pagerAdapter;
+
+    public void createActivityController(Bundle savedInstanceState) {
+        ActivityController<Activity> activityController = Robolectric.buildActivity(Activity.class).create().start().resume();
+        Router router = Conductor.attachRouter(activityController.get(), new FrameLayout(activityController.get()), savedInstanceState);
+        TestController controller = new TestController();
+        router.setRoot(RouterTransaction.with(controller));
+
+        pager = new FakePager(new FrameLayout(activityController.get()));
+        pager.setOffscreenPageLimit(1);
+
+        pagerAdapter = new RouterPagerAdapter(controller) {
+            @Override
+            public void configureRouter(@NonNull Router router, int position) {
+                if (!router.hasRootController()) {
+                    router.setRoot(RouterTransaction.with(new TestController()));
+                }
+            }
+
+            @Override
+            public int getCount() {
+                return 20;
+            }
+        };
+
+        pager.setAdapter(pagerAdapter);
+    }
+
+    @Before
+    public void setup() {
+        createActivityController(null);
+    }
+
+    @Test
+    public void testNoMaxSaves() {
+        // Load all pages
+        for (int i = 0; i < pagerAdapter.getCount(); i++) {
+            pager.pageTo(i);
+        }
+
+        pager.pageTo(pagerAdapter.getCount() / 2);
+
+        // Ensure all non-visible pages are saved
+        assertEquals(pagerAdapter.getCount() - 1 - pager.getOffscreenPageLimit() * 2, pagerAdapter.getSavedPages().size());
+    }
+
+    @Test
+    public void testMaxSavedSet() {
+        final int maxPages = 3;
+        pagerAdapter.setMaxPagesToStateSave(maxPages);
+
+        // Load all pages
+        for (int i = 0; i < pagerAdapter.getCount(); i++) {
+            pager.pageTo(i);
+        }
+
+        final int firstSelectedItem = pagerAdapter.getCount() / 2;
+        pager.pageTo(firstSelectedItem);
+
+        SparseArray<Bundle> savedPages = pagerAdapter.getSavedPages();
+
+        // Ensure correct number of pages are saved
+        assertEquals(maxPages, savedPages.size());
+
+        // Ensure correct pages are saved
+        assertEquals(pagerAdapter.getCount() - 3, savedPages.keyAt(0));
+        assertEquals(pagerAdapter.getCount() - 2, savedPages.keyAt(1));
+        assertEquals(pagerAdapter.getCount() - 1, savedPages.keyAt(2));
+
+        final int secondSelectedItem = 1;
+        pager.pageTo(secondSelectedItem);
+
+        savedPages = pagerAdapter.getSavedPages();
+
+        // Ensure correct number of pages are saved
+        assertEquals(maxPages, savedPages.size());
+
+        // Ensure correct pages are saved
+        assertEquals(firstSelectedItem - 1, savedPages.keyAt(0));
+        assertEquals(firstSelectedItem, savedPages.keyAt(1));
+        assertEquals(firstSelectedItem + 1, savedPages.keyAt(2));
+    }
+
+}

conductor-support/src/test/java/com/bluelinelabs/conductor/support/util/FakePager.java

@@ -0,0 +1,61 @@
+package com.bluelinelabs.conductor.support.util;
+
+import android.util.SparseArray;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.support.RouterPagerAdapter;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class FakePager {
+
+    private ViewGroup container;
+    private int offscreenPageLimit;
+    private final SparseArray<Object> pages = new SparseArray<>();
+
+    private RouterPagerAdapter adapter;
+
+    public FakePager(ViewGroup container) {
+        this.container = container;
+    }
+
+    public void setAdapter(RouterPagerAdapter adapter) {
+        this.adapter = adapter;
+    }
+
+    public void pageTo(int page) {
+        int firstPage = Math.max(0, page - offscreenPageLimit);
+        int lastPage = Math.min(adapter.getCount() - 1, page + offscreenPageLimit);
+
+        List<Integer> pagesI = new ArrayList<>();
+        for (int i = 0; i < pages.size(); i++) {
+            pagesI.add(pages.keyAt(i));
+        }
+
+        for (int i = pages.size() - 1; i >= 0; i--) {
+            int key = pages.keyAt(i);
+
+            if (key < firstPage || key > lastPage) {
+                adapter.destroyItem(container, key, pages.get(key));
+                pages.remove(key);
+            }
+        }
+
+        for (int key = firstPage; key <= lastPage; key++) {
+            if (pages.get(key) == null) {
+                pages.put(key, adapter.instantiateItem(container, key));
+            }
+        }
+
+        adapter.setPrimaryItem(container, page, pages.get(page));
+    }
+
+    public int getOffscreenPageLimit() {
+        return offscreenPageLimit;
+    }
+
+    public void setOffscreenPageLimit(int offscreenPageLimit) {
+        this.offscreenPageLimit = offscreenPageLimit;
+    }
+}

conductor-support/src/test/java/com/bluelinelabs/conductor/support/util/TestController.java

@@ -1,24 +1,18 @@
-package com.bluelinelabs.conductor;
+package com.bluelinelabs.conductor.support.util;
 
-import android.support.annotation.IdRes;
 import android.support.annotation.NonNull;
 import android.view.LayoutInflater;
 import android.view.View;
 import android.view.ViewGroup;
 import android.widget.FrameLayout;
 
+import com.bluelinelabs.conductor.Controller;
+
 public class TestController extends Controller {
 
-    @IdRes public static final int VIEW_ID = 2342;
-
-    public TestController() { }
-
-    @NonNull
-    @Override
+    @NonNull @Override
     protected View onCreateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container) {
-        View view = new FrameLayout(inflater.getContext());
-        view.setId(VIEW_ID);
-        return view;
+        return new FrameLayout(inflater.getContext());
     }
 
 }

conductor/build.gradle

@@ -14,10 +14,6 @@ android {
     compileSdkVersion rootProject.ext.compileSdkVersion
     buildToolsVersion rootProject.ext.buildToolsVersion
 
-    lintOptions {
-        abortOnError false
-    }
-
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_7
         targetCompatibility JavaVersion.VERSION_1_7
@@ -26,8 +22,9 @@ android {
     defaultConfig {
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode rootProject.ext.versionCode
-        versionName rootProject.ext.versionName
+        versionCode Integer.parseInt(project.VERSION_CODE)
+        versionName project.VERSION_NAME
+        consumerProguardFiles 'proguard-rules.txt'
     }
 }
 
@@ -67,4 +64,4 @@ project.afterEvaluate {
 ext.artifactId = 'conductor'
 
 apply from: rootProject.file('dependencies.gradle')
-apply from: rootProject.file('bll-gradle-push.gradle')
+apply from: rootProject.file('gradle-mvn-push.gradle')

conductor/gradle.properties

@@ -0,0 +1,3 @@
+POM_NAME=Conductor
+POM_ARTIFACT_ID=conductor
+POM_PACKAGING=aar

conductor/proguard-rules.txt

@@ -0,0 +1,5 @@
+# Retain constructor that is called by using reflection to recreate the Controller
+-keepclassmembers public class * extends com.bluelinelabs.conductor.Controller {
+   public <init>();
+   public <init>(android.os.Bundle);
+}

conductor/src/main/java/com/bluelinelabs/conductor/ActivityHostedRouter.java

@@ -0,0 +1,130 @@
+package com.bluelinelabs.conductor;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.content.IntentSender;
+import android.content.IntentSender.SendIntentException;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.ControllerChangeHandler.ControllerChangeListener;
+import com.bluelinelabs.conductor.internal.LifecycleHandler;
+import com.bluelinelabs.conductor.internal.TransactionIndexer;
+
+import java.util.List;
+
+public class ActivityHostedRouter extends Router {
+
+    private LifecycleHandler lifecycleHandler;
+    private final TransactionIndexer transactionIndexer = new TransactionIndexer();
+
+    public final void setHost(@NonNull LifecycleHandler lifecycleHandler, @NonNull ViewGroup container) {
+        if (this.lifecycleHandler != lifecycleHandler || this.container != container) {
+            if (this.container != null && this.container instanceof ControllerChangeListener) {
+                removeChangeListener((ControllerChangeListener)this.container);
+            }
+
+            if (container instanceof ControllerChangeListener) {
+                addChangeListener((ControllerChangeListener)container);
+            }
+
+            this.lifecycleHandler = lifecycleHandler;
+            this.container = container;
+        }
+    }
+
+    @Override
+    public void saveInstanceState(@NonNull Bundle outState) {
+        super.saveInstanceState(outState);
+
+        transactionIndexer.saveInstanceState(outState);
+    }
+
+    @Override
+    public void restoreInstanceState(@NonNull Bundle savedInstanceState) {
+        super.restoreInstanceState(savedInstanceState);
+
+        transactionIndexer.restoreInstanceState(savedInstanceState);
+    }
+
+    @Override @Nullable
+    public Activity getActivity() {
+        return lifecycleHandler != null ? lifecycleHandler.getLifecycleActivity() : null;
+    }
+
+    @Override
+    public void onActivityDestroyed(@NonNull Activity activity) {
+        super.onActivityDestroyed(activity);
+        lifecycleHandler = null;
+    }
+
+    @Override
+    public final void invalidateOptionsMenu() {
+        if (lifecycleHandler != null && lifecycleHandler.getFragmentManager() != null) {
+            lifecycleHandler.getFragmentManager().invalidateOptionsMenu();
+        }
+    }
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
+        lifecycleHandler.onActivityResult(requestCode, resultCode, data);
+    }
+
+    @Override
+    void startActivity(@NonNull Intent intent) {
+        lifecycleHandler.startActivity(intent);
+    }
+
+    @Override
+    void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode) {
+        lifecycleHandler.startActivityForResult(instanceId, intent, requestCode);
+    }
+
+    @Override
+    void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode, @Nullable Bundle options) {
+        lifecycleHandler.startActivityForResult(instanceId, intent, requestCode, options);
+    }
+
+    @Override
+    void startIntentSenderForResult(@NonNull String instanceId, @NonNull IntentSender intent, int requestCode, @Nullable Intent fillInIntent,
+                                    int flagsMask, int flagsValues, int extraFlags, @Nullable Bundle options) throws SendIntentException {
+        lifecycleHandler.startIntentSenderForResult(instanceId, intent, requestCode, fillInIntent, flagsMask, flagsValues, extraFlags, options);
+    }
+
+    @Override
+    void registerForActivityResult(@NonNull String instanceId, int requestCode) {
+        lifecycleHandler.registerForActivityResult(instanceId, requestCode);
+    }
+
+    @Override
+    void unregisterForActivityResults(@NonNull String instanceId) {
+        lifecycleHandler.unregisterForActivityResults(instanceId);
+    }
+
+    @Override
+    void requestPermissions(@NonNull String instanceId, @NonNull String[] permissions, int requestCode) {
+        lifecycleHandler.requestPermissions(instanceId, permissions, requestCode);
+    }
+
+    @Override
+    boolean hasHost() {
+        return lifecycleHandler != null;
+    }
+
+    @Override @NonNull
+    List<Router> getSiblingRouters() {
+        return lifecycleHandler.getRouters();
+    }
+
+    @Override @NonNull
+    Router getRootRouter() {
+        return this;
+    }
+
+    @Override @Nullable
+    TransactionIndexer getTransactionIndexer() {
+        return transactionIndexer;
+    }
+}

conductor/src/main/java/com/bluelinelabs/conductor/Backstack.java

@@ -1,10 +1,13 @@
 package com.bluelinelabs.conductor;
 
 import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 
 import java.util.ArrayDeque;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Deque;
 import java.util.Iterator;
 import java.util.List;
 
@@ -12,34 +15,37 @@ class Backstack implements Iterable<RouterTransaction> {
 
     private static final String KEY_ENTRIES = "Backstack.entries";
 
-    private final ArrayDeque<RouterTransaction> mBackStack = new ArrayDeque<>();
+    private final Deque<RouterTransaction> backstack = new ArrayDeque<>();
 
     @SuppressWarnings("BooleanMethodIsAlwaysInverted")
-    public boolean isEmpty() {
-        return mBackStack.isEmpty();
+    boolean isEmpty() {
+        return backstack.isEmpty();
     }
 
-    public int size() {
-        return mBackStack.size();
+    int size() {
+        return backstack.size();
     }
 
-    public RouterTransaction root() {
-        return mBackStack.size() > 0 ? mBackStack.getLast() : null;
+    @Nullable
+    RouterTransaction root() {
+        return backstack.size() > 0 ? backstack.getLast() : null;
     }
 
-    @Override
+    @Override @NonNull
     public Iterator<RouterTransaction> iterator() {
-        return mBackStack.iterator();
+        return backstack.iterator();
     }
 
-    public Iterator<RouterTransaction> reverseIterator() {
-        return mBackStack.descendingIterator();
+    @NonNull
+    Iterator<RouterTransaction> reverseIterator() {
+        return backstack.descendingIterator();
     }
 
-    public List<RouterTransaction> popTo(RouterTransaction transaction) {
+    @NonNull
+    List<RouterTransaction> popTo(@NonNull RouterTransaction transaction) {
         List<RouterTransaction> popped = new ArrayList<>();
-        if (mBackStack.contains(transaction)) {
-            while (mBackStack.peek() != transaction) {
+        if (backstack.contains(transaction)) {
+            while (backstack.peek() != transaction) {
                 RouterTransaction poppedTransaction = pop();
                 popped.add(poppedTransaction);
             }
@@ -49,25 +55,28 @@ class Backstack implements Iterable<RouterTransaction> {
         return popped;
     }
 
-    public RouterTransaction pop() {
-        RouterTransaction popped = mBackStack.pop();
-        popped.getController().destroy();
+    @NonNull
+    RouterTransaction pop() {
+        RouterTransaction popped = backstack.pop();
+        popped.controller.destroy();
         return popped;
     }
 
-    public RouterTransaction peek() {
-        return mBackStack.peek();
+    @Nullable
+    RouterTransaction peek() {
+        return backstack.peek();
     }
 
-    public void remove(RouterTransaction transaction) {
-        mBackStack.removeFirstOccurrence(transaction);
+    void remove(@NonNull RouterTransaction transaction) {
+        backstack.removeFirstOccurrence(transaction);
     }
 
-    public void push(RouterTransaction transaction) {
-        mBackStack.push(transaction);
+    void push(@NonNull RouterTransaction transaction) {
+        backstack.push(transaction);
     }
 
-    public List<RouterTransaction> popAll() {
+    @NonNull
+    List<RouterTransaction> popAll() {
         List<RouterTransaction> list = new ArrayList<>();
         while (!isEmpty()) {
             list.add(pop());
@@ -75,21 +84,46 @@ class Backstack implements Iterable<RouterTransaction> {
         return list;
     }
 
-    public void detachAndSaveInstanceState(Bundle outState) {
-        ArrayList<Bundle> entryBundles = new ArrayList<>(mBackStack.size());
-        for (RouterTransaction entry : mBackStack) {
-            entryBundles.add(entry.detachAndSaveInstanceState());
+    void setBackstack(@NonNull List<RouterTransaction> backstack) {
+        for (RouterTransaction existingTransaction : this.backstack) {
+            boolean contains = false;
+            for (RouterTransaction newTransaction : backstack) {
+                if (existingTransaction.controller == newTransaction.controller) {
+                    contains = true;
+                    break;
+                }
+            }
+
+            if (!contains) {
+                existingTransaction.controller.destroy();
+            }
+        }
+
+        this.backstack.clear();
+        for (RouterTransaction transaction : backstack) {
+            this.backstack.push(transaction);
+        }
+    }
+
+    boolean contains(@NonNull RouterTransaction transaction) {
+        return backstack.contains(transaction);
+    }
+
+    void saveInstanceState(@NonNull Bundle outState) {
+        ArrayList<Bundle> entryBundles = new ArrayList<>(backstack.size());
+        for (RouterTransaction entry : backstack) {
+            entryBundles.add(entry.saveInstanceState());
         }
 
         outState.putParcelableArrayList(KEY_ENTRIES, entryBundles);
     }
 
-    public void restoreInstanceState(Bundle savedInstanceState) {
+    void restoreInstanceState(@NonNull Bundle savedInstanceState) {
         ArrayList<Bundle> entryBundles = savedInstanceState.getParcelableArrayList(KEY_ENTRIES);
         if (entryBundles != null) {
             Collections.reverse(entryBundles);
             for (Bundle transactionBundle : entryBundles) {
-                mBackStack.push(new RouterTransaction(transactionBundle));
+                backstack.push(new RouterTransaction(transactionBundle));
             }
         }
     }

conductor/src/main/java/com/bluelinelabs/conductor/ChangeHandlerFrameLayout.java

@@ -3,6 +3,8 @@ package com.bluelinelabs.conductor;
 import android.annotation.TargetApi;
 import android.content.Context;
 import android.os.Build;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.AttributeSet;
 import android.view.MotionEvent;
 import android.view.ViewGroup;
@@ -17,7 +19,7 @@ import com.bluelinelabs.conductor.ControllerChangeHandler.ControllerChangeListen
  */
 public class ChangeHandlerFrameLayout extends FrameLayout implements ControllerChangeListener {
 
-    private int mInProgressTransactionCount;
+    private int inProgressTransactionCount;
 
     public ChangeHandlerFrameLayout(Context context) {
         super(context);
@@ -38,17 +40,17 @@ public class ChangeHandlerFrameLayout extends FrameLayout implements ControllerC
 
     @Override
     public boolean onInterceptTouchEvent(MotionEvent ev) {
-        return (mInProgressTransactionCount > 0) || super.onInterceptTouchEvent(ev);
+        return (inProgressTransactionCount > 0) || super.onInterceptTouchEvent(ev);
     }
 
     @Override
-    public void onChangeStarted(Controller to, Controller from, boolean isPush, ViewGroup container, ControllerChangeHandler handler) {
-        mInProgressTransactionCount++;
+    public void onChangeStarted(@Nullable Controller to, @Nullable Controller from, boolean isPush, @NonNull ViewGroup container, @NonNull ControllerChangeHandler handler) {
+        inProgressTransactionCount++;
     }
 
     @Override
-    public void onChangeCompleted(Controller to, Controller from, boolean isPush, ViewGroup container, ControllerChangeHandler handler) {
-        mInProgressTransactionCount--;
+    public void onChangeCompleted(@Nullable Controller to, @Nullable Controller from, boolean isPush, @NonNull ViewGroup container, @NonNull ControllerChangeHandler handler) {
+        inProgressTransactionCount--;
     }
 
 }

conductor/src/main/java/com/bluelinelabs/conductor/ChildControllerTransaction.java

@@ -1,79 +0,0 @@
-package com.bluelinelabs.conductor;
-
-import android.os.Bundle;
-import android.support.annotation.IdRes;
-import android.support.annotation.NonNull;
-
-/**
- * A {@link ControllerTransaction} implementation used for adding child {@link Controller}s.
- */
-public class ChildControllerTransaction extends ControllerTransaction {
-
-    private static final String KEY_CONTAINER_ID = "ChildControllerTransaction.containerId";
-    private static final String KEY_ADD_TO_LOCAL_BACKSTACK = "ChildControllerTransaction.addToLocalBackstack";
-
-    /** The ID of the ViewGroup that the child {@link Controller} will be added to */
-    public final int containerId;
-
-    /** If true, the hosting {@link Controller} will be responsible for reversing this transaction if the user presses the back button */
-    public final boolean addToLocalBackstack;
-
-    ChildControllerTransaction(Builder builder) {
-        super(builder);
-        containerId = builder.containerId;
-        addToLocalBackstack = builder.addToLocalBackstack;
-    }
-
-    ChildControllerTransaction(@NonNull Bundle bundle) {
-        super(bundle);
-        containerId = bundle.getInt(KEY_CONTAINER_ID);
-        addToLocalBackstack = bundle.getBoolean(KEY_ADD_TO_LOCAL_BACKSTACK);
-    }
-
-    @Override
-    public Bundle detachAndSaveInstanceState() {
-        Bundle bundle = super.detachAndSaveInstanceState();
-        bundle.putInt(KEY_CONTAINER_ID, containerId);
-        bundle.putBoolean(KEY_ADD_TO_LOCAL_BACKSTACK, addToLocalBackstack);
-        return bundle;
-    }
-
-    /**
-     * Creates a new Builder
-     *
-     * @param controller The Controller to add as a child
-     * @param containerId The ID of the ViewGroup to which the controller's view should be added
-     */
-    public static Builder builder(@NonNull Controller controller, @IdRes int containerId) {
-        return new Builder(controller, containerId);
-    }
-
-    /**
-     * A {@link ControllerTransaction.Builder} implementation used for adding child {@link Controller}s.
-     */
-    public static class Builder extends ControllerTransaction.Builder<Builder> {
-
-        @IdRes final int containerId;
-
-        boolean addToLocalBackstack;
-
-        Builder(@NonNull Controller controller, @IdRes int containerId) {
-            super(controller);
-            this.containerId = containerId;
-        }
-
-        /**
-         * If true, the hosting {@link Controller} will be responsible for reversing this transaction if the user presses the back button.
-         */
-        public Builder addToLocalBackstack(boolean addToLocalBackstack) {
-            this.addToLocalBackstack = addToLocalBackstack;
-            return this;
-        }
-
-        /** Creates the transaction */
-        public ChildControllerTransaction build() {
-            return new ChildControllerTransaction(this);
-        }
-
-    }
-}

conductor/src/main/java/com/bluelinelabs/conductor/Conductor.java

@@ -3,17 +3,20 @@ package com.bluelinelabs.conductor;
 import android.app.Activity;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
 import android.view.ViewGroup;
 
 import com.bluelinelabs.conductor.internal.LifecycleHandler;
+import com.bluelinelabs.conductor.internal.ThreadUtils;
 
 /**
  * Point of initial interaction with Conductor. Used to attach a {@link Router} to your Activity.
  */
 public final class Conductor {
-    
+
     private Conductor() {}
-    
+
     /**
      * Conductor will create a {@link Router} that has been initialized for your Activity and containing ViewGroup.
      * If an existing {@link Router} is already associated with this Activity/ViewGroup pair, either in memory
@@ -26,7 +29,10 @@ public final class Conductor {
      *                           for restoring the Router's state if possible.
      * @return A fully configured {@link Router} instance for use with this Activity/ViewGroup pair.
      */
-    public static Router attachRouter(@NonNull Activity activity, @NonNull ViewGroup container, Bundle savedInstanceState) {
+    @NonNull @UiThread
+    public static Router attachRouter(@NonNull Activity activity, @NonNull ViewGroup container, @Nullable Bundle savedInstanceState) {
+        ThreadUtils.ensureMainThread();
+
         LifecycleHandler lifecycleHandler = LifecycleHandler.install(activity);
 
         Router router = lifecycleHandler.getRouter(container, savedInstanceState);

conductor/src/main/java/com/bluelinelabs/conductor/ControllerChangeHandler.java

@@ -5,13 +5,14 @@ import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
+import android.view.ViewParent;
 
-import com.bluelinelabs.conductor.ControllerTransaction.ControllerChangeType;
 import com.bluelinelabs.conductor.changehandler.SimpleSwapChangeHandler;
 import com.bluelinelabs.conductor.internal.ClassUtils;
 
-import java.util.ArrayList;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 
 /**
  * ControllerChangeHandlers are responsible for swapping the View for one Controller to the View
@@ -23,16 +24,21 @@ public abstract class ControllerChangeHandler {
     private static final String KEY_CLASS_NAME = "ControllerChangeHandler.className";
     private static final String KEY_SAVED_STATE = "ControllerChangeHandler.savedState";
 
+    private static final Map<String, ControllerChangeHandler> inProgressPushHandlers = new HashMap<>();
+
+    private boolean forceRemoveViewOnPush;
+    private boolean hasBeenUsed;
+
     /**
      * Responsible for swapping Views from one Controller to another.
      *
-     * @param container The container these Views are hosted in.
-     * @param from The previous View in the container, if any.
-     * @param to The next View that should be put in the container, if any.
-     * @param isPush True if this is a push transaction, false if it's a pop.
+     * @param container      The container these Views are hosted in.
+     * @param from           The previous View in the container or {@code null} if there was no Controller before this transition
+     * @param to             The next View that should be put in the container or {@code null} if no Controller is being transitioned to
+     * @param isPush         True if this is a push transaction, false if it's a pop.
      * @param changeListener This listener must be called when any transitions or animations are completed.
      */
-    public abstract void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener);
+    public abstract void performChange(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener);
 
     public ControllerChangeHandler() {
         ensureDefaultConstructor();
@@ -52,9 +58,46 @@ public abstract class ControllerChangeHandler {
      */
     public void restoreFromBundle(@NonNull Bundle bundle) { }
 
+    /**
+     * Will be called on change handlers that push a controller if the controller being pushed is
+     * popped before it has completed.
+     *
+     * @param newHandler The change handler that has caused this push to be aborted
+     * @param newTop     The Controller that will now be at the top of the backstack or {@code null}
+     *                   if there will be no new Controller at the top
+     */
+    public void onAbortPush(@NonNull ControllerChangeHandler newHandler, @Nullable Controller newTop) { }
+
+    /**
+     * Will be called on change handlers that push a controller if the controller being pushed is
+     * needs to be attached immediately, without any animations or transitions.
+     */
+    public void completeImmediately() { }
+
+    /**
+     * Returns a copy of this ControllerChangeHandler. This method is internally used by the library, so
+     * ensure it will return an exact copy of your handler if overriding. If not overriding, the handler
+     * will be saved and restored from the Bundle format.
+     */
+    @NonNull
+    public ControllerChangeHandler copy() {
+        return fromBundle(toBundle());
+    }
+
+    /**
+     * Returns whether or not this is a reusable ControllerChangeHandler. Defaults to false and should
+     * ONLY be overridden if there are absolutely no side effects to using this handler more than once.
+     * In the case that a handler is not reusable, it will be copied using the {@link #copy()} method
+     * prior to use.
+     */
+    public boolean isReusable() {
+        return false;
+    }
+
+    @NonNull
     final Bundle toBundle() {
         Bundle bundle = new Bundle();
-        bundle.putString(KEY_CLASS_NAME, getClass().getCanonicalName());
+        bundle.putString(KEY_CLASS_NAME, getClass().getName());
 
         Bundle savedState = new Bundle();
         saveToBundle(savedState);
@@ -71,6 +114,7 @@ public abstract class ControllerChangeHandler {
         }
     }
 
+    @Nullable
     public static ControllerChangeHandler fromBundle(@Nullable Bundle bundle) {
         if (bundle != null) {
             String className = bundle.getString(KEY_CLASS_NAME);
@@ -83,20 +127,57 @@ public abstract class ControllerChangeHandler {
         }
     }
 
-    public static void executeChange(final Controller to, final Controller from, boolean isPush, ViewGroup container, ControllerChangeHandler inHandler) {
-        executeChange(to, from, isPush, container, inHandler, new ArrayList<ControllerChangeListener>());
+    static boolean completePushImmediately(@NonNull String controllerInstanceId) {
+        ControllerChangeHandler changeHandler = inProgressPushHandlers.get(controllerInstanceId);
+        if (changeHandler != null) {
+            changeHandler.completeImmediately();
+            inProgressPushHandlers.remove(controllerInstanceId);
+            return true;
+        }
+        return false;
     }
 
-    public static void executeChange(final Controller to, final Controller from, final boolean isPush, final ViewGroup container, final ControllerChangeHandler inHandler, @NonNull final List<ControllerChangeListener> listeners) {
+    static void abortPush(@NonNull Controller toAbort, @Nullable Controller newController, @NonNull ControllerChangeHandler newChangeHandler) {
+        ControllerChangeHandler handlerForPush = inProgressPushHandlers.get(toAbort.getInstanceId());
+        if (handlerForPush != null) {
+            handlerForPush.onAbortPush(newChangeHandler, newController);
+            inProgressPushHandlers.remove(toAbort.getInstanceId());
+        }
+    }
+
+    static void executeChange(@Nullable final Controller to, @Nullable final Controller from, final boolean isPush, @Nullable final ViewGroup container, @Nullable final ControllerChangeHandler inHandler, @NonNull final List<ControllerChangeListener> listeners) {
+        if (isPush && to != null && to.isDestroyed()) {
+            throw new IllegalStateException("Trying to push a controller that has already been destroyed. (" + to.getClass().getSimpleName() + ")");
+        }
+
         if (container != null) {
+            final ControllerChangeHandler handler;
+            if (inHandler == null) {
+                handler = new SimpleSwapChangeHandler();
+            } else if (inHandler.hasBeenUsed && !inHandler.isReusable()) {
+                handler = inHandler.copy();
+            } else {
+                handler = inHandler;
+            }
+            handler.hasBeenUsed = true;
+
+            if (isPush && to != null) {
+                inProgressPushHandlers.put(to.getInstanceId(), handler);
+
+                if (from != null) {
+                    completePushImmediately(from.getInstanceId());
+                }
+            } else if (!isPush && from != null) {
+                abortPush(from, to, handler);
+            }
+
             for (ControllerChangeListener listener : listeners) {
-                listener.onChangeStarted(to, from, isPush, container, inHandler);
+                listener.onChangeStarted(to, from, isPush, container, handler);
             }
 
             final ControllerChangeType toChangeType = isPush ? ControllerChangeType.PUSH_ENTER : ControllerChangeType.POP_ENTER;
             final ControllerChangeType fromChangeType = isPush ? ControllerChangeType.PUSH_EXIT : ControllerChangeType.POP_EXIT;
 
-            final ControllerChangeHandler handler = inHandler != null ? inHandler : new SimpleSwapChangeHandler();
             final View toView;
             if (to != null) {
                 toView = to.inflate(container);
@@ -121,17 +202,33 @@ public abstract class ControllerChangeHandler {
                     }
 
                     if (to != null) {
+                        inProgressPushHandlers.remove(to.getInstanceId());
                         to.changeEnded(handler, toChangeType);
                     }
 
                     for (ControllerChangeListener listener : listeners) {
-                        listener.onChangeCompleted(to, from, isPush, container, inHandler);
+                        listener.onChangeCompleted(to, from, isPush, container, handler);
+                    }
+
+                    if (handler.forceRemoveViewOnPush && fromView != null) {
+                        ViewParent fromParent = fromView.getParent();
+                        if (fromParent != null && fromParent instanceof ViewGroup) {
+                            ((ViewGroup)fromParent).removeView(fromView);
+                        }
                     }
                 }
             });
         }
     }
 
+    public boolean removesFromViewOnPush() {
+        return true;
+    }
+
+    public void setForceRemoveViewOnPush(boolean force) {
+        forceRemoveViewOnPush = force;
+    }
+
     /**
      * A listener interface useful for allowing external classes to be notified of change events.
      */
@@ -139,23 +236,24 @@ public abstract class ControllerChangeHandler {
         /**
          * Called when a {@link ControllerChangeHandler} has started changing {@link Controller}s
          *
-         * @param to The new Controller
-         * @param from The old Controller
-         * @param isPush True if this is a push operation, or false if it's a pop.
+         * @param to        The new Controller or {@code null} if no Controller is being transitioned to
+         * @param from      The old Controller or {@code null} if there was no Controller before this transition
+         * @param isPush    True if this is a push operation, or false if it's a pop.
          * @param container The containing ViewGroup
-         * @param handler The change handler being used.
+         * @param handler   The change handler being used.
          */
-        void onChangeStarted(Controller to, Controller from, boolean isPush, ViewGroup container, ControllerChangeHandler handler);
+        void onChangeStarted(@Nullable Controller to, @Nullable Controller from, boolean isPush, @NonNull ViewGroup container, @NonNull ControllerChangeHandler handler);
 
         /**
          * Called when a {@link ControllerChangeHandler} has completed changing {@link Controller}s
-         * @param to The new Controller
-         * @param from The old Controller
-         * @param isPush True if this was a push operation, or false if it's a pop.
+         *
+         * @param to        The new Controller or {@code null} if no Controller is being transitioned to
+         * @param from      The old Controller or {@code null} if there was no Controller before this transition
+         * @param isPush    True if this was a push operation, or false if it's a pop
          * @param container The containing ViewGroup
-         * @param handler The change handler that was used.
+         * @param handler   The change handler that was used.
          */
-        void onChangeCompleted(Controller to, Controller from, boolean isPush, ViewGroup container, ControllerChangeHandler handler);
+        void onChangeCompleted(@Nullable Controller to, @Nullable Controller from, boolean isPush, @NonNull ViewGroup container, @NonNull ControllerChangeHandler handler);
     }
 
     /**

conductor/src/main/java/com/bluelinelabs/conductor/ControllerChangeType.java

@@ -0,0 +1,26 @@
+package com.bluelinelabs.conductor;
+
+/**
+ * All possible types of {@link Controller} changes to be used in {@link ControllerChangeHandler}s
+ */
+public enum ControllerChangeType {
+    /** The Controller is being pushed to the host container */
+    PUSH_ENTER(true, true),
+
+    /** The Controller is being pushed to the backstack as another Controller is pushed to the host container */
+    PUSH_EXIT(true, false),
+
+    /** The Controller is being popped from the backstack and placed in the host container as another Controller is popped */
+    POP_ENTER(false, true),
+
+    /** The Controller is being popped from the host container */
+    POP_EXIT(false, false);
+
+    public boolean isPush;
+    public boolean isEnter;
+
+    ControllerChangeType(boolean isPush, boolean isEnter) {
+        this.isPush = isPush;
+        this.isEnter = isEnter;
+    }
+}

conductor/src/main/java/com/bluelinelabs/conductor/ControllerHostedRouter.java

@@ -0,0 +1,235 @@
+package com.bluelinelabs.conductor;
+
+import android.app.Activity;
+import android.content.Intent;
+import android.content.IntentSender;
+import android.content.IntentSender.SendIntentException;
+import android.os.Bundle;
+import android.support.annotation.IdRes;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.ControllerChangeHandler.ControllerChangeListener;
+import com.bluelinelabs.conductor.internal.TransactionIndexer;
+
+import java.util.ArrayList;
+import java.util.List;
+
+class ControllerHostedRouter extends Router {
+
+    private final String KEY_HOST_ID = "ControllerHostedRouter.hostId";
+    private final String KEY_TAG = "ControllerHostedRouter.tag";
+
+    private Controller hostController;
+
+    @IdRes private int hostId;
+    private String tag;
+    private boolean isDetachFrozen;
+
+    ControllerHostedRouter() { }
+
+    ControllerHostedRouter(int hostId, @Nullable String tag) {
+        this.hostId = hostId;
+        this.tag = tag;
+    }
+
+    final void setHost(@NonNull Controller controller, @NonNull ViewGroup container) {
+        if (hostController != controller || this.container != container) {
+            removeHost();
+
+            if (container instanceof ControllerChangeListener) {
+                addChangeListener((ControllerChangeListener)container);
+            }
+
+            hostController = controller;
+            this.container = container;
+        }
+    }
+
+    final void removeHost() {
+        if (container != null && container instanceof ControllerChangeListener) {
+            removeChangeListener((ControllerChangeListener)container);
+        }
+
+        final List<Controller> controllersToDestroy = new ArrayList<>(destroyingControllers);
+        for (Controller controller : controllersToDestroy) {
+            if (controller.getView() != null) {
+                controller.detach(controller.getView(), true, false);
+            }
+        }
+        for (RouterTransaction transaction : backstack) {
+            if (transaction.controller.getView() != null) {
+                transaction.controller.detach(transaction.controller.getView(), true, false);
+            }
+        }
+
+        prepareForContainerRemoval();
+        hostController = null;
+        container = null;
+    }
+
+    final void setDetachFrozen(boolean frozen) {
+        isDetachFrozen = frozen;
+        for (RouterTransaction transaction : backstack) {
+            transaction.controller.setDetachFrozen(frozen);
+        }
+    }
+
+    @Override
+    void destroy(boolean popViews) {
+        setDetachFrozen(false);
+        super.destroy(popViews);
+    }
+
+    @Override
+    protected void pushToBackstack(@NonNull RouterTransaction entry) {
+        if (isDetachFrozen) {
+            entry.controller.setDetachFrozen(true);
+        }
+        super.pushToBackstack(entry);
+    }
+
+    @Override
+    public void setBackstack(@NonNull List<RouterTransaction> newBackstack, @Nullable ControllerChangeHandler changeHandler) {
+        if (isDetachFrozen) {
+            for (RouterTransaction transaction : newBackstack) {
+                transaction.controller.setDetachFrozen(true);
+            }
+        }
+        super.setBackstack(newBackstack, changeHandler);
+    }
+
+    @Override @Nullable
+    public Activity getActivity() {
+        return hostController != null ? hostController.getActivity() : null;
+    }
+
+    @Override
+    public void onActivityDestroyed(@NonNull Activity activity) {
+        super.onActivityDestroyed(activity);
+
+        removeHost();
+    }
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, @Nullable Intent data) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().onActivityResult(requestCode, resultCode, data);
+        }
+    }
+
+    @Override
+    public void invalidateOptionsMenu() {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().invalidateOptionsMenu();
+        }
+    }
+
+    @Override
+    void startActivity(@NonNull Intent intent) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().startActivity(intent);
+        }
+    }
+
+    @Override
+    void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().startActivityForResult(instanceId, intent, requestCode);
+        }
+    }
+
+    @Override
+    void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode, @Nullable Bundle options) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().startActivityForResult(instanceId, intent, requestCode, options);
+        }
+    }
+
+    @Override
+    void startIntentSenderForResult(@NonNull String instanceId, @NonNull IntentSender intent, int requestCode, @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags, @Nullable Bundle options) throws SendIntentException {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().startIntentSenderForResult(instanceId, intent, requestCode, fillInIntent, flagsMask, flagsValues, extraFlags, options);
+        }
+    }
+
+    @Override
+    void registerForActivityResult(@NonNull String instanceId, int requestCode) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().registerForActivityResult(instanceId, requestCode);
+        }
+    }
+
+    @Override
+    void unregisterForActivityResults(@NonNull String instanceId) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().unregisterForActivityResults(instanceId);
+        }
+    }
+
+    @Override
+    void requestPermissions(@NonNull String instanceId, @NonNull String[] permissions, int requestCode) {
+        if (hostController != null && hostController.getRouter() != null) {
+            hostController.getRouter().requestPermissions(instanceId, permissions, requestCode);
+        }
+    }
+
+    @Override
+    boolean hasHost() {
+        return hostController != null;
+    }
+
+    @Override
+    public void saveInstanceState(@NonNull Bundle outState) {
+        super.saveInstanceState(outState);
+
+        outState.putInt(KEY_HOST_ID, hostId);
+        outState.putString(KEY_TAG, tag);
+    }
+
+    @Override
+    public void restoreInstanceState(@NonNull Bundle savedInstanceState) {
+        super.restoreInstanceState(savedInstanceState);
+
+        hostId = savedInstanceState.getInt(KEY_HOST_ID);
+        tag = savedInstanceState.getString(KEY_TAG);
+    }
+
+    @Override
+    void setControllerRouter(@NonNull Controller controller) {
+        super.setControllerRouter(controller);
+        controller.setParentController(hostController);
+    }
+
+    int getHostId() {
+        return hostId;
+    }
+
+    @Nullable
+    String getTag() {
+        return tag;
+    }
+
+    @Override @NonNull
+    List<Router> getSiblingRouters() {
+        List<Router> list = new ArrayList<>();
+        list.addAll(hostController.getChildRouters());
+        list.addAll(hostController.getRouter().getSiblingRouters());
+        return list;
+    }
+
+    @Override @NonNull
+    Router getRootRouter() {
+        if (hostController != null && hostController.getRouter() != null) {
+            return hostController.getRouter().getRootRouter();
+        } else {
+            return this;
+        }
+    }
+
+    @Override @Nullable
+    TransactionIndexer getTransactionIndexer() {
+        return getRootRouter().getTransactionIndexer();
+    }
+}

conductor/src/main/java/com/bluelinelabs/conductor/ControllerTransaction.java

@@ -1,148 +0,0 @@
-package com.bluelinelabs.conductor;
-
-import android.os.Bundle;
-import android.support.annotation.NonNull;
-
-/**
- * Metadata used to transition between {@link Controller}s.
- */
-public class ControllerTransaction {
-
-    /**
-     * All possible types of {@link Controller} changes to be used in {@link ControllerChangeHandler}s
-     */
-    public enum ControllerChangeType {
-        /** The Controller is being pushed to the host container */
-        PUSH_ENTER,
-
-        /** The Controller is being pushed to the backstack as another Controller is pushed to the host container */
-        PUSH_EXIT,
-
-        /** The Controller is being popped from the backstack and placed in the host container as another Controller is popped */
-        POP_ENTER,
-
-        /** The Controller is being popped from the host contianer */
-        POP_EXIT
-    }
-
-    private static final String KEY_VIEW_CONTROLLER_BUNDLE = "ControllerTransaction.controller.bundle";
-    private static final String KEY_PUSH_TRANSITION = "ControllerTransaction.pushControllerChangeHandler";
-    private static final String KEY_POP_TRANSITION = "ControllerTransaction.popControllerChangeHandler";
-    private static final String KEY_TAG = "ControllerTransaction.tag";
-
-    public final Controller controller;
-    public final String tag;
-
-    private final ControllerChangeHandler mPushControllerChangeHandler;
-    private final ControllerChangeHandler mPopControllerChangeHandler;
-
-    ControllerTransaction(Builder builder) {
-        controller = builder.controller;
-        tag = builder.tag;
-        mPushControllerChangeHandler = builder.pushControllerChangeHandler;
-        mPopControllerChangeHandler = builder.popControllerChangeHandler;
-    }
-
-    ControllerTransaction(@NonNull Bundle bundle) {
-        controller = Controller.newInstance(bundle.getBundle(KEY_VIEW_CONTROLLER_BUNDLE));
-        mPushControllerChangeHandler = ControllerChangeHandler.fromBundle(bundle.getBundle(KEY_PUSH_TRANSITION));
-        mPopControllerChangeHandler = ControllerChangeHandler.fromBundle(bundle.getBundle(KEY_POP_TRANSITION));
-        tag = bundle.getString(KEY_TAG);
-    }
-
-    public Controller getController() {
-        return controller;
-    }
-
-    public String getTag() {
-        return tag;
-    }
-
-    public ControllerChangeHandler getPushControllerChangeHandler() {
-        ControllerChangeHandler handler = controller.getOverriddenPushHandler();
-        if (handler == null) {
-            handler = mPushControllerChangeHandler;
-        }
-        return handler;
-    }
-
-    public ControllerChangeHandler getPopControllerChangeHandler() {
-        ControllerChangeHandler handler = controller.getOverriddenPopHandler();
-        if (handler == null) {
-            handler = mPopControllerChangeHandler;
-        }
-        return handler;
-    }
-
-    /**
-     * Used to serialize this transaction into a Bundle
-     */
-    public Bundle detachAndSaveInstanceState() {
-        Bundle bundle = new Bundle();
-
-        bundle.putBundle(KEY_VIEW_CONTROLLER_BUNDLE, controller.detachAndSaveInstanceState());
-
-        if (mPushControllerChangeHandler != null) {
-            bundle.putBundle(KEY_PUSH_TRANSITION, mPushControllerChangeHandler.toBundle());
-        }
-        if (mPopControllerChangeHandler != null) {
-            bundle.putBundle(KEY_POP_TRANSITION, mPopControllerChangeHandler.toBundle());
-        }
-
-        bundle.putString(KEY_TAG, tag);
-
-        return bundle;
-    }
-
-    /**
-     * Builder used to create transactions.
-     */
-    public static class Builder<T extends Builder<T>> {
-
-        final Controller controller;
-        ControllerChangeHandler pushControllerChangeHandler;
-        ControllerChangeHandler popControllerChangeHandler;
-        String tag;
-
-        public Builder(@NonNull Controller controller) {
-            this.controller = controller;
-        }
-
-        /**
-         * The {@link ControllerChangeHandler} that will be used when the {@link Controller} is pushed
-         * to the screen.
-         */
-        @SuppressWarnings("unchecked")
-        public T pushChangeHandler(ControllerChangeHandler pushControllerChangeHandler) {
-            this.pushControllerChangeHandler = pushControllerChangeHandler;
-            return (T)this;
-        }
-
-        /**
-         * The {@link ControllerChangeHandler} that will be used when the {@link Controller} is popped
-         * from the screen.
-         */
-        @SuppressWarnings("unchecked")
-        public T popChangeHandler(ControllerChangeHandler popControllerChangeHandler) {
-            this.popControllerChangeHandler = popControllerChangeHandler;
-            return (T)this;
-        }
-
-        /**
-         * The tag to use for this transaction. Tags can be used for finding transactions later on.
-         */
-        @SuppressWarnings("unchecked")
-        public T tag(String tag) {
-            this.tag = tag;
-            return (T)this;
-        }
-
-        /**
-         * Creates the transaction.
-         */
-        public ControllerTransaction build() {
-            return new ControllerTransaction(this);
-        }
-    }
-
-}

conductor/src/main/java/com/bluelinelabs/conductor/RestoreViewOnCreateController.java

