Version bump

Great catch, thanks!

.github/workflows/main.yml

@@ -31,8 +31,8 @@ jobs:
         java-version: '11'
     - name: Grant execute permission for gradlew
       run: chmod +x gradlew
-    - name: Test with Gradle
-      run: ./gradlew clean uploadArchives
+    - name: Release with Gradle
+      run: ./gradlew clean publishAllPublicationsToMavenCentral
       env:
-        ORG_GRADLE_PROJECT_SONATYPE_NEXUS_USERNAME: ${{ secrets.SONATYPE_NEXUS_USERNAME }}
-        ORG_GRADLE_PROJECT_SONATYPE_NEXUS_PASSWORD: ${{ secrets.SONATYPE_NEXUS_PASSWORD }}
+        ORG_GRADLE_PROJECT_mavenCentralUsername: ${{ secrets.SONATYPE_NEXUS_USERNAME }}
+        ORG_GRADLE_PROJECT_mavenCentralPassword: ${{ secrets.SONATYPE_NEXUS_PASSWORD }}

.gitignore

@@ -8,7 +8,9 @@
 *.iml
 *.ipr
 *.iws
-*.idea/dictionaries
+/.idea/*
+!/.idea/codeStyles/
+!/.idea/scopes/
 classes
 gen-external-apklibs
 

README.md

@@ -1,4 +1,4 @@
-[![Travis Build](https://travis-ci.com/bluelinelabs/Conductor.svg)](https://travis-ci.com/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)
+[![GitHub Actions Workflow](https://github.com/bluelinelabs/conductor/actions/workflows/main.yml/badge.svg)](https://github.com/bluelinelabs/conductor/actions/workflows/main.yml) [![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
 
@@ -20,27 +20,29 @@ Conductor is architecture-agnostic and does not try to force any design decision
 ## Installation
 
 ```gradle
-implementation 'com.bluelinelabs:conductor:3.1.5'
+def conductorVersion = '3.2.0'
+
+implementation "com.bluelinelabs:conductor:$conductorVersion"
 
 // AndroidX Transition change handlers:
-implementation 'com.bluelinelabs:conductor-androidx-transition:3.1.5'
+implementation "com.bluelinelabs:conductor-androidx-transition:$conductorVersion"
 
 // ViewPager PagerAdapter:
-implementation 'com.bluelinelabs:conductor-viewpager:3.1.5'
+implementation "com.bluelinelabs:conductor-viewpager:$conductorVersion"
 
 // ViewPager2 Adapter:
-implementation 'com.bluelinelabs:conductor-viewpager2:3.1.5'
+implementation "com.bluelinelabs:conductor-viewpager2:$conductorVersion"
 
 // RxJava2 Autodispose support:
-implementation 'com.bluelinelabs:conductor-autodispose:3.1.5'
+implementation "com.bluelinelabs:conductor-autodispose:$conductorVersion"
 
 // Lifecycle-aware Controllers (architecture components):
-implementation 'com.bluelinelabs:conductor-archlifecycle:3.1.5'
+implementation "com.bluelinelabs:conductor-archlifecycle:$conductorVersion"
 ```
 
 **SNAPSHOT**
 
-Just use `3.1.6-SNAPSHOT` as your version number in any of the dependencies above and add the url to the snapshot repository:
+Just use `3.2.1-SNAPSHOT` as your version number in any of the dependencies above and add the url to the snapshot repository:
 
 ```gradle
 allprojects {

build.gradle

@@ -1,15 +1,12 @@
 buildscript {
-    apply from: rootProject.file('dependencies.gradle')
-
     repositories {
         mavenCentral()
         google()
     }
     dependencies {
-        classpath "com.android.tools.build:gradle:$agpVersion"
-        classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlinVersion"
-        classpath "com.vanniktech:gradle-maven-publish-plugin:$mvnPublishVersion"
-        classpath "org.jetbrains.dokka:dokka-gradle-plugin:$dokkaVersion"
+        classpath libs.agp
+        classpath libs.kotlin.plugin
+        classpath libs.dokka
     }
 }
 
@@ -18,6 +15,20 @@ allprojects {
         mavenCentral()
         google()
     }
-}
 
-apply from: rootProject.file('dependencies.gradle')
+    if (project.hasProperty('maven_publish_url')) {
+        pluginManager.withPlugin("com.vanniktech.maven.publish") {
+            publishing {
+                repositories {
+                    maven {
+                        url = maven_publish_url
+                        credentials {
+                            username = maven_publish_username
+                            password = maven_publish_password
+                        }
+                    }
+                }
+            }
+        }
+    }
+}

conductor-lint/build.gradle

@@ -1,17 +1,17 @@
 apply plugin: 'kotlin'
 
 configurations {
-    lintChecks
+    libs.lint.checks
 }
 
 dependencies {
-    compileOnly rootProject.ext.lintapi
-    compileOnly rootProject.ext.lintchecks
-    compileOnly rootProject.ext.kotlinStd
+    compileOnly libs.lint.api
+    compileOnly libs.lint.checks
+    compileOnly libs.kotlin.stdlib
 
-    testImplementation rootProject.ext.junit
-    testImplementation rootProject.ext.lint
-    testImplementation rootProject.ext.lintTests
+    testImplementation libs.junit
