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 }}

README.md

@@ -1,4 +1,4 @@
-![GitHub Actions Workflow](https://github.com/bluelinelabs/conductor/actions/workflows/main.yml/badge.svg) [![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:3.1.6'
+def conductorVersion = '3.2.0'
+
+implementation "com.bluelinelabs:conductor:$conductorVersion"
 
 // AndroidX Transition change handlers:
-implementation 'com.bluelinelabs:conductor-androidx-transition:3.1.6'
+implementation "com.bluelinelabs:conductor-androidx-transition:$conductorVersion"
 
 // ViewPager PagerAdapter:
-implementation 'com.bluelinelabs:conductor-viewpager:3.1.6'
+implementation "com.bluelinelabs:conductor-viewpager:$conductorVersion"
 
 // ViewPager2 Adapter:
-implementation 'com.bluelinelabs:conductor-viewpager2:3.1.6'
+implementation "com.bluelinelabs:conductor-viewpager2:$conductorVersion"
 
 // RxJava2 Autodispose support:
-implementation 'com.bluelinelabs:conductor-autodispose:3.1.6'
+implementation "com.bluelinelabs:conductor-autodispose:$conductorVersion"
 
 // Lifecycle-aware Controllers (architecture components):
-implementation 'com.bluelinelabs:conductor-archlifecycle:3.1.6'
+implementation "com.bluelinelabs:conductor-archlifecycle:$conductorVersion"
 ```
 
 **SNAPSHOT**
 
-Just use `3.1.7-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

@@ -6,7 +6,6 @@ buildscript {
     dependencies {
         classpath libs.agp
         classpath libs.kotlin.plugin
-        classpath libs.mvnpublish
         classpath libs.dokka
     }
 }
@@ -16,4 +15,20 @@ allprojects {
         mavenCentral()
         google()
     }
+
+    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-modules/androidx-transition/build.gradle

@@ -1,4 +1,7 @@
-apply plugin: 'com.android.library'
+plugins {
+    id("com.android.library")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
     compileSdkVersion libs.versions.compilesdk.get() as Integer
@@ -19,5 +22,3 @@ dependencies {
 }
 
 ext.artifactId = 'conductor-androidx-transition'
-
-apply plugin: "com.vanniktech.maven.publish"

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

@@ -1,4 +1,7 @@
-apply plugin: 'com.android.library'
+plugins {
+    id("com.android.library")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
     compileSdkVersion libs.versions.compilesdk.get() as Integer
@@ -18,5 +21,3 @@ dependencies {
 }
 
 ext.artifactId = 'conductor-arch-components-lifecycle'
-
-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

@@ -1,5 +1,7 @@
-apply plugin: 'com.android.library'
-apply plugin: "com.vanniktech.maven.publish"
+plugins {
+    id("com.android.library")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
     compileSdkVersion libs.versions.compilesdk.get() as Integer

conductor-modules/viewpager/build.gradle

@@ -1,5 +1,8 @@
-apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+plugins {
+    id("com.android.library")
+    id("kotlin-android")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
     compileSdkVersion libs.versions.compilesdk.get() as Integer
@@ -21,4 +24,3 @@ dependencies {
 }
 
 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

@@ -1,6 +1,9 @@
-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 libs.versions.compilesdk.get() as Integer
@@ -29,4 +32,3 @@ dependencies {
 }
 
 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

@@ -1,5 +1,8 @@
-apply plugin: 'com.android.library'
-apply plugin: 'kotlin-android'
+plugins {
+    id("com.android.library")
+    id("kotlin-android")
+    alias(libs.plugins.mvnpublish)
+}
 
 android {
     compileSdkVersion libs.versions.compilesdk.get() as Integer
@@ -28,4 +31,3 @@ dependencies {
 }
 
 ext.artifactId = 'conductor'
-apply plugin: "com.vanniktech.maven.publish"

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

@@ -1081,8 +1081,9 @@ public abstract class Controller {
 
     final View inflate(@NonNull ViewGroup parent) {
         if (view != null && view.getParent() != null && view.getParent() != parent) {
+            View viewRef = view;
             detach(view, true, false);
-            removeViewReference(view.getContext());
+            removeViewReference(viewRef.getContext());
         }
 
         if (view == null) {

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) {
@@ -138,11 +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)
       }
     })
   }
@@ -151,40 +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
-        ) {
-          // 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 = 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
@@ -213,6 +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"
 
@@ -221,3 +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++

gradle.properties

@@ -1,5 +1,5 @@
 VERSION_CODE=3
-VERSION_NAME=3.1.6
+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

@@ -22,7 +22,7 @@ kotlin = "1.6.10"
 leakCanary = "2.7"
 lint = "30.2.1" # Should always be agp + 23
 material = "1.2.1"
-mvnpublish = "0.13.0"
+mvnpublish = "0.23.2"
 picasso = "2.5.2"
 robolectric = "4.5.1"
 rxjava2 = "2.1.14"
@@ -58,7 +58,9 @@ 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" }
-mvnpublish = { module = "com.vanniktech:gradle-maven-publish-plugin", version.ref = "mvnpublish" }
 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" }