@@ -0,0 +1,53 @@
+package com.bluelinelabs.conductor;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+
+/**
+ * A simple controller subclass that changes the onCreateView signature to include a saved view state parameter.
+ * This is necessary for some third party libraries like Google Maps, which require passing in a saved state
+ * bundle at the time of creation.
+ */
+abstract public class RestoreViewOnCreateController extends Controller {
+
+    /**
+     * Convenience constructor for use when no arguments are needed.
+     */
+    protected RestoreViewOnCreateController() {
+        super(null);
+    }
+
+    /**
+     * Constructor that takes arguments that need to be retained across restarts.
+     *
+     * @param args Any arguments that need to be retained.
+     */
+    protected RestoreViewOnCreateController(@Nullable Bundle args) {
+        super(args);
+    }
+
+    @Override @NonNull
+    protected final View onCreateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container) {
+        return onCreateView(inflater, container, viewState == null ? null : viewState.getBundle(KEY_VIEW_STATE_BUNDLE));
+    }
+
+    /**
+     * Called when the controller is ready to display its view. A valid view must be returned. The standard body
+     * for this method will be {@code return inflater.inflate(R.layout.my_layout, container, false);}, plus
+     * any binding and state restoration code.
+     *
+     * @param inflater       The LayoutInflater that should be used to inflate views
+     * @param container      The parent view that this Controller's view will eventually be attached to.
+     *                       This Controller's view should NOT be added in this method. It is simply passed in
+     *                       so that valid LayoutParams can be used during inflation.
+     * @param savedViewState A bundle for the view's state, which would have been created in {@link #onSaveViewState(View, Bundle)},
+     *                       or {@code null} if no saved state exists.
+     */
+    @NonNull
+    protected abstract View onCreateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container, @Nullable Bundle savedViewState);
+
+}

conductor/src/main/java/com/bluelinelabs/conductor/Router.java

@@ -2,18 +2,26 @@ package com.bluelinelabs.conductor;
 
 import android.app.Activity;
 import android.content.Intent;
+import android.content.IntentSender;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.annotation.UiThread;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
 import android.view.View;
 import android.view.ViewGroup;
 
 import com.bluelinelabs.conductor.Controller.LifecycleListener;
 import com.bluelinelabs.conductor.ControllerChangeHandler.ControllerChangeListener;
 import com.bluelinelabs.conductor.changehandler.SimpleSwapChangeHandler;
-import com.bluelinelabs.conductor.internal.LifecycleHandler;
 import com.bluelinelabs.conductor.internal.NoOpControllerChangeHandler;
+import com.bluelinelabs.conductor.internal.ThreadUtils;
+import com.bluelinelabs.conductor.internal.TransactionIndexer;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 
@@ -22,47 +30,46 @@ import java.util.List;
  * to Activity/containing ViewGroup pairs. Routers do not directly render or push Views to the container ViewGroup,
  * but instead defer this responsibility to the {@link ControllerChangeHandler} specified in a given transaction.
  */
-public class Router {
+public abstract class Router {
 
-    private final Backstack mBackStack = new Backstack();
-    private LifecycleHandler mLifecycleHandler;
-    private ViewGroup mContainer;
-    private final List<ControllerChangeListener> mChangeListeners = new ArrayList<>();
-    private final List<Controller> mDestroyingControllers = new ArrayList<>();
+    private static final String KEY_BACKSTACK = "Router.backstack";
+    private static final String KEY_POPS_LAST_VIEW = "Router.popsLastView";
+
+    protected final Backstack backstack = new Backstack();
+    private final List<ControllerChangeListener> changeListeners = new ArrayList<>();
+    final List<Controller> destroyingControllers = new ArrayList<>();
+
+    private boolean popsLastView = false;
+
+    ViewGroup container;
 
     /**
-     * Returns this Router's host Activity
+     * Returns this Router's host Activity or {@code null} if it has either not yet been attached to
+     * an Activity or if the Activity has been destroyed.
      */
-    public Activity getActivity() {
-        return mLifecycleHandler != null ? mLifecycleHandler.getLifecycleActivity() : null;
-    }
+    @Nullable
+    public abstract Activity getActivity();
 
     /**
-     * This should be called by the host Activity when its onActivityResult method is called. The call will be forwarded
-     * to the {@link Controller} with the instanceId passed in.
+     * This should be called by the host Activity when its onActivityResult method is called if the instanceId
+     * of the controller that called startActivityForResult is not known.
      *
-     * @param instanceId The instanceId of the Controller to which this result should be forwarded
      * @param requestCode The Activity's onActivityResult requestCode
-     * @param resultCode The Activity's onActivityResult resultCode
-     * @param data The Activity's onActivityResult data
+     * @param resultCode  The Activity's onActivityResult resultCode
+     * @param data        The Activity's onActivityResult data
      */
-    public void onActivityResult(String instanceId, int requestCode, int resultCode, Intent data) {
-        Controller controller = getControllerWithInstanceId(instanceId);
-        if (controller != null) {
-            controller.onActivityResult(requestCode, resultCode, data);
-        }
-    }
+    public abstract void onActivityResult(int requestCode, int resultCode, @Nullable Intent data);
 
     /**
      * This should be called by the host Activity when its onRequestPermissionsResult method is called. The call will be forwarded
      * to the {@link Controller} with the instanceId passed in.
      *
-     * @param instanceId The instanceId of the Controller to which this result should be forwarded
-     * @param requestCode The Activity's onRequestPermissionsResult requestCode
-     * @param permissions The Activity's onRequestPermissionsResult permissions
+     * @param instanceId   The instanceId of the Controller to which this result should be forwarded
+     * @param requestCode  The Activity's onRequestPermissionsResult requestCode
+     * @param permissions  The Activity's onRequestPermissionsResult permissions
      * @param grantResults The Activity's onRequestPermissionsResult grantResults
      */
-    public void onRequestPermissionsResult(String instanceId, int requestCode, String[] permissions, int[] grantResults) {
+    public void onRequestPermissionsResult(@NonNull String instanceId, int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         Controller controller = getControllerWithInstanceId(instanceId);
         if (controller != null) {
             controller.requestPermissionsResult(requestCode, permissions, grantResults);
@@ -72,10 +79,16 @@ public class Router {
     /**
      * This should be called by the host Activity when its onBackPressed method is called. The call will be forwarded
      * to its top {@link Controller}. If that controller doesn't handle it, then it will be popped.
+     *
+     * @return Whether or not a back action was handled by the Router
      */
+    @UiThread
     public boolean handleBack() {
-        if (!mBackStack.isEmpty()) {
-            if (mBackStack.peek().controller.handleBack()) {
+        ThreadUtils.ensureMainThread();
+
+        if (!backstack.isEmpty()) {
+            //noinspection ConstantConditions
+            if (backstack.peek().controller.handleBack()) {
                 return true;
             } else if (popCurrentController()) {
                 return true;
@@ -90,8 +103,16 @@ public class Router {
      *
      * @return Whether or not this Router still has controllers remaining on it after popping.
      */
+    @SuppressWarnings("WeakerAccess")
+    @UiThread
     public boolean popCurrentController() {
-        return popController(mBackStack.peek().controller);
+        ThreadUtils.ensureMainThread();
+
+        RouterTransaction transaction = backstack.peek();
+        if (transaction == null) {
+            throw new IllegalStateException("Trying to pop the current controller when there are none on the backstack.");
+        }
+        return popController(transaction.controller);
     }
 
     /**
@@ -100,26 +121,44 @@ public class Router {
      * @param controller The controller that should be popped from this Router
      * @return Whether or not this Router still has controllers remaining on it after popping.
      */
-    public boolean popController(Controller controller) {
-        RouterTransaction topController = mBackStack.peek();
-        boolean poppingTopController = topController.controller == controller;
+    @UiThread
+    public boolean popController(@NonNull Controller controller) {
+        ThreadUtils.ensureMainThread();
+
+        RouterTransaction topTransaction = backstack.peek();
+        boolean poppingTopController = topTransaction != null && topTransaction.controller == controller;
 
         if (poppingTopController) {
-            trackDestroyingController(mBackStack.pop());
+            trackDestroyingController(backstack.pop());
+            performControllerChange(backstack.peek(), topTransaction, false);
         } else {
-            for (RouterTransaction transaction : mBackStack) {
+            RouterTransaction removedTransaction = null;
+            RouterTransaction nextTransaction = null;
+            for (RouterTransaction transaction : backstack) {
                 if (transaction.controller == controller) {
-                    mBackStack.remove(transaction);
+                    if (controller.isAttached()) {
+                        trackDestroyingController(transaction);
+                    }
+                    backstack.remove(transaction);
+                    removedTransaction = transaction;
+                } else if (removedTransaction != null) {
+                    if (!transaction.controller.isAttached()) {
+                        nextTransaction = transaction;
+                    }
                     break;
                 }
             }
+
+            if (removedTransaction != null) {
+                performControllerChange(nextTransaction, removedTransaction, false);
+            }
         }
 
-        if (poppingTopController) {
-            performControllerChange(mBackStack.peek(), topController, false);
+        if (popsLastView) {
+            return topTransaction != null;
+        } else {
+            return !backstack.isEmpty();
         }
-
-        return !mBackStack.isEmpty();
     }
 
     /**
@@ -128,8 +167,11 @@ public class Router {
      * @param transaction The transaction detailing what should be pushed, including the {@link Controller},
      *                    and its push and pop {@link ControllerChangeHandler}, and its tag.
      */
+    @UiThread
     public void pushController(@NonNull RouterTransaction transaction) {
-        RouterTransaction from = mBackStack.peek();
+        ThreadUtils.ensureMainThread();
+
+        RouterTransaction from = backstack.peek();
         pushToBackstack(transaction);
         performControllerChange(transaction, from, true);
     }
@@ -140,14 +182,72 @@ public class Router {
      * @param transaction The transaction detailing what should be pushed, including the {@link Controller},
      *                    and its push and pop {@link ControllerChangeHandler}, and its tag.
      */
+    @SuppressWarnings("WeakerAccess")
+    @UiThread
     public void replaceTopController(@NonNull RouterTransaction transaction) {
-        RouterTransaction topTransaction = mBackStack.peek();
-        if (!mBackStack.isEmpty()) {
-            trackDestroyingController(mBackStack.pop());
+        ThreadUtils.ensureMainThread();
+
+        RouterTransaction topTransaction = backstack.peek();
+        if (!backstack.isEmpty()) {
+            trackDestroyingController(backstack.pop());
+        }
+
+        final ControllerChangeHandler handler = transaction.pushChangeHandler();
+        if (topTransaction != null) {
+            //noinspection ConstantConditions
+            final boolean oldHandlerRemovedViews = topTransaction.pushChangeHandler() == null || topTransaction.pushChangeHandler().removesFromViewOnPush();
+            final boolean newHandlerRemovesViews = handler == null || handler.removesFromViewOnPush();
+            if (!oldHandlerRemovedViews && newHandlerRemovesViews) {
+                for (RouterTransaction visibleTransaction : getVisibleTransactions(backstack.iterator())) {
+                    performControllerChange(null, visibleTransaction, true, handler);
+                }
+            }
         }
 
         pushToBackstack(transaction);
-        performControllerChange(transaction, topTransaction, true);
+
+        if (handler != null) {
+            handler.setForceRemoveViewOnPush(true);
+        }
+        performControllerChange(transaction.pushChangeHandler(handler), topTransaction, true);
+    }
+
+    void destroy(boolean popViews) {
+        popsLastView = true;
+        final List<RouterTransaction> poppedControllers = backstack.popAll();
+        trackDestroyingControllers(poppedControllers);
+
+        if (popViews && poppedControllers.size() > 0) {
+            RouterTransaction topTransaction = poppedControllers.get(0);
+            topTransaction.controller().addLifecycleListener(new LifecycleListener() {
+                @Override
+                public void onChangeEnd(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
+                    if (changeType == ControllerChangeType.POP_EXIT) {
+                        for (int i = poppedControllers.size() - 1; i > 0; i--) {
+                            RouterTransaction transaction = poppedControllers.get(i);
+                            performControllerChange(null, transaction, true, new SimpleSwapChangeHandler());
+                        }
+                    }
+                }
+            });
+
+            performControllerChange(null, topTransaction, false, topTransaction.popChangeHandler());
+        }
+    }
+
+    public int getContainerId() {
+        return container != null ? container.getId() : 0;
+    }
+
+    /**
+     * If set to true, this router will handle back presses by performing a change handler on the last controller and view
+     * in the stack. This defaults to false so that the developer can either finish its containing Activity or otherwise
+     * hide its parent view without any strange artifacting.
+     */
+    @NonNull
+    public Router setPopsLastView(boolean popsLastView) {
+        this.popsLastView = popsLastView;
+        return this;
     }
 
     /**
@@ -155,7 +255,10 @@ public class Router {
      *
      * @return Whether or not any {@link Controller}s were popped in order to get to the root transaction
      */
+    @UiThread
     public boolean popToRoot() {
+        ThreadUtils.ensureMainThread();
+
         return popToRoot(null);
     }
 
@@ -165,9 +268,14 @@ public class Router {
      * @param changeHandler The {@link ControllerChangeHandler} to handle this transaction
      * @return Whether or not any {@link Controller}s were popped in order to get to the root transaction
      */
-    public boolean popToRoot(ControllerChangeHandler changeHandler) {
-        if (mBackStack.size() > 1) {
-            popToTransaction(mBackStack.root(), changeHandler);
+    @SuppressWarnings("WeakerAccess")
+    @UiThread
+    public boolean popToRoot(@Nullable ControllerChangeHandler changeHandler) {
+        ThreadUtils.ensureMainThread();
+
+        if (backstack.size() > 1) {
+            //noinspection ConstantConditions
+            popToTransaction(backstack.root(), changeHandler);
             return true;
         } else {
             return false;
@@ -180,20 +288,27 @@ public class Router {
      * @param tag The tag being popped to
      * @return Whether or not any {@link Controller}s were popped in order to get to the transaction with the passed tag
      */
+    @UiThread
     public boolean popToTag(@NonNull String tag) {
+        ThreadUtils.ensureMainThread();
+
         return popToTag(tag, null);
     }
 
     /**
      * Pops all {@link Controller}s until the {@link Controller} with the passed tag is at the top
      *
-     * @param tag The tag being popped to
+     * @param tag           The tag being popped to
      * @param changeHandler The {@link ControllerChangeHandler} to handle this transaction
      * @return Whether or not the {@link Controller} with the passed tag is now at the top
      */
-    public boolean popToTag(@NonNull String tag, ControllerChangeHandler changeHandler) {
-        for (RouterTransaction transaction : mBackStack) {
-            if (tag.equals(transaction.tag)) {
+    @SuppressWarnings("WeakerAccess")
+    @UiThread
+    public boolean popToTag(@NonNull String tag, @Nullable ControllerChangeHandler changeHandler) {
+        ThreadUtils.ensureMainThread();
+
+        for (RouterTransaction transaction : backstack) {
+            if (tag.equals(transaction.tag())) {
                 popToTransaction(transaction, changeHandler);
                 return true;
             }
@@ -201,98 +316,47 @@ public class Router {
         return false;
     }
 
-    /**
-     * Sets the root {@link Controller}. If any {@link Controller}s are currently in the backstack, they will be removed.
-     *
-     * @param controller The new root {@link Controller}
-     */
-    public void setRoot(@NonNull Controller controller) {
-        setRoot(controller, null, null);
-    }
-
-    /**
-     * Sets the root {@link Controller}. If any {@link Controller}s are currently in the backstack, they will be removed.
-     *
-     * @param controller The new root {@link Controller}
-     * @param tag The tag to use for this {@link Controller}
-     */
-    public void setRoot(@NonNull Controller controller, String tag) {
-        setRoot(controller, tag, null);
-    }
-
-    /**
-     * Sets the root {@link Controller}. If any {@link Controller}s are currently in the backstack, they will be removed.
-     *
-     * @param controller The new root {@link Controller}
-     * @param changeHandler The {@link ControllerChangeHandler} to use for setting the root
-     */
-    public void setRoot(@NonNull Controller controller, ControllerChangeHandler changeHandler) {
-        setRoot(controller, null, changeHandler);
-    }
-
     /**
      * Sets the root Controller. If any {@link Controller}s are currently in the backstack, they will be removed.
      *
-     * @param controller The new root {@link Controller}
-     * @param tag The tag to use for this {@link Controller}
-     * @param changeHandler The {@link ControllerChangeHandler} to use for setting the root
+     * @param transaction The transaction detailing what should be pushed, including the {@link Controller},
+     *                    and its push and pop {@link ControllerChangeHandler}, and its tag.
      */
-    public void setRoot(@NonNull Controller controller, String tag, ControllerChangeHandler changeHandler) {
-        RouterTransaction currentTop = mBackStack.peek();
+    @UiThread
+    public void setRoot(@NonNull RouterTransaction transaction) {
+        ThreadUtils.ensureMainThread();
 
-        if (currentTop != null && currentTop.controller.getView() != null) {
-            final View fromView = currentTop.controller.getView();
-
-            final int childCount = mContainer.getChildCount();
-            for (int i = 0; i < childCount; i++) {
-                final View child = mContainer.getChildAt(i);
-                if (child != fromView) {
-                    mContainer.removeView(child);
-                }
-            }
-        }
-
-        trackDestroyingControllers(mBackStack.popAll());
-
-        RouterTransaction transaction = RouterTransaction.builder(controller)
-                .tag(tag)
-                .pushChangeHandler(changeHandler != null ? changeHandler : new SimpleSwapChangeHandler())
-                .popChangeHandler(new SimpleSwapChangeHandler())
-                .build();
-
-        pushToBackstack(transaction);
-        performControllerChange(transaction, currentTop, true);
+        List<RouterTransaction> transactions = Collections.singletonList(transaction);
+        setBackstack(transactions, transaction.pushChangeHandler());
     }
 
     /**
-     * Returns the hosted Controller with the given instance id, if available.
+     * Returns the hosted Controller with the given instance id or {@code null} if no such
+     * Controller exists in this Router.
      *
      * @param instanceId The instance ID being searched for
-     * @return The matching Controller, if one exists
      */
-    public Controller getControllerWithInstanceId(String instanceId) {
-        for (ControllerTransaction transaction : mBackStack) {
-            if (transaction.controller.getInstanceId().equals(instanceId)) {
-                return transaction.controller;
-            } else {
-                Controller childWithId = transaction.controller.getChildControllerWithInstanceId(instanceId);
-                if (childWithId != null) {
-                    return childWithId;
-                }
+    @Nullable
+    public Controller getControllerWithInstanceId(@NonNull String instanceId) {
+        for (RouterTransaction transaction : backstack) {
+            Controller controllerWithId = transaction.controller.findController(instanceId);
+            if (controllerWithId != null) {
+                return controllerWithId;
             }
         }
         return null;
     }
 
     /**
-     * Returns the hosted Controller that was pushed with the given tag, if available.
+     * Returns the hosted Controller that was pushed with the given tag or {@code null} if no
+     * such Controller exists in this Router.
      *
      * @param tag The tag being searched for
-     * @return The matching Controller, if one exists
      */
-    public Controller getControllerWithTag(String tag) {
-        for (ControllerTransaction transaction : mBackStack) {
-            if (tag.equals(transaction.tag)) {
+    @Nullable
+    public Controller getControllerWithTag(@NonNull String tag) {
+        for (RouterTransaction transaction : backstack) {
+            if (tag.equals(transaction.tag())) {
                 return transaction.controller;
             }
         }
@@ -302,8 +366,85 @@ public class Router {
     /**
      * Returns the number of {@link Controller}s currently in the backstack
      */
+    @SuppressWarnings("WeakerAccess")
     public int getBackstackSize() {
-        return mBackStack.size();
+        return backstack.size();
+    }
+
+    /**
+     * Returns the current backstack, ordered from root to most recently pushed.
+     */
+    @NonNull
+    public List<RouterTransaction> getBackstack() {
+        List<RouterTransaction> list = new ArrayList<>();
+        Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
+        while (backstackIterator.hasNext()) {
+            list.add(backstackIterator.next());
+        }
+        return list;
+    }
+
+    /**
+     * Sets the backstack, transitioning from the current top controller to the top of the new stack (if different)
+     * using the passed {@link ControllerChangeHandler}
+     *
+     * @param newBackstack  The new backstack
+     * @param changeHandler An optional change handler to be used to handle the root view of transition
+     */
+    @SuppressWarnings("WeakerAccess")
+    @UiThread
+    public void setBackstack(@NonNull List<RouterTransaction> newBackstack, @Nullable ControllerChangeHandler changeHandler) {
+        ThreadUtils.ensureMainThread();
+
+        List<RouterTransaction> oldVisibleTransactions = getVisibleTransactions(backstack.iterator());
+
+        boolean newRootRequiresPush = !(newBackstack.size() > 0 && backstack.contains(newBackstack.get(0)));
+
+        removeAllExceptVisibleAndUnowned();
+        ensureOrderedTransactionIndices(newBackstack);
+
+        backstack.setBackstack(newBackstack);
+        for (RouterTransaction transaction : backstack) {
+            transaction.onAttachedToRouter();
+        }
+
+        if (newBackstack.size() > 0) {
+            List<RouterTransaction> reverseNewBackstack = new ArrayList<>(newBackstack);
+            Collections.reverse(reverseNewBackstack);
+            List<RouterTransaction> newVisibleTransactions = getVisibleTransactions(reverseNewBackstack.iterator());
+
+            boolean visibleTransactionsChanged = !backstacksAreEqual(newVisibleTransactions, oldVisibleTransactions);
+            if (visibleTransactionsChanged) {
+                RouterTransaction rootTransaction = oldVisibleTransactions.size() > 0 ? oldVisibleTransactions.get(0) : null;
+                // Replace the old root with the new one
+                if (rootTransaction == null || rootTransaction.controller != newVisibleTransactions.get(0).controller) {
+                    performControllerChange(newVisibleTransactions.get(0), rootTransaction, newRootRequiresPush, changeHandler);
+                }
+
+                // Remove all visible controllers that were previously on the backstack
+                for (int i = oldVisibleTransactions.size() - 1; i > 0; i--) {
+                    RouterTransaction transaction = oldVisibleTransactions.get(i);
+                    if (!newVisibleTransactions.contains(transaction)) {
+                        ControllerChangeHandler localHandler = changeHandler != null ? changeHandler.copy() : new SimpleSwapChangeHandler();
+                        localHandler.setForceRemoveViewOnPush(true);
+                        performControllerChange(null, transaction, newRootRequiresPush, localHandler);
+                    }
+                }
+
+                // Add any new controllers to the backstack
+                for (int i = 1; i < newVisibleTransactions.size(); i++) {
+                    RouterTransaction transaction = newVisibleTransactions.get(i);
+                    if (!oldVisibleTransactions.contains(transaction)) {
+                        performControllerChange(transaction, newVisibleTransactions.get(i - 1), true, transaction.pushChangeHandler());
+                    }
+                }
+            }
+
+            // Ensure all new controllers have a valid router set
+            for (RouterTransaction transaction : newBackstack) {
+                transaction.controller.setRouter(this);
+            }
+        }
     }
 
     /**
@@ -318,9 +459,10 @@ public class Router {
      *
      * @param changeListener The listener
      */
-    public void addChangeListener(ControllerChangeListener changeListener) {
-        if (!mChangeListeners.contains(changeListener)) {
-            mChangeListeners.add(changeListener);
+    @SuppressWarnings("WeakerAccess")
+    public void addChangeListener(@NonNull ControllerChangeListener changeListener) {
+        if (!changeListeners.contains(changeListener)) {
+            changeListeners.add(changeListener);
         }
     }
 
@@ -329,111 +471,209 @@ public class Router {
      *
      * @param changeListener The listener to be removed
      */
-    public void removeChangeListener(ControllerChangeListener changeListener) {
-        mChangeListeners.remove(changeListener);
+    @SuppressWarnings("WeakerAccess")
+    public void removeChangeListener(@NonNull ControllerChangeListener changeListener) {
+        changeListeners.remove(changeListener);
     }
 
     /**
      * Attaches this Router's existing backstack to its container if one exists.
      */
-    void rebindIfNeeded() {
-        Iterator<RouterTransaction> backstackIterator = mBackStack.reverseIterator();
+    @UiThread
+    public void rebindIfNeeded() {
+        ThreadUtils.ensureMainThread();
+
+        Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
         while (backstackIterator.hasNext()) {
             RouterTransaction transaction = backstackIterator.next();
 
             if (transaction.controller.getNeedsAttach()) {
-                performControllerChange(transaction.controller, null, true, new SimpleSwapChangeHandler(false));
+                performControllerChange(transaction, null, true, new SimpleSwapChangeHandler(false));
             }
         }
     }
 
-    public final void onActivityStarted(Activity activity) {
-        for (RouterTransaction transaction : mBackStack) {
+    public final void onActivityResult(@NonNull String instanceId, int requestCode, int resultCode, @Nullable Intent data) {
+        Controller controller = getControllerWithInstanceId(instanceId);
+        if (controller != null) {
+            controller.onActivityResult(requestCode, resultCode, data);
+        }
+    }
+
+    public final void onActivityStarted(@NonNull Activity activity) {
+        for (RouterTransaction transaction : backstack) {
             transaction.controller.activityStarted(activity);
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onActivityStarted(activity);
+            }
         }
     }
 
-    public final void onActivityResumed(Activity activity) {
-        for (RouterTransaction transaction : mBackStack) {
+    public final void onActivityResumed(@NonNull Activity activity) {
+        for (RouterTransaction transaction : backstack) {
             transaction.controller.activityResumed(activity);
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onActivityResumed(activity);
+            }
         }
     }
 
-    public final void onActivityPaused(Activity activity) {
-        for (RouterTransaction transaction : mBackStack) {
+    public final void onActivityPaused(@NonNull Activity activity) {
+        for (RouterTransaction transaction : backstack) {
             transaction.controller.activityPaused(activity);
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onActivityPaused(activity);
+            }
         }
     }
 
-    public final void onActivityStopped(Activity activity) {
-        for (RouterTransaction transaction : mBackStack) {
+    public final void onActivityStopped(@NonNull Activity activity) {
+        for (RouterTransaction transaction : backstack) {
             transaction.controller.activityStopped(activity);
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onActivityStopped(activity);
+            }
         }
     }
 
-    public final void onActivitySaveInstanceState(Activity activity, Bundle outState) {
-        for (RouterTransaction transaction : mBackStack) {
-            transaction.controller.prepareForActivityPause();
-        }
+    public void onActivityDestroyed(@NonNull Activity activity) {
+        prepareForContainerRemoval();
+        changeListeners.clear();
 
-        mBackStack.detachAndSaveInstanceState(outState);
-    }
-
-    public final void onActivityDestroyed(Activity activity) {
-        mContainer.setOnHierarchyChangeListener(null);
-        mChangeListeners.clear();
-
-        for (RouterTransaction transaction : mBackStack) {
+        for (RouterTransaction transaction : backstack) {
             transaction.controller.activityDestroyed(activity.isChangingConfigurations());
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onActivityDestroyed(activity);
+            }
         }
 
-        for (Controller controller : mDestroyingControllers) {
+        for (int index = destroyingControllers.size() - 1; index >= 0; index--) {
+            Controller controller = destroyingControllers.get(index);
             controller.activityDestroyed(activity.isChangingConfigurations());
+
+            for (Router childRouter : controller.getChildRouters()) {
+                childRouter.onActivityDestroyed(activity);
+            }
         }
 
-        mLifecycleHandler = null;
-        mContainer = null;
+        container = null;
     }
 
-    public final void onRestoreInstanceState(Bundle savedInstanceState) {
-        mBackStack.restoreInstanceState(savedInstanceState);
+    void prepareForHostDetach() {
+        for (RouterTransaction transaction : backstack) {
+            if (ControllerChangeHandler.completePushImmediately(transaction.controller.getInstanceId())) {
+                transaction.controller.setNeedsAttach();
+            }
+            transaction.controller.prepareForHostDetach();
+        }
     }
 
-    private void popToTransaction(@NonNull RouterTransaction transaction, ControllerChangeHandler changeHandler) {
-        RouterTransaction topTransaction = mBackStack.peek();
-        List<RouterTransaction> poppedTransactions = mBackStack.popTo(transaction);
-        trackDestroyingControllers(poppedTransactions);
+    public void saveInstanceState(@NonNull Bundle outState) {
+        prepareForHostDetach();
+
+        Bundle backstackState = new Bundle();
+        backstack.saveInstanceState(backstackState);
+
+        outState.putParcelable(KEY_BACKSTACK, backstackState);
+        outState.putBoolean(KEY_POPS_LAST_VIEW, popsLastView);
+    }
+
+    public void restoreInstanceState(@NonNull Bundle savedInstanceState) {
+        Bundle backstackBundle = savedInstanceState.getParcelable(KEY_BACKSTACK);
+        //noinspection ConstantConditions
+        backstack.restoreInstanceState(backstackBundle);
+        popsLastView = savedInstanceState.getBoolean(KEY_POPS_LAST_VIEW);
+
+        Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
+        while (backstackIterator.hasNext()) {
+            setControllerRouter(backstackIterator.next().controller);
+        }
+    }
+
+    public final void onCreateOptionsMenu(@NonNull Menu menu, @NonNull MenuInflater inflater) {
+        for (RouterTransaction transaction : backstack) {
+            transaction.controller.createOptionsMenu(menu, inflater);
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onCreateOptionsMenu(menu, inflater);
+            }
+        }
+    }
+
+    public final void onPrepareOptionsMenu(@NonNull Menu menu) {
+        for (RouterTransaction transaction : backstack) {
+            transaction.controller.prepareOptionsMenu(menu);
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                childRouter.onPrepareOptionsMenu(menu);
+            }
+        }
+    }
+
+    public final boolean onOptionsItemSelected(@NonNull MenuItem item) {
+        for (RouterTransaction transaction : backstack) {
+            if (transaction.controller.optionsItemSelected(item)) {
+                return true;
+            }
+
+            for (Router childRouter : transaction.controller.getChildRouters()) {
+                if (childRouter.onOptionsItemSelected(item)) {
+                    return true;
+                }
+            }
+        }
+        return false;
+    }
+
+    private void popToTransaction(@NonNull RouterTransaction transaction, @Nullable ControllerChangeHandler changeHandler) {
+        if (backstack.size() > 0) {
+            RouterTransaction topTransaction = backstack.peek();
+
+            List<RouterTransaction> updatedBackstack = new ArrayList<>();
+            Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
+            while (backstackIterator.hasNext()) {
+                RouterTransaction existingTransaction = backstackIterator.next();
+                updatedBackstack.add(existingTransaction);
+                if (existingTransaction == transaction) {
+                    break;
+                }
+            }
 
-        if (poppedTransactions.size() > 0) {
             if (changeHandler == null) {
-                changeHandler = topTransaction.getPopControllerChangeHandler();
+                //noinspection ConstantConditions
+                changeHandler = topTransaction.popChangeHandler();
             }
 
-            performControllerChange(mBackStack.peek().controller, topTransaction.controller, false, changeHandler);
+            setBackstack(updatedBackstack, changeHandler);
         }
     }
 
-    public final void setHost(@NonNull LifecycleHandler lifecycleHandler, @NonNull ViewGroup container) {
-        if (mLifecycleHandler != lifecycleHandler || mContainer != container) {
-            if (mContainer != null && mContainer instanceof ControllerChangeListener) {
-                removeChangeListener((ControllerChangeListener)mContainer);
-            }
-
-            if (container instanceof ControllerChangeListener) {
-                addChangeListener((ControllerChangeListener)container);
-            }
-
-            mLifecycleHandler = lifecycleHandler;
-            mContainer = container;
+    void prepareForContainerRemoval() {
+        if (container != null) {
+            container.setOnHierarchyChangeListener(null);
         }
     }
 
-    final LifecycleHandler getLifecycleHandler() {
-        return mLifecycleHandler;
+    @NonNull
+    final List<Controller> getControllers() {
+        List<Controller> controllers = new ArrayList<>();
+
+        Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
+        while (backstackIterator.hasNext()) {
+            controllers.add(backstackIterator.next().controller);
+        }
+
+        return controllers;
     }
 
+    @Nullable
     public final Boolean handleRequestedPermission(@NonNull String permission) {
-        for (ControllerTransaction transaction : mBackStack) {
+        for (RouterTransaction transaction : backstack) {
             if (transaction.controller.didRequestPermission(permission)) {
                 return transaction.controller.shouldShowRequestPermissionRationale(permission);
             }
@@ -441,59 +681,161 @@ public class Router {
         return null;
     }
 
-    private void performControllerChange(RouterTransaction to, RouterTransaction from, boolean isPush) {
+    private void performControllerChange(@Nullable RouterTransaction to, @Nullable RouterTransaction from, boolean isPush) {
+        if (isPush && to != null) {
+            to.onAttachedToRouter();
+        }
+
         ControllerChangeHandler changeHandler;
         if (isPush) {
             //noinspection ConstantConditions
-            changeHandler = to.getPushControllerChangeHandler();
+            changeHandler = to.pushChangeHandler();
         } else if (from != null) {
-            changeHandler = from.getPopControllerChangeHandler();
+            changeHandler = from.popChangeHandler();
         } else {
-            changeHandler = new SimpleSwapChangeHandler();
+            changeHandler = null;
         }
 
+        performControllerChange(to, from, isPush, changeHandler);
+    }
+
+    private void performControllerChange(@Nullable final RouterTransaction to, @Nullable final RouterTransaction from, boolean isPush, @Nullable ControllerChangeHandler changeHandler) {
         Controller toController = to != null ? to.controller : null;
         Controller fromController = from != null ? from.controller : null;
 
-        performControllerChange(toController, fromController, isPush, changeHandler);
-    }
-
-    private void performControllerChange(final Controller to, final Controller from, boolean isPush, @NonNull ControllerChangeHandler changeHandler) {
         if (to != null) {
-            to.setRouter(this);
-        } else if (mBackStack.size() == 0) {
+            to.ensureValidIndex(getTransactionIndexer());
+            setControllerRouter(toController);
+        } else if (backstack.size() == 0 && !popsLastView) {
             // We're emptying out the backstack. Views get weird if you transition them out, so just no-op it. The hosting
             // Activity should be handling this by finishing or at least hiding this view.
             changeHandler = new NoOpControllerChangeHandler();
         }
 
-        if (mContainer != null) {
-            ControllerChangeHandler.executeChange(to, from, isPush, mContainer, changeHandler, mChangeListeners);
-        }
-
+        ControllerChangeHandler.executeChange(toController, fromController, isPush, container, changeHandler, changeListeners);
     }
 
-    private void pushToBackstack(@NonNull RouterTransaction entry) {
-        mBackStack.push(entry);
+    protected void pushToBackstack(@NonNull RouterTransaction entry) {
+        backstack.push(entry);
     }
 