+    testImplementation libs.lint
+    testImplementation libs.lint.tests
 }
 
 jar {
@@ -19,5 +19,3 @@ jar {
         attributes('Lint-Registry-v2': 'com.bluelinelabs.conductor.lint.IssueRegistry')
     }
 }
-
-apply from: rootProject.file('dependencies.gradle')

conductor-modules/androidx-transition/build.gradle

@@ -1,24 +1,24 @@
-apply plugin: 'com.android.library'
+plugins {
+    id("com.android.library")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion libs.versions.compilesdk.get() as Integer
 
     defaultConfig {
-        minSdkVersion rootProject.ext.minSdkVersion
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        minSdkVersion libs.versions.minsdk.get()
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
 }
 
 dependencies {
-    implementation rootProject.ext.androidxAppCompat
-    implementation rootProject.ext.androidxCollection
-    api rootProject.ext.androidxTransition
+    implementation libs.androidx.appcompat
+    implementation libs.androidx.collection
+    api libs.androidx.transition
     implementation project(':conductor')
 }
 
 ext.artifactId = 'conductor-androidx-transition'
-
-apply from: rootProject.file('dependencies.gradle')
-apply plugin: "com.vanniktech.maven.publish"

conductor-modules/arch-components-lifecycle/build.gradle

@@ -1,23 +1,23 @@
-apply plugin: 'com.android.library'
+plugins {
+    id("com.android.library")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion libs.versions.compilesdk.get() as Integer
 
     defaultConfig {
-        minSdkVersion rootProject.ext.minSdkVersion
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        minSdkVersion libs.versions.minsdk.get()
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
 }
 
 dependencies {
-    api rootProject.ext.archComponentsLifecycle
+    api libs.androidx.lifecycle.runtime
 
     implementation project(':conductor')
 }
 
 ext.artifactId = 'conductor-arch-components-lifecycle'
-
-apply from: rootProject.file('dependencies.gradle')
-apply plugin: "com.vanniktech.maven.publish"

conductor-modules/arch-components-lifecycle/src/main/java/com/bluelinelabs/conductor/archlifecycle/ControllerLifecycleOwner.java

@@ -51,7 +51,10 @@ public class ControllerLifecycleOwner implements LifecycleOwner {
 
             @Override
             public void preDestroy(@NonNull Controller controller) {
-                lifecycleRegistry.handleLifecycleEvent(Event.ON_DESTROY); // --> State.DESTROYED;
+                // Only act on Controllers that have had at least the onContextAvailable call made on them.
+                if (lifecycleRegistry.getCurrentState() != Lifecycle.State.INITIALIZED) {
+                    lifecycleRegistry.handleLifecycleEvent(Event.ON_DESTROY); // --> State.DESTROYED;
+                }
             }
 
         });

conductor-modules/autodispose/build.gradle

@@ -1,23 +1,23 @@
-apply from: rootProject.file('dependencies.gradle')
-
-apply plugin: 'com.android.library'
-apply plugin: "com.vanniktech.maven.publish"
+plugins {
+    id("com.android.library")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion libs.versions.compilesdk.get() as Integer
 
     defaultConfig {
-        minSdkVersion rootProject.ext.minSdkVersion
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        minSdkVersion libs.versions.minsdk.get()
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
 }
 
 dependencies {
-    api rootProject.ext.rxJava2
-    api rootProject.ext.autodispose
-    api rootProject.ext.autodisposeLifecycle
+    api libs.rxjava2
+    api libs.autodispose
+    api libs.autodispose.lifecycle
 
     implementation project(':conductor')
 }

conductor-modules/viewpager/build.gradle

@@ -1,26 +1,26 @@
-apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+plugins {
+    id("com.android.library")
+    id("kotlin-android")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion libs.versions.compilesdk.get() as Integer
 
     defaultConfig {
-        minSdkVersion rootProject.ext.minSdkVersion
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        minSdkVersion libs.versions.minsdk.get()
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
 }
 
 dependencies {
-    testImplementation rootProject.ext.junit
-    testImplementation rootProject.ext.robolectric
+    testImplementation libs.junit
+    testImplementation libs.robolectric
 
-    implementation rootProject.ext.androidxAppCompat
+    implementation libs.androidx.appcompat
     implementation project(':conductor')
 }
 
-apply from: rootProject.file('dependencies.gradle')
-
 ext.artifactId = 'conductor-viewpager'
