Activity Transitions: Fix memory leak.

Bug 15731459

Change-Id: Id357d841a0db832e2525b7bbd75c8d8ccdb757d1

core/java/android/app/ActivityTransitionCoordinator.java

@@ -191,7 +191,7 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
      */
     public static final int MSG_SEND_SHARED_ELEMENT_DESTINATION = 108;
 
-    final private Window mWindow;
+    private Window mWindow;
     final protected ArrayList<String> mAllSharedElementNames;
     final protected ArrayList<View> mSharedElements = new ArrayList<View>();
     final protected ArrayList<String> mSharedElementNames = new ArrayList<String>();
@@ -507,6 +507,17 @@ abstract class ActivityTransitionCoordinator extends ResultReceiver {
         return bundle;
     }
 
+    protected void clearState() {
+        // Clear the state so that we can't hold any references accidentally and leak memory.
+        mWindow = null;
+        mAllSharedElementNames.clear();
+        mSharedElements.clear();
+        mSharedElementNames.clear();
+        mTransitioningViews.clear();
+        mResultReceiver = null;
+        mPendingTransition = null;
+    }
+
     protected long getFadeDuration() {
         return getWindow().getTransitionBackgroundFadeDuration();
     }

core/java/android/app/ActivityTransitionState.java

@@ -215,6 +215,17 @@ class ActivityTransitionState {
         restoreExitedViews();
     }
 
+    public void clear() {
+        mEnteringNames = null;
+        mExitingFrom = null;
+        mExitingTo = null;
+        mExitingToView = null;
+        mCalledExitCoordinator = null;
+        mEnterTransitionCoordinator = null;
+        mEnterActivityOptions = null;
+        mExitTransitionCoordinators = null;
+    }
+
     private void restoreExitedViews() {
         if (mCalledExitCoordinator != null) {
             mCalledExitCoordinator.resetViews();

core/java/android/app/ExitTransitionCoordinator.java

@@ -134,6 +134,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
         transition.addListener(new Transition.TransitionListenerAdapter() {
             @Override
             public void onTransitionEnd(Transition transition) {
+                transition.removeListener(this);
                 setViewVisibility(mSharedElements, View.INVISIBLE);
                 ViewGroupOverlay overlay = getDecor().getOverlay();
                 if (mSharedElementSnapshots != null) {
@@ -196,8 +197,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
             @Override
             public void handleMessage(Message msg) {
                 mIsCanceled = true;
-                mActivity.finish();
-                mActivity = null;
+                finish();
             }
         };
         mHandler.sendEmptyMessageDelayed(MSG_CANCEL, MAX_WAIT_MS);
@@ -269,6 +269,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
             viewsTransition.addListener(new ContinueTransitionListener() {
                 @Override
                 public void onTransitionEnd(Transition transition) {
+                    transition.removeListener(this);
                     exitTransitionComplete();
                     if (mIsHidden) {
                         setViewVisibility(mTransitioningViews, View.VISIBLE);
@@ -295,6 +296,7 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
             sharedElementTransition.addListener(new ContinueTransitionListener() {
                 @Override
                 public void onTransitionEnd(Transition transition) {
+                    transition.removeListener(this);
                     sharedElementTransitionComplete();
                     if (mIsHidden) {
                         setViewVisibility(mSharedElements, View.VISIBLE);
@@ -364,15 +366,31 @@ class ExitTransitionCoordinator extends ActivityTransitionCoordinator {
 
     private void finishIfNecessary() {
         if (mIsReturning && mExitNotified && mActivity != null && mSharedElementSnapshots == null) {
-            mActivity.finish();
-            mActivity.overridePendingTransition(0, 0);
-            mActivity = null;
+            finish();
         }
         if (!mIsReturning && mExitNotified) {
             mActivity = null; // don't need it anymore
         }
     }
 
+    private void finish() {
+        mActivity.mActivityTransitionState.clear();
+        // Clear the state so that we can't hold any references accidentally and leak memory.
+        mHandler.removeMessages(MSG_CANCEL);
+        mHandler = null;
+        mActivity.finish();
+        mActivity.overridePendingTransition(0, 0);
+        mActivity = null;
+        mSharedElementBundle = null;
+        if (mBackgroundAnimator != null) {
+            mBackgroundAnimator.cancel();
+            mBackgroundAnimator = null;
+        }
+        mExitSharedElementBundle = null;
+        mSharedElementSnapshots = null;
+        clearState();
+    }
+
     @Override
     protected Transition getViewsTransition() {
         if (mIsReturning) {