-    private void trackDestroyingController(RouterTransaction transaction) {
+    private void trackDestroyingController(@NonNull RouterTransaction transaction) {
         if (!transaction.controller.isDestroyed()) {
-            mDestroyingControllers.add(transaction.controller);
+            destroyingControllers.add(transaction.controller);
 
             transaction.controller.addLifecycleListener(new LifecycleListener() {
                 @Override
                 public void postDestroy(@NonNull Controller controller) {
-                    mDestroyingControllers.remove(controller);
+                    destroyingControllers.remove(controller);
                 }
             });
         }
     }
 
-    private void trackDestroyingControllers(List<RouterTransaction> transactions) {
+    private void trackDestroyingControllers(@NonNull List<RouterTransaction> transactions) {
         for (RouterTransaction transaction : transactions) {
             trackDestroyingController(transaction);
         }
     }
 
+    private void removeAllExceptVisibleAndUnowned() {
+        List<View> views = new ArrayList<>();
+
+        for (RouterTransaction transaction : getVisibleTransactions(backstack.iterator())) {
+            if (transaction.controller.getView() != null) {
+                views.add(transaction.controller.getView());
+            }
+        }
+
+        for (Router router : getSiblingRouters()) {
+            if (router.container == container) {
+                addRouterViewsToList(router, views);
+            }
+        }
+
+        final int childCount = container.getChildCount();
+        for (int i = 0; i < childCount; i++) {
+            final View child = container.getChildAt(i);
+            if (!views.contains(child)) {
+                container.removeView(child);
+            }
+        }
+    }
+
+    // Swap around transaction indicies to ensure they don't get thrown out of order by the
+    // developer rearranging the backstack at runtime.
+    private void ensureOrderedTransactionIndices(List<RouterTransaction> backstack) {
+        List<Integer> indices = new ArrayList<>();
+        for (RouterTransaction transaction : backstack) {
+            transaction.ensureValidIndex(getTransactionIndexer());
+            indices.add(transaction.transactionIndex);
+        }
+
+        Collections.sort(indices);
+
+        for (int i = 0; i < backstack.size(); i++) {
+            backstack.get(i).transactionIndex = indices.get(i);
+        }
+    }
+
+    private void addRouterViewsToList(@NonNull Router router, @NonNull List<View> list) {
+        for (Controller controller : router.getControllers()) {
+            if (controller.getView() != null) {
+                list.add(controller.getView());
+            }
+
+            for (Router child : controller.getChildRouters()) {
+                addRouterViewsToList(child, list);
+            }
+        }
+    }
+
+    private List<RouterTransaction> getVisibleTransactions(@NonNull Iterator<RouterTransaction> backstackIterator) {
+        List<RouterTransaction> transactions = new ArrayList<>();
+        while (backstackIterator.hasNext()) {
+            RouterTransaction transaction = backstackIterator.next();
+            transactions.add(transaction);
+
+            //noinspection ConstantConditions
+            if (transaction.pushChangeHandler() == null || transaction.pushChangeHandler().removesFromViewOnPush()) {
+                break;
+            }
+        }
+
+        Collections.reverse(transactions);
+        return transactions;
+    }
+
+    private boolean backstacksAreEqual(List<RouterTransaction> lhs, List<RouterTransaction> rhs) {
+        if (lhs.size() != rhs.size()) {
+            return false;
+        }
+
+        for (int i = 0; i < rhs.size(); i++) {
+            if (rhs.get(i).controller() != lhs.get(i).controller()) {
+                return false;
+            }
+        }
+
+        return true;
+    }
+
+    void setControllerRouter(@NonNull Controller controller) {
+        controller.setRouter(this);
+    }
+
+    abstract void invalidateOptionsMenu();
+    abstract void startActivity(@NonNull Intent intent);
+    abstract void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode);
+    abstract void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode, @Nullable Bundle options);
+    abstract void startIntentSenderForResult(@NonNull String instanceId, @NonNull IntentSender intent, int requestCode, @Nullable Intent fillInIntent, int flagsMask,
+                                             int flagsValues, int extraFlags, @Nullable Bundle options) throws IntentSender.SendIntentException;
+    abstract void registerForActivityResult(@NonNull String instanceId, int requestCode);
+    abstract void unregisterForActivityResults(@NonNull String instanceId);
+    abstract void requestPermissions(@NonNull String instanceId, @NonNull String[] permissions, int requestCode);
+    abstract boolean hasHost();
+    @NonNull abstract List<Router> getSiblingRouters();
+    @NonNull abstract Router getRootRouter();
+    @Nullable abstract TransactionIndexer getTransactionIndexer();
+
 }

conductor/src/main/java/com/bluelinelabs/conductor/RouterTransaction.java

@@ -2,43 +2,142 @@ package com.bluelinelabs.conductor;
 
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+
+import com.bluelinelabs.conductor.internal.TransactionIndexer;
 
 /**
- * A {@link ControllerTransaction} implementation used for adding {@link Controller}s to a {@link Router}.
+ * Metadata used for adding {@link Controller}s to a {@link Router}.
  */
-public class RouterTransaction extends ControllerTransaction {
+public class RouterTransaction {
 
-    private RouterTransaction(Builder builder) {
-        super(builder);
+    private static int INVALID_INDEX = -1;
+
+    private static final String KEY_VIEW_CONTROLLER_BUNDLE = "RouterTransaction.controller.bundle";
+    private static final String KEY_PUSH_TRANSITION = "RouterTransaction.pushControllerChangeHandler";
+    private static final String KEY_POP_TRANSITION = "RouterTransaction.popControllerChangeHandler";
+    private static final String KEY_TAG = "RouterTransaction.tag";
+    private static final String KEY_INDEX = "RouterTransaction.transactionIndex";
+    private static final String KEY_ATTACHED_TO_ROUTER = "RouterTransaction.attachedToRouter";
+
+    @NonNull final Controller controller;
+    private String tag;
+
+    private ControllerChangeHandler pushControllerChangeHandler;
+    private ControllerChangeHandler popControllerChangeHandler;
+    private boolean attachedToRouter;
+    int transactionIndex = INVALID_INDEX;
+
+    @NonNull
+    public static RouterTransaction with(@NonNull Controller controller) {
+        return new RouterTransaction(controller);
+    }
+
+    private RouterTransaction(@NonNull Controller controller) {
+        this.controller = controller;
     }
 
     RouterTransaction(@NonNull Bundle bundle) {
-        super(bundle);
+        controller = Controller.newInstance(bundle.getBundle(KEY_VIEW_CONTROLLER_BUNDLE));
+        pushControllerChangeHandler = ControllerChangeHandler.fromBundle(bundle.getBundle(KEY_PUSH_TRANSITION));
+        popControllerChangeHandler = ControllerChangeHandler.fromBundle(bundle.getBundle(KEY_POP_TRANSITION));
+        tag = bundle.getString(KEY_TAG);
+        transactionIndex = bundle.getInt(KEY_INDEX);
+        attachedToRouter = bundle.getBoolean(KEY_ATTACHED_TO_ROUTER);
+    }
+
+    void onAttachedToRouter() {
+        attachedToRouter = true;
+    }
+
+    @NonNull
+    public Controller controller() {
+        return controller;
+    }
+
+    @Nullable
+    public String tag() {
+        return tag;
+    }
+
+    @NonNull
+    public RouterTransaction tag(@Nullable String tag) {
+        if (!attachedToRouter) {
+            this.tag = tag;
+            return this;
+        } else {
+            throw new RuntimeException(getClass().getSimpleName() + "s can not be modified after being added to a Router.");
+        }
+    }
+
+    @Nullable
+    public ControllerChangeHandler pushChangeHandler() {
+        ControllerChangeHandler handler = controller.getOverriddenPushHandler();
+        if (handler == null) {
+            handler = pushControllerChangeHandler;
+        }
+        return handler;
+    }
+
+    @NonNull
+    public RouterTransaction pushChangeHandler(@Nullable ControllerChangeHandler handler) {
+        if (!attachedToRouter) {
+            pushControllerChangeHandler = handler;
+            return this;
+        } else {
+            throw new RuntimeException(getClass().getSimpleName() + "s can not be modified after being added to a Router.");
+        }
+    }
+
+    @Nullable
+    public ControllerChangeHandler popChangeHandler() {
+        ControllerChangeHandler handler = controller.getOverriddenPopHandler();
+        if (handler == null) {
+            handler = popControllerChangeHandler;
+        }
+        return handler;
+    }
+
+    @NonNull
+    public RouterTransaction popChangeHandler(@Nullable ControllerChangeHandler handler) {
+        if (!attachedToRouter) {
+            popControllerChangeHandler = handler;
+            return this;
+        } else {
+            throw new RuntimeException(getClass().getSimpleName() + "s can not be modified after being added to a Router.");
+        }
+    }
+
+    void ensureValidIndex(@Nullable TransactionIndexer indexer) {
+        if (indexer == null) {
+            throw new RuntimeException();
+        }
+        if (transactionIndex == INVALID_INDEX && indexer != null) {
+            transactionIndex = indexer.nextIndex();
+        }
     }
 
     /**
-     * Creates a new Builder
-     *
-     * @param controller The {@link Controller} to add to the {@link Router}
+     * Used to serialize this transaction into a Bundle
      */
-    public static Builder builder(@NonNull Controller controller) {
-        return new Builder(controller);
-    }
+    @NonNull
+    public Bundle saveInstanceState() {
+        Bundle bundle = new Bundle();
 
-    /**
-     * A {@link ControllerTransaction.Builder} implementation used for adding {@link Controller}s to a {@link Router}.
-     */
-    public static class Builder extends ControllerTransaction.Builder<Builder> {
+        bundle.putBundle(KEY_VIEW_CONTROLLER_BUNDLE, controller.saveInstanceState());
 
-        Builder(@NonNull Controller controller) {
-            super(controller);
+        if (pushControllerChangeHandler != null) {
+            bundle.putBundle(KEY_PUSH_TRANSITION, pushControllerChangeHandler.toBundle());
+        }
+        if (popControllerChangeHandler != null) {
+            bundle.putBundle(KEY_POP_TRANSITION, popControllerChangeHandler.toBundle());
         }
 
-        /** Creates the transaction */
-        public RouterTransaction build() {
-            return new RouterTransaction(this);
-        }
+        bundle.putString(KEY_TAG, tag);
+        bundle.putInt(KEY_INDEX, transactionIndex);
+        bundle.putBoolean(KEY_ATTACHED_TO_ROUTER, attachedToRouter);
 
+        return bundle;
     }
 
 }

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/AnimatorChangeHandler.java

@@ -1,13 +1,16 @@
 package com.bluelinelabs.conductor.changehandler;
 
 import android.animation.Animator;
+import android.animation.Animator.AnimatorListener;
 import android.animation.AnimatorListenerAdapter;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 import android.view.ViewTreeObserver;
 
+import com.bluelinelabs.conductor.Controller;
 import com.bluelinelabs.conductor.ControllerChangeHandler;
 
 /**
@@ -20,8 +23,12 @@ public abstract class AnimatorChangeHandler extends ControllerChangeHandler {
 
     public static final long DEFAULT_ANIMATION_DURATION = -1;
 
-    private long mAnimationDuration;
-    private boolean mRemovesFromViewOnPush;
+    private long animationDuration;
+    private boolean removesFromViewOnPush;
+    private boolean canceled;
+    private boolean needsImmediateCompletion;
+    private boolean completed;
+    private Animator animator;
 
     public AnimatorChangeHandler() {
         this(DEFAULT_ANIMATION_DURATION, true);
@@ -36,42 +43,64 @@ public abstract class AnimatorChangeHandler extends ControllerChangeHandler {
     }
 
     public AnimatorChangeHandler(long duration, boolean removesFromViewOnPush) {
-        mAnimationDuration = duration;
-        mRemovesFromViewOnPush = removesFromViewOnPush;
+        animationDuration = duration;
+        this.removesFromViewOnPush = removesFromViewOnPush;
     }
 
     @Override
     public void saveToBundle(@NonNull Bundle bundle) {
         super.saveToBundle(bundle);
-        bundle.putLong(KEY_DURATION, mAnimationDuration);
-        bundle.putBoolean(KEY_REMOVES_FROM_ON_PUSH, mRemovesFromViewOnPush);
+        bundle.putLong(KEY_DURATION, animationDuration);
+        bundle.putBoolean(KEY_REMOVES_FROM_ON_PUSH, removesFromViewOnPush);
     }
 
     @Override
     public void restoreFromBundle(@NonNull Bundle bundle) {
         super.restoreFromBundle(bundle);
-        mAnimationDuration = bundle.getLong(KEY_DURATION);
-        mRemovesFromViewOnPush = bundle.getBoolean(KEY_REMOVES_FROM_ON_PUSH);
+        animationDuration = bundle.getLong(KEY_DURATION);
+        removesFromViewOnPush = bundle.getBoolean(KEY_REMOVES_FROM_ON_PUSH);
+    }
+
+    @Override
+    public void onAbortPush(@NonNull ControllerChangeHandler newHandler, @Nullable Controller newTop) {
+        super.onAbortPush(newHandler, newTop);
+
+        canceled = true;
+        if (animator != null) {
+            animator.cancel();
+        }
+    }
+
+    @Override
+    public void completeImmediately() {
+        super.completeImmediately();
+
+        needsImmediateCompletion = true;
+        if (animator != null) {
+            animator.end();
+        }
     }
 
     public long getAnimationDuration() {
-        return mAnimationDuration;
+        return animationDuration;
     }
 
+    @Override
     public boolean removesFromViewOnPush() {
-        return mRemovesFromViewOnPush;
+        return removesFromViewOnPush;
     }
 
     /**
      * Should be overridden to return the Animator to use while replacing Views.
      *
      * @param container The container these Views are hosted in.
-     * @param from The previous View in the container, if any.
-     * @param to The next View that should be put in the container, if any.
+     * @param from The previous View in the container or {@code null} if there was no Controller before this transition
+     * @param to The next View that should be put in the container or {@code null} if no Controller is being transitioned to
      * @param isPush True if this is a push transaction, false if it's a pop.
      * @param toAddedToContainer True if the "to" view was added to the container as a part of this ChangeHandler. False if it was already in the hierarchy.
      */
-    protected abstract Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer);
+    @NonNull
+    protected abstract Animator getAnimator(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, boolean toAddedToContainer);
 
     /**
      * Will be called after the animation is complete to reset the View that was removed to its pre-animation state.
@@ -79,27 +108,34 @@ public abstract class AnimatorChangeHandler extends ControllerChangeHandler {
     protected abstract void resetFromView(@NonNull View from);
 
     @Override
-    public final void performChange(@NonNull final ViewGroup container, final View from, final View to, final boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
+    public final void performChange(@NonNull final ViewGroup container, @Nullable final View from, @Nullable final View to, final boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
         boolean readyToAnimate = true;
         final boolean addingToView = to != null && to.getParent() == null;
 
         if (addingToView) {
             if (isPush || from == null) {
                 container.addView(to);
-            } else {
+            } else if (to.getParent() == null) {
                 container.addView(to, container.indexOfChild(from));
             }
 
             if (to.getWidth() <= 0 && to.getHeight() <= 0) {
                 readyToAnimate = false;
                 to.getViewTreeObserver().addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+                    boolean hasRun;
+
                     @Override
                     public boolean onPreDraw() {
                         final ViewTreeObserver observer = to.getViewTreeObserver();
                         if (observer.isAlive()) {
                             observer.removeOnPreDrawListener(this);
                         }
-                        performAnimation(container, from, to, isPush, addingToView, changeListener);
+
+                        // Apparently this gets called multiple times, even if removeOnPreDrawListener is called successfully.
+                        if (!hasRun) {
+                            hasRun = true;
+                            performAnimation(container, from, to, isPush, addingToView, changeListener);
+                        }
                         return true;
                     }
                 });
@@ -111,32 +147,69 @@ public abstract class AnimatorChangeHandler extends ControllerChangeHandler {
         }
     }
 
-    private void performAnimation(@NonNull final ViewGroup container, final View from, View to, final boolean isPush, final boolean toAddedToContainer, @NonNull final ControllerChangeCompletedListener changeListener) {
-        Animator animator = getAnimator(container, from, to, isPush, toAddedToContainer);
+    private void complete(@NonNull ControllerChangeCompletedListener changeListener, @Nullable AnimatorListener animatorListener) {
+        if (!completed) {
+            completed = true;
+            changeListener.onChangeCompleted();
+        }
 
-        if (mAnimationDuration > 0) {
-            animator.setDuration(mAnimationDuration);
+        if (animator != null) {
+            if (animatorListener != null) {
+                animator.removeListener(animatorListener);
+            }
+            animator.cancel();
+            animator = null;
+        }
+    }
+
+    private void performAnimation(@NonNull final ViewGroup container, @Nullable final View from, @Nullable final View to, final boolean isPush, final boolean toAddedToContainer, @NonNull final ControllerChangeCompletedListener changeListener) {
+        if (canceled) {
+            complete(changeListener, null);
+            return;
+        }
+        if (needsImmediateCompletion) {
+            if (from != null && (!isPush || removesFromViewOnPush)) {
+                container.removeView(from);
+            }
+            complete(changeListener, null);
+            if (isPush && from != null) {
+                resetFromView(from);
+            }
+            return;
+        }
+
+        animator = getAnimator(container, from, to, isPush, toAddedToContainer);
+
+        if (animationDuration > 0) {
+            animator.setDuration(animationDuration);
         }
 
         animator.addListener(new AnimatorListenerAdapter() {
             @Override
             public void onAnimationCancel(Animator animation) {
-                changeListener.onChangeCompleted();
+                if (from != null && (!isPush || removesFromViewOnPush) && needsImmediateCompletion) {
+                    container.removeView(from);
+                }
+
+                complete(changeListener, this);
             }
 
             @Override
             public void onAnimationEnd(Animator animation) {
-                if (from != null && (!isPush || mRemovesFromViewOnPush)) {
-                    container.removeView(from);
-                }
+                if (!canceled && animator != null) {
+                    if (from != null && (!isPush || removesFromViewOnPush)) {
+                        container.removeView(from);
+                    }
 
-                changeListener.onChangeCompleted();
+                    complete(changeListener, this);
 
-                if (isPush && from != null) {
-                    resetFromView(from);
+                    if (isPush && from != null) {
+                        resetFromView(from);
+                    }
                 }
             }
         });
+
         animator.start();
     }
 

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/AutoTransitionChangeHandler.java

@@ -3,21 +3,28 @@ package com.bluelinelabs.conductor.changehandler;
 import android.annotation.TargetApi;
 import android.os.Build;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.transition.AutoTransition;
 import android.transition.Transition;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+
 /**
  * A change handler that will use an AutoTransition.
  */
 @TargetApi(Build.VERSION_CODES.LOLLIPOP)
 public class AutoTransitionChangeHandler extends TransitionChangeHandler {
 
-    @Override
-    @NonNull
-    protected Transition getTransition(@NonNull ViewGroup container, View from, View to, boolean isPush) {
+    @Override @NonNull
+    protected Transition getTransition(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush) {
         return new AutoTransition();
     }
 
+    @Override @NonNull
+    public ControllerChangeHandler copy() {
+        return new AutoTransitionChangeHandler();
+    }
+
 }

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/FadeChangeHandler.java

@@ -4,9 +4,12 @@ import android.animation.Animator;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+
 /**
  * An {@link AnimatorChangeHandler} that will cross fade two views
  */
@@ -26,14 +29,15 @@ public class FadeChangeHandler extends AnimatorChangeHandler {
         super(duration, removesFromViewOnPush);
     }
 
-    @Override
-    protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
+    @Override @NonNull
+    protected Animator getAnimator(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, boolean toAddedToContainer) {
         AnimatorSet animator = new AnimatorSet();
-        if (to != null && toAddedToContainer) {
-            animator.play(ObjectAnimator.ofFloat(to, View.ALPHA, 0, 1));
+        if (to != null) {
+            float start = toAddedToContainer ? 0 : to.getAlpha();
+            animator.play(ObjectAnimator.ofFloat(to, View.ALPHA, start, 1));
         }
 
-        if (from != null) {
+        if (from != null && removesFromViewOnPush()) {
             animator.play(ObjectAnimator.ofFloat(from, View.ALPHA, 0));
         }
 
@@ -44,4 +48,10 @@ public class FadeChangeHandler extends AnimatorChangeHandler {
     protected void resetFromView(@NonNull View from) {
         from.setAlpha(1);
     }
+
+    @Override @NonNull
+    public ControllerChangeHandler copy() {
+        return new FadeChangeHandler(getAnimationDuration(), removesFromViewOnPush());
+    }
+
 }

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/HorizontalChangeHandler.java

@@ -4,9 +4,12 @@ import android.animation.Animator;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+
 /**
  * An {@link AnimatorChangeHandler} that will slide the views left or right, depending on if it's a push or pop.
  */
@@ -26,8 +29,8 @@ public class HorizontalChangeHandler extends AnimatorChangeHandler {
         super(duration, removesFromViewOnPush);
     }
 
-    @Override
-    protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
+    @Override @NonNull
+    protected Animator getAnimator(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, boolean toAddedToContainer) {
         AnimatorSet animatorSet = new AnimatorSet();
 
         if (isPush) {
@@ -42,7 +45,9 @@ public class HorizontalChangeHandler extends AnimatorChangeHandler {
                 animatorSet.play(ObjectAnimator.ofFloat(from, View.TRANSLATION_X, from.getWidth()));
             }
             if (to != null) {
-                animatorSet.play(ObjectAnimator.ofFloat(to, View.TRANSLATION_X, -to.getWidth(), 0));
+                // Allow this to have a nice transition when coming off an aborted push animation
+                float fromLeft = from != null ? from.getTranslationX() : 0;
+                animatorSet.play(ObjectAnimator.ofFloat(to, View.TRANSLATION_X, fromLeft - to.getWidth(), 0));
             }
         }
 
@@ -51,6 +56,12 @@ public class HorizontalChangeHandler extends AnimatorChangeHandler {
 
     @Override
     protected void resetFromView(@NonNull View from) {
-        from.setTranslationY(0);
+        from.setTranslationX(0);
     }
+
+    @Override @NonNull
+    public ControllerChangeHandler copy() {
+        return new HorizontalChangeHandler(getAnimationDuration(), removesFromViewOnPush());
+    }
+
 }

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/SimpleSwapChangeHandler.java

@@ -2,51 +2,114 @@ package com.bluelinelabs.conductor.changehandler;
 
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
+import android.view.View.OnAttachStateChangeListener;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.Controller;
 import com.bluelinelabs.conductor.ControllerChangeHandler;
 
 /**
  * A {@link ControllerChangeHandler} that will instantly swap Views with no animations or transitions.
  */
-public class SimpleSwapChangeHandler extends ControllerChangeHandler {
+public class SimpleSwapChangeHandler extends ControllerChangeHandler implements OnAttachStateChangeListener {
 
     private static final String KEY_REMOVES_FROM_ON_PUSH = "SimpleSwapChangeHandler.removesFromViewOnPush";
 
-    private boolean mRemovesFromViewOnPush;
+    private boolean removesFromViewOnPush;
+
+    private boolean canceled;
+
+    private ViewGroup container;
+    private ControllerChangeCompletedListener changeListener;
 
     public SimpleSwapChangeHandler() {
         this(true);
     }
 
     public SimpleSwapChangeHandler(boolean removesFromViewOnPush) {
-        mRemovesFromViewOnPush = removesFromViewOnPush;
+        this.removesFromViewOnPush = removesFromViewOnPush;
     }
 
     @Override
     public void saveToBundle(@NonNull Bundle bundle) {
         super.saveToBundle(bundle);
-        bundle.putBoolean(KEY_REMOVES_FROM_ON_PUSH, mRemovesFromViewOnPush);
+        bundle.putBoolean(KEY_REMOVES_FROM_ON_PUSH, removesFromViewOnPush);
     }
 
     @Override
     public void restoreFromBundle(@NonNull Bundle bundle) {
         super.restoreFromBundle(bundle);
-        mRemovesFromViewOnPush = bundle.getBoolean(KEY_REMOVES_FROM_ON_PUSH);
+        removesFromViewOnPush = bundle.getBoolean(KEY_REMOVES_FROM_ON_PUSH);
     }
 
     @Override
-    public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
-        if (from != null && (!isPush || mRemovesFromViewOnPush)) {
-            container.removeView(from);
-        }
+    public void onAbortPush(@NonNull ControllerChangeHandler newHandler, @Nullable Controller newTop) {
+        super.onAbortPush(newHandler, newTop);
 
-        if (to != null && to.getParent() == null) {
-            container.addView(to);
-        }
-
-        changeListener.onChangeCompleted();
+        canceled = true;
     }
 
-}
+    @Override
+    public void completeImmediately() {
+        if (changeListener != null) {
+            changeListener.onChangeCompleted();
+            changeListener = null;
+
+            container.removeOnAttachStateChangeListener(this);
+            container = null;
+        }
+    }
+
+    @Override
+    public void performChange(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
+        if (!canceled) {
+            if (from != null && (!isPush || removesFromViewOnPush)) {
+                container.removeView(from);
+            }
+
+            if (to != null && to.getParent() == null) {
+                container.addView(to);
+            }
+        }
+
+        if (container.getWindowToken() != null) {
+            changeListener.onChangeCompleted();
+        } else {
+            this.changeListener = changeListener;
+            this.container = container;
+            container.addOnAttachStateChangeListener(this);
+        }
+
+    }
+
+    @Override
+    public boolean removesFromViewOnPush() {
+        return removesFromViewOnPush;
+    }
+
+    @Override
+    public void onViewAttachedToWindow(@NonNull View v) {
+        v.removeOnAttachStateChangeListener(this);
+
+        if (changeListener != null) {
+            changeListener.onChangeCompleted();
+            changeListener = null;
+            container = null;
+        }
+    }
+
+    @Override
+    public void onViewDetachedFromWindow(@NonNull View v) { }
+
+    @Override @NonNull
+    public ControllerChangeHandler copy() {
+        return new SimpleSwapChangeHandler(removesFromViewOnPush());
+    }
+
+    @Override
+    public boolean isReusable() {
+        return true;
+    }
+}

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/TransitionChangeHandler.java

@@ -3,12 +3,14 @@ package com.bluelinelabs.conductor.changehandler;
 import android.annotation.TargetApi;
 import android.os.Build;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.transition.Transition;
 import android.transition.Transition.TransitionListener;
 import android.transition.TransitionManager;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.Controller;
 import com.bluelinelabs.conductor.ControllerChangeHandler;
 
 /**
@@ -17,20 +19,51 @@ import com.bluelinelabs.conductor.ControllerChangeHandler;
 @TargetApi(Build.VERSION_CODES.LOLLIPOP)
 public abstract class TransitionChangeHandler extends ControllerChangeHandler {
 
+    public interface OnTransitionPreparedListener {
+        void onPrepared();
+    }
+
+    private boolean canceled;
+    private boolean needsImmediateCompletion;
+
     /**
      * Should be overridden to return the Transition to use while replacing Views.
      *
-     * @param container The container these Views are hosted in.
-     * @param from The previous View in the container, if any.
-     * @param to The next View that should be put in the container, if any.
-     * @param isPush True if this is a push transaction, false if it's a pop.
+     * @param container The container these Views are hosted in
+     * @param from      The previous View in the container or {@code null} if there was no Controller before this transition
+     * @param to        The next View that should be put in the container or {@code null} if no Controller is being transitioned to
+     * @param isPush    True if this is a push transaction, false if it's a pop
      */
     @NonNull
-    protected abstract Transition getTransition(@NonNull ViewGroup container, View from, View to, boolean isPush);
+    protected abstract Transition getTransition(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush);
 
     @Override
-    public void performChange(@NonNull final ViewGroup container, View from, View to, boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
-        Transition transition = getTransition(container, from, to, isPush);
+    public void onAbortPush(@NonNull ControllerChangeHandler newHandler, @Nullable Controller newTop) {
+        super.onAbortPush(newHandler, newTop);
+
+        canceled = true;
+    }
+
+    @Override
+    public void completeImmediately() {
+        super.completeImmediately();
+
+        needsImmediateCompletion = true;
+    }
+
+    @Override
+    public void performChange(@NonNull final ViewGroup container, @Nullable final View from, @Nullable final View to, final boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
+        if (canceled) {
+            changeListener.onChangeCompleted();
+            return;
+        }
+        if (needsImmediateCompletion) {
+            executePropertyChanges(container, from, to, null, isPush);
+            changeListener.onChangeCompleted();
+            return;
+        }
+
+        final Transition transition = getTransition(container, from, to, isPush);
         transition.addListener(new TransitionListener() {
             @Override
             public void onTransitionStart(Transition transition) { }
@@ -52,11 +85,51 @@ public abstract class TransitionChangeHandler extends ControllerChangeHandler {
             public void onTransitionResume(Transition transition) { }
         });
 
-        TransitionManager.beginDelayedTransition(container, transition);
-        if (from != null) {
+        prepareForTransition(container, from, to, transition, isPush, new OnTransitionPreparedListener() {
+            @Override
+            public void onPrepared() {
+                if (!canceled) {
+                    TransitionManager.beginDelayedTransition(container, transition);
+                    executePropertyChanges(container, from, to, transition, isPush);
+                }
+            }
+        });
+    }
+
+    @Override
+    public boolean removesFromViewOnPush() {
+        return true;
+    }
+
+    /**
+     * Called before a transition occurs. This can be used to reorder views, set their transition names, etc. The transition will begin
+     * when {@code onTransitionPreparedListener} is called.
+     *
+     * @param container  The container these Views are hosted in
+     * @param from       The previous View in the container or {@code null} if there was no Controller before this transition
+     * @param to         The next View that should be put in the container or {@code null} if no Controller is being transitioned to
+     * @param transition The transition that is being prepared for
+     * @param isPush     True if this is a push transaction, false if it's a pop
+     */
+    public void prepareForTransition(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, @NonNull Transition transition, boolean isPush, @NonNull OnTransitionPreparedListener onTransitionPreparedListener) {
+        onTransitionPreparedListener.onPrepared();
+    }
+
+    /**
+     * This should set all view properties needed for the transition to work properly. By default it removes the "from" view
+     * and adds the "to" view.
+     *
+     * @param container  The container these Views are hosted in
+     * @param from       The previous View in the container or {@code null} if there was no Controller before this transition
+     * @param to         The next View that should be put in the container or {@code null} if no Controller is being transitioned to
+     * @param transition The transition with which {@code TransitionManager.beginDelayedTransition} has been called. This will be null only if another ControllerChangeHandler immediately overrides this one.
+     * @param isPush     True if this is a push transaction, false if it's a pop
+     */
+    public void executePropertyChanges(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, @Nullable Transition transition, boolean isPush) {
+        if (from != null && (removesFromViewOnPush() || !isPush) && from.getParent() == container) {
             container.removeView(from);
         }
-        if (to != null) {
+        if (to != null && to.getParent() == null) {
             container.addView(to);
         }
     }

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/TransitionChangeHandlerCompat.java

@@ -3,9 +3,11 @@ package com.bluelinelabs.conductor.changehandler;
 import android.os.Build;
 import android.os.Bundle;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.Controller;
 import com.bluelinelabs.conductor.ControllerChangeHandler;
 import com.bluelinelabs.conductor.internal.ClassUtils;
 
@@ -15,13 +17,10 @@ import com.bluelinelabs.conductor.internal.ClassUtils;
  */
 public class TransitionChangeHandlerCompat extends ControllerChangeHandler {
 
-    private static final String KEY_TRANSITION_HANDLER_CLASS = "TransitionChangeHandlerCompat.transitionChangeHandler.class";
-    private static final String KEY_FALLBACK_HANDLER_CLASS = "TransitionChangeHandlerCompat.fallbackChangeHandler.class";
-    private static final String KEY_TRANSITION_HANDLER_STATE = "TransitionChangeHandlerCompat.transitionChangeHandler.state";
-    private static final String KEY_FALLBACK_HANDLER_STATE = "TransitionChangeHandlerCompat.fallbackChangeHandler.state";
+    private static final String KEY_CHANGE_HANDLER_CLASS = "TransitionChangeHandlerCompat.changeHandler.class";
+    private static final String KEY_HANDLER_STATE = "TransitionChangeHandlerCompat.changeHandler.state";
 
-    private TransitionChangeHandler mTransitionChangeHandler;
-    private ControllerChangeHandler mFallbackChangeHandler;
+    private ControllerChangeHandler changeHandler;
 
     public TransitionChangeHandlerCompat() { }
 
@@ -32,49 +31,67 @@ public class TransitionChangeHandlerCompat extends ControllerChangeHandler {
      * @param transitionChangeHandler The change handler that will be used on API 21 and above
      * @param fallbackChangeHandler The change handler that will be used on APIs below 21
      */
-    public TransitionChangeHandlerCompat(TransitionChangeHandler transitionChangeHandler, ControllerChangeHandler fallbackChangeHandler) {
-        mTransitionChangeHandler = transitionChangeHandler;
-        mFallbackChangeHandler = fallbackChangeHandler;
+    public TransitionChangeHandlerCompat(@NonNull TransitionChangeHandler transitionChangeHandler, @NonNull ControllerChangeHandler fallbackChangeHandler) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            changeHandler = transitionChangeHandler;
+        } else {
+            changeHandler = fallbackChangeHandler;
+        }
     }
 
     @Override
-    public void performChange(@NonNull final ViewGroup container, View from, View to, boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
-        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
-            mTransitionChangeHandler.performChange(container, from, to, isPush, changeListener);
-        } else {
-            mFallbackChangeHandler.performChange(container, from, to, isPush, changeListener);
-        }
+    public void performChange(@NonNull final ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, @NonNull final ControllerChangeCompletedListener changeListener) {
+        changeHandler.performChange(container, from, to, isPush, changeListener);
     }
 
     @Override
     public void saveToBundle(@NonNull Bundle bundle) {
         super.saveToBundle(bundle);
 
-        bundle.putString(KEY_TRANSITION_HANDLER_CLASS, mTransitionChangeHandler.getClass().getCanonicalName());
-        bundle.putString(KEY_FALLBACK_HANDLER_CLASS, mFallbackChangeHandler.getClass().getCanonicalName());
+        bundle.putString(KEY_CHANGE_HANDLER_CLASS, changeHandler.getClass().getName());
 
-        Bundle transitionBundle = new Bundle();
-        mTransitionChangeHandler.saveToBundle(transitionBundle);
-        bundle.putBundle(KEY_TRANSITION_HANDLER_STATE, transitionBundle);
-
-        Bundle fallbackBundle = new Bundle();
-        mFallbackChangeHandler.saveToBundle(fallbackBundle);
-        bundle.putBundle(KEY_FALLBACK_HANDLER_STATE, fallbackBundle);
+        Bundle stateBundle = new Bundle();
+        changeHandler.saveToBundle(stateBundle);
+        bundle.putBundle(KEY_HANDLER_STATE, stateBundle);
     }
 
     @Override
     public void restoreFromBundle(@NonNull Bundle bundle) {
         super.restoreFromBundle(bundle);
 
-        String transitionClassName = bundle.getString(KEY_TRANSITION_HANDLER_CLASS);
-        mTransitionChangeHandler = ClassUtils.newInstance(transitionClassName);
+        String className = bundle.getString(KEY_CHANGE_HANDLER_CLASS);
+        changeHandler = ClassUtils.newInstance(className);
         //noinspection ConstantConditions
-        mTransitionChangeHandler.restoreFromBundle(bundle.getBundle(KEY_TRANSITION_HANDLER_STATE));
+        changeHandler.restoreFromBundle(bundle.getBundle(KEY_HANDLER_STATE));
+    }
 
-        String fallbackClassName = bundle.getString(KEY_FALLBACK_HANDLER_CLASS);
-        mFallbackChangeHandler = ClassUtils.newInstance(fallbackClassName);
-        //noinspection ConstantConditions
-        mFallbackChangeHandler.restoreFromBundle(bundle.getBundle(KEY_FALLBACK_HANDLER_STATE));
+    @Override
+    public boolean removesFromViewOnPush() {
+        return changeHandler.removesFromViewOnPush();
+    }
+
+    @Override @NonNull
+    public ControllerChangeHandler copy() {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            return new TransitionChangeHandlerCompat((TransitionChangeHandler)changeHandler.copy(), null);
+        } else {
+            return new TransitionChangeHandlerCompat(null, changeHandler.copy());
+        }
+    }
+
+    @Override
+    public void onAbortPush(@NonNull ControllerChangeHandler newHandler, @Nullable Controller newTop) {
+        changeHandler.onAbortPush(newHandler, newTop);
+    }
+
+    @Override
+    public void completeImmediately() {
+        changeHandler.completeImmediately();
+    }
+
+    @Override
+    public void setForceRemoveViewOnPush(boolean force) {
+        changeHandler.setForceRemoveViewOnPush(force);
     }
 
 }

conductor/src/main/java/com/bluelinelabs/conductor/changehandler/VerticalChangeHandler.java

@@ -4,9 +4,12 @@ import android.animation.Animator;
 import android.animation.AnimatorSet;
 import android.animation.ObjectAnimator;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+
 import java.util.ArrayList;
 import java.util.List;
 
@@ -30,8 +33,8 @@ public class VerticalChangeHandler extends AnimatorChangeHandler {
         super(duration, removesFromViewOnPush);
     }
 
-    @Override
-    protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
+    @Override @NonNull
+    protected Animator getAnimator(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, boolean toAddedToContainer) {
         AnimatorSet animator = new AnimatorSet();
         List<Animator> viewAnimators = new ArrayList<>();
 
@@ -48,4 +51,9 @@ public class VerticalChangeHandler extends AnimatorChangeHandler {
     @Override
     protected void resetFromView(@NonNull View from) { }
 
+    @Override @NonNull
+    public ControllerChangeHandler copy() {
+        return new VerticalChangeHandler(getAnimationDuration(), removesFromViewOnPush());
+    }
+
 }

conductor/src/main/java/com/bluelinelabs/conductor/internal/ClassUtils.java

@@ -1,16 +1,13 @@
 package com.bluelinelabs.conductor.internal;
 
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.text.TextUtils;
 
 public class ClassUtils {
 
-    @SuppressWarnings("unchecked")
-    public static <T> Class<? extends T> classForName(String className) {
-        return classForName(className, true);
-    }
-
-    @SuppressWarnings("unchecked")
-    public static <T> Class<? extends T> classForName(String className, boolean allowEmptyName) {
+    @Nullable @SuppressWarnings("unchecked")
+    public static <T> Class<? extends T> classForName(@NonNull String className, boolean allowEmptyName) {
         if (allowEmptyName && TextUtils.isEmpty(className)) {
             return null;
         }
@@ -22,10 +19,10 @@ public class ClassUtils {
         }
     }
 
-    @SuppressWarnings("unchecked")
-    public static <T> T newInstance(String className) {
+    @Nullable @SuppressWarnings("unchecked")
+    public static <T> T newInstance(@NonNull String className) {
         try {
-            Class<? extends T> cls = classForName(className);
+            Class<? extends T> cls = classForName(className, true);
             return cls != null ? cls.newInstance() : null;
         } catch (Exception e) {
             throw new RuntimeException("An exception occurred while creating a new instance of " + className + ". " + e.getMessage());

conductor/src/main/java/com/bluelinelabs/conductor/internal/LifecycleHandler.java

@@ -4,38 +4,56 @@ import android.annotation.TargetApi;
 import android.app.Activity;
 import android.app.Application.ActivityLifecycleCallbacks;
 import android.app.Fragment;
+import android.content.Context;
 import android.content.Intent;
+import android.content.IntentSender;
 import android.os.Build;
 import android.os.Bundle;
+import android.os.Parcel;
+import android.os.Parcelable;
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.util.SparseArray;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.MenuItem;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.ActivityHostedRouter;
 import com.bluelinelabs.conductor.Router;
 