-apply plugin: "com.vanniktech.maven.publish"

conductor-modules/viewpager/src/main/java/com/bluelinelabs/conductor/viewpager/RouterPagerAdapter.java

@@ -77,7 +77,8 @@ public abstract class RouterPagerAdapter extends PagerAdapter {
             savedPages.remove(position);
         }
 
-        Router router = host.getChildRouter(container, name);
+        Router router = host.getChildRouter(container, name)
+                .setPopRootControllerMode(Router.PopRootControllerMode.NEVER);
         if (!router.hasRootController()) {
             Bundle routerSavedState = savedPages.get(position);
 

conductor-modules/viewpager2/build.gradle

@@ -1,13 +1,16 @@
-apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
-apply plugin: 'kotlin-parcelize'
+plugins {
+    id("com.android.library")
+    id("kotlin-android")
+    id("kotlin-parcelize")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion libs.versions.compilesdk.get() as Integer
 
     defaultConfig {
-        minSdkVersion rootProject.ext.minSdkVersion
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        minSdkVersion libs.versions.minsdk.get()
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
     }
@@ -20,15 +23,12 @@ android {
 }
 
 dependencies {
-    testImplementation rootProject.ext.junit
-    testImplementation rootProject.ext.robolectric
+    testImplementation libs.junit
+    testImplementation libs.robolectric
 
-    implementation rootProject.ext.androidxAppCompat
-    implementation rootProject.ext.androidxViewPager2
+    implementation libs.androidx.appcompat
+    implementation libs.androidx.viewpager2
     implementation project(':conductor')
 }
 
-apply from: rootProject.file('dependencies.gradle')
-
 ext.artifactId = 'conductor-viewpager2'
-apply plugin: "com.vanniktech.maven.publish"

conductor-modules/viewpager2/src/main/java/com/bluelinelabs/conductor/viewpager2/RouterStateAdapter.kt

@@ -155,6 +155,7 @@ abstract class RouterStateAdapter(private val host: Controller) :
   private fun attachRouter(holder: RouterViewHolder, position: Int) {
     val itemId = getItemId(position)
     val router = host.getChildRouter(holder.container, "$itemId", true, false)!!
+            .setPopRootControllerMode(Router.PopRootControllerMode.NEVER)
 
     // This should have already been handled by onViewRecycled, but it seems like this wasn't
     // always reliably called

conductor/build.gradle

@@ -1,12 +1,15 @@
-apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+plugins {
+    id("com.android.library")
+    id("kotlin-android")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion libs.versions.compilesdk.get() as Integer
 
     defaultConfig {
-        minSdkVersion rootProject.ext.minSdkVersion
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        minSdkVersion libs.versions.minsdk.get()
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode Integer.parseInt(project.VERSION_CODE)
         versionName project.VERSION_NAME
         consumerProguardFiles 'proguard-rules.txt'
@@ -14,20 +17,17 @@ android {
 }
 
 dependencies {
-    implementation savedState
-    testImplementation rootProject.ext.junit
-    testImplementation rootProject.ext.robolectric
-    testImplementation kotestAssertions
+    implementation libs.androidx.savedstate.ktx
+    testImplementation libs.junit
+    testImplementation libs.robolectric
+    testImplementation libs.kotest
 
-    implementation archComponentsLifecycle
+    implementation libs.androidx.lifecycle.runtime
 
-    api rootProject.ext.androidxAnnotations
-    api kotlinStd
+    api libs.androidx.annotation
+    api libs.kotlin.stdlib
 
     lintPublish project(':conductor-lint')
 }
 
-apply from: rootProject.file('dependencies.gradle')
-
 ext.artifactId = 'conductor'
-apply plugin: "com.vanniktech.maven.publish"

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

@@ -709,7 +709,7 @@ public abstract class Controller {
     public void setRetainViewMode(@NonNull RetainViewMode retainViewMode) {
         this.retainViewMode = retainViewMode != null ? retainViewMode : RetainViewMode.RELEASE_DETACH;
         if (this.retainViewMode == RetainViewMode.RELEASE_DETACH && !attached) {
-            removeViewReference();
+            removeViewReference(null);
         }
     }
 
@@ -873,11 +873,11 @@ public abstract class Controller {
     }
 
     final void onContextUnavailable(@NonNull Context context) {
-        if (isContextAvailable) {
-            for (Router childRouter : childRouters) {
-                childRouter.onContextUnavailable(context);
-            }
+        for (Router childRouter : childRouters) {
