Plug leaks in transitions

Transitions were leaking views due to TransitionsValues holding references
to views/parents. The references were fine, but the retention of the transition
objects themselves were not. There were a few different places that needed to
be plugged:
- clones were not making new copies of some fields, leading to caching references
in the original object (which was then cloned later to other clones)
- Visibility was using a persistent field to cache temporary values. This transition,
when cloned, would retain these instances, keeping references to views
- ViewTreeObserver had a bug that would leak listeners

Issue #10749071 Activity instance leak between TransitionManager and InputMethodManager

Change-Id: I1d5d457dc5e020c7b9e8392a95e3b2c488461119

4 files changed, 23 insertions, 15 deletions

diff --git a/core/java/android/transition/Transition.java b/core/java/android/transition/Transition.java
index c588c6bf4c7a..2fb32aafad0c 100644
--- a/core/java/android/transition/Transition.java
+++ b/core/java/android/transition/Transition.java
@@ -1451,6 +1451,8 @@ public abstract class Transition implements Cloneable {
         try {
             clone = (Transition) super.clone();
             clone.mAnimators = new ArrayList<Animator>();
+            clone.mStartValues = new TransitionValuesMaps();
+            clone.mEndValues = new TransitionValuesMaps();
         } catch (CloneNotSupportedException e) {}
 
         return clone;
diff --git a/core/java/android/transition/TransitionManager.java b/core/java/android/transition/TransitionManager.java
index 54d801eba443..727a98dceb9a 100644
--- a/core/java/android/transition/TransitionManager.java
+++ b/core/java/android/transition/TransitionManager.java
@@ -22,6 +22,7 @@ import android.util.Log;
 import android.view.ViewGroup;
 import android.view.ViewTreeObserver;
 
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 
 /**
@@ -68,8 +69,9 @@ public class TransitionManager {
     ArrayMap<Scene, Transition> mSceneTransitions = new ArrayMap<Scene, Transition>();
     ArrayMap<Scene, ArrayMap<Scene, Transition>> mScenePairTransitions =
             new ArrayMap<Scene, ArrayMap<Scene, Transition>>();
-    private static ThreadLocal<ArrayMap<ViewGroup, ArrayList<Transition>>> sRunningTransitions =
-            new ThreadLocal<ArrayMap<ViewGroup, ArrayList<Transition>>>();
+    private static ThreadLocal<WeakReference<ArrayMap<ViewGroup, ArrayList<Transition>>>>
+            sRunningTransitions =
+            new ThreadLocal<WeakReference<ArrayMap<ViewGroup, ArrayList<Transition>>>>();
     private static ArrayList<ViewGroup> sPendingTransitions = new ArrayList<ViewGroup>();
 
 
@@ -184,20 +186,24 @@ public class TransitionManager {
     }
 
     private static ArrayMap<ViewGroup, ArrayList<Transition>> getRunningTransitions() {
-        ArrayMap<ViewGroup, ArrayList<Transition>> runningTransitions =
+        WeakReference<ArrayMap<ViewGroup, ArrayList<Transition>>> runningTransitions =
                 sRunningTransitions.get();
-        if (runningTransitions == null) {
-            runningTransitions = new ArrayMap<ViewGroup, ArrayList<Transition>>();
+        if (runningTransitions == null || runningTransitions.get() == null) {
+            ArrayMap<ViewGroup, ArrayList<Transition>> transitions =
+                    new ArrayMap<ViewGroup, ArrayList<Transition>>();
+            runningTransitions = new WeakReference<ArrayMap<ViewGroup, ArrayList<Transition>>>(
+                    transitions);
             sRunningTransitions.set(runningTransitions);
         }
-        return runningTransitions;
+        return runningTransitions.get();
     }
 
     private static void sceneChangeRunTransition(final ViewGroup sceneRoot,
             final Transition transition) {
         if (transition != null) {
             final ViewTreeObserver observer = sceneRoot.getViewTreeObserver();
-            observer.addOnPreDrawListener(new ViewTreeObserver.OnPreDrawListener() {
+            final ViewTreeObserver.OnPreDrawListener listener =
+                    new ViewTreeObserver.OnPreDrawListener() {
                 public boolean onPreDraw() {
                     sceneRoot.getViewTreeObserver().removeOnPreDrawListener(this);
                     sPendingTransitions.remove(sceneRoot);
@@ -236,7 +242,8 @@ public class TransitionManager {
                     // values set on them again and avoid artifacts.
                     return false;
                 }
-            });
+            };
+            observer.addOnPreDrawListener(listener);
         }
     }
 
@@ -355,10 +362,10 @@ public class TransitionManager {
 //            if (transition == null) {
 //                transition = sDefaultTransition;
 //            }
-//            final Transition finalTransition = transition.clone();
-//            sceneChangeSetup(sceneRoot, transition);
+//            final Transition transitionClone = transition.clone();
+//            sceneChangeSetup(sceneRoot, transitionClone);
 //            Scene.setCurrentScene(sceneRoot, null);
-//            sceneChangeRunTransition(sceneRoot, finalTransition);
+//            sceneChangeRunTransition(sceneRoot, transitionClone);
 //        }
     }
 }
diff --git a/core/java/android/transition/Visibility.java b/core/java/android/transition/Visibility.java
index 75d3e7c0b4e0..f49821fab1c3 100644
--- a/core/java/android/transition/Visibility.java
+++ b/core/java/android/transition/Visibility.java
@@ -65,9 +65,6 @@ public abstract class Visibility extends Transition {
         ViewGroup endParent;
     }
 
-    // Temporary structure, used in calculating state in setup() and play()
-    private VisibilityInfo mTmpVisibilityInfo = new VisibilityInfo();
-
     @Override
     public String[] getTransitionProperties() {
         return sTransitionProperties;
@@ -161,7 +158,7 @@ public abstract class Visibility extends Transition {
 
     private VisibilityInfo getVisibilityChangeInfo(TransitionValues startValues,
             TransitionValues endValues) {
-        final VisibilityInfo visInfo = mTmpVisibilityInfo;
+        final VisibilityInfo visInfo = new VisibilityInfo();
         visInfo.visibilityChange = false;
         visInfo.fadeIn = false;
         if (startValues != null) {
diff --git a/core/java/android/view/ViewTreeObserver.java b/core/java/android/view/ViewTreeObserver.java
index 730c4eb01cd0..ad8b51db4a1a 100644
--- a/core/java/android/view/ViewTreeObserver.java
+++ b/core/java/android/view/ViewTreeObserver.java
@@ -992,6 +992,8 @@ public final class ViewTreeObserver {
                 mData = mDataCopy;
             }
             mDataCopy = null;
+            mAccess.mData.clear();
+            mAccess.mSize = 0;
         }
 
         int size() {