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
 
 public class LifecycleHandler extends Fragment implements ActivityLifecycleCallbacks {
 
     private static final String FRAGMENT_TAG = "LifecycleHandler";
 
+    private static final String KEY_PENDING_PERMISSION_REQUESTS = "LifecycleHandler.pendingPermissionRequests";
     private static final String KEY_PERMISSION_REQUEST_CODES = "LifecycleHandler.permissionRequests";
     private static final String KEY_ACTIVITY_REQUEST_CODES = "LifecycleHandler.activityRequests";
+    private static final String KEY_ROUTER_STATE_PREFIX = "LifecycleHandler.routerState";
 
-    private Activity mActivity;
-    private boolean mHasRegisteredCallbacks;
+    private Activity activity;
+    private boolean hasRegisteredCallbacks;
+    private boolean destroyed;
+    private boolean attached;
 
-    private SparseArray<String> mPermissionRequestMap = new SparseArray<>();
-    private SparseArray<String> mActivityRequestMap = new SparseArray<>();
+    private SparseArray<String> permissionRequestMap = new SparseArray<>();
+    private SparseArray<String> activityRequestMap = new SparseArray<>();
+    private ArrayList<PendingPermissionRequest> pendingPermissionRequests = new ArrayList<>();
 
-    private final Map<Integer, Router> mRouterMap = new HashMap<>();
+    private final Map<Integer, ActivityHostedRouter> routerMap = new HashMap<>();
 
     public LifecycleHandler() {
         setRetainInstance(true);
+        setHasOptionsMenu(true);
     }
 
-    private static LifecycleHandler findInActivity(Activity activity) {
+    @Nullable
+    private static LifecycleHandler findInActivity(@NonNull Activity activity) {
         LifecycleHandler lifecycleHandler = (LifecycleHandler)activity.getFragmentManager().findFragmentByTag(FRAGMENT_TAG);
         if (lifecycleHandler != null) {
             lifecycleHandler.registerActivityListener(activity);
@@ -43,7 +61,8 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
         return lifecycleHandler;
     }
 
-    public static LifecycleHandler install(Activity activity) {
+    @NonNull
+    public static LifecycleHandler install(@NonNull Activity activity) {
         LifecycleHandler lifecycleHandler = findInActivity(activity);
         if (lifecycleHandler == null) {
             lifecycleHandler = new LifecycleHandler();
@@ -53,33 +72,46 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
         return lifecycleHandler;
     }
 
-    public Router getRouter(ViewGroup container, Bundle savedInstanceState) {
-        Router router = mRouterMap.get(getRouterHashKey(container));
+    @NonNull
+    public Router getRouter(@NonNull ViewGroup container, @Nullable Bundle savedInstanceState) {
+        ActivityHostedRouter router = routerMap.get(getRouterHashKey(container));
         if (router == null) {
-            router = new Router();
+            router = new ActivityHostedRouter();
+            router.setHost(this, container);
+
             if (savedInstanceState != null) {
-                router.onRestoreInstanceState(savedInstanceState);
+                Bundle routerSavedState = savedInstanceState.getBundle(KEY_ROUTER_STATE_PREFIX + router.getContainerId());
+                if (routerSavedState != null) {
+                    router.restoreInstanceState(routerSavedState);
+                }
             }
-            mRouterMap.put(getRouterHashKey(container), router);
+            routerMap.put(getRouterHashKey(container), router);
+        } else {
+            router.setHost(this, container);
         }
 
-        router.setHost(this, container);
         return router;
     }
 
-    public Activity getLifecycleActivity() {
-        return mActivity;
+    @NonNull
+    public List<Router> getRouters() {
+        return new ArrayList<Router>(routerMap.values());
     }
 
-    private static int getRouterHashKey(ViewGroup viewGroup) {
+    @Nullable
+    public Activity getLifecycleActivity() {
+        return activity;
+    }
+
+    private static int getRouterHashKey(@NonNull ViewGroup viewGroup) {
         return viewGroup.getId();
     }
 
-    private void registerActivityListener(Activity activity) {
-        mActivity = activity;
+    private void registerActivityListener(@NonNull Activity activity) {
+        this.activity = activity;
 
-        if (!mHasRegisteredCallbacks) {
-            mHasRegisteredCallbacks = true;
+        if (!hasRegisteredCallbacks) {
+            hasRegisteredCallbacks = true;
             activity.getApplication().registerActivityLifecycleCallbacks(this);
         }
     }
@@ -90,10 +122,13 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
 
         if (savedInstanceState != null) {
             StringSparseArrayParceler permissionParcel = savedInstanceState.getParcelable(KEY_PERMISSION_REQUEST_CODES);
-            mPermissionRequestMap = permissionParcel != null ? permissionParcel.getStringSparseArray() : null;
+            permissionRequestMap = permissionParcel != null ? permissionParcel.getStringSparseArray() : new SparseArray<String>();
 
             StringSparseArrayParceler activityParcel = savedInstanceState.getParcelable(KEY_ACTIVITY_REQUEST_CODES);
-            mActivityRequestMap = activityParcel != null ? activityParcel.getStringSparseArray() : null;
+            activityRequestMap = activityParcel != null ? activityParcel.getStringSparseArray() : new SparseArray<String>();
+
+            ArrayList<PendingPermissionRequest> pendingRequests = savedInstanceState.getParcelableArrayList(KEY_PENDING_PERMISSION_REQUESTS);
+            pendingPermissionRequests = pendingRequests != null ? pendingRequests : new ArrayList<PendingPermissionRequest>();
         }
     }
 
@@ -101,22 +136,65 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
     public void onSaveInstanceState(Bundle outState) {
         super.onSaveInstanceState(outState);
 
-        outState.putParcelable(KEY_PERMISSION_REQUEST_CODES, new StringSparseArrayParceler(mPermissionRequestMap));
-        outState.putParcelable(KEY_ACTIVITY_REQUEST_CODES, new StringSparseArrayParceler(mActivityRequestMap));
+        outState.putParcelable(KEY_PERMISSION_REQUEST_CODES, new StringSparseArrayParceler(permissionRequestMap));
+        outState.putParcelable(KEY_ACTIVITY_REQUEST_CODES, new StringSparseArrayParceler(activityRequestMap));
+        outState.putParcelableArrayList(KEY_PENDING_PERMISSION_REQUESTS, pendingPermissionRequests);
     }
 
     @Override
     public void onDestroy() {
         super.onDestroy();
 
-        if (mActivity != null) {
-            mActivity.getApplication().unregisterActivityLifecycleCallbacks(this);
+        if (activity != null) {
+            activity.getApplication().unregisterActivityLifecycleCallbacks(this);
+            destroyRouters();
+            activity = null;
+        }
+    }
 
-            for (Router router : mRouterMap.values()) {
-                router.onActivityDestroyed(mActivity);
+    @SuppressWarnings("deprecation")
+    @Override
+    public void onAttach(Activity activity) {
+        super.onAttach(activity);
+        destroyed = false;
+        setAttached();
+    }
+
+    @Override
+    public void onAttach(Context context) {
+        super.onAttach(context);
+        destroyed = false;
+        setAttached();
+    }
+
+    @Override
+    public void onDetach() {
+        super.onDetach();
+
+        attached = false;
+        destroyRouters();
+    }
+
+    private void setAttached() {
+        if (!attached) {
+            attached = true;
+
+            for (int i = pendingPermissionRequests.size() - 1; i >= 0; i--) {
+                PendingPermissionRequest request = pendingPermissionRequests.remove(i);
+                requestPermissions(request.instanceId, request.permissions, request.requestCode);
             }
+        }
+    }
 
-            mActivity = null;
+    private void destroyRouters() {
+        if (!destroyed) {
+            destroyed = true;
+
+            if (activity != null) {
+                for (Router router : routerMap.values()) {
+                    router.onActivityDestroyed(activity);
+                }
+            }
         }
     }
 
@@ -124,9 +202,9 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
     public void onActivityResult(int requestCode, int resultCode, Intent data) {
         super.onActivityResult(requestCode, resultCode, data);
 
-        String instanceId = mActivityRequestMap.get(requestCode);
+        String instanceId = activityRequestMap.get(requestCode);
         if (instanceId != null) {
-            for (Router router : mRouterMap.values()) {
+            for (Router router : routerMap.values()) {
                 router.onActivityResult(instanceId, requestCode, resultCode, data);
             }
         }
@@ -136,9 +214,9 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
     public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
         super.onRequestPermissionsResult(requestCode, permissions, grantResults);
 
-        String instanceId = mPermissionRequestMap.get(requestCode);
+        String instanceId = permissionRequestMap.get(requestCode);
         if (instanceId != null) {
-            for (Router router : mRouterMap.values()) {
+            for (Router router : routerMap.values()) {
                 router.onRequestPermissionsResult(instanceId, requestCode, permissions, grantResults);
             }
         }
@@ -146,7 +224,7 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
 
     @Override
     public boolean shouldShowRequestPermissionRationale(@NonNull String permission) {
-        for (Router router : mRouterMap.values()) {
+        for (Router router : routerMap.values()) {
             Boolean handled = router.handleRequestedPermission(permission);
             if (handled != null) {
                 return handled;
@@ -155,33 +233,86 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
         return super.shouldShowRequestPermissionRationale(permission);
     }
 
-    public void startActivityForResult(String instanceId, Intent intent, int requestCode) {
-        mActivityRequestMap.put(requestCode, instanceId);
+    @Override
+    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+        super.onCreateOptionsMenu(menu, inflater);
+
+        for (Router router : routerMap.values()) {
+            router.onCreateOptionsMenu(menu, inflater);
+        }
+    }
+
+    @Override
+    public void onPrepareOptionsMenu(Menu menu) {
+        super.onPrepareOptionsMenu(menu);
+
+        for (Router router : routerMap.values()) {
+            router.onPrepareOptionsMenu(menu);
+        }
+    }
+
+    @Override
+    public boolean onOptionsItemSelected(MenuItem item) {
+        for (Router router : routerMap.values()) {
+            if (router.onOptionsItemSelected(item)) {
+                return true;
+            }
+        }
+
+        return super.onOptionsItemSelected(item);
+    }
+
+    public void registerForActivityResult(@NonNull String instanceId, int requestCode) {
+        activityRequestMap.put(requestCode, instanceId);
+    }
+
+    public void unregisterForActivityResults(@NonNull String instanceId) {
+        for (int i = activityRequestMap.size() - 1; i >= 0; i--) {
+            if (instanceId.equals(activityRequestMap.get(activityRequestMap.keyAt(i)))) {
+                activityRequestMap.removeAt(i);
+            }
+        }
+    }
+
+    public void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode) {
+        registerForActivityResult(instanceId, requestCode);
         startActivityForResult(intent, requestCode);
     }
 
-    public void startActivityForResult(String instanceId, Intent intent, int requestCode, Bundle options) {
-        mActivityRequestMap.put(requestCode, instanceId);
+    public void startActivityForResult(@NonNull String instanceId, @NonNull Intent intent, int requestCode, @Nullable Bundle options) {
+        registerForActivityResult(instanceId, requestCode);
         startActivityForResult(intent, requestCode, options);
     }
 
+    @TargetApi(Build.VERSION_CODES.N)
+    public void startIntentSenderForResult(@NonNull String instanceId, @NonNull IntentSender intent, int requestCode,
+                                           @Nullable Intent fillInIntent, int flagsMask, int flagsValues, int extraFlags,
+                                           @Nullable Bundle options) throws IntentSender.SendIntentException {
+        registerForActivityResult(instanceId, requestCode);
+        startIntentSenderForResult(intent, requestCode, fillInIntent, flagsMask, flagsValues, extraFlags, options);
+    }
+
     @TargetApi(Build.VERSION_CODES.M)
-    public void requestPermissions(String instanceId, String[] permissions, int requestCode) {
-        mPermissionRequestMap.put(requestCode, instanceId);
-        requestPermissions(permissions, requestCode);
+    public void requestPermissions(@NonNull String instanceId, @NonNull String[] permissions, int requestCode) {
+        if (attached) {
+            permissionRequestMap.put(requestCode, instanceId);
+            requestPermissions(permissions, requestCode);
+        } else {
+            pendingPermissionRequests.add(new PendingPermissionRequest(instanceId, permissions, requestCode));
+        }
     }
 
     @Override
     public void onActivityCreated(Activity activity, Bundle savedInstanceState) {
-        if (mActivity == null && findInActivity(activity) == LifecycleHandler.this) {
-            mActivity = activity;
+        if (this.activity == null && findInActivity(activity) == LifecycleHandler.this) {
+            this.activity = activity;
         }
     }
 
     @Override
     public void onActivityStarted(Activity activity) {
-        if (mActivity == activity) {
-            for (Router router : mRouterMap.values()) {
+        if (this.activity == activity) {
+            for (Router router : routerMap.values()) {
                 router.onActivityStarted(activity);
             }
         }
@@ -189,8 +320,8 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
 
     @Override
     public void onActivityResumed(Activity activity) {
-        if (mActivity == activity) {
-            for (Router router : mRouterMap.values()) {
+        if (this.activity == activity) {
+            for (Router router : routerMap.values()) {
                 router.onActivityResumed(activity);
             }
         }
@@ -198,8 +329,8 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
 
     @Override
     public void onActivityPaused(Activity activity) {
-        if (mActivity == activity) {
-            for (Router router : mRouterMap.values()) {
+        if (this.activity == activity) {
+            for (Router router : routerMap.values()) {
                 router.onActivityPaused(activity);
             }
         }
@@ -207,8 +338,8 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
 
     @Override
     public void onActivityStopped(Activity activity) {
-        if (mActivity == activity) {
-            for (Router router : mRouterMap.values()) {
+        if (this.activity == activity) {
+            for (Router router : routerMap.values()) {
                 router.onActivityStopped(activity);
             }
         }
@@ -216,13 +347,58 @@ public class LifecycleHandler extends Fragment implements ActivityLifecycleCallb
 
     @Override
     public void onActivitySaveInstanceState(Activity activity, Bundle outState) {
-        if (mActivity == activity) {
-            for (Router router : mRouterMap.values()) {
-                router.onActivitySaveInstanceState(activity, outState);
+        if (this.activity == activity) {
+            for (Router router : routerMap.values()) {
+                Bundle bundle = new Bundle();
+                router.saveInstanceState(bundle);
+                outState.putBundle(KEY_ROUTER_STATE_PREFIX + router.getContainerId(), bundle);
             }
         }
     }
 
     @Override
     public void onActivityDestroyed(Activity activity) { }
+
+    private static class PendingPermissionRequest implements Parcelable {
+        final String instanceId;
+        final String[] permissions;
+        final int requestCode;
+
+        PendingPermissionRequest(@NonNull String instanceId, @NonNull String[] permissions, int requestCode) {
+            this.instanceId = instanceId;
+            this.permissions = permissions;
+            this.requestCode = requestCode;
+        }
+
+        private PendingPermissionRequest(Parcel in) {
+            instanceId = in.readString();
+            permissions = in.createStringArray();
+            requestCode = in.readInt();
+        }
+
+        @Override
+        public int describeContents() {
+            return 0;
+        }
+
+        @Override
+        public void writeToParcel(Parcel out, int flags) {
+            out.writeString(instanceId);
+            out.writeStringArray(permissions);
+            out.writeInt(requestCode);
+        }
+
+        public static final Parcelable.Creator<PendingPermissionRequest> CREATOR = new Parcelable.Creator<PendingPermissionRequest>() {
+            @Override
+            public PendingPermissionRequest createFromParcel(Parcel in) {
+                return new PendingPermissionRequest(in);
+            }
+
+            @Override
+            public PendingPermissionRequest[] newArray(int size) {
+                return new PendingPermissionRequest[size];
+            }
+        };
+
+    }
 }

conductor/src/main/java/com/bluelinelabs/conductor/internal/NoOpControllerChangeHandler.java

@@ -1,6 +1,7 @@
 package com.bluelinelabs.conductor.internal;
 
 import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
 import android.view.View;
 import android.view.ViewGroup;
 
@@ -9,8 +10,18 @@ import com.bluelinelabs.conductor.ControllerChangeHandler;
 public class NoOpControllerChangeHandler extends ControllerChangeHandler {
 
     @Override
-    public void performChange(@NonNull ViewGroup container, @NonNull View from, @NonNull View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
+    public void performChange(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
         changeListener.onChangeCompleted();
     }
 
+    @NonNull
+    @Override
+    public ControllerChangeHandler copy() {
+        return new NoOpControllerChangeHandler();
+    }
+
+    @Override
+    public boolean isReusable() {
+        return true;
+    }
 }

conductor/src/main/java/com/bluelinelabs/conductor/internal/RouterRequiringFunc.java

@@ -0,0 +1,5 @@
+package com.bluelinelabs.conductor.internal;
+
+public interface RouterRequiringFunc {
+    void execute();
+}

conductor/src/main/java/com/bluelinelabs/conductor/internal/StringSparseArrayParceler.java

@@ -2,52 +2,58 @@ package com.bluelinelabs.conductor.internal;
 
 import android.os.Parcel;
 import android.os.Parcelable;
+import android.support.annotation.NonNull;
 import android.util.SparseArray;
 
 public class StringSparseArrayParceler implements Parcelable {
 
-    private final SparseArray<String> mStringSparseArray;
+    private final SparseArray<String> stringSparseArray;
 
-    public StringSparseArrayParceler(SparseArray<String> stringSparseArray) {
-        mStringSparseArray = stringSparseArray;
+    public StringSparseArrayParceler(@NonNull SparseArray<String> stringSparseArray) {
+        this.stringSparseArray = stringSparseArray;
     }
 
-    private StringSparseArrayParceler(Parcel in) {
-        mStringSparseArray = new SparseArray<>();
+    private StringSparseArrayParceler(@NonNull Parcel in) {
+        stringSparseArray = new SparseArray<>();
 
         final int size = in.readInt();
 
         for (int i = 0; i < size; i++) {
-            mStringSparseArray.put(in.readInt(), in.readString());
+            stringSparseArray.put(in.readInt(), in.readString());
         }
     }
 
+    @NonNull
     public SparseArray<String> getStringSparseArray() {
-        return mStringSparseArray;
+        return stringSparseArray;
     }
 
+    @Override
     public int describeContents() {
         return 0;
     }
 
+    @Override
     public void writeToParcel(Parcel out, int flags) {
-        final int size = mStringSparseArray.size();
+        final int size = stringSparseArray.size();
 
         out.writeInt(size);
 
         for (int i = 0; i < size; i++) {
-            int key = mStringSparseArray.keyAt(i);
+            int key = stringSparseArray.keyAt(i);
 
             out.writeInt(key);
-            out.writeString(mStringSparseArray.get(key));
+            out.writeString(stringSparseArray.get(key));
         }
     }
 
     public static final Parcelable.Creator<StringSparseArrayParceler> CREATOR = new Parcelable.Creator<StringSparseArrayParceler>() {
+        @Override
         public StringSparseArrayParceler createFromParcel(Parcel in) {
             return new StringSparseArrayParceler(in);
         }
 
+        @Override
         public StringSparseArrayParceler[] newArray(int size) {
             return new StringSparseArrayParceler[size];
         }

conductor/src/main/java/com/bluelinelabs/conductor/internal/ThreadUtils.java

@@ -0,0 +1,20 @@
+package com.bluelinelabs.conductor.internal;
+
+import android.os.Looper;
+import android.util.AndroidRuntimeException;
+
+public class ThreadUtils {
+
+    public static void ensureMainThread() {
+        if (Looper.getMainLooper().getThread() != Thread.currentThread()) {
+            throw new CalledFromWrongThreadException("Methods that affect the view hierarchy can can only be called from the main thread.");
+        }
+    }
+
+    private static final class CalledFromWrongThreadException extends AndroidRuntimeException {
+        CalledFromWrongThreadException(String msg) {
+            super(msg);
+        }
+    }
+
+}

conductor/src/main/java/com/bluelinelabs/conductor/internal/TransactionIndexer.java

@@ -0,0 +1,24 @@
+package com.bluelinelabs.conductor.internal;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+
+public class TransactionIndexer {
+
+    private static final String KEY_INDEX = "TransactionIndexer.currentIndex";
+
+    private int currentIndex;
+
+    public int nextIndex() {
+        return ++currentIndex;
+    }
+
+    public void saveInstanceState(@NonNull Bundle outState) {
+        outState.putInt(KEY_INDEX, currentIndex);
+    }
+
+    public void restoreInstanceState(@NonNull Bundle savedInstanceState) {
+        currentIndex = savedInstanceState.getInt(KEY_INDEX);
+    }
+
+}

conductor/src/main/java/com/bluelinelabs/conductor/internal/ViewAttachHandler.java

@@ -0,0 +1,151 @@
+package com.bluelinelabs.conductor.internal;
+
+import android.view.View;
+import android.view.View.OnAttachStateChangeListener;
+import android.view.ViewGroup;
+
+public class ViewAttachHandler implements OnAttachStateChangeListener {
+
+    private enum ReportedState {
+        VIEW_DETACHED,
+        ACTIVITY_STOPPED,
+        ATTACHED
+    }
+
+    public interface ViewAttachListener {
+        void onAttached();
+        void onDetached(boolean fromActivityStop);
+        void onViewDetachAfterStop();
+    }
+
+    private interface ChildAttachListener {
+        void onAttached();
+    }
+
+    private boolean rootAttached = false;
+    private boolean childrenAttached = false;
+    private boolean activityStopped = false;
+    private ReportedState reportedState = ReportedState.VIEW_DETACHED;
+    private ViewAttachListener attachListener;
+    private OnAttachStateChangeListener childOnAttachStateChangeListener;
+
+    public ViewAttachHandler(ViewAttachListener attachListener) {
+        this.attachListener = attachListener;
+    }
+
+    @Override
+    public void onViewAttachedToWindow(final View v) {
+        if (rootAttached) {
+            return;
+        }
+
+        rootAttached = true;
+        listenForDeepestChildAttach(v, new ChildAttachListener() {
+            @Override
+            public void onAttached() {
+                childrenAttached = true;
+                reportAttached();
+
+            }
+        });
+    }
+
+    @Override
+    public void onViewDetachedFromWindow(View v) {
+        rootAttached = false;
+        if (childrenAttached) {
+            childrenAttached = false;
+            reportDetached(false);
+        }
+    }
+
+    public void listenForAttach(final View view) {
+        view.addOnAttachStateChangeListener(this);
+    }
+
+    public void unregisterAttachListener(View view) {
+        view.removeOnAttachStateChangeListener(this);
+
+        if (childOnAttachStateChangeListener != null && view instanceof ViewGroup) {
+            findDeepestChild((ViewGroup)view).removeOnAttachStateChangeListener(childOnAttachStateChangeListener);
+        }
+    }
+
+    public void onActivityStarted() {
+        activityStopped = false;
+        reportAttached();
+    }
+
+    public void onActivityStopped() {
+        activityStopped = true;
+        reportDetached(true);
+    }
+
+    private void reportAttached() {
+        if (rootAttached && childrenAttached && !activityStopped && reportedState != ReportedState.ATTACHED) {
+            reportedState = ReportedState.ATTACHED;
+            attachListener.onAttached();
+        }
+    }
+
+    private void reportDetached(boolean detachedForActivity) {
+        boolean wasDetachedForActivity = reportedState == ReportedState.ACTIVITY_STOPPED;
+
+        if (detachedForActivity) {
+            reportedState = ReportedState.ACTIVITY_STOPPED;
+        } else {
+            reportedState = ReportedState.VIEW_DETACHED;
+        }
+
+        if (wasDetachedForActivity && !detachedForActivity) {
+            attachListener.onViewDetachAfterStop();
+        } else {
+            attachListener.onDetached(detachedForActivity);
+        }
+    }
+
+    private void listenForDeepestChildAttach(final View view, final ChildAttachListener attachListener) {
+        if (!(view instanceof ViewGroup)) {
+            attachListener.onAttached();
+            return;
+        }
+
+        ViewGroup viewGroup = (ViewGroup)view;
+        if (viewGroup.getChildCount() == 0) {
+            attachListener.onAttached();
+            return;
+        }
+
+        childOnAttachStateChangeListener = new OnAttachStateChangeListener() {
+            boolean attached = false;
+
+            @Override
+            public void onViewAttachedToWindow(View v) {
+                if (!attached) {
+                    attached = true;
+                    attachListener.onAttached();
+                    v.removeOnAttachStateChangeListener(this);
+                    childOnAttachStateChangeListener = null;
+                }
+            }
+
+            @Override
+            public void onViewDetachedFromWindow(View v) { }
+        };
+        findDeepestChild(viewGroup).addOnAttachStateChangeListener(childOnAttachStateChangeListener);
+    }
+
+    private View findDeepestChild(ViewGroup viewGroup) {
+        if (viewGroup.getChildCount() == 0) {
+            return viewGroup;
+        }
+
+        View lastChild = viewGroup.getChildAt(viewGroup.getChildCount() - 1);
+        if (lastChild instanceof ViewGroup) {
+            return findDeepestChild((ViewGroup)lastChild);
+        } else {
+            return lastChild;
+        }
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/BackstackTests.java

@@ -1,66 +1,69 @@
 package com.bluelinelabs.conductor;
 
-import org.junit.Assert;
+import com.bluelinelabs.conductor.util.TestController;
+
 import org.junit.Before;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class BackstackTests {
 
-    private Backstack mBackstack;
+    private Backstack backstack;
 
     @Before
     public void setup() {
-        mBackstack = new Backstack();
+        backstack = new Backstack();
     }
 
     @Test
     public void testPush() {
-        Assert.assertEquals(0, mBackstack.size());
-        mBackstack.push(RouterTransaction.builder(new TestController()).build());
-        Assert.assertEquals(1, mBackstack.size());
+        assertEquals(0, backstack.size());
+        backstack.push(RouterTransaction.with(new TestController()));
+        assertEquals(1, backstack.size());
     }
 
     @Test
     public void testPop() {
-        mBackstack.push(RouterTransaction.builder(new TestController()).build());
-        mBackstack.push(RouterTransaction.builder(new TestController()).build());
-        Assert.assertEquals(2, mBackstack.size());
-        mBackstack.pop();
-        Assert.assertEquals(1, mBackstack.size());
-        mBackstack.pop();
-        Assert.assertEquals(0, mBackstack.size());
+        backstack.push(RouterTransaction.with(new TestController()));
+        backstack.push(RouterTransaction.with(new TestController()));
+        assertEquals(2, backstack.size());
+        backstack.pop();
+        assertEquals(1, backstack.size());
+        backstack.pop();
+        assertEquals(0, backstack.size());
     }
 
     @Test
     public void testPeek() {
-        RouterTransaction transaction1 = RouterTransaction.builder(new TestController()).build();
-        RouterTransaction transaction2 = RouterTransaction.builder(new TestController()).build();
+        RouterTransaction transaction1 = RouterTransaction.with(new TestController());
+        RouterTransaction transaction2 = RouterTransaction.with(new TestController());
 
-        mBackstack.push(transaction1);
-        Assert.assertEquals(transaction1, mBackstack.peek());
+        backstack.push(transaction1);
+        assertEquals(transaction1, backstack.peek());
 
-        mBackstack.push(transaction2);
-        Assert.assertEquals(transaction2, mBackstack.peek());
+        backstack.push(transaction2);
+        assertEquals(transaction2, backstack.peek());
 
-        mBackstack.pop();
-        Assert.assertEquals(transaction1, mBackstack.peek());
+        backstack.pop();
+        assertEquals(transaction1, backstack.peek());
     }
 
     @Test
     public void testPopTo() {
-        RouterTransaction transaction1 = RouterTransaction.builder(new TestController()).build();
-        RouterTransaction transaction2 = RouterTransaction.builder(new TestController()).build();
-        RouterTransaction transaction3 = RouterTransaction.builder(new TestController()).build();
+        RouterTransaction transaction1 = RouterTransaction.with(new TestController());
+        RouterTransaction transaction2 = RouterTransaction.with(new TestController());
+        RouterTransaction transaction3 = RouterTransaction.with(new TestController());
 
-        mBackstack.push(transaction1);
-        mBackstack.push(transaction2);
-        mBackstack.push(transaction3);
+        backstack.push(transaction1);
+        backstack.push(transaction2);
+        backstack.push(transaction3);
 
-        Assert.assertEquals(3, mBackstack.size());
+        assertEquals(3, backstack.size());
 
-        mBackstack.popTo(transaction1);
+        backstack.popTo(transaction1);
 
-        Assert.assertEquals(1, mBackstack.size());
-        Assert.assertEquals(transaction1, mBackstack.peek());
+        assertEquals(1, backstack.size());
+        assertEquals(transaction1, backstack.peek());
     }
 }

conductor/src/test/java/com/bluelinelabs/conductor/ControllerChangeHandlerTests.java

@@ -2,10 +2,12 @@ package com.bluelinelabs.conductor;
 
 import com.bluelinelabs.conductor.changehandler.FadeChangeHandler;
 import com.bluelinelabs.conductor.changehandler.HorizontalChangeHandler;
+import com.bluelinelabs.conductor.util.TestController;
 
-import org.junit.Assert;
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class ControllerChangeHandlerTests {
 
     @Test
@@ -13,26 +15,25 @@ public class ControllerChangeHandlerTests {
         HorizontalChangeHandler horizontalChangeHandler = new HorizontalChangeHandler();
         FadeChangeHandler fadeChangeHandler = new FadeChangeHandler(120, false);
 
-        RouterTransaction transaction = RouterTransaction.builder(new TestController())
+        RouterTransaction transaction = RouterTransaction.with(new TestController())
                 .pushChangeHandler(horizontalChangeHandler)
-                .popChangeHandler(fadeChangeHandler)
-                .build();
-        RouterTransaction restoredTransaction = new RouterTransaction(transaction.detachAndSaveInstanceState());
+                .popChangeHandler(fadeChangeHandler);
+        RouterTransaction restoredTransaction = new RouterTransaction(transaction.saveInstanceState());
 
-        ControllerChangeHandler restoredHorizontal = restoredTransaction.getPushControllerChangeHandler();
-        ControllerChangeHandler restoredFade = restoredTransaction.getPopControllerChangeHandler();
+        ControllerChangeHandler restoredHorizontal = restoredTransaction.pushChangeHandler();
+        ControllerChangeHandler restoredFade = restoredTransaction.popChangeHandler();
 
-        Assert.assertEquals(horizontalChangeHandler.getClass(), restoredHorizontal.getClass());
-        Assert.assertEquals(fadeChangeHandler.getClass(), restoredFade.getClass());
+        assertEquals(horizontalChangeHandler.getClass(), restoredHorizontal.getClass());
+        assertEquals(fadeChangeHandler.getClass(), restoredFade.getClass());
 
         HorizontalChangeHandler restoredHorizontalCast = (HorizontalChangeHandler)restoredHorizontal;
         FadeChangeHandler restoredFadeCast = (FadeChangeHandler)restoredFade;
 
-        Assert.assertEquals(horizontalChangeHandler.getAnimationDuration(), restoredHorizontalCast.getAnimationDuration());
-        Assert.assertEquals(horizontalChangeHandler.removesFromViewOnPush(), restoredHorizontalCast.removesFromViewOnPush());
+        assertEquals(horizontalChangeHandler.getAnimationDuration(), restoredHorizontalCast.getAnimationDuration());
+        assertEquals(horizontalChangeHandler.removesFromViewOnPush(), restoredHorizontalCast.removesFromViewOnPush());
 
-        Assert.assertEquals(fadeChangeHandler.getAnimationDuration(), restoredFadeCast.getAnimationDuration());
-        Assert.assertEquals(fadeChangeHandler.removesFromViewOnPush(), restoredFadeCast.removesFromViewOnPush());
+        assertEquals(fadeChangeHandler.getAnimationDuration(), restoredFadeCast.getAnimationDuration());
+        assertEquals(fadeChangeHandler.removesFromViewOnPush(), restoredFadeCast.removesFromViewOnPush());
     }
 
 }

conductor/src/test/java/com/bluelinelabs/conductor/ControllerLifecycleActivityReferenceTests.java

@@ -0,0 +1,269 @@
+package com.bluelinelabs.conductor;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.MockChangeHandler;
+import com.bluelinelabs.conductor.util.TestController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import java.util.ArrayList;
+import java.util.Arrays;
+import java.util.Collections;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class ControllerLifecycleActivityReferenceTests {
+
+    private Router router;
+
+    private ActivityProxy activityProxy;
+
+    public void createActivityController(Bundle savedInstanceState, boolean includeStartAndResume) {
+        activityProxy = new ActivityProxy().create(savedInstanceState);
+
+        if (includeStartAndResume) {
+            activityProxy.start().resume();
+        }
+
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), savedInstanceState);
+        router.setPopsLastView(true);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new TestController()));
+        }
+    }
+
+    @Before
+    public void setup() {
+        createActivityController(null, true);
+    }
+
+    @Test
+    public void testSingleControllerActivityOnPush() {
+        Controller controller = new TestController();
+
+        assertNull(controller.getActivity());
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        controller.addLifecycleListener(listener);
+
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertEquals(Collections.singletonList(true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.emptyList(), listener.postDetachReferences);
+        assertEquals(Collections.emptyList(), listener.postDestroyViewReferences);
+        assertEquals(Collections.emptyList(), listener.postDestroyReferences);
+    }
+
+    @Test
+    public void testChildControllerActivityOnPush() {
+        Controller parent = new TestController();
+        router.pushController(RouterTransaction.with(parent)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        TestController child = new TestController();
+
+        assertNull(child.getActivity());
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        child.addLifecycleListener(listener);
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter.pushController(RouterTransaction.with(child)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertEquals(Collections.singletonList(true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.emptyList(), listener.postDetachReferences);
+        assertEquals(Collections.emptyList(), listener.postDestroyViewReferences);
+        assertEquals(Collections.emptyList(), listener.postDestroyReferences);
+    }
+
+    @Test
+    public void testSingleControllerActivityOnPop() {
+        Controller controller = new TestController();
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        controller.addLifecycleListener(listener);
+
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        router.popCurrentController();
+
+        assertEquals(Arrays.asList(true, true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDetachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyReferences);
+    }
+
+    @Test
+    public void testChildControllerActivityOnPop() {
+        Controller parent = new TestController();
+
+        router.pushController(RouterTransaction.with(parent)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        TestController child = new TestController();
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        child.addLifecycleListener(listener);
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter.setPopsLastView(true);
+        childRouter.pushController(RouterTransaction.with(child)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        childRouter.popCurrentController();
+
+        assertEquals(Arrays.asList(true, true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDetachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyReferences);
+    }
+
+    @Test
+    public void testChildControllerActivityOnParentPop() {
+        Controller parent = new TestController();
+
+        router.pushController(RouterTransaction.with(parent)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        TestController child = new TestController();
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        child.addLifecycleListener(listener);
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter.setPopsLastView(true);
+        childRouter.pushController(RouterTransaction.with(child)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        router.popCurrentController();
+
+        assertEquals(Collections.singletonList(true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDetachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyReferences);
+    }
+
+    @Test
+    public void testSingleControllerActivityOnDestroy() {
+        Controller controller = new TestController();
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        controller.addLifecycleListener(listener);
+
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        activityProxy.pause().stop(false).destroy();
+
+        assertEquals(Collections.singletonList(true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDetachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyReferences);
+    }
+
+    @Test
+    public void testChildControllerActivityOnDestroy() {
+        Controller parent = new TestController();
+
+        router.pushController(RouterTransaction.with(parent)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        TestController child = new TestController();
+
+        ActivityReferencingLifecycleListener listener = new ActivityReferencingLifecycleListener();
+        child.addLifecycleListener(listener);
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter.setPopsLastView(true);
+        childRouter.pushController(RouterTransaction.with(child)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        activityProxy.pause().stop(false).destroy();
+
+        assertEquals(Collections.singletonList(true), listener.changeEndReferences);
+        assertEquals(Collections.singletonList(true), listener.postCreateViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postAttachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDetachReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyViewReferences);
+        assertEquals(Collections.singletonList(true), listener.postDestroyReferences);
+    }
+
+    static class ActivityReferencingLifecycleListener extends Controller.LifecycleListener {
+        final List<Boolean> changeEndReferences = new ArrayList<>();
+        final List<Boolean> postCreateViewReferences = new ArrayList<>();
+        final List<Boolean> postAttachReferences = new ArrayList<>();
+        final List<Boolean> postDetachReferences = new ArrayList<>();
+        final List<Boolean> postDestroyViewReferences = new ArrayList<>();
+        final List<Boolean> postDestroyReferences = new ArrayList<>();
+
+        @Override
+        public void onChangeEnd(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
+            changeEndReferences.add(controller.getActivity() != null);
+        }
+
+        @Override
+        public void postCreateView(@NonNull Controller controller, @NonNull View view) {
+            postCreateViewReferences.add(controller.getActivity() != null);
+        }
+
+        @Override
+        public void postAttach(@NonNull Controller controller, @NonNull View view) {
+            postAttachReferences.add(controller.getActivity() != null);
+        }
+
+        @Override
+        public void postDetach(@NonNull Controller controller, @NonNull View view) {
+            postDetachReferences.add(controller.getActivity() != null);
+        }
+
+        @Override
+        public void postDestroyView(@NonNull Controller controller) {
+            postDestroyViewReferences.add(controller.getActivity() != null);
+        }
+
+        @Override
+        public void postDestroy(@NonNull Controller controller) {
+            postDestroyReferences.add(controller.getActivity() != null);
+        }
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/ControllerLifecycleCallbacksTests.java