+            childRouter.onContextUnavailable(context);
+        }
 
+        if (isContextAvailable) {
             List<LifecycleListener> listeners = new ArrayList<>(lifecycleListeners);
             for (LifecycleListener lifecycleListener : listeners) {
                 lifecycleListener.preContextUnavailable(this, context);
@@ -995,7 +995,7 @@ public abstract class Controller {
         }
     }
 
-    void detach(@NonNull View view, boolean forceViewRefRemoval, boolean blockViewRefRemoval) {
+    void detach(View view, boolean forceViewRefRemoval, boolean blockViewRefRemoval) {
         if (!attachedToUnownedParent) {
             for (ControllerHostedRouter router : childRouters) {
                 router.prepareForHostDetach();
@@ -1030,12 +1030,16 @@ public abstract class Controller {
         awaitingParentAttach = false;
 
         if (removeViewRef) {
-            removeViewReference();
+            removeViewReference(view != null ? view.getContext() : null);
         }
     }
 
-    private void removeViewReference() {
+    private void removeViewReference(@Nullable Context context) {
         if (view != null) {
+            if (context == null) {
+                context = view.getContext();
+            }
+
             if (!isBeingDestroyed && !hasSavedViewState) {
                 saveViewState(view);
             }
@@ -1071,14 +1075,15 @@ public abstract class Controller {
         }
 
         if (isBeingDestroyed) {
-            performDestroy();
+            performDestroy(context);
         }
     }
 
     final View inflate(@NonNull ViewGroup parent) {
         if (view != null && view.getParent() != null && view.getParent() != parent) {
+            View viewRef = view;
             detach(view, true, false);
-            removeViewReference();
+            removeViewReference(viewRef.getContext());
         }
 
         if (view == null) {
@@ -1148,9 +1153,13 @@ public abstract class Controller {
         }
     }
 
-    private void performDestroy() {
+    private void performDestroy(@Nullable Context context) {
+        if (context == null) {
+            context = getActivity();
+        }
+
         if (isContextAvailable) {
-            onContextUnavailable(getActivity());
+            onContextUnavailable(context);
         }
 
         if (!destroyed) {
@@ -1188,7 +1197,7 @@ public abstract class Controller {
         }
 
         if (!attached) {
-            removeViewReference();
+            removeViewReference(null);
         } else if (removeViews) {
             detach(view, true, false);
         }

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

@@ -225,8 +225,9 @@ public abstract class Router {
         final List<RouterTransaction> poppedControllers = backstack.popAll();
         trackDestroyingControllers(poppedControllers);
 
+        RouterTransaction topTransaction = null;
         if (popViews && poppedControllers.size() > 0) {
-            RouterTransaction topTransaction = poppedControllers.get(0);
+            topTransaction = poppedControllers.get(0);
             topTransaction.controller().addLifecycleListener(new Controller.LifecycleListener() {
                 @Override
                 public void onChangeEnd(@NonNull Controller controller, @NonNull ControllerChangeHandler changeHandler, @NonNull ControllerChangeType changeType) {
@@ -241,6 +242,16 @@ public abstract class Router {
 
             performControllerChange(null, topTransaction, false, topTransaction.popChangeHandler());
         }
+
+        if (poppedControllers.size() > 0) {
+            NoOpControllerChangeHandler changeHandler = new NoOpControllerChangeHandler();
+            for (RouterTransaction routerTransaction : poppedControllers) {
+                if (routerTransaction != topTransaction) {
+                    routerTransaction.controller().changeStarted(changeHandler, ControllerChangeType.POP_EXIT);
+                    routerTransaction.controller().changeEnded(changeHandler, ControllerChangeType.POP_EXIT);
+                }
+            }
+        }
     }
 
     public int getContainerId() {
@@ -560,10 +571,9 @@ public abstract class Router {
     public void rebindIfNeeded() {
         ThreadUtils.ensureMainThread();
 
-        Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
-        while (backstackIterator.hasNext()) {
-            RouterTransaction transaction = backstackIterator.next();
-
+        // Not directly using the iterator in order to prevent ConcurrentModificationExceptions if controllers pop
+        // themselves on re-attach.
+        for (RouterTransaction transaction : getTransactions()) {
             if (transaction.controller().getNeedsAttach()) {
                 performControllerChange(transaction, null, true, new SimpleSwapChangeHandler(false));
             } else {
@@ -782,6 +792,18 @@ public abstract class Router {
         return controllers;
     }
 
+    @NonNull
+    final List<RouterTransaction> getTransactions() {
+        List<RouterTransaction> transactions = new ArrayList<>(backstack.getSize());
+
+        Iterator<RouterTransaction> backstackIterator = backstack.reverseIterator();
+        while (backstackIterator.hasNext()) {
+            transactions.add(backstackIterator.next());
+        }
+
+        return transactions;
+    }
+
     @Nullable
     public final Boolean handleRequestedPermission(@NonNull String permission) {
         for (RouterTransaction transaction : backstack) {
@@ -863,12 +885,7 @@ public abstract class Router {
             }
             pendingControllerChanges.add(transaction);
             if (container != null) {
-                container.post(new Runnable() {
-                    @Override
-                    public void run() {
-                        performPendingControllerChanges();
-                    }
-                });
+                container.post(this::performPendingControllerChanges);
             }
         } else {
             ControllerChangeHandler.executeChange(transaction);

conductor/src/main/java/com/bluelinelabs/conductor/internal/OwnViewTreeLifecycleAndRegistry.kt

@@ -29,7 +29,6 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
 
   private var hasSavedState = false
   private var savedRegistryState = Bundle.EMPTY
-  private val parentChangeListeners = mutableMapOf<String, Controller.LifecycleListener>()
 
   init {
     controller.addLifecycleListener(object : Controller.LifecycleListener() {
@@ -97,6 +96,8 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
           changeHandler = changeHandler,
           changeType = changeType,
         )
+
+        GlobalChangeStartListener.onChangeStart(changeController, changeHandler, changeType)
       }
 
       override fun preDetach(controller: Controller, view: View) {
@@ -125,8 +126,7 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
       override fun preDestroyView(controller: Controller, view: View) {
         if (controller.isBeingDestroyed && controller.router.backstackSize == 0) {
           val parent = view.parent as? View
-          parent?.addOnAttachStateChangeListener(object :
-            View.OnAttachStateChangeListener {
+          parent?.addOnAttachStateChangeListener(object : View.OnAttachStateChangeListener {
             override fun onViewAttachedToWindow(v: View?) = Unit
             override fun onViewDetachedFromWindow(v: View?) {
               parent.removeOnAttachStateChangeListener(this)
@@ -139,11 +139,11 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
       }
 
       override fun postContextAvailable(controller: Controller, context: Context) {
-        listenForParentChangeStart(controller)
+        listenForAncestorChangeStart(controller)
       }
 
       override fun preContextUnavailable(controller: Controller, context: Context) {
-        stopListeningForParentChangeStart(controller)
+        stopListeningForAncestorChangeStart(controller)
       }
     })
   }
@@ -152,36 +152,23 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
 
   override fun getSavedStateRegistry() = savedStateRegistryController.savedStateRegistry
 
-  private fun listenForParentChangeStart(controller: Controller) {
-    controller.parentController?.let { parent ->
-      val changeListener = object : Controller.LifecycleListener() {
-        override fun onChangeStart(
-          controller: Controller,
-          changeHandler: ControllerChangeHandler,
-          changeType: ControllerChangeType
-        ) {
-          pauseOnChangeStart(
-            targetController = parent,
-            changeController = controller,
-            changeHandler = changeHandler,
-            changeType = changeType,
-          )
-        }
+  private fun listenForAncestorChangeStart(controller: Controller) {
+    GlobalChangeStartListener.subscribe(controller, controller.ancestors()) { ancestor, changeHandler, changeType ->
+      // No-op on the case where we (the child controller) hasn't yet created a View as our parent is being
+      // changed out.
+      if (::lifecycleRegistry.isInitialized) {
+        pauseOnChangeStart(
+          targetController = ancestor,
+          changeController = ancestor,
+          changeHandler = changeHandler,
+          changeType = changeType,
+        )
       }
-
-      parent.addLifecycleListener(changeListener)
-      parentChangeListeners[controller.instanceId] = changeListener
-
-      listenForParentChangeStart(parent)
     }
   }
 
-  private fun stopListeningForParentChangeStart(controller: Controller) {
-    controller.parentController?.let { parent ->
-      parentChangeListeners.remove(parent.instanceId)?.let { listener ->
-        parent.removeLifecycleListener(listener)
-      }
-    }
+  private fun stopListeningForAncestorChangeStart(controller: Controller) {
+    GlobalChangeStartListener.unsubscribe(controller)
   }
 
   // AbstractComposeView adds its own OnAttachStateChangeListener by default. Since it
@@ -210,6 +197,16 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
     }
   }
 
+  private fun Controller.ancestors(): Collection<String> {
+    return buildList {
+      var ancestor = parentController
+      while (ancestor != null) {
+        add(ancestor.instanceId)
+        ancestor = ancestor.parentController
+      }
+    }
+  }
+
   companion object {
     private const val KEY_SAVED_STATE = "Registry.savedState"
 
@@ -218,3 +215,37 @@ internal class OwnViewTreeLifecycleAndRegistry private constructor(
     }
   }
 }
+
+// In order to prevent child controllers from having strong references to all of their ancestors, some of which may
+// break their connection before the child is made aware, this shared listener is used to call all interested parties
+// when a controller begins transitioning.