@@ -0,0 +1,605 @@
+package com.bluelinelabs.conductor;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.Controller.LifecycleListener;
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.CallState;
+import com.bluelinelabs.conductor.util.MockChangeHandler;
+import com.bluelinelabs.conductor.util.MockChangeHandler.ChangeHandlerListener;
+import com.bluelinelabs.conductor.util.TestController;
+import com.bluelinelabs.conductor.util.ViewUtils;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class ControllerLifecycleCallbacksTests {
+
+    private Router router;
+
+    private ActivityProxy activityProxy;
+    private CallState currentCallState;
+
+    public void createActivityController(Bundle savedInstanceState, boolean includeStartAndResume) {
+        activityProxy = new ActivityProxy().create(savedInstanceState);
+
+        if (includeStartAndResume) {
+            activityProxy.start().resume();
+        }
+
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new TestController()));
+        }
+    }
+
+    @Before
+    public void setup() {
+        createActivityController(null, true);
+
+        currentCallState = new CallState();
+    }
+
+    @Test
+    public void testNormalLifecycle() {
+        TestController controller = new TestController();
+        attachLifecycleListener(controller);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, controller);
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(getPushHandler(expectedCallState, controller))
+                .popChangeHandler(getPopHandler(expectedCallState, controller)));
+
+        assertCalls(expectedCallState, controller);
+
+        router.popCurrentController();
+
+        assertNull(controller.getView());
+
+        assertCalls(expectedCallState, controller);
+    }
+
+    @Test
+    public void testLifecycleWithActivityStop() {
+        TestController controller = new TestController();
+        attachLifecycleListener(controller);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, controller);
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(getPushHandler(expectedCallState, controller)));
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.getActivity().isDestroying = true;
+        activityProxy.pause();
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.stop(false);
+
+        expectedCallState.detachCalls++;
+        assertCalls(expectedCallState, controller);
+
+        assertNotNull(controller.getView());
+        ViewUtils.reportAttached(controller.getView(), false);
+
+        expectedCallState.saveViewStateCalls++;
+        expectedCallState.destroyViewCalls++;
+        assertCalls(expectedCallState, controller);
+    }
+
+    @Test
+    public void testLifecycleWithActivityDestroy() {
+        TestController controller = new TestController();
+        attachLifecycleListener(controller);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, controller);
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(getPushHandler(expectedCallState, controller)));
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.getActivity().isDestroying = true;
+        activityProxy.pause();
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.stop(true);
+
+        expectedCallState.saveViewStateCalls++;
+        expectedCallState.detachCalls++;
+        expectedCallState.destroyViewCalls++;
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.destroy();
+
+        expectedCallState.destroyCalls++;
+        assertCalls(expectedCallState, controller);
+    }
+
+    @Test
+    public void testLifecycleWithActivityConfigurationChange() {
+        TestController controller = new TestController();
+        attachLifecycleListener(controller);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, controller);
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(getPushHandler(expectedCallState, controller))
+                .tag("root"));
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.getActivity().isChangingConfigurations = true;
+
+        Bundle bundle = new Bundle();
+        activityProxy.saveInstanceState(bundle);
+
+        expectedCallState.saveViewStateCalls++;
+        expectedCallState.saveInstanceStateCalls++;
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.pause();
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.stop(true);
+        expectedCallState.detachCalls++;
+        expectedCallState.destroyViewCalls++;
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.destroy();
+        assertCalls(expectedCallState, controller);
+
+        createActivityController(bundle, false);
+        controller = (TestController)router.getControllerWithTag("root");
+
+        expectedCallState.restoreInstanceStateCalls++;
+        expectedCallState.restoreViewStateCalls++;
+        expectedCallState.changeStartCalls++;
+        expectedCallState.createViewCalls++;
+
+        // Lifecycle listener isn't attached during restore, grab the current views from the controller for this stuff...
+        currentCallState.restoreInstanceStateCalls = controller.currentCallState.restoreInstanceStateCalls;
+        currentCallState.restoreViewStateCalls = controller.currentCallState.restoreViewStateCalls;
+        currentCallState.changeStartCalls = controller.currentCallState.changeStartCalls;
+        currentCallState.changeEndCalls = controller.currentCallState.changeEndCalls;
+        currentCallState.createViewCalls = controller.currentCallState.createViewCalls;
+        currentCallState.attachCalls = controller.currentCallState.attachCalls;
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.start().resume();
+        currentCallState.changeEndCalls = controller.currentCallState.changeEndCalls;
+        currentCallState.attachCalls = controller.currentCallState.attachCalls;
+        expectedCallState.changeEndCalls++;
+        expectedCallState.attachCalls++;
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.resume();
+        assertCalls(expectedCallState, controller);
+    }
+
+    @Test
+    public void testLifecycleWithActivityBackground() {
+        TestController controller = new TestController();
+        attachLifecycleListener(controller);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, controller);
+        router.pushController(RouterTransaction.with(controller)
+                .pushChangeHandler(getPushHandler(expectedCallState, controller)));
+
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.pause();
+
+        Bundle bundle = new Bundle();
+        activityProxy.saveInstanceState(bundle);
+
+        expectedCallState.saveInstanceStateCalls++;
+        expectedCallState.saveViewStateCalls++;
+        assertCalls(expectedCallState, controller);
+
+        activityProxy.resume();
+    }
+
+    @Test
+    public void testLifecycleCallOrder() {
+        final TestController testController = new TestController();
+        final CallState callState = new CallState();
+
+        testController.addLifecycleListener(new LifecycleListener() {
+            @Override
+            public void preCreateView(@NonNull Controller controller) {
+                callState.createViewCalls++;
+                assertEquals(1, callState.createViewCalls);
+                assertEquals(0, testController.currentCallState.createViewCalls);
+
+                assertEquals(0, callState.attachCalls);
+                assertEquals(0, testController.currentCallState.attachCalls);
+
+                assertEquals(0, callState.detachCalls);
+                assertEquals(0, testController.currentCallState.detachCalls);
+
+                assertEquals(0, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void postCreateView(@NonNull Controller controller, @NonNull View view) {
+                callState.createViewCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(0, callState.attachCalls);
+                assertEquals(0, testController.currentCallState.attachCalls);
+
+                assertEquals(0, callState.detachCalls);
+                assertEquals(0, testController.currentCallState.detachCalls);
+
+                assertEquals(0, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void preAttach(@NonNull Controller controller, @NonNull View view) {
+                callState.attachCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(1, callState.attachCalls);
+                assertEquals(0, testController.currentCallState.attachCalls);
+
+                assertEquals(0, callState.detachCalls);
+                assertEquals(0, testController.currentCallState.detachCalls);
+
+                assertEquals(0, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void postAttach(@NonNull Controller controller, @NonNull View view) {
+                callState.attachCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(0, callState.detachCalls);
+                assertEquals(0, testController.currentCallState.detachCalls);
+
+                assertEquals(0, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void preDetach(@NonNull Controller controller, @NonNull View view) {
+                callState.detachCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(1, callState.detachCalls);
+                assertEquals(0, testController.currentCallState.detachCalls);
+
+                assertEquals(0, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void postDetach(@NonNull Controller controller, @NonNull View view) {
+                callState.detachCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(2, callState.detachCalls);
+                assertEquals(1, testController.currentCallState.detachCalls);
+
+                assertEquals(0, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void preDestroyView(@NonNull Controller controller, @NonNull View view) {
+                callState.destroyViewCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(2, callState.detachCalls);
+                assertEquals(1, testController.currentCallState.detachCalls);
+
+                assertEquals(1, callState.destroyViewCalls);
+                assertEquals(0, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void postDestroyView(@NonNull Controller controller) {
+                callState.destroyViewCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(2, callState.detachCalls);
+                assertEquals(1, testController.currentCallState.detachCalls);
+
+                assertEquals(2, callState.destroyViewCalls);
+                assertEquals(1, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(0, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void preDestroy(@NonNull Controller controller) {
+                callState.destroyCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(2, callState.detachCalls);
+                assertEquals(1, testController.currentCallState.detachCalls);
+
+                assertEquals(2, callState.destroyViewCalls);
+                assertEquals(1, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(1, callState.destroyCalls);
+                assertEquals(0, testController.currentCallState.destroyCalls);
+            }
+
+            @Override
+            public void postDestroy(@NonNull Controller controller) {
+                callState.destroyCalls++;
+                assertEquals(2, callState.createViewCalls);
+                assertEquals(1, testController.currentCallState.createViewCalls);
+
+                assertEquals(2, callState.attachCalls);
+                assertEquals(1, testController.currentCallState.attachCalls);
+
+                assertEquals(2, callState.detachCalls);
+                assertEquals(1, testController.currentCallState.detachCalls);
+
+                assertEquals(2, callState.destroyViewCalls);
+                assertEquals(1, testController.currentCallState.destroyViewCalls);
+
+                assertEquals(2, callState.destroyCalls);
+                assertEquals(1, testController.currentCallState.destroyCalls);
+            }
+        });
+
+        router.pushController(RouterTransaction.with(testController)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        router.popController(testController);
+
+        assertEquals(2, callState.createViewCalls);
+        assertEquals(2, callState.attachCalls);
+        assertEquals(2, callState.detachCalls);
+        assertEquals(2, callState.destroyViewCalls);
+        assertEquals(2, callState.destroyCalls);
+    }
+
+    @Test
+    public void testChildLifecycle() {
+        Controller parent = new TestController();
+        router.pushController(RouterTransaction.with(parent)
+                .pushChangeHandler(MockChangeHandler.defaultHandler()));
+
+        TestController child = new TestController();
+        attachLifecycleListener(child);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, child);
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+            childRouter
+                .setRoot(RouterTransaction.with(child)
+                        .pushChangeHandler(getPushHandler(expectedCallState, child))
+                        .popChangeHandler(getPopHandler(expectedCallState, child)));
+
+        assertCalls(expectedCallState, child);
+
+        parent.removeChildRouter(childRouter);
+
+        assertCalls(expectedCallState, child);
+    }
+
+    @Test
+    public void testChildLifecycle2() {
+        Controller parent = new TestController();
+        router.pushController(RouterTransaction.with(parent)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        TestController child = new TestController();
+        attachLifecycleListener(child);
+
+        CallState expectedCallState = new CallState();
+
+        assertCalls(expectedCallState, child);
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter
+                .setRoot(RouterTransaction.with(child)
+                        .pushChangeHandler(getPushHandler(expectedCallState, child))
+                        .popChangeHandler(getPopHandler(expectedCallState, child)));
+
+        assertCalls(expectedCallState, child);
+
+        router.popCurrentController();
+
+        expectedCallState.detachCalls++;
+        expectedCallState.destroyViewCalls++;
+        expectedCallState.destroyCalls++;
+
+        assertCalls(expectedCallState, child);
+    }
+
+    private MockChangeHandler getPushHandler(final CallState expectedCallState, final TestController controller) {
+        return MockChangeHandler.listeningChangeHandler(new ChangeHandlerListener() {
+            @Override
+            public void willStartChange() {
+                expectedCallState.changeStartCalls++;
+                expectedCallState.createViewCalls++;
+                assertCalls(expectedCallState, controller);
+            }
+
+            @Override
+            public void didAttachOrDetach() {
+                expectedCallState.attachCalls++;
+                assertCalls(expectedCallState, controller);
+            }
+
+            @Override
+            public void didEndChange() {
+                expectedCallState.changeEndCalls++;
+                assertCalls(expectedCallState, controller);
+            }
+        });
+    }
+
+    private MockChangeHandler getPopHandler(final CallState expectedCallState, final TestController controller) {
+        return MockChangeHandler.listeningChangeHandler(new ChangeHandlerListener() {
+            @Override
+            public void willStartChange() {
+                expectedCallState.changeStartCalls++;
+                assertCalls(expectedCallState, controller);
+            }
+
+            @Override
+            public void didAttachOrDetach() {
+                expectedCallState.destroyViewCalls++;
+                expectedCallState.detachCalls++;
+                expectedCallState.destroyCalls++;
+                assertCalls(expectedCallState, controller);
+            }
+
+            @Override
+            public void didEndChange() {
+                expectedCallState.changeEndCalls++;
+                assertCalls(expectedCallState, controller);
+            }
+        });
+    }
+
+    private void assertCalls(CallState callState, TestController controller) {
+        assertEquals("Expected call counts and controller call counts do not match.", callState, controller.currentCallState);
+        assertEquals("Expected call counts and lifecycle call counts do not match.", callState, currentCallState);
+    }
+
+    private void attachLifecycleListener(Controller controller) {
+        controller.addLifecycleListener(new LifecycleListener() {
+            @Override
+            public void onChangeStart(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
+                currentCallState.changeStartCalls++;
+            }
+
+            @Override
+            public void onChangeEnd(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
+                currentCallState.changeEndCalls++;
+            }
+
+            @Override
+            public void postCreateView(@NonNull Controller controller, @NonNull View view) {
+                currentCallState.createViewCalls++;
+            }
+
+            @Override
+            public void postAttach(@NonNull Controller controller, @NonNull View view) {
+                currentCallState.attachCalls++;
+            }
+
+            @Override
+            public void postDestroyView(@NonNull Controller controller) {
+                currentCallState.destroyViewCalls++;
+            }
+
+            @Override
+            public void postDetach(@NonNull Controller controller, @NonNull View view) {
+                currentCallState.detachCalls++;
+            }
+
+            @Override
+            public void postDestroy(@NonNull Controller controller) {
+                currentCallState.destroyCalls++;
+            }
+
+            @Override
+            public void onSaveInstanceState(@NonNull Controller controller, @NonNull Bundle outState) {
+                currentCallState.saveInstanceStateCalls++;
+            }
+
+            @Override
+            public void onRestoreInstanceState(@NonNull Controller controller, @NonNull Bundle savedInstanceState) {
+                currentCallState.restoreInstanceStateCalls++;
+            }
+
+            @Override
+            public void onSaveViewState(@NonNull Controller controller, @NonNull Bundle outState) {
+                currentCallState.saveViewStateCalls++;
+            }
+
+            @Override
+            public void onRestoreViewState(@NonNull Controller controller, @NonNull Bundle savedViewState) {
+                currentCallState.restoreViewStateCalls++;
+            }
+        });
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/ControllerTests.java

@@ -1,296 +1,412 @@
 package com.bluelinelabs.conductor;
 
 import android.app.Activity;
-import android.support.annotation.NonNull;
+import android.content.Intent;
+import android.os.Bundle;
 import android.view.View;
 import android.view.ViewGroup;
-import android.widget.FrameLayout;
 
-import com.bluelinelabs.conductor.Controller.LifecycleListener;
 import com.bluelinelabs.conductor.Controller.RetainViewMode;
-import com.bluelinelabs.conductor.ControllerChangeHandler.ControllerChangeCompletedListener;
-import com.bluelinelabs.conductor.ControllerTransaction.ControllerChangeType;
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.CallState;
+import com.bluelinelabs.conductor.util.TestController;
+import com.bluelinelabs.conductor.util.ViewUtils;
 
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
-import org.robolectric.util.ActivityController;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
 
 @RunWith(RobolectricTestRunner.class)
 @Config(manifest = Config.NONE)
 public class ControllerTests {
 
-    private ActivityController<TestActivity> mActivityController;
-    private Router mRouter;
+    private ActivityProxy activityProxy;
+    private Router router;
 
-    private int mChangeStartCalls;
-    private int mChangeEndCalls;
-    private int mCreateViewCalls;
-    private int mAttachCalls;
-    private int mDestroyViewCalls;
-    private int mDetachCalls;
-    private int mDestroyCalls;
+    public void createActivityController(Bundle savedInstanceState) {
+        activityProxy = new ActivityProxy().create(savedInstanceState).start().resume();
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new TestController()));
+        }
+    }
 
     @Before
     public void setup() {
-        mActivityController = Robolectric.buildActivity(TestActivity.class).create();
-        Activity activity = mActivityController.get();
-        mRouter = Conductor.attachRouter(activity, new FrameLayout(activity), null);
-        mRouter.setRoot(new TestController());
-
-        mChangeStartCalls = 0;
-        mChangeEndCalls = 0;
-        mCreateViewCalls = 0;
-        mAttachCalls = 0;
-        mDestroyViewCalls = 0;
-        mDestroyCalls = 0;
-        mDestroyCalls = 0;
-    }
-
-    @Test
-    public void testNormalLifecycle() {
-        Controller controller = new TestController();
-        attachLifecycleListener(controller);
-
-        assertCalls(0, 0, 0, 0, 0, 0, 0);
-        mRouter.pushController(RouterTransaction.builder(controller)
-                .pushChangeHandler(getPushHandler(0, 0, 0, 0, 0, 0, 0))
-                .popChangeHandler(getPopHandler(1, 1, 1, 1, 0, 0, 0))
-                .build()
-        );
-
-        assertCalls(1, 1, 1, 1, 0, 0, 0);
-
-        mRouter.popCurrentController();
-
-        Assert.assertNull(controller.getView());
-
-        assertCalls(2, 2, 1, 1, 1, 1, 1);
-    }
-
-    @Test
-    public void testLifecycleWithActivityDestroy() {
-        Controller controller = new TestController();
-        attachLifecycleListener(controller);
-
-        assertCalls(0, 0, 0, 0, 0, 0, 0);
-        mRouter.pushController(RouterTransaction.builder(controller)
-                .pushChangeHandler(getPushHandler(0, 0, 0, 0, 0, 0, 0))
-                .build()
-        );
-
-        assertCalls(1, 1, 1, 1, 0, 0, 0);
-
-        mActivityController.pause();
-
-        assertCalls(1, 1, 1, 1, 0, 0, 0);
-
-        mActivityController.stop();
-
-        assertCalls(1, 1, 1, 1, 0, 0, 0);
-
-        mActivityController.destroy();
-
-        assertCalls(1, 1, 1, 1, 1, 1, 1);
-    }
-
-    @Test
-    public void testChildLifecycle() {
-        Controller parent = new TestController();
-        mRouter.pushController(RouterTransaction.builder(parent)
-                .pushChangeHandler(new ChangeHandler(new ChangeHandlerListener() {
-                    @Override
-                    public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
-                        container.addView(to);
-                        ViewUtils.setAttached(to, true);
-                        changeListener.onChangeCompleted();
-                    }
-                }))
-                .build());
-
-        Controller child = new TestController();
-        attachLifecycleListener(child);
-
-        assertCalls(0, 0, 0, 0, 0, 0, 0);
-
-        parent.addChildController(ChildControllerTransaction.builder(child, TestController.VIEW_ID)
-                .pushChangeHandler(getPushHandler(0, 0, 0, 0, 0, 0, 0))
-                .popChangeHandler(getPopHandler(1, 1, 1, 1, 0, 0, 0))
-                .build()
-        );
-
-        assertCalls(1, 1, 1, 1, 0, 0, 0);
-
-        parent.removeChildController(child);
-
-        assertCalls(2, 2, 1, 1, 1, 1, 1);
-    }
-
-    @Test
-    public void testChildLifecycle2() {
-        Controller parent = new TestController();
-        mRouter.pushController(RouterTransaction.builder(parent)
-                .pushChangeHandler(new ChangeHandler(new ChangeHandlerListener() {
-                    @Override
-                    public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
-                        container.addView(to);
-                        ViewUtils.setAttached(to, true);
-                        changeListener.onChangeCompleted();
-                    }
-                }))
-                .popChangeHandler(new ChangeHandler(new ChangeHandlerListener() {
-                    @Override
-                    public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
-                        container.removeView(from);
-                        ViewUtils.setAttached(from, false);
-                        changeListener.onChangeCompleted();
-                    }
-                }))
-                .build());
-
-        Controller child = new TestController();
-        attachLifecycleListener(child);
-
-        assertCalls(0, 0, 0, 0, 0, 0, 0);
-
-        parent.addChildController(ChildControllerTransaction.builder(child, TestController.VIEW_ID)
-                .pushChangeHandler(getPushHandler(0, 0, 0, 0, 0, 0, 0))
-                .popChangeHandler(getPopHandler(1, 1, 1, 1, 0, 0, 0))
-                .build()
-        );
-
-        assertCalls(1, 1, 1, 1, 0, 0, 0);
-
-        mRouter.popCurrentController();
-        ViewUtils.setAttached(child.getView(), false);
-
-        assertCalls(1, 1, 1, 1, 1, 1, 1);
+        createActivityController(null);
     }
 
     @Test
     public void testViewRetention() {
         Controller controller = new TestController();
+        controller.setRouter(router);
 
         // Test View getting released w/ RELEASE_DETACH
         controller.setRetainViewMode(RetainViewMode.RELEASE_DETACH);
-        Assert.assertNull(controller.getView());
-        View view = controller.inflate(new FrameLayout(mRouter.getActivity()));
-        Assert.assertNotNull(controller.getView());
-        ViewUtils.setAttached(view, true);
-        Assert.assertNotNull(controller.getView());
-        ViewUtils.setAttached(view, false);
-        Assert.assertNull(controller.getView());
+        assertNull(controller.getView());
+        View view = controller.inflate(router.container);
+        assertNotNull(controller.getView());
+        ViewUtils.reportAttached(view, true);
+        assertNotNull(controller.getView());
+        ViewUtils.reportAttached(view, false);
+        assertNull(controller.getView());
 
         // Test View getting retained w/ RETAIN_DETACH
         controller.setRetainViewMode(RetainViewMode.RETAIN_DETACH);
-        view = controller.inflate(new FrameLayout(mRouter.getActivity()));
-        Assert.assertNotNull(controller.getView());
-        ViewUtils.setAttached(view, true);
-        Assert.assertNotNull(controller.getView());
-        ViewUtils.setAttached(view, false);
-        Assert.assertNotNull(controller.getView());
+        view = controller.inflate(router.container);
+        assertNotNull(controller.getView());
+        ViewUtils.reportAttached(view, true);
+        assertNotNull(controller.getView());
+        ViewUtils.reportAttached(view, false);
+        assertNotNull(controller.getView());
 
         // Ensure re-setting RELEASE_DETACH releases
         controller.setRetainViewMode(RetainViewMode.RELEASE_DETACH);
-        Assert.assertNull(controller.getView());
+        assertNull(controller.getView());
     }
 
-    private ChangeHandler getPushHandler(final int changeStart, final int changeEnd, final int bindView, final int attach, final int unbindView, final int detach, final int destroy) {
-        return new ChangeHandler(new ChangeHandlerListener() {
-            @Override
-            public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
-                assertCalls(changeStart + 1, changeEnd, bindView + 1, attach, unbindView, detach, destroy);
-                container.addView(to);
-                ViewUtils.setAttached(to, true);
-                assertCalls(changeStart + 1, changeEnd, bindView + 1, attach + 1, unbindView, detach, destroy);
-                changeListener.onChangeCompleted();
-            }
-        });
+    @Test
+    public void testActivityResult() {
+        TestController controller = new TestController();
+        CallState expectedCallState = new CallState(true);
+
+        router.pushController(RouterTransaction.with(controller));
+
+        // Ensure that calling onActivityResult w/o requesting a result doesn't do anything
+        router.onActivityResult(1, Activity.RESULT_OK, null);
+        assertCalls(expectedCallState, controller);
+
+        // Ensure starting an activity for result gets us the result back
+        controller.startActivityForResult(new Intent("action"), 1);
+        router.onActivityResult(1, Activity.RESULT_OK, null);
+        expectedCallState.onActivityResultCalls++;
+        assertCalls(expectedCallState, controller);
+
+        // Ensure requesting a result w/o calling startActivityForResult works
+        controller.registerForActivityResult(2);
+        router.onActivityResult(2, Activity.RESULT_OK, null);
+        expectedCallState.onActivityResultCalls++;
+        assertCalls(expectedCallState, controller);
     }
 
-    private ChangeHandler getPopHandler(final int changeStart, final int changeEnd, final int bindView, final int attach, final int unbindView, final int detach, final int destroy) {
-        return new ChangeHandler(new ChangeHandlerListener() {
-            @Override
-            public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
-                assertCalls(changeStart + 1, changeEnd, bindView, attach, unbindView, detach, destroy);
-                container.removeView(from);
-                ViewUtils.setAttached(from, false);
-                assertCalls(changeStart + 1, changeEnd, bindView, attach, unbindView + 1, detach + 1, destroy + 1);
-                changeListener.onChangeCompleted();
-            }
-        });
+    @Test
+    public void testActivityResultForChild() {
+        TestController parent = new TestController();
+        TestController child = new TestController();
+
+        router.pushController(RouterTransaction.with(parent));
+        parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID))
+                .setRoot(RouterTransaction.with(child));
+
+        CallState childExpectedCallState = new CallState(true);
+        CallState parentExpectedCallState = new CallState(true);
+
+        // Ensure that calling onActivityResult w/o requesting a result doesn't do anything
+        router.onActivityResult(1, Activity.RESULT_OK, null);
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
+
+        // Ensure starting an activity for result gets us the result back
+        child.startActivityForResult(new Intent("action"), 1);
+        router.onActivityResult(1, Activity.RESULT_OK, null);
+        childExpectedCallState.onActivityResultCalls++;
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
+
+        // Ensure requesting a result w/o calling startActivityForResult works
+        child.registerForActivityResult(2);
+        router.onActivityResult(2, Activity.RESULT_OK, null);
+        childExpectedCallState.onActivityResultCalls++;
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
     }
 
-    private void assertCalls(int changeStart, int changeEnd, int bindView, int attach, int unbindView, int detach, int destroy) {
-        Assert.assertEquals(changeStart, mChangeStartCalls);
-        Assert.assertEquals(changeEnd, mChangeEndCalls);
-        Assert.assertEquals(bindView, mCreateViewCalls);
-        Assert.assertEquals(attach, mAttachCalls);
-        Assert.assertEquals(unbindView, mDestroyViewCalls);
-        Assert.assertEquals(detach, mDetachCalls);
-        Assert.assertEquals(destroy, mDestroyCalls);
+    @Test
+    public void testPermissionResult() {
+        final String[] requestedPermissions = new String[] {"test"};
+
+        TestController controller = new TestController();
+        CallState expectedCallState = new CallState(true);
+
+        router.pushController(RouterTransaction.with(controller));
+
+        // Ensure that calling handleRequestedPermission w/o requesting a result doesn't do anything
+        router.onRequestPermissionsResult("anotherId", 1, requestedPermissions, new int[] {1});
+        assertCalls(expectedCallState, controller);
+
+        // Ensure requesting the permission gets us the result back
+        try {
+            controller.requestPermissions(requestedPermissions, 1);
+        } catch (NoSuchMethodError ignored) { }
+
+        router.onRequestPermissionsResult(controller.getInstanceId(), 1, requestedPermissions, new int[] {1});
+        expectedCallState.onRequestPermissionsResultCalls++;
+        assertCalls(expectedCallState, controller);
     }
 
-    private void attachLifecycleListener(Controller controller) {
-        controller.addLifecycleListener(new LifecycleListener() {
-            @Override
-            public void onChangeStart(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
-                mChangeStartCalls++;
-            }
+    @Test
+    public void testPermissionResultForChild() {
+        final String[] requestedPermissions = new String[] {"test"};
 
-            @Override
-            public void onChangeEnd(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
-                mChangeEndCalls++;
-            }
+        TestController parent = new TestController();
+        TestController child = new TestController();
 
-            @Override
-            public void postCreateView(@NonNull Controller controller, @NonNull View view) {
-                mCreateViewCalls++;
-            }
+        router.pushController(RouterTransaction.with(parent));
+        parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID))
+                .setRoot(RouterTransaction.with(child));
 
-            @Override
-            public void postAttach(@NonNull Controller controller, @NonNull View view) {
-                mAttachCalls++;
-            }
+        CallState childExpectedCallState = new CallState(true);
+        CallState parentExpectedCallState = new CallState(true);
 
-            @Override
-            public void postDestroyView(@NonNull Controller controller) {
-                mDestroyViewCalls++;
-            }
+        // Ensure that calling handleRequestedPermission w/o requesting a result doesn't do anything
+        router.onRequestPermissionsResult("anotherId", 1, requestedPermissions, new int[] {1});
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
 
-            @Override
-            public void postDetach(@NonNull Controller controller, @NonNull View view) {
-                mDetachCalls++;
-            }
+        // Ensure requesting the permission gets us the result back
+        try {
+            child.requestPermissions(requestedPermissions, 1);
+        } catch (NoSuchMethodError ignored) { }
 
-            @Override
-            public void postDestroy(@NonNull Controller controller) {
-                mDestroyCalls++;
-            }
-        });
+        router.onRequestPermissionsResult(child.getInstanceId(), 1, requestedPermissions, new int[] {1});
+        childExpectedCallState.onRequestPermissionsResultCalls++;
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
     }
 
-    interface ChangeHandlerListener {
-        void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener);
+    @Test
+    public void testOptionsMenu() {
+        TestController controller = new TestController();
+        CallState expectedCallState = new CallState(true);
+
+        router.pushController(RouterTransaction.with(controller));
+
+        // Ensure that calling onCreateOptionsMenu w/o declaring that we have one doesn't do anything
+        router.onCreateOptionsMenu(null, null);
+        assertCalls(expectedCallState, controller);
+
+        // Ensure calling onCreateOptionsMenu with a menu works
+        controller.setHasOptionsMenu(true);
+
+        // Ensure it'll still get called back next time onCreateOptionsMenu is called
+        router.onCreateOptionsMenu(null, null);
+        expectedCallState.createOptionsMenuCalls++;
+        assertCalls(expectedCallState, controller);
+
+        // Ensure we stop getting them when we hide it
+        controller.setOptionsMenuHidden(true);
+        router.onCreateOptionsMenu(null, null);
+        assertCalls(expectedCallState, controller);
+
+        // Ensure we get the callback them when we un-hide it
+        controller.setOptionsMenuHidden(false);
+        router.onCreateOptionsMenu(null, null);
+        expectedCallState.createOptionsMenuCalls++;
+        assertCalls(expectedCallState, controller);
+
+        // Ensure we don't get the callback when we no longer have a menu
+        controller.setHasOptionsMenu(false);
+        router.onCreateOptionsMenu(null, null);
+        assertCalls(expectedCallState, controller);
     }
 
-    public static class ChangeHandler extends ControllerChangeHandler {
+    @Test
+    public void testOptionsMenuForChild() {
+        TestController parent = new TestController();
+        TestController child = new TestController();
 
-        private ChangeHandlerListener mListener;
+        router.pushController(RouterTransaction.with(parent));
+        parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID))
+                .setRoot(RouterTransaction.with(child));
 
-        public ChangeHandler() { }
+        CallState childExpectedCallState = new CallState(true);
+        CallState parentExpectedCallState = new CallState(true);
 
-        public ChangeHandler(ChangeHandlerListener listener) {
-            mListener = listener;
-        }
+        // Ensure that calling onCreateOptionsMenu w/o declaring that we have one doesn't do anything
+        router.onCreateOptionsMenu(null, null);
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
 
-        @Override
-        public void performChange(@NonNull ViewGroup container, View from, View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
-            mListener.performChange(container, from, to, isPush, changeListener);
-        }
+        // Ensure calling onCreateOptionsMenu with a menu works
+        child.setHasOptionsMenu(true);
+
+        // Ensure it'll still get called back next time onCreateOptionsMenu is called
+        router.onCreateOptionsMenu(null, null);
+        childExpectedCallState.createOptionsMenuCalls++;
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
+
+        // Ensure we stop getting them when we hide it
+        child.setOptionsMenuHidden(true);
+        router.onCreateOptionsMenu(null, null);
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
+
+        // Ensure we get the callback them when we un-hide it
+        child.setOptionsMenuHidden(false);
+        router.onCreateOptionsMenu(null, null);
+        childExpectedCallState.createOptionsMenuCalls++;
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
+
+        // Ensure we don't get the callback when we no longer have a menu
+        child.setHasOptionsMenu(false);
+        router.onCreateOptionsMenu(null, null);
+        assertCalls(childExpectedCallState, child);
+        assertCalls(parentExpectedCallState, parent);
     }
+
+    @Test
+    public void testAddRemoveChildControllers() {
+        TestController parent = new TestController();
+        TestController child1 = new TestController();
+        TestController child2 = new TestController();
+
+        router.pushController(RouterTransaction.with(parent));
+
+        assertEquals(0, parent.getChildRouters().size());
+        assertNull(child1.getParentController());
+        assertNull(child2.getParentController());
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter.setPopsLastView(true);
+        childRouter.setRoot(RouterTransaction.with(child1));
+
+        assertEquals(1, parent.getChildRouters().size());
+        assertEquals(childRouter, parent.getChildRouters().get(0));
+        assertEquals(1, childRouter.getBackstackSize());
+        assertEquals(child1, childRouter.getControllers().get(0));
+        assertEquals(parent, child1.getParentController());
+        assertNull(child2.getParentController());
+
+        childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.VIEW_ID));
+        childRouter.pushController(RouterTransaction.with(child2));
+
+        assertEquals(1, parent.getChildRouters().size());
+        assertEquals(childRouter, parent.getChildRouters().get(0));
+        assertEquals(2, childRouter.getBackstackSize());
+        assertEquals(child1, childRouter.getControllers().get(0));
+        assertEquals(child2, childRouter.getControllers().get(1));
+        assertEquals(parent, child1.getParentController());
+        assertEquals(parent, child2.getParentController());
+
+        childRouter.popController(child2);
+
+        assertEquals(1, parent.getChildRouters().size());
+        assertEquals(childRouter, parent.getChildRouters().get(0));
+        assertEquals(1, childRouter.getBackstackSize());
+        assertEquals(child1, childRouter.getControllers().get(0));
+        assertEquals(parent, child1.getParentController());
+        assertNull(child2.getParentController());
+
+        childRouter.popController(child1);
+
+        assertEquals(1, parent.getChildRouters().size());
+        assertEquals(childRouter, parent.getChildRouters().get(0));
+        assertEquals(0, childRouter.getBackstackSize());
+        assertNull(child1.getParentController());
+        assertNull(child2.getParentController());
+    }
+
+    @Test
+    public void testAddRemoveChildRouters() {
+        TestController parent = new TestController();
+
+        TestController child1 = new TestController();
+        TestController child2 = new TestController();
+
+        router.pushController(RouterTransaction.with(parent));
+
+        assertEquals(0, parent.getChildRouters().size());
+        assertNull(child1.getParentController());
+        assertNull(child2.getParentController());
+
+        Router childRouter1 = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.CHILD_VIEW_ID_1));
+        Router childRouter2 = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.CHILD_VIEW_ID_2));
+
+        childRouter1.setRoot(RouterTransaction.with(child1));
+        childRouter2.setRoot(RouterTransaction.with(child2));
+
+        assertEquals(2, parent.getChildRouters().size());
+        assertEquals(childRouter1, parent.getChildRouters().get(0));
+        assertEquals(childRouter2, parent.getChildRouters().get(1));
+        assertEquals(1, childRouter1.getBackstackSize());
+        assertEquals(1, childRouter2.getBackstackSize());
+        assertEquals(child1, childRouter1.getControllers().get(0));
+        assertEquals(child2, childRouter2.getControllers().get(0));
+        assertEquals(parent, child1.getParentController());
+        assertEquals(parent, child2.getParentController());
+
+        parent.removeChildRouter(childRouter2);
+
+        assertEquals(1, parent.getChildRouters().size());
+        assertEquals(childRouter1, parent.getChildRouters().get(0));
+        assertEquals(1, childRouter1.getBackstackSize());
+        assertEquals(0, childRouter2.getBackstackSize());
+        assertEquals(child1, childRouter1.getControllers().get(0));
+        assertEquals(parent, child1.getParentController());
+        assertNull(child2.getParentController());
+
+        parent.removeChildRouter(childRouter1);
+
+        assertEquals(0, parent.getChildRouters().size());
+        assertEquals(0, childRouter1.getBackstackSize());
+        assertEquals(0, childRouter2.getBackstackSize());
+        assertNull(child1.getParentController());
+        assertNull(child2.getParentController());
+    }
+
+    @Test
+    public void testRestoredChildRouterBackstack() {
+        TestController parent = new TestController();
+        router.pushController(RouterTransaction.with(parent));
+        ViewUtils.reportAttached(parent.getView(), true);
+
+        RouterTransaction childTransaction1 = RouterTransaction.with(new TestController());
+        RouterTransaction childTransaction2 = RouterTransaction.with(new TestController());
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.CHILD_VIEW_ID_1));
+        childRouter.setPopsLastView(true);
+        childRouter.setRoot(childTransaction1);
+        childRouter.pushController(childTransaction2);
+
+        Bundle savedState = new Bundle();
+        childRouter.saveInstanceState(savedState);
+        parent.removeChildRouter(childRouter);
+
+        childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.CHILD_VIEW_ID_1));
+        assertEquals(0, childRouter.getBackstackSize());
+
+        childRouter.restoreInstanceState(savedState);
+        childRouter.rebindIfNeeded();
+
+        assertEquals(2, childRouter.getBackstackSize());
+
+        RouterTransaction restoredChildTransaction1 = childRouter.getBackstack().get(0);
+        RouterTransaction restoredChildTransaction2 = childRouter.getBackstack().get(1);
+
+        assertEquals(childTransaction1.transactionIndex, restoredChildTransaction1.transactionIndex);
+        assertEquals(childTransaction1.controller.getInstanceId(), restoredChildTransaction1.controller.getInstanceId());
+        assertEquals(childTransaction2.transactionIndex, restoredChildTransaction2.transactionIndex);
+        assertEquals(childTransaction2.controller.getInstanceId(), restoredChildTransaction2.controller.getInstanceId());
+
+        assertTrue(parent.handleBack());
+        assertEquals(1, childRouter.getBackstackSize());
+        assertEquals(restoredChildTransaction1, childRouter.getBackstack().get(0));
+
+        assertTrue(parent.handleBack());
+        assertEquals(0, childRouter.getBackstackSize());
+    }
+
+    private void assertCalls(CallState callState, TestController controller) {
+        assertEquals("Expected call counts and controller call counts do not match.", callState, controller.currentCallState);
+    }
+
 }

conductor/src/test/java/com/bluelinelabs/conductor/ControllerTransactionTests.java

@@ -1,52 +1,32 @@
 package com.bluelinelabs.conductor;
 
 import android.os.Bundle;
-import android.support.annotation.IdRes;
 
 import com.bluelinelabs.conductor.changehandler.HorizontalChangeHandler;
 import com.bluelinelabs.conductor.changehandler.VerticalChangeHandler;
-
-import junit.framework.Assert;
+import com.bluelinelabs.conductor.util.TestController;
 
 import org.junit.Test;
 
+import static org.junit.Assert.assertEquals;
+
 public class ControllerTransactionTests {
 
     @Test
     public void testRouterSaveRestore() {
-        RouterTransaction transaction = RouterTransaction.builder(new TestController())
+        RouterTransaction transaction = RouterTransaction.with(new TestController())
                 .pushChangeHandler(new HorizontalChangeHandler())
                 .popChangeHandler(new VerticalChangeHandler())
-                .tag("Test Tag")
-                .build();
+                .tag("Test Tag");
 
-        Bundle bundle = transaction.detachAndSaveInstanceState();
+        Bundle bundle = transaction.saveInstanceState();
 
         RouterTransaction restoredTransaction = new RouterTransaction(bundle);
 
-        Assert.assertEquals(transaction.getController().getClass(), restoredTransaction.getController().getClass());
-        Assert.assertEquals(transaction.getPushControllerChangeHandler().getClass(), restoredTransaction.getPushControllerChangeHandler().getClass());
-        Assert.assertEquals(transaction.getPopControllerChangeHandler().getClass(), restoredTransaction.getPopControllerChangeHandler().getClass());
-        Assert.assertEquals(transaction.getTag(), restoredTransaction.getTag());
+        assertEquals(transaction.controller.getClass(), restoredTransaction.controller.getClass());
+        assertEquals(transaction.pushChangeHandler().getClass(), restoredTransaction.pushChangeHandler().getClass());
+        assertEquals(transaction.popChangeHandler().getClass(), restoredTransaction.popChangeHandler().getClass());
+        assertEquals(transaction.tag(), restoredTransaction.tag());
     }
 