+private object GlobalChangeStartListener {
+  private val listeners = mutableMapOf<String, Listener>()
+
+  fun subscribe(
+    controller: Controller,
+    targetControllers: Collection<String>,
+    listener: (Controller, ControllerChangeHandler, ControllerChangeType) -> Unit,
+  ) {
+    listeners[controller.instanceId] = Listener(targetControllers, listener)
+  }
+
+  fun unsubscribe(controller: Controller) {
+    listeners.remove(controller.instanceId)
+  }
+
+  fun onChangeStart(controller: Controller, changeHandler: ControllerChangeHandler, changeType: ControllerChangeType) {
+    listeners.values.forEach { it.call(controller, changeHandler, changeType) }
+  }
+
+  private class Listener(
+    private val targetControllers: Collection<String>,
+    private val listener: (Controller, ControllerChangeHandler, ControllerChangeType) -> Unit,
+  ) {
+    fun call(controller: Controller, changeHandler: ControllerChangeHandler, changeType: ControllerChangeType) {
+      if (targetControllers.contains(controller.instanceId)) {
+        listener(controller, changeHandler, changeType)
+      }
+    }
+  }
+}

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

@@ -155,7 +155,7 @@ class ControllerLifecycleActivityReferenceTests {
     )
     activity.router.popCurrentController()
 
-    Assert.assertEquals(listOf(true), listener.changeEndReferences)
+    Assert.assertEquals(listOf(true, true), listener.changeEndReferences)
     Assert.assertEquals(listOf(true), listener.postCreateViewReferences)
     Assert.assertEquals(listOf(true), listener.postAttachReferences)
     Assert.assertEquals(listOf(true), listener.postDetachReferences)
@@ -208,7 +208,7 @@ class ControllerLifecycleActivityReferenceTests {
     )
     activityController.pause().stop().destroy()
 
-    Assert.assertEquals(listOf(true), listener.changeEndReferences)
+    Assert.assertEquals(listOf(true, true), listener.changeEndReferences)
     Assert.assertEquals(listOf(true), listener.postCreateViewReferences)
     Assert.assertEquals(listOf(true), listener.postAttachReferences)
     Assert.assertEquals(listOf(true), listener.postDetachReferences)

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

@@ -465,6 +465,8 @@ class ControllerLifecycleCallbacksTests {
     assertCalls(expectedCallState, child)
 
     activityController.get().router.popCurrentController()
+    expectedCallState.changeStartCalls++
+    expectedCallState.changeEndCalls++
     expectedCallState.detachCalls++
     expectedCallState.destroyViewCalls++
     expectedCallState.contextUnavailableCalls++

demo/build.gradle

@@ -5,7 +5,7 @@ android {
     defaultConfig {
         applicationId "com.bluelinelabs.conductor.demo"
         minSdkVersion 21
-        targetSdkVersion rootProject.ext.targetSdkVersion
+        targetSdkVersion libs.versions.targetsdk.get()
         versionCode 1
         versionName "1.0.0"
         vectorDrawables.useSupportLibrary true
@@ -27,7 +27,7 @@ android {
         compose = true
     }
 
-    compileSdkVersion rootProject.ext.compileSdkVersion
+    compileSdkVersion 31
 
     compileOptions {
         sourceCompatibility JavaVersion.VERSION_1_8
@@ -39,21 +39,19 @@ android {
     }
 
     composeOptions {
-        kotlinCompilerExtensionVersion composeVersion
+        kotlinCompilerExtensionVersion libs.versions.compose.get()
     }
 }
 
 dependencies {
-    implementation rootProject.ext.androidxAppCompat
-    implementation rootProject.ext.androidxViewPager2
-    implementation rootProject.ext.material
-    implementation rootProject.ext.androidxCoreKtx
+    implementation libs.androidx.appcompat
+    implementation libs.androidx.viewpager2
+    implementation libs.material
+    implementation libs.androidx.core.ktx
 
-    implementation rootProject.ext.archComponentsLiveDataCore // Fix duplicate classes
+    implementation libs.picasso
 
-    implementation rootProject.ext.picasso
-
-    implementation rootProject.ext.autodisposeKtx
+    implementation libs.autodispose.ktx
 
     implementation project(':conductor')
     implementation project(':conductor-modules:viewpager')
@@ -62,14 +60,11 @@ dependencies {
     implementation project(':conductor-modules:arch-components-lifecycle')
     implementation project(':conductor-modules:androidx-transition')
 
-    implementation "androidx.compose.ui:ui:$composeVersion"
-    implementation "androidx.compose.ui:ui-tooling:$composeVersion"
-    implementation "androidx.compose.foundation:foundation:$composeVersion"
-    implementation "androidx.compose.material:material:$composeVersion"
-    implementation "androidx.compose.material:material-icons-core:$composeVersion"
-    implementation "androidx.compose.material:material-icons-extended:$composeVersion"
-    implementation "androidx.activity:activity-compose:1.3.0-beta02"
-    implementation "androidx.lifecycle:lifecycle-viewmodel-compose:1.0.0-alpha07"
+    implementation libs.compose.ui
+    implementation libs.compose.ui.tooling
+    implementation libs.compose.foundation
+    implementation libs.compose.material
+    implementation libs.activity.compose
 
-    implementation rootProject.ext.leakCanary
+    implementation libs.leakCanary
 }

demo/src/main/java/com/bluelinelabs/conductor/demo/controllers/base/controllerLeakWatcher.kt

@@ -1,5 +1,6 @@
 package com.bluelinelabs.conductor.demo.controllers.base
 
+import android.view.View
 import com.bluelinelabs.conductor.Controller
 import com.bluelinelabs.conductor.ControllerChangeHandler
 import com.bluelinelabs.conductor.ControllerChangeType
@@ -15,6 +16,13 @@ private class RefWatchingControllerLifecycleListener : Controller.LifecycleListe
     }
   }
 
+  override fun preDestroyView(controller: Controller, view: View) {
+    AppWatcher.objectWatcher.expectWeaklyReachable(
+      view,
+      "A destroyed controller view should have only weak references."