-    @Test
-    public void testChildSaveRestore() {
-        @IdRes int layoutId = 234;
-        ChildControllerTransaction transaction = ChildControllerTransaction.builder(new TestController(), layoutId)
-                .pushChangeHandler(new HorizontalChangeHandler())
-                .popChangeHandler(new VerticalChangeHandler())
-                .tag("Test Tag")
-                .build();
-
-        Bundle bundle = transaction.detachAndSaveInstanceState();
-
-        ChildControllerTransaction restoredTransaction = new ChildControllerTransaction(bundle);
-
-        Assert.assertEquals(transaction.containerId, restoredTransaction.containerId);
-        Assert.assertEquals(transaction.getController().getClass(), restoredTransaction.getController().getClass());
-        Assert.assertEquals(transaction.getPushControllerChangeHandler().getClass(), restoredTransaction.getPushControllerChangeHandler().getClass());
-        Assert.assertEquals(transaction.getPopControllerChangeHandler().getClass(), restoredTransaction.getPopControllerChangeHandler().getClass());
-        Assert.assertEquals(transaction.getTag(), restoredTransaction.getTag());
-    }
 }

conductor/src/test/java/com/bluelinelabs/conductor/ReattachCaseTests.java

@@ -0,0 +1,240 @@
+package com.bluelinelabs.conductor;
+
+import android.os.Bundle;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.MockChangeHandler;
+import com.bluelinelabs.conductor.util.TestController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class ReattachCaseTests {
+
+    private ActivityProxy activityProxy;
+    private Router router;
+
+    public void createActivityController(Bundle savedInstanceState) {
+        activityProxy = new ActivityProxy().create(savedInstanceState).start().resume();
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new TestController()));
+        }
+    }
+
+    @Before
+    public void setup() {
+        createActivityController(null);
+    }
+
+    @Test
+    public void testNeedsAttachingOnPauseAndOrientation() {
+        final TestController controllerA = new TestController();
+        final TestController controllerB = new TestController();
+
+        router.pushController(RouterTransaction.with(controllerA)
+            .pushChangeHandler(MockChangeHandler.defaultHandler())
+            .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertTrue(controllerA.isAttached());
+        assertFalse(controllerB.isAttached());
+
+        sleepWakeDevice();
+
+        assertTrue(controllerA.isAttached());
+        assertFalse(controllerB.isAttached());
+
+        router.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+
+        activityProxy.rotate();
+        router.rebindIfNeeded();
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+    }
+
+    @Test
+    public void testChildNeedsAttachOnPauseAndOrientation() {
+        final Controller controllerA = new TestController();
+        final Controller childController = new TestController();
+        final Controller controllerB = new TestController();
+
+        router.pushController(RouterTransaction.with(controllerA)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        Router childRouter = controllerA.getChildRouter((ViewGroup)controllerA.getView().findViewById(TestController.VIEW_ID));
+        childRouter.pushController(RouterTransaction.with(childController)
+            .pushChangeHandler(MockChangeHandler.defaultHandler())
+            .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertTrue(controllerA.isAttached());
+        assertTrue(childController.isAttached());
+        assertFalse(controllerB.isAttached());
+
+        sleepWakeDevice();
+
+        assertTrue(controllerA.isAttached());
+        assertTrue(childController.isAttached());
+        assertFalse(controllerB.isAttached());
+
+        router.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertFalse(controllerA.isAttached());
+        assertFalse(childController.isAttached());
+        assertTrue(controllerB.isAttached());
+
+        activityProxy.rotate();
+        router.rebindIfNeeded();
+
+        assertFalse(controllerA.isAttached());
+        assertFalse(childController.isAttached());
+        assertTrue(childController.getNeedsAttach());
+        assertTrue(controllerB.isAttached());
+    }
+
+    @Test
+    public void testChildHandleBackOnOrientation() {
+        final TestController controllerA = new TestController();
+        final TestController controllerB = new TestController();
+        final TestController childController = new TestController();
+
+        router.pushController(RouterTransaction.with(controllerA)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertTrue(controllerA.isAttached());
+        assertFalse(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+
+        router.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        Router childRouter = controllerB.getChildRouter((ViewGroup)controllerB.getView().findViewById(TestController.VIEW_ID));
+        childRouter.setPopsLastView(true);
+        childRouter.pushController(RouterTransaction.with(childController)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertTrue(childController.isAttached());
+
+        activityProxy.rotate();
+        router.rebindIfNeeded();
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertTrue(childController.isAttached());
+
+        router.handleBack();
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+
+        router.handleBack();
+
+        assertTrue(controllerA.isAttached());
+        assertFalse(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+    }
+
+    // Attempt to test https://github.com/bluelinelabs/Conductor/issues/86#issuecomment-231381271
+    @Test
+    public void testReusedChildRouterHandleBackOnOrientation() {
+        TestController controllerA = new TestController();
+        TestController controllerB = new TestController();
+        TestController childController = new TestController();
+
+        router.pushController(RouterTransaction.with(controllerA)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertTrue(controllerA.isAttached());
+        assertFalse(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+
+        router.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        Router childRouter = controllerB.getChildRouter((ViewGroup)controllerB.getView().findViewById(TestController.VIEW_ID));
+        childRouter.setPopsLastView(true);
+        childRouter.pushController(RouterTransaction.with(childController)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertTrue(childController.isAttached());
+
+        router.handleBack();
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+
+        childController = new TestController();
+        childRouter.pushController(RouterTransaction.with(childController)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertTrue(childController.isAttached());
+
+        activityProxy.rotate();
+        router.rebindIfNeeded();
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertTrue(childController.isAttached());
+
+        router.handleBack();
+
+        childController = new TestController();
+        childRouter.pushController(RouterTransaction.with(childController)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertTrue(childController.isAttached());
+
+        router.handleBack();
+
+        assertFalse(controllerA.isAttached());
+        assertTrue(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+
+        router.handleBack();
+
+        assertTrue(controllerA.isAttached());
+        assertFalse(controllerB.isAttached());
+        assertFalse(childController.isAttached());
+    }
+
+    private void sleepWakeDevice() {
+        activityProxy.saveInstanceState(new Bundle()).pause();
+        activityProxy.resume();
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/RouterChangeHandlerTests.java

@@ -0,0 +1,239 @@
+package com.bluelinelabs.conductor;
+
+import android.view.View;
+
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.MockChangeHandler;
+import com.bluelinelabs.conductor.util.TestController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class RouterChangeHandlerTests {
+
+    private Router router;
+
+    @Before
+    public void setup() {
+        ActivityProxy activityProxy = new ActivityProxy().create(null).start().resume();
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), null);
+    }
+
+    @Test
+    public void testSetRootHandler() {
+        MockChangeHandler handler = MockChangeHandler.taggedHandler("root", true);
+        TestController rootController = new TestController();
+        router.setRoot(RouterTransaction.with(rootController).pushChangeHandler(handler));
+
+        assertTrue(rootController.changeHandlerHistory.isValidHistory);
+        assertNull(rootController.changeHandlerHistory.latestFromView());
+        assertNotNull(rootController.changeHandlerHistory.latestToView());
+        assertEquals(rootController.getView(), rootController.changeHandlerHistory.latestToView());
+        assertTrue(rootController.changeHandlerHistory.latestIsPush());
+        assertEquals(handler.tag, rootController.changeHandlerHistory.latestChangeHandler().tag);
+    }
+
+    @Test
+    public void testPushPopHandlers() {
+        TestController rootController = new TestController();
+        router.setRoot(RouterTransaction.with(rootController).pushChangeHandler(MockChangeHandler.defaultHandler()));
+        View rootView = rootController.getView();
+
+        MockChangeHandler pushHandler = MockChangeHandler.taggedHandler("push", true);
+        MockChangeHandler popHandler = MockChangeHandler.taggedHandler("pop", true);
+        TestController pushController = new TestController();
+        router.pushController(RouterTransaction.with(pushController).pushChangeHandler(pushHandler).popChangeHandler(popHandler));
+
+        assertTrue(rootController.changeHandlerHistory.isValidHistory);
+        assertTrue(pushController.changeHandlerHistory.isValidHistory);
+
+        assertNotNull(pushController.changeHandlerHistory.latestFromView());
+        assertNotNull(pushController.changeHandlerHistory.latestToView());
+        assertEquals(rootView, pushController.changeHandlerHistory.latestFromView());
+        assertEquals(pushController.getView(), pushController.changeHandlerHistory.latestToView());
+        assertTrue(pushController.changeHandlerHistory.latestIsPush());
+        assertEquals(pushHandler.tag, pushController.changeHandlerHistory.latestChangeHandler().tag);
+
+        View pushView = pushController.getView();
+        router.popController(pushController);
+
+        assertNotNull(pushController.changeHandlerHistory.latestFromView());
+        assertNotNull(pushController.changeHandlerHistory.latestToView());
+        assertEquals(pushView, pushController.changeHandlerHistory.fromViewAt(1));
+        assertEquals(rootController.getView(), pushController.changeHandlerHistory.latestToView());
+        assertFalse(pushController.changeHandlerHistory.latestIsPush());
+        assertEquals(popHandler.tag, pushController.changeHandlerHistory.latestChangeHandler().tag);
+    }
+
+    @Test
+    public void testResetRootHandlers() {
+        TestController initialController1 = new TestController();
+        MockChangeHandler initialPushHandler1 = MockChangeHandler.taggedHandler("initialPush1", true);
+        MockChangeHandler initialPopHandler1 = MockChangeHandler.taggedHandler("initialPop1", true);
+        router.setRoot(RouterTransaction.with(initialController1).pushChangeHandler(initialPushHandler1).popChangeHandler(initialPopHandler1));
+        TestController initialController2 = new TestController();
+        MockChangeHandler initialPushHandler2 = MockChangeHandler.taggedHandler("initialPush2", false);
+        MockChangeHandler initialPopHandler2 = MockChangeHandler.taggedHandler("initialPop2", false);
+        router.pushController(RouterTransaction.with(initialController2).pushChangeHandler(initialPushHandler2).popChangeHandler(initialPopHandler2));
+
+        View initialView1 = initialController1.getView();
+        View initialView2 = initialController2.getView();
+
+        TestController newRootController = new TestController();
+        MockChangeHandler newRootHandler = MockChangeHandler.taggedHandler("newRootHandler", true);
+
+        router.setRoot(RouterTransaction.with(newRootController).pushChangeHandler(newRootHandler));
+
+        assertTrue(initialController1.changeHandlerHistory.isValidHistory);
+        assertTrue(initialController2.changeHandlerHistory.isValidHistory);
+        assertTrue(newRootController.changeHandlerHistory.isValidHistory);
+
+        assertEquals(3, initialController1.changeHandlerHistory.size());
+        assertEquals(2, initialController2.changeHandlerHistory.size());
+        assertEquals(1, newRootController.changeHandlerHistory.size());
+
+        assertNotNull(initialController1.changeHandlerHistory.latestToView());
+        assertEquals(newRootController.getView(), initialController1.changeHandlerHistory.latestToView());
+        assertEquals(initialView1, initialController1.changeHandlerHistory.latestFromView());
+        assertEquals(newRootHandler.tag, initialController1.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(initialController1.changeHandlerHistory.latestIsPush());
+
+        assertNull(initialController2.changeHandlerHistory.latestToView());
+        assertEquals(initialView2, initialController2.changeHandlerHistory.latestFromView());
+        assertEquals(newRootHandler.tag, initialController2.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(initialController2.changeHandlerHistory.latestIsPush());
+
+        assertNotNull(newRootController.changeHandlerHistory.latestToView());
+        assertEquals(newRootController.getView(), newRootController.changeHandlerHistory.latestToView());
+        assertEquals(initialView1, newRootController.changeHandlerHistory.latestFromView());
+        assertEquals(newRootHandler.tag, newRootController.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(newRootController.changeHandlerHistory.latestIsPush());
+    }
+
+    @Test
+    public void testSetBackstackHandlers() {
+        TestController initialController1 = new TestController();
+        MockChangeHandler initialPushHandler1 = MockChangeHandler.taggedHandler("initialPush1", true);
+        MockChangeHandler initialPopHandler1 = MockChangeHandler.taggedHandler("initialPop1", true);
+        router.setRoot(RouterTransaction.with(initialController1).pushChangeHandler(initialPushHandler1).popChangeHandler(initialPopHandler1));
+        TestController initialController2 = new TestController();
+        MockChangeHandler initialPushHandler2 = MockChangeHandler.taggedHandler("initialPush2", false);
+        MockChangeHandler initialPopHandler2 = MockChangeHandler.taggedHandler("initialPop2", false);
+        router.pushController(RouterTransaction.with(initialController2).pushChangeHandler(initialPushHandler2).popChangeHandler(initialPopHandler2));
+
+        View initialView1 = initialController1.getView();
+        View initialView2 = initialController2.getView();
+
+        TestController newController1 = new TestController();
+        TestController newController2 = new TestController();
+        MockChangeHandler setBackstackHandler = MockChangeHandler.taggedHandler("setBackstackHandler", true);
+
+        List<RouterTransaction> newBackstack = Arrays.asList(
+                RouterTransaction.with(newController1),
+                RouterTransaction.with(newController2)
+        );
+
+        router.setBackstack(newBackstack, setBackstackHandler);
+
+        assertTrue(initialController1.changeHandlerHistory.isValidHistory);
+        assertTrue(initialController2.changeHandlerHistory.isValidHistory);
+        assertTrue(newController1.changeHandlerHistory.isValidHistory);
+
+        assertEquals(3, initialController1.changeHandlerHistory.size());
+        assertEquals(2, initialController2.changeHandlerHistory.size());
+        assertEquals(0, newController1.changeHandlerHistory.size());
+        assertEquals(1, newController2.changeHandlerHistory.size());
+
+        assertNotNull(initialController1.changeHandlerHistory.latestToView());
+        assertEquals(newController2.getView(), initialController1.changeHandlerHistory.latestToView());
+        assertEquals(initialView1, initialController1.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, initialController1.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(initialController1.changeHandlerHistory.latestIsPush());
+
+        assertNull(initialController2.changeHandlerHistory.latestToView());
+        assertEquals(initialView2, initialController2.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, initialController2.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(initialController2.changeHandlerHistory.latestIsPush());
+
+        assertNotNull(newController2.changeHandlerHistory.latestToView());
+        assertEquals(newController2.getView(), newController2.changeHandlerHistory.latestToView());
+        assertEquals(initialView1, newController2.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, newController2.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(newController2.changeHandlerHistory.latestIsPush());
+    }
+
+    @Test
+    public void testSetBackstackWithTwoVisibleHandlers() {
+        TestController initialController1 = new TestController();
+        MockChangeHandler initialPushHandler1 = MockChangeHandler.taggedHandler("initialPush1", true);
+        MockChangeHandler initialPopHandler1 = MockChangeHandler.taggedHandler("initialPop1", true);
+        router.setRoot(RouterTransaction.with(initialController1).pushChangeHandler(initialPushHandler1).popChangeHandler(initialPopHandler1));
+        TestController initialController2 = new TestController();
+        MockChangeHandler initialPushHandler2 = MockChangeHandler.taggedHandler("initialPush2", false);
+        MockChangeHandler initialPopHandler2 = MockChangeHandler.taggedHandler("initialPop2", false);
+        router.pushController(RouterTransaction.with(initialController2).pushChangeHandler(initialPushHandler2).popChangeHandler(initialPopHandler2));
+
+        View initialView1 = initialController1.getView();
+        View initialView2 = initialController2.getView();
+
+        TestController newController1 = new TestController();
+        TestController newController2 = new TestController();
+        MockChangeHandler setBackstackHandler = MockChangeHandler.taggedHandler("setBackstackHandler", true);
+
+        List<RouterTransaction> newBackstack = Arrays.asList(
+                RouterTransaction.with(newController1),
+                RouterTransaction.with(newController2).pushChangeHandler(MockChangeHandler.noRemoveViewOnPushHandler())
+        );
+
+        router.setBackstack(newBackstack, setBackstackHandler);
+
+        assertTrue(initialController1.changeHandlerHistory.isValidHistory);
+        assertTrue(initialController2.changeHandlerHistory.isValidHistory);
+        assertTrue(newController1.changeHandlerHistory.isValidHistory);
+
+        assertEquals(3, initialController1.changeHandlerHistory.size());
+        assertEquals(2, initialController2.changeHandlerHistory.size());
+        assertEquals(2, newController1.changeHandlerHistory.size());
+        assertEquals(1, newController2.changeHandlerHistory.size());
+
+        assertNotNull(initialController1.changeHandlerHistory.latestToView());
+        assertEquals(newController1.getView(), initialController1.changeHandlerHistory.latestToView());
+        assertEquals(initialView1, initialController1.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, initialController1.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(initialController1.changeHandlerHistory.latestIsPush());
+
+        assertNull(initialController2.changeHandlerHistory.latestToView());
+        assertEquals(initialView2, initialController2.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, initialController2.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(initialController2.changeHandlerHistory.latestIsPush());
+
+        assertNotNull(newController1.changeHandlerHistory.latestToView());
+        assertEquals(newController1.getView(), newController1.changeHandlerHistory.toViewAt(0));
+        assertEquals(newController2.getView(), newController1.changeHandlerHistory.latestToView());
+        assertEquals(initialView1, newController1.changeHandlerHistory.fromViewAt(0));
+        assertEquals(newController1.getView(), newController1.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, newController1.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(newController1.changeHandlerHistory.latestIsPush());
+
+        assertNotNull(newController2.changeHandlerHistory.latestToView());
+        assertEquals(newController2.getView(), newController2.changeHandlerHistory.latestToView());
+        assertEquals(newController1.getView(), newController2.changeHandlerHistory.latestFromView());
+        assertEquals(setBackstackHandler.tag, newController2.changeHandlerHistory.latestChangeHandler().tag);
+        assertTrue(newController2.changeHandlerHistory.latestIsPush());
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/RouterTests.java

@@ -1,26 +1,37 @@
 package com.bluelinelabs.conductor;
 
-import android.app.Activity;
-import android.widget.FrameLayout;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.changehandler.FadeChangeHandler;
+import com.bluelinelabs.conductor.changehandler.HorizontalChangeHandler;
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.MockChangeHandler;
+import com.bluelinelabs.conductor.util.TestController;
 
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.Test;
 import org.junit.runner.RunWith;
-import org.robolectric.Robolectric;
 import org.robolectric.RobolectricTestRunner;
 import org.robolectric.annotation.Config;
 
+import java.util.Arrays;
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNull;
+import static org.junit.Assert.assertTrue;
+
 @RunWith(RobolectricTestRunner.class)
 @Config(manifest = Config.NONE)
 public class RouterTests {
 
-    private Router mRouter;
+    private Router router;
 
     @Before
     public void setup() {
-        Activity activity = Robolectric.buildActivity(TestActivity.class).create().get();
-        mRouter = Conductor.attachRouter(activity, new FrameLayout(activity), null);
+        ActivityProxy activityProxy = new ActivityProxy().create(null).start().resume();
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), null);
     }
 
     @Test
@@ -29,13 +40,13 @@ public class RouterTests {
 
         Controller rootController = new TestController();
 
-        Assert.assertFalse(mRouter.hasRootController());
+        assertFalse(router.hasRootController());
 
-        mRouter.setRoot(rootController, rootTag);
+        router.setRoot(RouterTransaction.with(rootController).tag(rootTag));
 
-        Assert.assertTrue(mRouter.hasRootController());
+        assertTrue(router.hasRootController());
 
-        Assert.assertEquals(rootController, mRouter.getControllerWithTag(rootTag));
+        assertEquals(rootController, router.getControllerWithTag(rootTag));
     }
 
     @Test
@@ -46,21 +57,21 @@ public class RouterTests {
         Controller oldRootController = new TestController();
         Controller newRootController = new TestController();
 
-        mRouter.setRoot(oldRootController, oldRootTag);
-        mRouter.setRoot(newRootController, newRootTag);
+        router.setRoot(RouterTransaction.with(oldRootController).tag(oldRootTag));
+        router.setRoot(RouterTransaction.with(newRootController).tag(newRootTag));
 
-        Assert.assertNull(mRouter.getControllerWithTag(oldRootTag));
-        Assert.assertEquals(newRootController, mRouter.getControllerWithTag(newRootTag));
+        assertNull(router.getControllerWithTag(oldRootTag));
+        assertEquals(newRootController, router.getControllerWithTag(newRootTag));
     }
 
     @Test
     public void testGetByInstanceId() {
         Controller controller = new TestController();
 
-        mRouter.pushController(RouterTransaction.builder(controller).build());
+        router.pushController(RouterTransaction.with(controller));
 
-        Assert.assertEquals(controller, mRouter.getControllerWithInstanceId(controller.getInstanceId()));
-        Assert.assertNull(mRouter.getControllerWithInstanceId("fake id"));
+        assertEquals(controller, router.getControllerWithInstanceId(controller.getInstanceId()));
+        assertNull(router.getControllerWithInstanceId("fake id"));
     }
 
     @Test
@@ -71,16 +82,14 @@ public class RouterTests {
         Controller controller1 = new TestController();
         Controller controller2 = new TestController();
 
-        mRouter.pushController(RouterTransaction.builder(controller1)
-                .tag(controller1Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller1)
+                .tag(controller1Tag));
 
-        mRouter.pushController(RouterTransaction.builder(controller2)
-                .tag(controller2Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller2)
+                .tag(controller2Tag));
 
-        Assert.assertEquals(controller1, mRouter.getControllerWithTag(controller1Tag));
-        Assert.assertEquals(controller2, mRouter.getControllerWithTag(controller2Tag));
+        assertEquals(controller1, router.getControllerWithTag(controller1Tag));
+        assertEquals(controller2, router.getControllerWithTag(controller2Tag));
     }
 
     @Test
@@ -91,31 +100,29 @@ public class RouterTests {
         Controller controller1 = new TestController();
         Controller controller2 = new TestController();
 
-        mRouter.pushController(RouterTransaction.builder(controller1)
-                .tag(controller1Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller1)
+                .tag(controller1Tag));
 
-        Assert.assertEquals(1, mRouter.getBackstackSize());
+        assertEquals(1, router.getBackstackSize());
 
-        mRouter.pushController(RouterTransaction.builder(controller2)
-                .tag(controller2Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller2)
+                .tag(controller2Tag));
 
-        Assert.assertEquals(2, mRouter.getBackstackSize());
+        assertEquals(2, router.getBackstackSize());
 
-        mRouter.popCurrentController();
+        router.popCurrentController();
 
-        Assert.assertEquals(1, mRouter.getBackstackSize());
+        assertEquals(1, router.getBackstackSize());
 
-        Assert.assertEquals(controller1, mRouter.getControllerWithTag(controller1Tag));
-        Assert.assertNull(mRouter.getControllerWithTag(controller2Tag));
+        assertEquals(controller1, router.getControllerWithTag(controller1Tag));
+        assertNull(router.getControllerWithTag(controller2Tag));
 
-        mRouter.popCurrentController();
+        router.popCurrentController();
 
-        Assert.assertEquals(0, mRouter.getBackstackSize());
+        assertEquals(0, router.getBackstackSize());
 
-        Assert.assertNull(mRouter.getControllerWithTag(controller1Tag));
-        Assert.assertNull(mRouter.getControllerWithTag(controller2Tag));
+        assertNull(router.getControllerWithTag(controller1Tag));
+        assertNull(router.getControllerWithTag(controller2Tag));
     }
 
     @Test
@@ -130,29 +137,25 @@ public class RouterTests {
         Controller controller3 = new TestController();
         Controller controller4 = new TestController();
 
-        mRouter.pushController(RouterTransaction.builder(controller1)
-                .tag(controller1Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller1)
+                .tag(controller1Tag));
 
-        mRouter.pushController(RouterTransaction.builder(controller2)
-                .tag(controller2Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller2)
+                .tag(controller2Tag));
 
-        mRouter.pushController(RouterTransaction.builder(controller3)
-                .tag(controller3Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller3)
+                .tag(controller3Tag));
 
-        mRouter.pushController(RouterTransaction.builder(controller4)
-                .tag(controller4Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller4)
+                .tag(controller4Tag));
 
-        mRouter.popToTag(controller2Tag);
+        router.popToTag(controller2Tag);
 
-        Assert.assertEquals(2, mRouter.getBackstackSize());
-        Assert.assertEquals(controller1, mRouter.getControllerWithTag(controller1Tag));
-        Assert.assertEquals(controller2, mRouter.getControllerWithTag(controller2Tag));
-        Assert.assertNull(mRouter.getControllerWithTag(controller3Tag));
-        Assert.assertNull(mRouter.getControllerWithTag(controller4Tag));
+        assertEquals(2, router.getBackstackSize());
+        assertEquals(controller1, router.getControllerWithTag(controller1Tag));
+        assertEquals(controller2, router.getControllerWithTag(controller2Tag));
+        assertNull(router.getControllerWithTag(controller3Tag));
+        assertNull(router.getControllerWithTag(controller4Tag));
     }
 
     @Test
@@ -165,24 +168,267 @@ public class RouterTests {
         Controller controller2 = new TestController();
         Controller controller3 = new TestController();
 
-        mRouter.pushController(RouterTransaction.builder(controller1)
-                .tag(controller1Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller1)
+                .tag(controller1Tag));
 
-        mRouter.pushController(RouterTransaction.builder(controller2)
-                .tag(controller2Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller2)
+                .tag(controller2Tag));
 
-        mRouter.pushController(RouterTransaction.builder(controller3)
-                .tag(controller3Tag)
-                .build());
+        router.pushController(RouterTransaction.with(controller3)
+                .tag(controller3Tag));
 
-        mRouter.popController(controller2);
+        router.popController(controller2);
 
-        Assert.assertEquals(2, mRouter.getBackstackSize());
-        Assert.assertEquals(controller1, mRouter.getControllerWithTag(controller1Tag));
-        Assert.assertNull(mRouter.getControllerWithTag(controller2Tag));
-        Assert.assertEquals(controller3, mRouter.getControllerWithTag(controller3Tag));
+        assertEquals(2, router.getBackstackSize());
+        assertEquals(controller1, router.getControllerWithTag(controller1Tag));
+        assertNull(router.getControllerWithTag(controller2Tag));
+        assertEquals(controller3, router.getControllerWithTag(controller3Tag));
+    }
+
+    @Test
+    public void testSetBackstack() {
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction middleTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction topTransaction = RouterTransaction.with(new TestController());
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, middleTransaction, topTransaction);
+        router.setBackstack(backstack, null);
+
+        assertEquals(3, router.getBackstackSize());
+
+        List<RouterTransaction> fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(middleTransaction, fetchedBackstack.get(1));
+        assertEquals(topTransaction, fetchedBackstack.get(2));
+    }
+
+    @Test
+    public void testNewSetBackstack() {
+        router.setRoot(RouterTransaction.with(new TestController()));
+
+        assertEquals(1, router.getBackstackSize());
+
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction middleTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction topTransaction = RouterTransaction.with(new TestController());
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, middleTransaction, topTransaction);
+        router.setBackstack(backstack, null);
+
+        assertEquals(3, router.getBackstackSize());
+
+        List<RouterTransaction> fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(middleTransaction, fetchedBackstack.get(1));
+        assertEquals(topTransaction, fetchedBackstack.get(2));
+
+        assertEquals(router, rootTransaction.controller.getRouter());
+        assertEquals(router, middleTransaction.controller.getRouter());
+        assertEquals(router, topTransaction.controller.getRouter());
+    }
+
+    @Test
+    public void testNewSetBackstackWithNoRemoveViewOnPush() {
+        RouterTransaction oldRootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction oldTopTransaction = RouterTransaction.with(new TestController()).pushChangeHandler(MockChangeHandler.noRemoveViewOnPushHandler());
+
+        router.setRoot(oldRootTransaction);
+        router.pushController(oldTopTransaction);
+        assertEquals(2, router.getBackstackSize());
+
+        assertTrue(oldRootTransaction.controller.isAttached());
+        assertTrue(oldTopTransaction.controller.isAttached());
+
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction middleTransaction = RouterTransaction.with(new TestController()).pushChangeHandler(MockChangeHandler.noRemoveViewOnPushHandler());
+        RouterTransaction topTransaction = RouterTransaction.with(new TestController()).pushChangeHandler(MockChangeHandler.noRemoveViewOnPushHandler());
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, middleTransaction, topTransaction);
+        router.setBackstack(backstack, null);
+
+        assertEquals(3, router.getBackstackSize());
+
+        List<RouterTransaction> fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(middleTransaction, fetchedBackstack.get(1));
+        assertEquals(topTransaction, fetchedBackstack.get(2));
+
+        assertFalse(oldRootTransaction.controller.isAttached());
+        assertFalse(oldTopTransaction.controller.isAttached());
+        assertTrue(rootTransaction.controller.isAttached());
+        assertTrue(middleTransaction.controller.isAttached());
+        assertTrue(topTransaction.controller.isAttached());
+    }
+
+    @Test
+    public void testPopToRoot() {
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction transaction1 = RouterTransaction.with(new TestController());
+        RouterTransaction transaction2 = RouterTransaction.with(new TestController());
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, transaction1, transaction2);
+        router.setBackstack(backstack, null);
+
+        assertEquals(3, router.getBackstackSize());
+
+        router.popToRoot();
+
+        assertEquals(1, router.getBackstackSize());
+        assertEquals(rootTransaction, router.getBackstack().get(0));
+
+        assertTrue(rootTransaction.controller.isAttached());
+        assertFalse(transaction1.controller.isAttached());
+        assertFalse(transaction2.controller.isAttached());
+    }
+
+    @Test
+    public void testPopToRootWithNoRemoveViewOnPush() {
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController()).pushChangeHandler(new HorizontalChangeHandler(false));
+        RouterTransaction transaction1 = RouterTransaction.with(new TestController()).pushChangeHandler(new HorizontalChangeHandler(false));
+        RouterTransaction transaction2 = RouterTransaction.with(new TestController()).pushChangeHandler(new HorizontalChangeHandler(false));
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, transaction1, transaction2);
+        router.setBackstack(backstack, null);
+
+        assertEquals(3, router.getBackstackSize());
+
+        router.popToRoot();
+
+        assertEquals(1, router.getBackstackSize());
+        assertEquals(rootTransaction, router.getBackstack().get(0));
+
+        assertTrue(rootTransaction.controller.isAttached());
+        assertFalse(transaction1.controller.isAttached());
+        assertFalse(transaction2.controller.isAttached());
+    }
+
+    @Test
+    public void testReplaceTopController() {
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction topTransaction = RouterTransaction.with(new TestController());
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, topTransaction);
+        router.setBackstack(backstack, null);
+
+        assertEquals(2, router.getBackstackSize());
+
+        List<RouterTransaction> fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(topTransaction, fetchedBackstack.get(1));
+
+        RouterTransaction newTopTransaction = RouterTransaction.with(new TestController());
+        router.replaceTopController(newTopTransaction);
+
+        assertEquals(2, router.getBackstackSize());
+
+        fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(newTopTransaction, fetchedBackstack.get(1));
+    }
+
+    @Test
+    public void testReplaceTopControllerWithNoRemoveViewOnPush() {
+        RouterTransaction rootTransaction = RouterTransaction.with(new TestController());
+        RouterTransaction topTransaction = RouterTransaction.with(new TestController()).pushChangeHandler(MockChangeHandler.noRemoveViewOnPushHandler());
+
+        List<RouterTransaction> backstack = Arrays.asList(rootTransaction, topTransaction);
+        router.setBackstack(backstack, null);
+
+        assertEquals(2, router.getBackstackSize());
+
+        assertTrue(rootTransaction.controller.isAttached());
+        assertTrue(topTransaction.controller.isAttached());
+
+        List<RouterTransaction> fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(topTransaction, fetchedBackstack.get(1));
+
+        RouterTransaction newTopTransaction = RouterTransaction.with(new TestController()).pushChangeHandler(MockChangeHandler.noRemoveViewOnPushHandler());
+        router.replaceTopController(newTopTransaction);
+        newTopTransaction.pushChangeHandler().completeImmediately();
+
+        assertEquals(2, router.getBackstackSize());
+
+        fetchedBackstack = router.getBackstack();
+        assertEquals(rootTransaction, fetchedBackstack.get(0));
+        assertEquals(newTopTransaction, fetchedBackstack.get(1));
+
+        assertTrue(rootTransaction.controller.isAttached());
+        assertFalse(topTransaction.controller.isAttached());
+        assertTrue(newTopTransaction.controller.isAttached());
+    }
+
+    @Test
+    public void testRearrangeTransactionBackstack() {
+        RouterTransaction transaction1 = RouterTransaction.with(new TestController());
+        RouterTransaction transaction2 = RouterTransaction.with(new TestController());
+
+        List<RouterTransaction> backstack = Arrays.asList(transaction1, transaction2);
+        router.setBackstack(backstack, null);
+
+        assertEquals(1, transaction1.transactionIndex);
+        assertEquals(2, transaction2.transactionIndex);
+
+        backstack = Arrays.asList(transaction2, transaction1);
+        router.setBackstack(backstack, null);
+
+        assertEquals(1, transaction2.transactionIndex);
+        assertEquals(2, transaction1.transactionIndex);
+
+        router.handleBack();
+
+        assertEquals(1, router.getBackstackSize());
+        assertEquals(transaction2, router.getBackstack().get(0));
+
+        router.handleBack();
+        assertEquals(0, router.getBackstackSize());
+    }
+
+    @Test
+    public void testChildRouterRearrangeTransactionBackstack() {
+        Controller parent = new TestController();
+        router.setRoot(RouterTransaction.with(parent));
+
+        Router childRouter = parent.getChildRouter((ViewGroup)parent.getView().findViewById(TestController.CHILD_VIEW_ID_1));
+
+        RouterTransaction transaction1 = RouterTransaction.with(new TestController());
+        RouterTransaction transaction2 = RouterTransaction.with(new TestController());
+
+        List<RouterTransaction> backstack = Arrays.asList(transaction1, transaction2);
+        childRouter.setBackstack(backstack, null);
+
+        assertEquals(2, transaction1.transactionIndex);
+        assertEquals(3, transaction2.transactionIndex);
+
+        backstack = Arrays.asList(transaction2, transaction1);
+        childRouter.setBackstack(backstack, null);
+
+        assertEquals(2, transaction2.transactionIndex);
+        assertEquals(3, transaction1.transactionIndex);
+
+        childRouter.handleBack();
+
+        assertEquals(1, childRouter.getBackstackSize());
+        assertEquals(transaction2, childRouter.getBackstack().get(0));
+
+        childRouter.handleBack();
+        assertEquals(0, childRouter.getBackstackSize());
+    }
+
+    @Test
+    public void testRemovesAllViewsOnDestroy() {
+        Controller controller1 = new TestController();
+        Controller controller2 = new TestController();
+
+        router.setRoot(RouterTransaction.with(controller1));
+        router.pushController(RouterTransaction.with(controller2)
+                .pushChangeHandler(new FadeChangeHandler(false)));
+
+        assertEquals(2, router.container.getChildCount());
+
+        router.destroy(true);
+
+        assertEquals(0, router.container.getChildCount());
     }
 
 }

conductor/src/test/java/com/bluelinelabs/conductor/TargetControllerTests.java

@@ -0,0 +1,106 @@
+package com.bluelinelabs.conductor;
+
+import android.os.Bundle;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.MockChangeHandler;
+import com.bluelinelabs.conductor.util.TestController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNull;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class TargetControllerTests {
+
+    private Router router;
+
+    public void createActivityController(Bundle savedInstanceState) {
+        ActivityProxy activityProxy = new ActivityProxy().create(savedInstanceState).start().resume();
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new TestController()));
+        }
+    }
+
+    @Before
+    public void setup() {
+        createActivityController(null);
+    }
+
+    @Test
+    public void testSiblingTarget() {
+        final TestController controllerA = new TestController();
+        final TestController controllerB = new TestController();
+
+        assertNull(controllerA.getTargetController());
+        assertNull(controllerB.getTargetController());
+
+        router.pushController(RouterTransaction.with(controllerA)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        controllerB.setTargetController(controllerA);
+
+        router.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertNull(controllerA.getTargetController());
+        assertEquals(controllerA, controllerB.getTargetController());
+    }
+
+    @Test
+    public void testParentChildTarget() {
+        final TestController controllerA = new TestController();
+        final TestController controllerB = new TestController();
+
+        assertNull(controllerA.getTargetController());
+        assertNull(controllerB.getTargetController());
+
+        router.pushController(RouterTransaction.with(controllerA)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        controllerB.setTargetController(controllerA);
+
+        Router childRouter = controllerA.getChildRouter((ViewGroup)controllerA.getView().findViewById(TestController.VIEW_ID));
+        childRouter.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertNull(controllerA.getTargetController());
+        assertEquals(controllerA, controllerB.getTargetController());
+    }
+
+    @Test
+    public void testChildParentTarget() {
+        final TestController controllerA = new TestController();
+        final TestController controllerB = new TestController();
+
+        assertNull(controllerA.getTargetController());
+        assertNull(controllerB.getTargetController());
+
+        router.pushController(RouterTransaction.with(controllerA)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        controllerA.setTargetController(controllerB);
+
+        Router childRouter = controllerA.getChildRouter((ViewGroup)controllerA.getView().findViewById(TestController.VIEW_ID));
+        childRouter.pushController(RouterTransaction.with(controllerB)
+                .pushChangeHandler(MockChangeHandler.defaultHandler())
+                .popChangeHandler(MockChangeHandler.defaultHandler()));
+
+        assertNull(controllerB.getTargetController());
+        assertEquals(controllerB, controllerA.getTargetController());
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/TestActivity.java

@@ -1,6 +0,0 @@
-package com.bluelinelabs.conductor;
-
-import android.app.Activity;
-
-public class TestActivity extends Activity {
-}

conductor/src/test/java/com/bluelinelabs/conductor/ViewAttachHandlerTests.java

@@ -0,0 +1,236 @@
+package com.bluelinelabs.conductor;
+
+import android.app.Activity;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.LinearLayout;
+
+import com.bluelinelabs.conductor.internal.ViewAttachHandler;
+import com.bluelinelabs.conductor.internal.ViewAttachHandler.ViewAttachListener;
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.ViewUtils;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.junit.Assert.assertEquals;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class ViewAttachHandlerTests {
+
+    private Activity activity;
+    private ViewAttachHandler viewAttachHandler;
+    private CountingViewAttachListener viewAttachListener;
+
+    @Before
+    public void setup() {
+        activity = new ActivityProxy().create(null).getActivity();
+        viewAttachListener = new CountingViewAttachListener();
+        viewAttachHandler = new ViewAttachHandler(viewAttachListener);
+    }
+
+    @Test
+    public void testSimpleViewAttachDetach() {
+        View view = new View(activity);
+        viewAttachHandler.listenForAttach(view);
+
+        assertEquals(0, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        viewAttachHandler.onActivityStopped();
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+
+        viewAttachHandler.onActivityStarted();
+        assertEquals(3, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+    }
+
+    @Test
+    public void testSimpleViewGroupAttachDetach() {
+        View view = new View(activity);
+        viewAttachHandler.listenForAttach(view);
+
+        assertEquals(0, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        viewAttachHandler.onActivityStopped();
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+
+        viewAttachHandler.onActivityStarted();
+        assertEquals(3, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+    }
+
+    @Test
+    public void testNestedViewGroupAttachDetach() {
+        ViewGroup view = new LinearLayout(activity);
+        View child = new LinearLayout(activity);
+        view.addView(child);
+        viewAttachHandler.listenForAttach(view);
+
+        assertEquals(0, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true, false);
+        assertEquals(0, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(child, true, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true, false);
+        ViewUtils.reportAttached(child, true, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(0, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true, false);
+        assertEquals(1, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(child, true, false);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(1, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        viewAttachHandler.onActivityStopped();
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(0, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, false, false);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+
+        ViewUtils.reportAttached(view, true, false);
+        ViewUtils.reportAttached(child, true, false);
+        assertEquals(2, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+
+        viewAttachHandler.onActivityStarted();
+        assertEquals(3, viewAttachListener.attaches);
+        assertEquals(2, viewAttachListener.detaches);
+        assertEquals(1, viewAttachListener.detachAfterStops);
+    }
+
+    private static class CountingViewAttachListener implements ViewAttachListener {
+        int attaches;
+        int detaches;
+        int detachAfterStops;
+
+        @Override
+        public void onAttached() {
+            attaches++;
+        }
+
+        @Override
+        public void onDetached(boolean fromActivityStop) {
+            detaches++;
+        }
+
+        @Override
+        public void onViewDetachAfterStop() {
+            detachAfterStops++;
+        }
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/ViewLeakTests.java

@@ -0,0 +1,132 @@
+package com.bluelinelabs.conductor;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.util.ActivityProxy;
+import com.bluelinelabs.conductor.util.TestController;
+
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.annotation.Config;
+
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertNull;
+
+@RunWith(RobolectricTestRunner.class)
+@Config(manifest = Config.NONE)
+public class ViewLeakTests {
+
+    private ActivityProxy activityProxy;
+    private Router router;
+
+    public void createActivityController(Bundle savedInstanceState) {
+        activityProxy = new ActivityProxy().create(savedInstanceState).start().resume();
+        router = Conductor.attachRouter(activityProxy.getActivity(), activityProxy.getView(), savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new TestController()));
+        }
+    }
+
+    @Before
+    public void setup() {
+        createActivityController(null);
+    }
+
+    @Test
+    public void testPop() {
+        Controller controller = new TestController();
+        router.pushController(RouterTransaction.with(controller));
+
+        assertNotNull(controller.getView());
+
+        router.popCurrentController();
+
+        assertNull(controller.getView());
+    }
+
+    @Test
+    public void testPopWhenPushNeverAdded() {
+        Controller controller = new TestController();
+        router.pushController(RouterTransaction.with(controller).pushChangeHandler(new NeverAddChangeHandler()));
+
+        assertNotNull(controller.getView());
+
+        router.popCurrentController();
+
+        assertNull(controller.getView());
+    }
+
+    @Test
+    public void testPopWhenPushNeverCompleted() {
+        Controller controller = new TestController();
+        router.pushController(RouterTransaction.with(controller).pushChangeHandler(new NeverCompleteChangeHandler()));
+
+        assertNotNull(controller.getView());
+
+        router.popCurrentController();
+
+        assertNull(controller.getView());
+    }
+
+    @Test
+    public void testActivityStop() {
+        Controller controller = new TestController();
+        router.pushController(RouterTransaction.with(controller));
+
+        assertNotNull(controller.getView());
+
+        activityProxy.stop(true);
+
+        assertNull(controller.getView());
+    }
+
+    @Test
+    public void testActivityStopWhenPushNeverCompleted() {
+        Controller controller = new TestController();
+        router.pushController(RouterTransaction.with(controller).pushChangeHandler(new NeverCompleteChangeHandler()));
+
+        assertNotNull(controller.getView());
+
+        activityProxy.stop(true);
+
+        assertNull(controller.getView());
+    }
+
+    @Test
+    public void testActivityDestroyWhenPushNeverAdded() {
+        Controller controller = new TestController();
+        router.pushController(RouterTransaction.with(controller).pushChangeHandler(new NeverAddChangeHandler()));
+
+        assertNotNull(controller.getView());
+
+        activityProxy.stop(true).destroy();
+
+        assertNull(controller.getView());
+    }
+
+    public static class NeverAddChangeHandler extends ControllerChangeHandler {
+        @Override
+        public void performChange(@NonNull final ViewGroup container, @Nullable View from, @Nullable final View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
+            if (from != null) {
+                container.removeView(from);
+            }
+        }
+    }
+
+    public static class NeverCompleteChangeHandler extends ControllerChangeHandler {
+        @Override
+        public void performChange(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
+            if (from != null) {
+                container.removeView(from);
+            }
+            container.addView(to);
+        }
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/ViewUtils.java

@@ -1,25 +0,0 @@
-package com.bluelinelabs.conductor;
-
-import android.view.View;
-import android.view.View.OnAttachStateChangeListener;
-
-import org.robolectric.util.ReflectionHelpers;
-
-import java.util.List;
-
-public class ViewUtils {
-
-    static void setAttached(View view, boolean attached) {
-        Object listenerInfo = ReflectionHelpers.callInstanceMethod(view, "getListenerInfo");
-        List<OnAttachStateChangeListener> listeners = ReflectionHelpers.getField(listenerInfo, "mOnAttachStateChangeListeners");
-
-        for (OnAttachStateChangeListener listener : listeners) {
-            if (attached) {
-                listener.onViewAttachedToWindow(view);
-            } else {
-                listener.onViewDetachedFromWindow(view);
-            }
-        }
-    }
-
-}

conductor/src/test/java/com/bluelinelabs/conductor/util/ActivityProxy.java

@@ -0,0 +1,77 @@
+package com.bluelinelabs.conductor.util;
+
+import android.os.Bundle;
+import android.support.annotation.IdRes;
+
+import org.robolectric.Robolectric;
+import org.robolectric.util.ActivityController;
+
+public class ActivityProxy {
+
+    private ActivityController<TestActivity> activityController;
+    private AttachFakingFrameLayout view;
+
+    public ActivityProxy() {
+        activityController = Robolectric.buildActivity(TestActivity.class);
+
+        @IdRes int containerId = 4;
+        view = new AttachFakingFrameLayout(activityController.get());
+        view.setId(containerId);
+    }
+
+    public ActivityProxy create(Bundle savedInstanceState) {
+        activityController.create(savedInstanceState);
+        return this;
+    }
+
+    public ActivityProxy start() {
+        activityController.start();
+        view.setAttached(true);
+        return this;
+    }
+
+    public ActivityProxy resume() {
+        activityController.resume();
+        return this;
+    }
+
+    public ActivityProxy pause() {
+        activityController.pause();
+        return this;
+    }
+
+    public ActivityProxy saveInstanceState(Bundle outState) {
+        activityController.saveInstanceState(outState);
+        return this;
+    }
+
+    public ActivityProxy stop(boolean detachView) {
+        activityController.stop();
+
+        if (detachView) {
+            view.setAttached(false);
+        }
+
+        return this;
+    }
+
+    public ActivityProxy destroy() {
+        activityController.destroy();
+        view.setAttached(false);
+        return this;
+    }
+
+    public ActivityProxy rotate() {
+        getActivity().isChangingConfigurations = true;
+        getActivity().recreate();
+        return this;
+    }
+
+    public TestActivity getActivity() {
+        return activityController.get();
+    }
+
+    public AttachFakingFrameLayout getView() {
+        return view;
+    }
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/AttachFakingFrameLayout.java

@@ -0,0 +1,113 @@
+package com.bluelinelabs.conductor.util;
+
+import android.content.Context;
+import android.os.IBinder;
+import android.os.IInterface;
+import android.os.Parcel;
+import android.os.RemoteException;
+import android.util.AttributeSet;
+import android.view.View;
+import android.widget.FrameLayout;
+
+import java.io.FileDescriptor;
+
+public class AttachFakingFrameLayout extends FrameLayout {
+
+    final IBinder fakeWindowToken = new IBinder() {
+        @Override
+        public String getInterfaceDescriptor() throws RemoteException {
+            return null;
+        }
+
+        @Override
+        public boolean pingBinder() {
+            return false;
+        }
+
+        @Override
+        public boolean isBinderAlive() {
+            return false;
+        }
+
+        @Override
+        public IInterface queryLocalInterface(String descriptor) {
+            return null;
+        }
+
+        @Override
+        public void dump(FileDescriptor fd, String[] args) throws RemoteException {
+
+        }
+
+        @Override
+        public void dumpAsync(FileDescriptor fd, String[] args) throws RemoteException {
+
+        }
+
+        @Override
+        public boolean transact(int code, Parcel data, Parcel reply, int flags) throws RemoteException {
+            return false;
+        }
+
+        @Override
+        public void linkToDeath(DeathRecipient recipient, int flags) throws RemoteException {
+
+        }
+
+        @Override
+        public boolean unlinkToDeath(DeathRecipient recipient, int flags) {
+            return false;
+        }
+    };
+
+    private boolean reportAttached;
+
+    public AttachFakingFrameLayout(Context context) {
+        super(context);
+    }
+
+    public AttachFakingFrameLayout(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    public AttachFakingFrameLayout(Context context, AttributeSet attrs, int defStyleAttr) {
+        super(context, attrs, defStyleAttr);
+    }
+
+    @Override
+    public final IBinder getWindowToken() {
+        return reportAttached ? fakeWindowToken : null;
+    }
+
+    public void setAttached(boolean attached) {
+        setAttached(attached, true);
+    }
+
+    public void setAttached(boolean attached, boolean reportToViewUtils) {
+        if (reportAttached != attached) {
+            reportAttached = attached;
+            if (reportToViewUtils) {
+                ViewUtils.reportAttached(this, attached);
+            }
+
+            for (int i = 0; i < getChildCount(); i++) {
+                ViewUtils.reportAttached(getChildAt(i), attached);
+            }
+        }
+    }
+
+    @Override
+    public void onViewAdded(View child) {
+        if (reportAttached) {
+            ViewUtils.reportAttached(child, true);
+        }
+        super.onViewAdded(child);
+    }
+
+    @Override
+    public void onViewRemoved(View child) {
+        ViewUtils.reportAttached(child, false);
+        super.onViewRemoved(child);
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/CallState.java

@@ -0,0 +1,175 @@
+package com.bluelinelabs.conductor.util;
+
+import android.os.Parcel;
+import android.os.Parcelable;
+
+public class CallState implements Parcelable {
+
+    public int changeStartCalls;
+    public int changeEndCalls;
+    public int createViewCalls;
+    public int attachCalls;
+    public int destroyViewCalls;
+    public int detachCalls;
+    public int destroyCalls;
+    public int saveInstanceStateCalls;
+    public int restoreInstanceStateCalls;
+    public int saveViewStateCalls;
+    public int restoreViewStateCalls;
+    public int onActivityResultCalls;
+    public int onRequestPermissionsResultCalls;
+    public int createOptionsMenuCalls;
+
+    public CallState() {
+        this(false);
+    }
+
+    public CallState(boolean setupForAddedController) {
+        if (setupForAddedController) {
+            changeStartCalls++;
+            changeEndCalls++;
+            createViewCalls++;
+            attachCalls++;
+        }
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o) {
+            return true;
+        }
+        if (o == null || getClass() != o.getClass()) {
+            return false;
+        }
+
+        CallState callState = (CallState)o;
+
+        if (changeStartCalls != callState.changeStartCalls) {
+            return false;
+        }
+        if (changeEndCalls != callState.changeEndCalls) {
+            return false;
+        }
+        if (createViewCalls != callState.createViewCalls) {
+            return false;
+        }
+        if (attachCalls != callState.attachCalls) {
+            return false;
+        }
+        if (destroyViewCalls != callState.destroyViewCalls) {
+            return false;
+        }
+        if (detachCalls != callState.detachCalls) {
+            return false;
+        }
+        if (destroyCalls != callState.destroyCalls) {
+            return false;
+        }
+        if (saveInstanceStateCalls != callState.saveInstanceStateCalls) {
+            return false;
+        }
+        if (saveViewStateCalls != callState.saveViewStateCalls) {
+            return false;
+        }
+        if (restoreViewStateCalls != callState.restoreViewStateCalls) {
+            return false;
+        }
+        if (onActivityResultCalls != callState.onActivityResultCalls) {
+            return false;
+        }
+        if (onRequestPermissionsResultCalls != callState.onRequestPermissionsResultCalls) {
+            return false;
+        }
+        if (createOptionsMenuCalls != callState.createOptionsMenuCalls) {
+            return false;
+        }
+        return restoreInstanceStateCalls == callState.restoreInstanceStateCalls;
+    }
+
+    @Override
+    public int hashCode() {
+        int result = changeStartCalls;
+        result = 31 * result + changeEndCalls;
+        result = 31 * result + createViewCalls;
+        result = 31 * result + attachCalls;
+        result = 31 * result + destroyViewCalls;
+        result = 31 * result + detachCalls;
+        result = 31 * result + destroyCalls;
+        result = 31 * result + saveInstanceStateCalls;
+        result = 31 * result + restoreInstanceStateCalls;
+        result = 31 * result + saveViewStateCalls;
+        result = 31 * result + restoreViewStateCalls;
+        result = 31 * result + onActivityResultCalls;
+        result = 31 * result + onRequestPermissionsResultCalls;
+        result = 31 * result + createOptionsMenuCalls;
+        return result;
+    }
+
+    @Override
+    public String toString() {
+        return "\nCallState{" +
+                "\n    changeStartCalls=" + changeStartCalls +
+                "\n    changeEndCalls=" + changeEndCalls +
+                "\n    createViewCalls=" + createViewCalls +
+                "\n    attachCalls=" + attachCalls +
+                "\n    destroyViewCalls=" + destroyViewCalls +
+                "\n    detachCalls=" + detachCalls +
+                "\n    destroyCalls=" + destroyCalls +
+                "\n    saveInstanceStateCalls=" + saveInstanceStateCalls +
+                "\n    restoreInstanceStateCalls=" + restoreInstanceStateCalls +
+                "\n    saveViewStateCalls=" + saveViewStateCalls +
+                "\n    restoreViewStateCalls=" + restoreViewStateCalls +
+                "\n    onActivityResultCalls=" + onActivityResultCalls +
+                "\n    onRequestPermissionsResultCalls=" + onRequestPermissionsResultCalls +
+                "\n    createOptionsMenuCalls=" + createOptionsMenuCalls +
+                "}\n";
+    }
+
+    public int describeContents() {
+        return 0;
+    }
+
+    public void writeToParcel(Parcel out, int flags) {
+        out.writeInt(changeStartCalls);
+        out.writeInt(changeEndCalls);
+        out.writeInt(createViewCalls);
+        out.writeInt(attachCalls);
+        out.writeInt(destroyViewCalls);
+        out.writeInt(detachCalls);
+        out.writeInt(destroyCalls);
+        out.writeInt(saveInstanceStateCalls);
+        out.writeInt(restoreInstanceStateCalls);
+        out.writeInt(saveViewStateCalls);
+        out.writeInt(restoreViewStateCalls);
+        out.writeInt(onActivityResultCalls);
+        out.writeInt(onRequestPermissionsResultCalls);
+        out.writeInt(createOptionsMenuCalls);
+    }
+
+    public static final Parcelable.Creator<CallState> CREATOR  = new Parcelable.Creator<CallState>() {
+        public CallState createFromParcel(Parcel in) {
+            CallState state = new CallState();
+
+            state.changeStartCalls = in.readInt();
+            state.changeEndCalls = in.readInt();
+            state.createViewCalls = in.readInt();
+            state.attachCalls = in.readInt();
+            state.destroyViewCalls = in.readInt();
+            state.detachCalls = in.readInt();
+            state.destroyCalls = in.readInt();
+            state.saveInstanceStateCalls = in.readInt();
+            state.restoreInstanceStateCalls = in.readInt();
+            state.saveViewStateCalls = in.readInt();
+            state.restoreViewStateCalls = in.readInt();
+            state.onActivityResultCalls = in.readInt();
+            state.onRequestPermissionsResultCalls = in.readInt();
+            state.createOptionsMenuCalls = in.readInt();
+
+            return state;
+        }
+
+        public CallState[] newArray(int size) {
+            return new CallState[size];
+        }
+    };
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/ChangeHandlerHistory.java

@@ -0,0 +1,67 @@
+package com.bluelinelabs.conductor.util;
+
+import android.view.View;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ChangeHandlerHistory {
+
+    private List<Entry> entries = new ArrayList<>();
+    public boolean isValidHistory = true;
+
+    public void addEntry(View from, View to, boolean isPush, MockChangeHandler handler) {
+        entries.add(new Entry(from, to, isPush, handler));
+    }
+
+    public int size() {
+        return entries.size();
+    }
+
+    public View fromViewAt(int index) {
+        return entries.get(index).from;
+    }
+
+    public View toViewAt(int index) {
+        return entries.get(index).to;
+    }
+
+    public boolean isPushAt(int index) {
+        return entries.get(index).isPush;
+    }
+
+    public MockChangeHandler changeHandlerAt(int index) {
+        return entries.get(index).changeHandler;
+    }
+
+    public View latestFromView() {
+        return fromViewAt(size() - 1);
+    }
+
+    public View latestToView() {
+        return toViewAt(size() - 1);
+    }
+
+    public boolean latestIsPush() {
+        return isPushAt(size() - 1);
+    }
+
+    public MockChangeHandler latestChangeHandler() {
+        return changeHandlerAt(size() - 1);
+    }
+
+    private static class Entry {
+        final View from;
+        final View to;
+        final boolean isPush;
+        final MockChangeHandler changeHandler;
+
+        Entry(View from, View to, boolean isPush, MockChangeHandler changeHandler) {
+            this.from = from;
+            this.to = to;
+            this.isPush = isPush;
+            this.changeHandler = changeHandler;
+        }
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/MockChangeHandler.java

@@ -0,0 +1,118 @@
+package com.bluelinelabs.conductor.util;
+
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+
+public class MockChangeHandler extends ControllerChangeHandler {
+
+    private static final String KEY_REMOVES_FROM_VIEW_ON_PUSH = "MockChangeHandler.removesFromViewOnPush";
+    private static final String KEY_TAG = "MockChangeHandler.tag";
+
+    public static class ChangeHandlerListener {
+        public void willStartChange() { }
+        public void didAttachOrDetach() { }
+        public void didEndChange() { }
+    }
+
+    private final ChangeHandlerListener listener;
+    private boolean removesFromViewOnPush;
+
+    public View from;
+    public View to;
+    public String tag;
+
+    public static MockChangeHandler defaultHandler() {
+        return new MockChangeHandler(true, null, null);
+    }
+
+    public static MockChangeHandler noRemoveViewOnPushHandler() {
+        return new MockChangeHandler(false, null, null);
+    }
+
+    public static MockChangeHandler listeningChangeHandler(@NonNull ChangeHandlerListener listener) {
+        return new MockChangeHandler(true, null, listener);
+    }
+
+    public static MockChangeHandler taggedHandler(String tag, boolean removeViewOnPush) {
+        return new MockChangeHandler(removeViewOnPush, tag, null);
+    }
+
+    public MockChangeHandler() {
+        listener = null;
+    }
+
+    private MockChangeHandler(boolean removesFromViewOnPush, String tag, ChangeHandlerListener listener) {
+        this.removesFromViewOnPush = removesFromViewOnPush;
+
+        if (listener == null) {
+            this.listener = new ChangeHandlerListener() { };
+        } else {
+            this.listener = listener;
+        }
+    }
+
+    @Override
+    public void performChange(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, boolean isPush, @NonNull ControllerChangeCompletedListener changeListener) {
+        this.from = from;
+        this.to = to;
+
+        listener.willStartChange();
+
+        if (isPush) {
+            if (to != null) {
+                container.addView(to);
+                listener.didAttachOrDetach();
+            }
+
+            if (removesFromViewOnPush && from != null) {
+                container.removeView(from);
+            }
+        } else {
+            container.removeView(from);
+            listener.didAttachOrDetach();
+
+            if (to != null) {
+                container.addView(to);
+            }
+
+        }
+
+        changeListener.onChangeCompleted();
+        listener.didEndChange();
+    }
+
+    @Override
+    public boolean removesFromViewOnPush() {
+        return removesFromViewOnPush;
+    }
+
+    @Override
+    public void saveToBundle(@NonNull Bundle bundle) {
+        super.saveToBundle(bundle);
+        bundle.putBoolean(KEY_REMOVES_FROM_VIEW_ON_PUSH, removesFromViewOnPush);
+        bundle.putString(KEY_TAG, tag);
+    }
+
+    @Override
+    public void restoreFromBundle(@NonNull Bundle bundle) {
+        super.restoreFromBundle(bundle);
+        removesFromViewOnPush = bundle.getBoolean(KEY_REMOVES_FROM_VIEW_ON_PUSH);
+        tag = bundle.getString(KEY_TAG);
+    }
+
+    @NonNull
+    @Override
+    public ControllerChangeHandler copy() {
+        return new MockChangeHandler(removesFromViewOnPush, tag, listener);
+    }
+
+    @Override
+    public boolean isReusable() {
+        return true;
+    }
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/TestActivity.java

@@ -0,0 +1,19 @@
+package com.bluelinelabs.conductor.util;
+
+import android.app.Activity;
+
+public class TestActivity extends Activity {
+
+    public boolean isChangingConfigurations = false;
+    public boolean isDestroying = false;
+
+    @Override
+    public boolean isChangingConfigurations() {
+        return isChangingConfigurations;
+    }
+
+    @Override
+    public boolean isDestroyed() {
+        return isDestroying || super.isDestroyed();
+    }
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/TestController.java

@@ -0,0 +1,141 @@
+package com.bluelinelabs.conductor.util;
+
+import android.content.Intent;
+import android.os.Bundle;
+import android.support.annotation.IdRes;
+import android.support.annotation.NonNull;
+import android.view.LayoutInflater;
+import android.view.Menu;
+import android.view.MenuInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.FrameLayout;
+
+import com.bluelinelabs.conductor.Controller;
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+import com.bluelinelabs.conductor.ControllerChangeType;
+
+public class TestController extends Controller {
+
+    @IdRes public static final int VIEW_ID = 2342;
+    @IdRes public static final int CHILD_VIEW_ID_1 = 2343;
+    @IdRes public static final int CHILD_VIEW_ID_2 = 2344;
+
+    private static final String KEY_CALL_STATE = "TestController.currentCallState";
+
+    public CallState currentCallState = new CallState();
+    public ChangeHandlerHistory changeHandlerHistory = new ChangeHandlerHistory();
+
+    @NonNull
+    @Override
+    protected View onCreateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container) {
+        currentCallState.createViewCalls++;
+        FrameLayout view = new AttachFakingFrameLayout(inflater.getContext());
+        view.setId(VIEW_ID);
+
+        FrameLayout childContainer1 = new AttachFakingFrameLayout(inflater.getContext());
+        childContainer1.setId(CHILD_VIEW_ID_1);
+        view.addView(childContainer1);
+
+        FrameLayout childContainer2 = new AttachFakingFrameLayout(inflater.getContext());
+        childContainer2.setId(CHILD_VIEW_ID_2);
+        view.addView(childContainer2);
+
+        return view;
+    }
+
+    @Override
+    protected void onChangeStarted(@NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
+        super.onChangeStarted(changeHandler, changeType);
+        currentCallState.changeStartCalls++;
+    }
+
+    @Override
+    protected void onChangeEnded(@NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
+        super.onChangeEnded(changeHandler, changeType);
+        currentCallState.changeEndCalls++;
+
+        if (changeHandler instanceof MockChangeHandler) {
+            MockChangeHandler mockHandler = (MockChangeHandler)changeHandler;
+            changeHandlerHistory.addEntry(mockHandler.from, mockHandler.to, changeType.isPush, mockHandler);
+        } else {
+            changeHandlerHistory.isValidHistory = false;
+        }
+    }
+
+    @Override
+    protected void onAttach(@NonNull View view) {
+        super.onAttach(view);
+        currentCallState.attachCalls++;
+    }
+
+    @Override
+    protected void onDetach(@NonNull View view) {
+        super.onDetach(view);
+        currentCallState.detachCalls++;
+    }
+
+    @Override
+    protected void onDestroyView(@NonNull View view) {
+        super.onDestroyView(view);
+        currentCallState.destroyViewCalls++;
+    }
+
+    @Override
+    protected void onDestroy() {
+        super.onDestroy();
+        currentCallState.destroyCalls++;
+    }
+
+    @Override
+    protected void onSaveViewState(@NonNull View view, @NonNull Bundle outState) {
+        super.onSaveViewState(view, outState);
+        currentCallState.saveViewStateCalls++;
+    }
+
+    @Override
+    protected void onRestoreViewState(@NonNull View view, @NonNull Bundle savedViewState) {
+        super.onRestoreViewState(view, savedViewState);
+        currentCallState.restoreViewStateCalls++;
+    }
+
+    @Override
+    protected void onSaveInstanceState(@NonNull Bundle outState) {
+        currentCallState.saveInstanceStateCalls++;
+
+        outState.putParcelable(KEY_CALL_STATE, currentCallState);
+
+        super.onSaveInstanceState(outState);
+    }
+
+    @Override
+    protected void onRestoreInstanceState(@NonNull Bundle savedInstanceState) {
+        super.onRestoreInstanceState(savedInstanceState);
+
+        currentCallState = savedInstanceState.getParcelable(KEY_CALL_STATE);
+
+        currentCallState.restoreInstanceStateCalls++;
+    }
+
+    @Override
+    public void onActivityResult(int requestCode, int resultCode, Intent data) {
+        super.onActivityResult(requestCode, resultCode, data);
+
+        currentCallState.onActivityResultCalls++;
+    }
+
+    @Override
+    public void onRequestPermissionsResult(int requestCode, @NonNull String[] permissions, @NonNull int[] grantResults) {
+        super.onRequestPermissionsResult(requestCode, permissions, grantResults);
+
+        currentCallState.onRequestPermissionsResultCalls++;
+    }
+
+    @Override
+    public void onCreateOptionsMenu(Menu menu, MenuInflater inflater) {
+        super.onCreateOptionsMenu(menu, inflater);
+
+        currentCallState.createOptionsMenuCalls++;
+    }
+
+}

conductor/src/test/java/com/bluelinelabs/conductor/util/ViewUtils.java

@@ -0,0 +1,61 @@
+package com.bluelinelabs.conductor.util;
+
+import android.view.View;
+import android.view.View.OnAttachStateChangeListener;
+import android.view.ViewGroup;
+
+import org.robolectric.util.ReflectionHelpers;
+
+import java.util.List;
+
+public class ViewUtils {
+
+    public static void reportAttached(View view, boolean attached) {
+        reportAttached(view, attached, true);
+    }
+
+    public static void reportAttached(View view, boolean attached, boolean propogateToChildren) {
+        if (view instanceof AttachFakingFrameLayout) {
+            ((AttachFakingFrameLayout)view).setAttached(attached, false);
+        }
+
+        List<OnAttachStateChangeListener> listeners = getAttachStateListeners(view);
+
+        // Add, then remove an OnAttachStateChangeListener to initialize the attachStateListeners variable inside a view
+        if (listeners == null) {
+            OnAttachStateChangeListener tmpListener = new OnAttachStateChangeListener() {
+                @Override
+                public void onViewAttachedToWindow(View v) { }
+
+                @Override
+                public void onViewDetachedFromWindow(View v) { }
+            };
+            view.addOnAttachStateChangeListener(tmpListener);
+            view.removeOnAttachStateChangeListener(tmpListener);
+            listeners = getAttachStateListeners(view);
+        }
+
+        for (OnAttachStateChangeListener listener : listeners) {
+            if (attached) {
+                listener.onViewAttachedToWindow(view);
+            } else {
+                listener.onViewDetachedFromWindow(view);
+            }
+        }
+
+        if (propogateToChildren && view instanceof ViewGroup) {
+            ViewGroup viewGroup = (ViewGroup)view;
+            int childCount = viewGroup.getChildCount();
+            for (int i = 0; i < childCount; i++) {
+                reportAttached(viewGroup.getChildAt(i), attached, true);
+            }
+        }
+
+    }
+
+    private static List<OnAttachStateChangeListener> getAttachStateListeners(View view) {
+        Object listenerInfo = ReflectionHelpers.callInstanceMethod(view, "getListenerInfo");
+        return ReflectionHelpers.getField(listenerInfo, "mOnAttachStateChangeListeners");
+    }
+
+}

demo/build.gradle

@@ -11,8 +11,13 @@ apply plugin: 'com.android.application'
 apply plugin: 'com.neenbedankt.android-apt'
 
 android {
-    compileSdkVersion 23
-    buildToolsVersion "23.0.2"
+    compileSdkVersion rootProject.ext.compileSdkVersion
+    buildToolsVersion rootProject.ext.buildToolsVersion
+
+    lintOptions {
+        abortOnError true
+        ignore 'UnusedResources'
+    }
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_7
@@ -21,10 +26,11 @@ android {
 
     defaultConfig {
         applicationId "com.bluelinelabs.conductor.demo"
-        minSdkVersion 16
-        targetSdkVersion 23
+        minSdkVersion rootProject.ext.minSdkVersion
+        targetSdkVersion rootProject.ext.targetSdkVersion
         versionCode 1
         versionName "1.0.0"
+        vectorDrawables.useSupportLibrary true
     }
 
     buildTypes {
@@ -33,20 +39,23 @@ android {
             proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
         }
     }
+
+    packagingOptions {
+        exclude 'META-INF/rxjava.properties'
+    }
 }
 
 dependencies {
     compile rootProject.ext.supportV4
     compile rootProject.ext.supportDesign
 
+    apt rootProject.ext.butterknifeCompiler
     compile rootProject.ext.butterknife
+    compile rootProject.ext.picasso
 
-    compile 'com.bluelinelabs:conductor:' + rootProject.ext.publishedVersionName
-    compile 'com.bluelinelabs:conductor-support:' + rootProject.ext.publishedVersionName
-    compile 'com.bluelinelabs:conductor-rxlifecycle:' + rootProject.ext.publishedVersionName
-
-//    compile project(':conductor-support')
-//    compile project(':conductor-rxlifecycle')
+    compile project(':conductor-support')
+    compile project(':conductor-rxlifecycle')
+    compile project(':conductor-rxlifecycle2')
 
     debugCompile rootProject.ext.leakCanary
     releaseCompile rootProject.ext.leakCanaryNoOp

demo/src/main/java/com/bluelinelabs/conductor/demo/ActionBarProvider.java

@@ -0,0 +1,7 @@
+package com.bluelinelabs.conductor.demo;
+
+import android.support.v7.app.ActionBar;
+
+public interface ActionBarProvider {
+    ActionBar getSupportActionBar();
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/MainActivity.java

@@ -1,21 +1,24 @@
 package com.bluelinelabs.conductor.demo;
 
-import android.app.Activity;
 import android.os.Bundle;
+import android.support.v7.app.AppCompatActivity;
+import android.support.v7.widget.Toolbar;
 import android.view.ViewGroup;
 
 import com.bluelinelabs.conductor.Conductor;
 import com.bluelinelabs.conductor.Router;
+import com.bluelinelabs.conductor.RouterTransaction;
 import com.bluelinelabs.conductor.demo.controllers.HomeController;
 
-import butterknife.Bind;
+import butterknife.BindView;
 import butterknife.ButterKnife;
 
-public class MainActivity extends Activity {
+public final class MainActivity extends AppCompatActivity implements ActionBarProvider {
 
-    @Bind(R.id.controller_container) ViewGroup mContainer;
+    @BindView(R.id.toolbar) Toolbar toolbar;
+    @BindView(R.id.controller_container) ViewGroup container;
 
-    private Router mRouter;
+    private Router router;
 
     @Override
     protected void onCreate(Bundle savedInstanceState) {
@@ -24,23 +27,19 @@ public class MainActivity extends Activity {
         setContentView(R.layout.activity_main);
         ButterKnife.bind(this);
 
-        mRouter = Conductor.attachRouter(this, mContainer, savedInstanceState);
-        if (!mRouter.hasRootController()) {
-            mRouter.setRoot(new HomeController());
+        setSupportActionBar(toolbar);
+
+        router = Conductor.attachRouter(this, container, savedInstanceState);
+        if (!router.hasRootController()) {
+            router.setRoot(RouterTransaction.with(new HomeController()));
         }
     }
 
     @Override
     public void onBackPressed() {
-        if (!mRouter.handleBack()) {
+        if (!router.handleBack()) {
             super.onBackPressed();
         }
     }
 
-    @Override
-    protected void onDestroy() {
-        super.onDestroy();
-        ButterKnife.unbind(this);
-    }
-
 }

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/CircularRevealChangeHandler.java

@@ -1,4 +1,4 @@
-package com.bluelinelabs.conductor.changehandler;
+package com.bluelinelabs.conductor.demo.changehandler;
 
 import android.animation.Animator;
 import android.annotation.TargetApi;
@@ -9,6 +9,8 @@ import android.view.View;
 import android.view.ViewAnimationUtils;
 import android.view.ViewGroup;
 
+import com.bluelinelabs.conductor.changehandler.AnimatorChangeHandler;
+
 /**
  * An {@link AnimatorChangeHandler} that will perform a circular reveal
  */
@@ -18,8 +20,8 @@ public class CircularRevealChangeHandler extends AnimatorChangeHandler {
     private static final String KEY_CX = "CircularRevealChangeHandler.cx";
     private static final String KEY_CY = "CircularRevealChangeHandler.cy";
 
-    private int mCx;
-    private int mCy;
+    private int cx;
+    private int cy;
 
     public CircularRevealChangeHandler() { }
 
@@ -71,8 +73,8 @@ public class CircularRevealChangeHandler extends AnimatorChangeHandler {
         int relativeLeft = fromLocation[0] - containerLocation[0];
         int relativeTop  = fromLocation[1] - containerLocation[1];
 
-        mCx = fromView.getWidth() / 2 + relativeLeft;
-        mCy = fromView.getHeight() / 2 + relativeTop;
+        cx = fromView.getWidth() / 2 + relativeLeft;
+        cy = fromView.getHeight() / 2 + relativeTop;
     }
 
     /**
@@ -114,18 +116,18 @@ public class CircularRevealChangeHandler extends AnimatorChangeHandler {
      */
     public CircularRevealChangeHandler(int cx, int cy, long duration, boolean removesFromViewOnPush) {
         super(duration, removesFromViewOnPush);
-        mCx = cx;
-        mCy = cy;
+        this.cx = cx;
+        this.cy = cy;
     }
 
-    @Override
+    @Override @NonNull
     protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
-        final float radius = (float) Math.hypot(mCx, mCy);
+        final float radius = (float) Math.hypot(cx, cy);
         Animator animator = null;
         if (isPush && to != null) {
-            animator = ViewAnimationUtils.createCircularReveal(to, mCx, mCy, 0, radius);
+            animator = ViewAnimationUtils.createCircularReveal(to, cx, cy, 0, radius);
         } else if (!isPush && from != null) {
-            animator = ViewAnimationUtils.createCircularReveal(from, mCx, mCy, radius, 0);
+            animator = ViewAnimationUtils.createCircularReveal(from, cx, cy, radius, 0);
         }
         return animator;
     }
@@ -136,14 +138,14 @@ public class CircularRevealChangeHandler extends AnimatorChangeHandler {
     @Override
     public void saveToBundle(@NonNull Bundle bundle) {
         super.saveToBundle(bundle);
-        bundle.putInt(KEY_CX, mCx);
-        bundle.putInt(KEY_CY, mCy);
+        bundle.putInt(KEY_CX, cx);
+        bundle.putInt(KEY_CY, cy);
     }
 
     @Override
     public void restoreFromBundle(@NonNull Bundle bundle) {
         super.restoreFromBundle(bundle);
-        mCx = bundle.getInt(KEY_CX);
-        mCy = bundle.getInt(KEY_CY);
+        cx = bundle.getInt(KEY_CX);
+        cy = bundle.getInt(KEY_CY);
     }
 }

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/CircularRevealChangeHandlerCompat.java

@@ -0,0 +1,37 @@
+package com.bluelinelabs.conductor.demo.changehandler;
+
+import android.animation.Animator;
+import android.animation.AnimatorSet;
+import android.animation.ObjectAnimator;
+import android.os.Build;
+import android.support.annotation.NonNull;
+import android.view.View;
+import android.view.ViewGroup;
+
+public class CircularRevealChangeHandlerCompat extends CircularRevealChangeHandler {
+
+    public CircularRevealChangeHandlerCompat() { }
+
+    public CircularRevealChangeHandlerCompat(@NonNull View fromView, @NonNull View containerView) {
+        super(fromView, containerView);
+    }
+
+    @Override @NonNull
+    protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            return super.getAnimator(container, from, to, isPush, toAddedToContainer);
+        } else {
+            AnimatorSet animator = new AnimatorSet();
+            if (to != null) {
+                float start = toAddedToContainer ? 0 : to.getAlpha();
+                animator.play(ObjectAnimator.ofFloat(to, View.ALPHA, start, 1));
+            }
+
+            if (from != null) {
+                animator.play(ObjectAnimator.ofFloat(from, View.ALPHA, 0));
+            }
+
+            return animator;
+        }
+    }
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/FabToDialogTransitionChangeHandler.java

@@ -0,0 +1,110 @@
+package com.bluelinelabs.conductor.demo.changehandler;
+
+import android.annotation.TargetApi;
+import android.os.Build;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.support.v4.content.ContextCompat;
+import android.transition.Fade;
+import android.transition.Transition;
+import android.transition.TransitionSet;
+import android.view.View;
+import android.view.ViewGroup;
+
+import com.bluelinelabs.conductor.changehandler.TransitionChangeHandler;
+import com.bluelinelabs.conductor.demo.R;
+import com.bluelinelabs.conductor.demo.changehandler.transitions.FabTransform;
+import com.bluelinelabs.conductor.demo.util.AnimUtils;
+
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+public class FabToDialogTransitionChangeHandler extends TransitionChangeHandler {
+
+    private View fab;
+    private View dialogBackground;
+    private ViewGroup fabParent;
+
+    @NonNull @Override
+    protected Transition getTransition(@NonNull final ViewGroup container, @Nullable final View from, @Nullable final View to, boolean isPush) {
+        Transition backgroundFade = new Fade();
+        backgroundFade.addTarget(R.id.dialog_background);
+
+        Transition fabTransform = new FabTransform(ContextCompat.getColor(container.getContext(), R.color.colorAccent), R.drawable.ic_github_face);
+
+        TransitionSet set = new TransitionSet();
+        set.addTransition(backgroundFade);
+        set.addTransition(fabTransform);
+
+        return set;
+    }
+
+    @Override
+    public void prepareForTransition(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, @NonNull Transition transition, boolean isPush, @NonNull OnTransitionPreparedListener onTransitionPreparedListener) {
+        fab = isPush ? from.findViewById(R.id.fab) : to.findViewById(R.id.fab);
+        fabParent = (ViewGroup)fab.getParent();
+
+        if (!isPush) {
+             /*
+             * Before we transition back we want to remove the fab
+             * in order to add it again for the TransitionManager to be able to detect the change
+             */
+            fabParent.removeView(fab);
+            fab.setVisibility(View.VISIBLE);
+
+             /*
+             * Before we transition back we need to move the dialog's background to the new view
+             * so its fade won't take place over the fab transition
+             */
+            dialogBackground = from.findViewById(R.id.dialog_background);
+            ((ViewGroup)dialogBackground.getParent()).removeView(dialogBackground);
+            fabParent.addView(dialogBackground);
+        }
+
+        onTransitionPreparedListener.onPrepared();
+    }
+
+    @Override
+    public void executePropertyChanges(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, @Nullable Transition transition, boolean isPush) {
+        if (isPush) {
+            fabParent.removeView(fab);
+            container.addView(to);
+
+            /*
+             * After the transition is finished we have to add the fab back to the original container.
+             * Because otherwise we will be lost when trying to transition back.
+             * Set it to invisible because we don't want it to jump back after the transition
+             */
+            AnimUtils.TransitionEndListener endListener = new AnimUtils.TransitionEndListener() {
+                @Override
+                public void onTransitionCompleted(Transition transition) {
+                    fab.setVisibility(View.GONE);
+                    fabParent.addView(fab);
+                    fab = null;
+                    fabParent = null;
+                }
+            };
+            if (transition != null) {
+                transition.addListener(endListener);
+            } else {
+                endListener.onTransitionCompleted(null);
+            }
+        } else {
+            dialogBackground.setVisibility(View.INVISIBLE);
+            fabParent.addView(fab);
+            container.removeView(from);
+
+            AnimUtils.TransitionEndListener endListener = new AnimUtils.TransitionEndListener() {
+                @Override
+                public void onTransitionCompleted(Transition transition) {
+                    fabParent.removeView(dialogBackground);
+                    dialogBackground = null;
+                }
+            };
+            if (transition != null) {
+                transition.addListener(endListener);
+            } else {
+                endListener.onTransitionCompleted(null);
+            }
+        }
+    }
+
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/FlipChangeHandler.java

@@ -32,8 +32,8 @@ public class FlipChangeHandler extends AnimatorChangeHandler {
         }
     }
 
-    private final long mAnimationDuration;
-    private final FlipDirection mFlipDirection;
+    private final long animationDuration;
+    private final FlipDirection flipDirection;
 
     public FlipChangeHandler() {
         this(FlipDirection.RIGHT);
@@ -48,33 +48,33 @@ public class FlipChangeHandler extends AnimatorChangeHandler {
     }
 
     public FlipChangeHandler(FlipDirection flipDirection, long animationDuration) {
-        mFlipDirection = flipDirection;
-        mAnimationDuration = animationDuration;
+        this.flipDirection = flipDirection;
+        this.animationDuration = animationDuration;
     }
 
-    @Override
+    @Override @NonNull
     protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
         AnimatorSet animatorSet = new AnimatorSet();
 
         if (to != null) {
             to.setAlpha(0);
 
-            ObjectAnimator rotation = ObjectAnimator.ofFloat(to, mFlipDirection.property, mFlipDirection.inStartRotation, 0).setDuration(mAnimationDuration);
+            ObjectAnimator rotation = ObjectAnimator.ofFloat(to, flipDirection.property, flipDirection.inStartRotation, 0).setDuration(animationDuration);
             rotation.setInterpolator(new AccelerateDecelerateInterpolator());
             animatorSet.play(rotation);
 