+    )
+  }
+
   override fun onChangeEnd(
     controller: Controller,
     changeHandler: ControllerChangeHandler,

dependencies.gradle

@@ -1,55 +0,0 @@
-ext {
-    minSdkVersion = 16
-    compileSdkVersion = 28
-    targetSdkVersion = 28
-
-    picassoVersion = '2.5.2'
-    rxJava2Version = '2.1.14'
-    autodisposeVersion = '1.0.0'
-    archComponentsVersion = '2.3.1'
-    junitVersion = '4.12'
-    mvnPublishVersion = '0.13.0'    
-    dokkaVersion = '1.4.32'
-    composeVersion = "1.0.0-beta09"
-
-    agpVersion = '7.0.3'
-    lintVersion = agpVersion.replaceFirst(~/\d*/) { version ->
-        // the major version of lint is always 23 version higher than the major version of agp
-        version.toInteger() + 23
-    }
-
-    kotlinVersion = '1.5.10'
-    kotlinStd = "org.jetbrains.kotlin:kotlin-stdlib-jdk8:$kotlinVersion"
-
-    material = "com.google.android.material:material:1.1.0"
-    androidxAnnotations = "androidx.annotation:annotation:1.1.0"
-    androidxAppCompat = "androidx.appcompat:appcompat:1.3.0"
-    androidxTransition = "androidx.transition:transition:1.3.1"
-    androidxCollection = "androidx.collection:collection:1.1.0"
-    androidxViewPager2 = "androidx.viewpager2:viewpager2:1.0.0"
-    androidxCoreKtx = "androidx.core:core-ktx:1.3.2"
-
-    picasso = "com.squareup.picasso:picasso:$picassoVersion"
-
-    leakCanary = "com.squareup.leakcanary:leakcanary-android:2.7"
-
-    rxJava2 = "io.reactivex.rxjava2:rxjava:$rxJava2Version"
-
-    autodispose = "com.uber.autodispose:autodispose:$autodisposeVersion"
-    autodisposeLifecycle = "com.uber.autodispose:autodispose-lifecycle:$autodisposeVersion"
-    autodisposeKtx = "com.uber.autodispose:autodispose-ktx:$autodisposeVersion"
-
-    archComponentsLifecycle = "androidx.lifecycle:lifecycle-runtime:$archComponentsVersion"
-    archComponentsLiveDataCore = "androidx.lifecycle:lifecycle-livedata-core:$archComponentsVersion"
-
-    savedState = "androidx.savedstate:savedstate-ktx:1.1.0"
-
-    junit = "junit:junit:$junitVersion"
-    robolectric = "org.robolectric:robolectric:4.5.1"
-    kotestAssertions = "io.kotest:kotest-assertions-core:4.6.0"
-
-    lintapi = "com.android.tools.lint:lint-api:$lintVersion"
-    lintchecks = "com.android.tools.lint:lint-checks:$lintVersion"
-    lint = "com.android.tools.lint:lint:$lintVersion"
-    lintTests = "com.android.tools.lint:lint-tests:$lintVersion"
-}

gradle.properties

@@ -1,5 +1,5 @@
 VERSION_CODE=3
-VERSION_NAME=3.1.6-SNAPSHOT
+VERSION_NAME=3.2.1-SNAPSHOT
 android.useAndroidX=true
 org.gradle.jvmargs=-Xmx1536m
 
@@ -14,3 +14,5 @@ POM_LICENCE_URL=http://www.apache.org/licenses/LICENSE-2.0.txt
 POM_LICENCE_DIST=repo
 POM_DEVELOPER_ID=erickuck
 POM_DEVELOPER_NAME=Eric Kuck
+SONATYPE_HOST=DEFAULT
+RELEASE_SIGNING_ENABLED=true

gradle/libs.versions.toml

@@ -0,0 +1,66 @@
+[versions]
+minsdk = "16"
+compilesdk = "28"
+targetsdk = "28"
+
+activity-compose = "1.3.0"
+agp = "7.2.1" # Note: update lint version whenever this is updated
+androidx-annotation = "1.1.0"
+androidx-appcompat = "1.3.0"
+androidx-collection = "1.1.0"
+androidx-core = "1.3.2"
+androidx-lifecycle = "2.3.1"
+androidx-savedstate = "1.1.0"
+androidx-transition = "1.3.1"
+androidx-viewpager2 = "1.0.0"
+autodispose = "1.0.0"
+compose = "1.1.0"
+dokka = "1.4.32"
+junit = "4.13"
+kotest = "4.6.0"
+kotlin = "1.6.10"
+leakCanary = "2.7"
+lint = "30.2.1" # Should always be agp + 23
+material = "1.2.1"
+mvnpublish = "0.23.2"
+picasso = "2.5.2"
+robolectric = "4.5.1"
+rxjava2 = "2.1.14"
+
+[libraries]