-            Animator alpha = ObjectAnimator.ofFloat(to, View.ALPHA, 1).setDuration(mAnimationDuration / 2);
-            alpha.setStartDelay(mAnimationDuration / 3);
+            Animator alpha = ObjectAnimator.ofFloat(to, View.ALPHA, 1).setDuration(animationDuration / 2);
+            alpha.setStartDelay(animationDuration / 3);
             animatorSet.play(alpha);
         }
 
         if (from != null) {
-            ObjectAnimator rotation = ObjectAnimator.ofFloat(from, mFlipDirection.property, 0, mFlipDirection.outEndRotation).setDuration(mAnimationDuration);
+            ObjectAnimator rotation = ObjectAnimator.ofFloat(from, flipDirection.property, 0, flipDirection.outEndRotation).setDuration(animationDuration);
             rotation.setInterpolator(new AccelerateDecelerateInterpolator());
             animatorSet.play(rotation);
 
-            Animator alpha = ObjectAnimator.ofFloat(from, View.ALPHA, 0).setDuration(mAnimationDuration / 2);
-            alpha.setStartDelay(mAnimationDuration / 3);
+            Animator alpha = ObjectAnimator.ofFloat(from, View.ALPHA, 0).setDuration(animationDuration / 2);
+            alpha.setStartDelay(animationDuration / 3);
             animatorSet.play(alpha);
         }
 
@@ -85,7 +85,7 @@ public class FlipChangeHandler extends AnimatorChangeHandler {
     protected void resetFromView(@NonNull View from) {
         from.setAlpha(1);
 
-        switch (mFlipDirection) {
+        switch (flipDirection) {
             case LEFT:
             case RIGHT:
                 from.setRotationY(0);

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/ScaleFadeChangeHandler.java

@@ -15,11 +15,12 @@ public class ScaleFadeChangeHandler extends AnimatorChangeHandler {
         super(DEFAULT_ANIMATION_DURATION, true);
     }
 
-    @Override
+    @Override @NonNull
     protected Animator getAnimator(@NonNull ViewGroup container, View from, View to, boolean isPush, boolean toAddedToContainer) {
         AnimatorSet animator = new AnimatorSet();
-        if (to != null && toAddedToContainer) {
-            animator.play(ObjectAnimator.ofFloat(to, View.ALPHA, 0, 1));
+        if (to != null) {
+            float start = toAddedToContainer ? 0 : to.getAlpha();
+            animator.play(ObjectAnimator.ofFloat(to, View.ALPHA, start, 1));
         }
 
         if (from != null) {

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/SharedElementDelayingChangeHandler.java

@@ -0,0 +1,163 @@
+package com.bluelinelabs.conductor.demo.changehandler;
+
+import android.annotation.TargetApi;
+import android.os.Build;
+import android.os.Bundle;
+import android.support.annotation.NonNull;
+import android.support.annotation.Nullable;
+import android.transition.Transition;
+import android.view.View;
+import android.view.ViewGroup;
+import android.view.ViewTreeObserver.OnPreDrawListener;
+
+import com.bluelinelabs.conductor.Controller;
+import com.bluelinelabs.conductor.ControllerChangeHandler;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * A TransitionChangeHandler that will wait for views with the passed transition names to be fully laid out
+ * before executing. An OnPreDrawListener will be added to the "to" view, then to all of its subviews that
+ * match the transaction names we're interested in. Once all of the views are fully ready, the "to" view
+ * is set to invisible so that it'll fade in nicely, and the views that we want to use as shared elements
+ * are removed from their containers, then immediately re-added within the beginDelayedTransition call so
+ * the system picks them up as shared elements.
+ */
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+public class SharedElementDelayingChangeHandler extends ArcFadeMoveChangeHandler {
+
+    private static final String KEY_WAIT_FOR_TRANSITION_NAMES = "SharedElementDelayingChangeHandler.waitForTransitionNames";
+
+    private final ArrayList<String> waitForTransitionNames;
+    private final ArrayList<ViewParentPair> removedViews = new ArrayList<>();
+    private OnPreDrawListener onPreDrawListener;
+
+    public SharedElementDelayingChangeHandler() {
+        waitForTransitionNames = new ArrayList<>();
+    }
+
+    public SharedElementDelayingChangeHandler(@NonNull List<String> waitForTransitionNames) {
+        this.waitForTransitionNames = new ArrayList<>(waitForTransitionNames);
+    }
+
+    @Override
+    public void prepareForTransition(@NonNull final ViewGroup container, @Nullable View from, @Nullable final View to, @NonNull Transition transition, boolean isPush, @NonNull final OnTransitionPreparedListener onTransitionPreparedListener) {
+        if (to != null && to.getParent() == null && waitForTransitionNames.size() > 0) {
+            onPreDrawListener = new OnPreDrawListener() {
+                boolean addedSubviewListeners;
+
+                @Override
+                public boolean onPreDraw() {
+                    List<View> foundViews = new ArrayList<>();
+                    for (String transitionName : waitForTransitionNames) {
+                        foundViews.add(getViewWithTransitionName(to, transitionName));
+                    }
+
+                    if (!foundViews.contains(null) && !addedSubviewListeners) {
+                        addedSubviewListeners = true;
+
+                        for (final View view : foundViews) {
+                            view.getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
+                                @Override
+                                public boolean onPreDraw() {
+                                    view.getViewTreeObserver().removeOnPreDrawListener(this);
+                                    waitForTransitionNames.remove(view.getTransitionName());
+
+                                    ViewGroup parent = (ViewGroup)view.getParent();
+                                    removedViews.add(new ViewParentPair(view, parent));
+                                    parent.removeView(view);
+
+                                    if (waitForTransitionNames.size() == 0) {
+                                        to.getViewTreeObserver().removeOnPreDrawListener(onPreDrawListener);
+
+                                        to.setVisibility(View.INVISIBLE);
+
+                                        onTransitionPreparedListener.onPrepared();
+                                    }
+                                    return true;
+                                }
+                            });
+                        }
+                    }
+
+
+                    return false;
+                }
+            };
+
+            to.getViewTreeObserver().addOnPreDrawListener(onPreDrawListener);
+
+            container.addView(to);
+        } else {
+            onTransitionPreparedListener.onPrepared();
+        }
+    }
+
+    @Override
+    public void executePropertyChanges(@NonNull ViewGroup container, @Nullable View from, @Nullable View to, @Nullable Transition transition, boolean isPush) {
+        if (to != null) {
+            to.setVisibility(View.VISIBLE);
+
+            for (ViewParentPair removedView : removedViews) {
+                removedView.parent.addView(removedView.view);
+            }
+
+            removedViews.clear();
+        }
+
+        super.executePropertyChanges(container, from, to, transition, isPush);
+    }
+
+    @Override
+    public void saveToBundle(@NonNull Bundle bundle) {
+        bundle.putStringArrayList(KEY_WAIT_FOR_TRANSITION_NAMES, waitForTransitionNames);
+    }
+
+    @Override
+    public void restoreFromBundle(@NonNull Bundle bundle) {
+        List<String> savedNames = bundle.getStringArrayList(KEY_WAIT_FOR_TRANSITION_NAMES);
+        if (savedNames != null) {
+            waitForTransitionNames.addAll(savedNames);
+        }
+    }
+
+    @Override
+    public void onAbortPush(@NonNull ControllerChangeHandler newHandler, @Nullable Controller newTop) {
+        super.onAbortPush(newHandler, newTop);
+
+        removedViews.clear();
+    }
+
+    @Nullable
+    View getViewWithTransitionName(@NonNull View view, @NonNull String transitionName) {
+        if (transitionName.equals(view.getTransitionName())) {
+            return view;
+        }
+
+        if (view instanceof ViewGroup) {
+            ViewGroup viewGroup = (ViewGroup)view;
+            int childCount = viewGroup.getChildCount();
+
+            for (int i = 0; i < childCount; i++) {
+                View viewWithTransitionName = getViewWithTransitionName(viewGroup.getChildAt(i), transitionName);
+                if (viewWithTransitionName != null) {
+                    return viewWithTransitionName;
+                }
+            }
+        }
+
+        return null;
+    }
+
+    private static class ViewParentPair {
+        View view;
+        ViewGroup parent;
+
+        public ViewParentPair(View view, ViewGroup parent) {
+            this.view = view;
+            this.parent = parent;
+        }
+    }
+
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/transitions/FabTransform.java

@@ -0,0 +1,295 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+/**
+ * Example from https://github.com/nickbutcher/plaid
+ */
+package com.bluelinelabs.conductor.demo.changehandler.transitions;
+
+import android.animation.Animator;
+import android.animation.AnimatorListenerAdapter;
+import android.animation.AnimatorSet;
+import android.animation.ObjectAnimator;
+import android.annotation.TargetApi;
+import android.graphics.Bitmap;
+import android.graphics.Outline;
+import android.graphics.Rect;
+import android.graphics.drawable.BitmapDrawable;
+import android.graphics.drawable.ColorDrawable;
+import android.graphics.drawable.Drawable;
+import android.os.Build;
+import android.support.annotation.ColorInt;
+import android.support.annotation.DrawableRes;
+import android.support.v4.content.ContextCompat;
+import android.transition.Transition;
+import android.transition.TransitionValues;
+import android.view.View;
+import android.view.ViewAnimationUtils;
+import android.view.ViewGroup;
+import android.view.ViewOutlineProvider;
+import android.view.ViewTreeObserver.OnPreDrawListener;
+import android.view.animation.Interpolator;
+
+import com.bluelinelabs.conductor.demo.util.AnimUtils;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import static android.view.View.MeasureSpec.makeMeasureSpec;
+
+/**
+ * A transition between a FAB & another surface using a circular reveal moving along an arc.
+ * <p>
+ * See: https://www.google.com/design/spec/motion/transforming-material.html#transforming-material-radial-transformation
+ */
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+public class FabTransform extends Transition {
+
+    private static final long DEFAULT_DURATION = 240L;
+    private static final String PROP_BOUNDS = "plaid:fabTransform:bounds";
+    private static final String[] TRANSITION_PROPERTIES = {
+            PROP_BOUNDS
+    };
+
+    private final int color;
+    private final int icon;
+
+    public FabTransform(@ColorInt int fabColor, @DrawableRes int fabIconResId) {
+        color = fabColor;
+        icon = fabIconResId;
+        setPathMotion(new GravityArcMotion());
+        setDuration(DEFAULT_DURATION);
+    }
+
+    @Override
+    public String[] getTransitionProperties() {
+        return TRANSITION_PROPERTIES;
+    }
+
+    @Override
+    public void captureStartValues(TransitionValues transitionValues) {
+        captureValues(transitionValues);
+    }
+
+    @Override
+    public void captureEndValues(TransitionValues transitionValues) {
+        captureValues(transitionValues);
+    }
+
+    @Override
+    public Animator createAnimator(final ViewGroup sceneRoot,
+                                   final TransitionValues startValues,
+                                   final TransitionValues endValues) {
+        if (startValues == null || endValues == null)  return null;
+
+        final Rect startBounds = (Rect) startValues.values.get(PROP_BOUNDS);
+        final Rect endBounds = (Rect) endValues.values.get(PROP_BOUNDS);
+
+        final boolean fromFab = endBounds.width() > startBounds.width();
+        final View view = endValues.view;
+        final Rect dialogBounds = fromFab ? endBounds : startBounds;
+        final Interpolator fastOutSlowInInterpolator =
+                AnimUtils.getFastOutSlowInInterpolator();
+        final long duration = getDuration();
+        final long halfDuration = duration / 2;
+        final long twoThirdsDuration = duration * 2 / 3;
+
+        if (!fromFab) {
+            // Force measure / layout the dialog back to it's original bounds
+            view.measure(
+                    makeMeasureSpec(startBounds.width(), View.MeasureSpec.EXACTLY),
+                    makeMeasureSpec(startBounds.height(), View.MeasureSpec.EXACTLY));
+            view.layout(startBounds.left, startBounds.top, startBounds.right, startBounds.bottom);
+        }
+
+        final int translationX = startBounds.centerX() - endBounds.centerX();
+        final int translationY = startBounds.centerY() - endBounds.centerY();
+        if (fromFab) {
+            view.setTranslationX(translationX);
+            view.setTranslationY(translationY);
+        }
+
+        // Add a color overlay to fake appearance of the FAB
+        final ColorDrawable fabColor = new ColorDrawable(color);
+        fabColor.setBounds(0, 0, dialogBounds.width(), dialogBounds.height());
+        if (!fromFab) fabColor.setAlpha(0);
+        view.getOverlay().add(fabColor);
+
+        // Add an icon overlay again to fake the appearance of the FAB
+        final Drawable fabIcon =
+                ContextCompat.getDrawable(sceneRoot.getContext(), icon).mutate();
+        final int iconLeft = (dialogBounds.width() - fabIcon.getIntrinsicWidth()) / 2;
+        final int iconTop = (dialogBounds.height() - fabIcon.getIntrinsicHeight()) / 2;
+        fabIcon.setBounds(iconLeft, iconTop,
+                iconLeft + fabIcon.getIntrinsicWidth(),
+                iconTop + fabIcon.getIntrinsicHeight());
+        if (!fromFab) fabIcon.setAlpha(0);
+        view.getOverlay().add(fabIcon);
+
+        // Since the view that's being transition to always seems to be on the top (z-order), we have
+        // to make a copy of the "from" view and put it in the "to" view's overlay, then fade it out.
+        // There has to be another way to do this, right?
+        Drawable dialogView = null;
+        if (!fromFab) {
+            startValues.view.setDrawingCacheEnabled(true);
+            startValues.view.buildDrawingCache();
+            Bitmap viewBitmap = startValues.view.getDrawingCache();
+            dialogView = new BitmapDrawable(view.getResources(), viewBitmap);
+            dialogView.setBounds(0, 0, dialogBounds.width(), dialogBounds.height());
+            view.getOverlay().add(dialogView);
+        }
+
+        // Circular clip from/to the FAB size
+        final Animator circularReveal;
+        if (fromFab) {
+            circularReveal = ViewAnimationUtils.createCircularReveal(view,
+                    view.getWidth() / 2,
+                    view.getHeight() / 2,
+                    startBounds.width() / 2,
+                    (float) Math.hypot(endBounds.width() / 2, endBounds.height() / 2));
+            circularReveal.setInterpolator(
+                    AnimUtils.getFastOutLinearInInterpolator());
+        } else {
+            circularReveal = ViewAnimationUtils.createCircularReveal(view,
+                    view.getWidth() / 2,
+                    view.getHeight() / 2,
+                    (float) Math.hypot(startBounds.width() / 2, startBounds.height() / 2),
+                    endBounds.width() / 2);
+            circularReveal.setInterpolator(
+                    AnimUtils.getLinearOutSlowInInterpolator());
+
+            // Persist the end clip i.e. stay at FAB size after the reveal has run
+            circularReveal.addListener(new AnimatorListenerAdapter() {
+                @Override
+                public void onAnimationEnd(Animator animation) {
+                    final ViewOutlineProvider fabOutlineProvider = view.getOutlineProvider();
+
+                    view.setOutlineProvider(new ViewOutlineProvider() {
+                        boolean hasRun = false;
+
+                        @Override
+                        public void getOutline(final View view, Outline outline) {
+                            final int left = (view.getWidth() - endBounds.width()) / 2;
+                            final int top = (view.getHeight() - endBounds.height()) / 2;
+
+                            outline.setOval(
+                                    left, top, left + endBounds.width(), top + endBounds.height());
+
+                            if (!hasRun) {
+                                hasRun = true;
+                                view.setClipToOutline(true);
+
+                                // We have to remove this as soon as it's laid out so we can get the shadow back
+                                view.getViewTreeObserver().addOnPreDrawListener(new OnPreDrawListener() {
+                                    @Override
+                                    public boolean onPreDraw() {
+                                        if (view.getWidth() == endBounds.width() && view.getHeight() == endBounds.height()) {
+                                            view.setOutlineProvider(fabOutlineProvider);
+                                            view.setClipToOutline(false);
+                                            view.getViewTreeObserver().removeOnPreDrawListener(this);
+                                            return true;
+                                        }
+
+                                        return true;
+                                    }
+                                });
+                            }
+                        }
+                    });
+                }
+            });
+        }
+        circularReveal.setDuration(duration);
+
+        // Translate to end position along an arc
+        final Animator translate = ObjectAnimator.ofFloat(
+                view,
+                View.TRANSLATION_X,
+                View.TRANSLATION_Y,
+                fromFab ? getPathMotion().getPath(translationX, translationY, 0, 0)
+                        : getPathMotion().getPath(0, 0, -translationX, -translationY));
+        translate.setDuration(duration);
+        translate.setInterpolator(fastOutSlowInInterpolator);
+
+        // Fade contents of non-FAB view in/out
+        List<Animator> fadeContents = null;
+        if (view instanceof ViewGroup) {
+            final ViewGroup vg = ((ViewGroup) view);
+            fadeContents = new ArrayList<>(vg.getChildCount());
+            for (int i = vg.getChildCount() - 1; i >= 0; i--) {
+                final View child = vg.getChildAt(i);
+                final Animator fade =
+                        ObjectAnimator.ofFloat(child, View.ALPHA, fromFab ? 1f : 0f);
+                if (fromFab) {
+                    child.setAlpha(0f);
+                }
+                fade.setDuration(twoThirdsDuration);
+                fade.setInterpolator(fastOutSlowInInterpolator);
+                fadeContents.add(fade);
+            }
+        }
+
+        // Fade in/out the fab color & icon overlays
+        final Animator colorFade = ObjectAnimator.ofInt(fabColor, "alpha", fromFab ? 0 : 255);
+        final Animator iconFade = ObjectAnimator.ofInt(fabIcon, "alpha", fromFab ? 0 : 255);
+        if (!fromFab) {
+            colorFade.setStartDelay(halfDuration);
+            iconFade.setStartDelay(halfDuration);
+        }
+        colorFade.setDuration(halfDuration);
+        iconFade.setDuration(halfDuration);
+        colorFade.setInterpolator(fastOutSlowInInterpolator);
+        iconFade.setInterpolator(fastOutSlowInInterpolator);
+
+        // Run all animations together
+        final AnimatorSet transition = new AnimatorSet();
+        transition.playTogether(circularReveal, translate, colorFade, iconFade);
+        transition.playTogether(fadeContents);
+        if (dialogView != null) {
+            final Animator dialogViewFade = ObjectAnimator.ofInt(dialogView, "alpha", 0).setDuration(twoThirdsDuration);
+            dialogViewFade.setInterpolator(fastOutSlowInInterpolator);
+            transition.playTogether(dialogViewFade);
+        }
+        transition.addListener(new AnimatorListenerAdapter() {
+            @Override
+            public void onAnimationEnd(Animator animation) {
+                // Clean up
+                view.getOverlay().clear();
+
+                if (!fromFab) {
+                    view.setTranslationX(0);
+                    view.setTranslationY(0);
+                    view.setTranslationZ(0);
+
+                    view.measure(
+                            makeMeasureSpec(endBounds.width(), View.MeasureSpec.EXACTLY),
+                            makeMeasureSpec(endBounds.height(), View.MeasureSpec.EXACTLY));
+                    view.layout(endBounds.left, endBounds.top, endBounds.right, endBounds.bottom);
+                }
+
+            }
+        });
+        return new AnimUtils.NoPauseAnimator(transition);
+    }
+
+    private void captureValues(TransitionValues transitionValues) {
+        final View view = transitionValues.view;
+        if (view == null || view.getWidth() <= 0 || view.getHeight() <= 0) return;
+
+        transitionValues.values.put(PROP_BOUNDS, new Rect(view.getLeft(), view.getTop(),
+                view.getRight(), view.getBottom()));
+    }
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/changehandler/transitions/GravityArcMotion.java

@@ -0,0 +1,217 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package com.bluelinelabs.conductor.demo.changehandler.transitions;
+
+import android.annotation.TargetApi;
+import android.content.Context;
+import android.graphics.Path;
+import android.os.Build;
+import android.transition.ArcMotion;
+import android.util.AttributeSet;
+
+/**
+ * A tweak to {@link ArcMotion} which slightly alters the path calculation. In the real world
+ * gravity slows upward motion and accelerates downward motion. This class emulates this behavior
+ * to make motion paths appear more natural.
+ * <p>
+ * See https://www.google.com/design/spec/motion/movement.html#movement-movement-within-screen-bounds
+ */
+@TargetApi(Build.VERSION_CODES.LOLLIPOP)
+public class GravityArcMotion extends ArcMotion {
+
+    private static final float DEFAULT_MIN_ANGLE_DEGREES = 0;
+    private static final float DEFAULT_MAX_ANGLE_DEGREES = 70;
+    private static final float DEFAULT_MAX_TANGENT = (float)
+            Math.tan(Math.toRadians(DEFAULT_MAX_ANGLE_DEGREES/2));
+
+    private float mMinimumHorizontalAngle = 0;
+    private float mMinimumVerticalAngle = 0;
+    private float mMaximumAngle = DEFAULT_MAX_ANGLE_DEGREES;
+    private float mMinimumHorizontalTangent = 0;
+    private float mMinimumVerticalTangent = 0;
+    private float mMaximumTangent = DEFAULT_MAX_TANGENT;
+
+    public GravityArcMotion() {}
+
+    public GravityArcMotion(Context context, AttributeSet attrs) {
+        super(context, attrs);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public void setMinimumHorizontalAngle(float angleInDegrees) {
+        mMinimumHorizontalAngle = angleInDegrees;
+        mMinimumHorizontalTangent = toTangent(angleInDegrees);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public float getMinimumHorizontalAngle() {
+        return mMinimumHorizontalAngle;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public void setMinimumVerticalAngle(float angleInDegrees) {
+        mMinimumVerticalAngle = angleInDegrees;
+        mMinimumVerticalTangent = toTangent(angleInDegrees);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public float getMinimumVerticalAngle() {
+        return mMinimumVerticalAngle;
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public void setMaximumAngle(float angleInDegrees) {
+        mMaximumAngle = angleInDegrees;
+        mMaximumTangent = toTangent(angleInDegrees);
+    }
+
+    /**
+     * @inheritDoc
+     */
+    @Override
+    public float getMaximumAngle() {
+        return mMaximumAngle;
+    }
+
+    private static float toTangent(float arcInDegrees) {
+        if (arcInDegrees < 0 || arcInDegrees > 90) {
+            throw new IllegalArgumentException("Arc must be between 0 and 90 degrees");
+        }
+        return (float) Math.tan(Math.toRadians(arcInDegrees / 2));
+    }
+
+    @Override
+    public Path getPath(float startX, float startY, float endX, float endY) {
+        // Here's a little ascii art to show how this is calculated:
+        // c---------- b
+        //  \        / |
+        //    \     d  |
+        //      \  /   e
+        //        a----f
+        // This diagram assumes that the horizontal distance is less than the vertical
+        // distance between The start point (a) and end point (b).
+        // d is the midpoint between a and b. c is the center point of the circle with
+        // This path is formed by assuming that start and end points are in
+        // an arc on a circle. The end point is centered in the circle vertically
+        // and start is a point on the circle.
+
+        // Triangles bfa and bde form similar right triangles. The control points
+        // for the cubic Bezier arc path are the midpoints between a and e and e and b.
+
+        Path path = new Path();
+        path.moveTo(startX, startY);
+
+        float ex;
+        float ey;
+        if (startY == endY) {
+            ex = (startX + endX) / 2;
+            ey = startY + mMinimumHorizontalTangent * Math.abs(endX - startX) / 2;
+        } else if (startX == endX) {
+            ex = startX + mMinimumVerticalTangent * Math.abs(endY - startY) / 2;
+            ey = (startY + endY) / 2;
+        } else {
+            float deltaX = endX - startX;
+
+            /**
+             * This is the only change to ArcMotion
+             */
+            float deltaY;
+            if (endY < startY) {
+                deltaY = startY - endY; // Y is inverted compared to diagram above.
+            } else {
+                deltaY = endY - startY;
+            }
+            /**
+             * End changes
+             */
+
+            // hypotenuse squared.
+            float h2 = deltaX * deltaX + deltaY * deltaY;
+
+            // Midpoint between start and end
+            float dx = (startX + endX) / 2;
+            float dy = (startY + endY) / 2;
+
+            // Distance squared between end point and mid point is (1/2 hypotenuse)^2
+            float midDist2 = h2 * 0.25f;
+
+            float minimumArcDist2 = 0;
+
+            if (Math.abs(deltaX) < Math.abs(deltaY)) {
+                // Similar triangles bfa and bde mean that (ab/fb = eb/bd)
+                // Therefore, eb = ab * bd / fb
+                // ab = hypotenuse
+                // bd = hypotenuse/2
+                // fb = deltaY
+                float eDistY = h2 / (2 * deltaY);
+                ey = endY + eDistY;
+                ex = endX;
+
+                minimumArcDist2 = midDist2 * mMinimumVerticalTangent
+                        * mMinimumVerticalTangent;
+            } else {
+                // Same as above, but flip X & Y
+                float eDistX = h2 / (2 * deltaX);
+                ex = endX + eDistX;
+                ey = endY;
+
+                minimumArcDist2 = midDist2 * mMinimumHorizontalTangent
+                        * mMinimumHorizontalTangent;
+            }
+            float arcDistX = dx - ex;
+            float arcDistY = dy - ey;
+            float arcDist2 = arcDistX * arcDistX + arcDistY * arcDistY;
+
+            float maximumArcDist2 = midDist2 * mMaximumTangent * mMaximumTangent;
+
+            float newArcDistance2 = 0;
+            if (arcDist2 < minimumArcDist2) {
+                newArcDistance2 = minimumArcDist2;
+            } else if (arcDist2 > maximumArcDist2) {
+                newArcDistance2 = maximumArcDist2;
+            }
+            if (newArcDistance2 != 0) {
+                float ratio2 = newArcDistance2 / arcDist2;
+                float ratio = (float) Math.sqrt(ratio2);
+                ex = dx + (ratio * (ex - dx));
+                ey = dy + (ratio * (ey - dy));
+            }
+        }
+        float controlX1 = (startX + ex) / 2;
+        float controlY1 = (startY + ey) / 2;
+        float controlX2 = (ex + endX) / 2;
+        float controlY2 = (ey + endY) / 2;
+        path.cubicTo(controlX1, controlY1, controlX2, controlY2, endX, endY);
+        return path;
+    }
+
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/controllers/ChildController.java

@@ -8,19 +8,19 @@ import android.view.View;
 import android.view.ViewGroup;
 import android.widget.TextView;
 
-import com.bluelinelabs.conductor.demo.util.BundleBuilder;
 import com.bluelinelabs.conductor.demo.R;
-import com.bluelinelabs.conductor.demo.controllers.base.RefWatchingController;
+import com.bluelinelabs.conductor.demo.controllers.base.BaseController;
+import com.bluelinelabs.conductor.demo.util.BundleBuilder;
 
-import butterknife.Bind;
+import butterknife.BindView;
 
-public class ChildController extends RefWatchingController {
+public class ChildController extends BaseController {
 
     private static final String KEY_TITLE = "ChildController.title";
     private static final String KEY_BG_COLOR = "ChildController.bgColor";
     private static final String KEY_COLOR_IS_RES = "ChildController.colorIsResId";
 
-    @Bind(R.id.tv_title) TextView mTvTitle;
+    @BindView(R.id.tv_title) TextView tvTitle;
 
     public ChildController(String title, int backgroundColor, boolean colorIsResId) {
         this(new BundleBuilder(new Bundle())
@@ -44,7 +44,7 @@ public class ChildController extends RefWatchingController {
     protected void onViewBound(@NonNull View view) {
         super.onViewBound(view);
 
-        mTvTitle.setText(getArgs().getString(KEY_TITLE));
+        tvTitle.setText(getArgs().getString(KEY_TITLE));
 
         int bgColor = getArgs().getInt(KEY_BG_COLOR);
         if (getArgs().getBoolean(KEY_COLOR_IS_RES)) {

demo/src/main/java/com/bluelinelabs/conductor/demo/controllers/CityDetailController.java

@@ -0,0 +1,169 @@
+package com.bluelinelabs.conductor.demo.controllers;
+
+import android.os.Build;
+import android.os.Bundle;
+import android.support.annotation.DrawableRes;
+import android.support.annotation.NonNull;
+import android.support.v7.widget.LinearLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import com.bluelinelabs.conductor.demo.R;
+import com.bluelinelabs.conductor.demo.controllers.base.BaseController;
+import com.bluelinelabs.conductor.demo.util.BundleBuilder;
+
+import butterknife.BindView;
+import butterknife.ButterKnife;
+
+public class CityDetailController extends BaseController {
+
+    private static final String KEY_TITLE = "CityDetailController.title";
+    private static final String KEY_IMAGE = "CityDetailController.image";
+
+    private static final String[] LIST_ROWS = new String[] {
+            "• This is a city.",
+            "• There's some cool stuff about it.",
+            "• But really this is just a demo, not a city guide app.",
+            "• This demo is meant to show some nice transitions, as long as you're on Lollipop or later.",
+            "• You should have seen some sweet shared element transitions using the ImageView and the TextView in the \"header\" above.",
+            "• This transition utilized some callbacks to ensure all the necessary rows in the RecyclerView were laid about before the transition occurred.",
+            "• Just adding some more lines so it scrolls now...\n\n\n\n\n\n\nThe end."
+    };
+
+    @BindView(R.id.recycler_view) RecyclerView recyclerView;
+
+    @DrawableRes private int imageDrawableRes;
+    private String title;
+
+    public CityDetailController(@DrawableRes int imageDrawableRes, String title) {
+        this(new BundleBuilder(new Bundle())
+                .putInt(KEY_IMAGE, imageDrawableRes)
+                .putString(KEY_TITLE, title)
+                .build());
+    }
+
+    public CityDetailController(Bundle args) {
+        super(args);
+        imageDrawableRes = getArgs().getInt(KEY_IMAGE);
+        title = getArgs().getString(KEY_TITLE);
+    }
+
+    @NonNull
+    @Override
+    protected View inflateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container) {
+        return inflater.inflate(R.layout.controller_city_detail, container, false);
+    }
+
+    @Override
+    protected void onViewBound(@NonNull View view) {
+        super.onViewBound(view);
+
+        recyclerView.setHasFixedSize(true);
+        recyclerView.setLayoutManager(new LinearLayoutManager(view.getContext()));
+        recyclerView.setAdapter(new CityDetailAdapter(LayoutInflater.from(view.getContext()), title, imageDrawableRes, LIST_ROWS, title));
+    }
+
+    @Override
+    protected String getTitle() {
+        return title;
+    }
+
+    static class CityDetailAdapter extends RecyclerView.Adapter<CityDetailAdapter.ViewHolder> {
+
+        private static final int VIEW_TYPE_HEADER = 0;
+        private static final int VIEW_TYPE_DETAIL = 1;
+
+        private final LayoutInflater inflater;
+        private final String title;
+        @DrawableRes private final int imageDrawableRes;
+        private final String imageViewTransitionName;
+        private final String textViewTransitionName;
+        private final String[] details;
+
+        public CityDetailAdapter(LayoutInflater inflater, @DrawableRes String title, int imageDrawableRes, String[] details, String transitionNameBase) {
+            this.inflater = inflater;
+            this.title = title;
+            this.imageDrawableRes = imageDrawableRes;
+            this.details = details;
+            imageViewTransitionName = inflater.getContext().getResources().getString(R.string.transition_tag_image_named, transitionNameBase);
+            textViewTransitionName = inflater.getContext().getResources().getString(R.string.transition_tag_title_named, transitionNameBase);
+        }
+
+        @Override
+        public int getItemViewType(int position) {
+            if (position == 0) {
+                return VIEW_TYPE_HEADER;
+            } else {
+                return VIEW_TYPE_DETAIL;
+            }
+        }
+
+        @Override
+        public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+            if (viewType == VIEW_TYPE_HEADER) {
+                return new HeaderViewHolder(inflater.inflate(R.layout.row_city_header, parent, false));
+            } else {
+                return new DetailViewHolder(inflater.inflate(R.layout.row_city_detail, parent, false));
+            }
+        }
+
+        @Override
+        public void onBindViewHolder(ViewHolder holder, int position) {
+            if (getItemViewType(position) == VIEW_TYPE_HEADER) {
+                ((HeaderViewHolder)holder).bind(imageDrawableRes, title, imageViewTransitionName, textViewTransitionName);
+            } else {
+                ((DetailViewHolder)holder).bind(details[position - 1]);
+            }
+        }
+
+        @Override
+        public int getItemCount() {
+            return 1 + details.length;
+        }
+
+        static class ViewHolder extends RecyclerView.ViewHolder {
+            ViewHolder(View itemView) {
+                super(itemView);
+                ButterKnife.bind(this, itemView);
+            }
+        }
+
+        static class HeaderViewHolder extends ViewHolder {
+
+            @BindView(R.id.image_view) ImageView imageView;
+            @BindView(R.id.text_view) TextView textView;
+
+            public HeaderViewHolder(View itemView) {
+                super(itemView);
+            }
+
+            void bind(@DrawableRes int imageDrawableRes, String title, String imageTransitionName, String textViewTransitionName) {
+                imageView.setImageResource(imageDrawableRes);
+                textView.setText(title);
+
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                    imageView.setTransitionName(imageTransitionName);
+                    textView.setTransitionName(textViewTransitionName);
+                }
+            }
+        }
+
+        static class DetailViewHolder extends ViewHolder {
+
+            @BindView(R.id.text_view) TextView textView;
+
+            public DetailViewHolder(View itemView) {
+                super(itemView);
+            }
+
+            void bind(String detail) {
+                textView.setText(detail);
+            }
+
+        }
+    }
+}

demo/src/main/java/com/bluelinelabs/conductor/demo/controllers/CityGridController.java

@@ -0,0 +1,174 @@
+package com.bluelinelabs.conductor.demo.controllers;
+
+import android.graphics.PorterDuff.Mode;
+import android.os.Build;
+import android.os.Bundle;
+import android.support.annotation.DrawableRes;
+import android.support.annotation.NonNull;
+import android.support.v4.content.ContextCompat;
+import android.support.v7.widget.GridLayoutManager;
+import android.support.v7.widget.RecyclerView;
+import android.view.LayoutInflater;
+import android.view.View;
+import android.view.ViewGroup;
+import android.widget.ImageView;
+import android.widget.TextView;
+
+import com.bluelinelabs.conductor.RouterTransaction;
+import com.bluelinelabs.conductor.changehandler.FadeChangeHandler;
+import com.bluelinelabs.conductor.changehandler.TransitionChangeHandlerCompat;
+import com.bluelinelabs.conductor.demo.R;
+import com.bluelinelabs.conductor.demo.changehandler.SharedElementDelayingChangeHandler;
+import com.bluelinelabs.conductor.demo.controllers.base.BaseController;
+import com.bluelinelabs.conductor.demo.util.BundleBuilder;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import butterknife.BindView;
+import butterknife.ButterKnife;
+import butterknife.OnClick;
+
+public class CityGridController extends BaseController {
+
+    private static final String KEY_TITLE = "CityGridController.title";
+    private static final String KEY_DOT_COLOR = "CityGridController.dotColor";
+    private static final String KEY_FROM_POSITION = "CityGridController.position";
+
+    private static final CityModel[] CITY_MODELS = new CityModel[] {
+            new CityModel(R.drawable.chicago, "Chicago"),
+            new CityModel(R.drawable.jakarta, "Jakarta"),
+            new CityModel(R.drawable.london, "London"),
+            new CityModel(R.drawable.sao_paulo, "Sao Paulo"),
+            new CityModel(R.drawable.tokyo, "Tokyo")
+    };
+
+    @BindView(R.id.tv_title) TextView tvTitle;
+    @BindView(R.id.img_dot) ImageView imgDot;
+    @BindView(R.id.recycler_view) RecyclerView recyclerView;
+
+    private String title;
+    private int dotColor;
+    private int fromPosition;
+
+    public CityGridController(String title, int dotColor, int fromPosition) {
+        this(new BundleBuilder(new Bundle())
+                .putString(KEY_TITLE, title)
+                .putInt(KEY_DOT_COLOR, dotColor)
+                .putInt(KEY_FROM_POSITION, fromPosition)
+                .build());
+    }
+
+    public CityGridController(Bundle args) {
+        super(args);
+        title = getArgs().getString(KEY_TITLE);
+        dotColor = getArgs().getInt(KEY_DOT_COLOR);
+        fromPosition = getArgs().getInt(KEY_FROM_POSITION);
+    }
+
+    @NonNull
+    @Override
+    protected View inflateView(@NonNull LayoutInflater inflater, @NonNull ViewGroup container) {
+        return inflater.inflate(R.layout.controller_city_grid, container, false);
+    }
+
+    @Override
+    protected void onViewBound(@NonNull View view) {
+        super.onViewBound(view);
+
+        tvTitle.setText(title);
+        imgDot.getDrawable().setColorFilter(ContextCompat.getColor(getActivity(), dotColor), Mode.SRC_ATOP);
+
+        if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+            tvTitle.setTransitionName(getResources().getString(R.string.transition_tag_title_indexed, fromPosition));
+            imgDot.setTransitionName(getResources().getString(R.string.transition_tag_dot_indexed, fromPosition));
+        }
+
+        recyclerView.setHasFixedSize(true);
+        recyclerView.setLayoutManager(new GridLayoutManager(view.getContext(), 2));
+        recyclerView.setAdapter(new CityGridAdapter(LayoutInflater.from(view.getContext()), CITY_MODELS));
+    }
+
+    @Override
+    protected String getTitle() {
+        return "Shared Element Demos";
+    }
+
+    void onModelRowClick(CityModel model) {
+        String imageTransitionName = getResources().getString(R.string.transition_tag_image_named, model.title);
+        String titleTransitionName = getResources().getString(R.string.transition_tag_title_named, model.title);
+
+        List<String> names = new ArrayList<>();
+        names.add(imageTransitionName);
+        names.add(titleTransitionName);
+
+        getRouter().pushController(RouterTransaction.with(new CityDetailController(model.drawableRes, model.title))
+                .pushChangeHandler(new TransitionChangeHandlerCompat(new SharedElementDelayingChangeHandler(names), new FadeChangeHandler()))
+                .popChangeHandler(new TransitionChangeHandlerCompat(new SharedElementDelayingChangeHandler(names), new FadeChangeHandler())));
+    }
+
+    class CityGridAdapter extends RecyclerView.Adapter<CityGridAdapter.ViewHolder> {
+
+        private final LayoutInflater inflater;
+        private final CityModel[] items;
+
+        public CityGridAdapter(LayoutInflater inflater, CityModel[] items) {
+            this.inflater = inflater;
+            this.items = items;
+        }
+
+        @Override
+        public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
+            return new ViewHolder(inflater.inflate(R.layout.row_city_grid, parent, false));
+        }
+
+        @Override
+        public void onBindViewHolder(ViewHolder holder, int position) {
+            holder.bind(items[position]);
+        }
+
+        @Override
+        public int getItemCount() {
+            return items.length;
+        }
+
+        class ViewHolder extends RecyclerView.ViewHolder {
+
+            @BindView(R.id.tv_title) TextView textView;
+            @BindView(R.id.img_city) ImageView imageView;
+            private CityModel model;
+
+            public ViewHolder(View itemView) {
+                super(itemView);
+                ButterKnife.bind(this, itemView);
+            }
+
+            void bind(CityModel item) {
+                model = item;
+                imageView.setImageResource(item.drawableRes);
+                textView.setText(item.title);
+
+                if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.LOLLIPOP) {
+                    textView.setTransitionName(getResources().getString(R.string.transition_tag_title_named, model.title));
+                    imageView.setTransitionName(getResources().getString(R.string.transition_tag_image_named, model.title));
+                }
+            }
+
+            @OnClick(R.id.row_root)
+            void onRowClick() {
+                onModelRowClick(model);
+            }
+
+        }
+    }
+
+    private static class CityModel {
+        @DrawableRes int drawableRes;
+        String title;
+
+        public CityModel(@DrawableRes int drawableRes, String title) {
+            this.drawableRes = drawableRes;
+            this.title = title;
+        }
+    }
+}