+activity-compose = { module = "androidx.activity:activity-compose", version.ref = "activity-compose" }
+agp = { module = "com.android.tools.build:gradle", version.ref = "agp" }
+androidx-annotation = { module = "androidx.annotation:annotation", version.ref = "androidx-annotation" }
+androidx-appcompat = { module = "androidx.appcompat:appcompat", version.ref = "androidx-appcompat" }
+androidx-collection = { module = "androidx.collection:collection", version.ref = "androidx-collection" }
+androidx-core-ktx = { module = "androidx.core:core-ktx", version.ref = "androidx-core" }
+androidx-lifecycle-runtime = { module = "androidx.lifecycle:lifecycle-runtime", version.ref = "androidx-lifecycle" }
+androidx-lifecycle-livedata-core = { module = "androidx.lifecycle:lifecycle-livedata-core", version.ref = "androidx-lifecycle" }
+androidx-savedstate-ktx = { module = "androidx.savedstate:savedstate-ktx", version.ref = "androidx-savedstate" }
+androidx-transition = { module = "androidx.transition:transition", version.ref = "androidx-transition" }
+androidx-viewpager2 = { module = "androidx.viewpager2:viewpager2", version.ref = "androidx-viewpager2" }
+autodispose = { module = "com.uber.autodispose:autodispose", version.ref = "autodispose" }
+autodispose-lifecycle = { module = "com.uber.autodispose:autodispose-lifecycle", version.ref = "autodispose" }
+autodispose-ktx = { module = "com.uber.autodispose:autodispose-ktx", version.ref = "autodispose" }
+compose-foundation = { module = "androidx.compose.foundation:foundation", version.ref = "compose" }
+compose-ui = { module = "androidx.compose.ui:ui", version.ref = "compose" }
+compose-ui-tooling = { module = "androidx.compose.ui:ui-tooling", version.ref = "compose" }
+compose-ui-tooling-preview = { module = "androidx.compose.ui:ui-tooling-preview", version.ref = "compose" }
+compose-material = { module = "androidx.compose.material:material", version.ref = "compose" }
+dokka = { module = "org.jetbrains.dokka:dokka-gradle-plugin", version.ref = "dokka" }
+junit = { module = "junit:junit", version.ref = "junit" }
+kotest = { module = "io.kotest:kotest-assertions-core", version.ref = "kotest" }
+kotlin-plugin = { module = "org.jetbrains.kotlin:kotlin-gradle-plugin", version.ref = "kotlin" }
+kotlin-stdlib = { module = "org.jetbrains.kotlin:kotlin-stdlib-jdk8", version.ref = "kotlin" }
+leakCanary = { module = "com.squareup.leakcanary:leakcanary-android", version.ref = "leakCanary" }
+lint = { module = "com.android.tools.lint:lint", version.ref = "lint" }
+lint-api = { module = "com.android.tools.lint:lint-api", version.ref = "lint" }
+lint-checks = { module = "com.android.tools.lint:lint-checks", version.ref = "lint" }
+lint-tests = { module = "com.android.tools.lint:lint-tests", version.ref = "lint" }
+material = { module = "com.google.android.material:material", version.ref = "material" }
+picasso = { module = "com.squareup.picasso:picasso", version.ref = "picasso" }
+robolectric = { module = "org.robolectric:robolectric", version.ref = "robolectric" }
+rxjava2 = { module = "io.reactivex.rxjava2:rxjava", version.ref = "rxjava2" }
+
+[plugins]
+mvnpublish = { id = "com.vanniktech.maven.publish", version.ref = "mvnpublish" }

gradle/wrapper/gradle-wrapper.properties

@@ -1,5 +1,5 @@
 distributionBase=GRADLE_USER_HOME
 distributionPath=wrapper/dists
-distributionUrl=https\://services.gradle.org/distributions/gradle-7.1-bin.zip
+distributionUrl=https\://services.gradle.org/distributions/gradle-7.4-bin.zip
 zipStoreBase=GRADLE_USER_HOME
 zipStorePath=wrapper/dists