Fix artifact with LayoutTransitions on disappearing window.

Logic in performTraversals() starts a transition running at the
proper time. But when a view's parent window goes away, this transition
may not start at that time because drawing gets canceled. But the
transition still hung off of the ViewRoot, waiting until some later
drawing operation to kick it off. This resulted in some weird animations
like the Recents panel appearing and having a single item animate off of it.

The fix is to delete pending transitions when drawing is skipped.

Change-Id: I3ab7702c16e069644a163424f977350743e2cecc

3 files changed, 7 insertions, 2 deletions

diff --git a/core/java/android/animation/ObjectAnimator.java b/core/java/android/animation/ObjectAnimator.java
index 31c5f8d..d2d66b6 100644
--- a/core/java/android/animation/ObjectAnimator.java
+++ b/core/java/android/animation/ObjectAnimator.java
@@ -351,7 +351,7 @@ public final class ObjectAnimator extends ValueAnimator {
     @Override
     public void start() {
         if (DBG) {
-            Log.d("ObjectAnimator", "Anim target, duration" + mTarget + ", " + getDuration());
+            Log.d("ObjectAnimator", "Anim target, duration: " + mTarget + ", " + getDuration());
             for (int i = 0; i < mValues.length; ++i) {
                 PropertyValuesHolder pvh = mValues[i];
                 ArrayList<Keyframe> keyframes = pvh.mKeyframeSet.mKeyframes;
diff --git a/core/java/android/view/ViewRootImpl.java b/core/java/android/view/ViewRootImpl.java
index 7db1b32..7ca8174 100644
--- a/core/java/android/view/ViewRootImpl.java
+++ b/core/java/android/view/ViewRootImpl.java
@@ -1599,6 +1599,11 @@ public final class ViewRootImpl extends Handler implements ViewParent,
                 }
             }
         } else {
+            // If we're not drawing, then we don't need to draw the transitions, either
+            if (mPendingTransitions != null) {
+                mPendingTransitions.clear();
+            }
+
             // We were supposed to report when we are done drawing. Since we canceled the
             // draw, remember it here.
             if ((relayoutResult&WindowManagerImpl.RELAYOUT_FIRST_TIME) != 0) {
diff --git a/packages/SystemUI/src/com/android/systemui/statusbar/tablet/NotificationPanel.java b/packages/SystemUI/src/com/android/systemui/statusbar/tablet/NotificationPanel.java
index 4a1cafd..510fd3b 100644
--- a/packages/SystemUI/src/com/android/systemui/statusbar/tablet/NotificationPanel.java
+++ b/packages/SystemUI/src/com/android/systemui/statusbar/tablet/NotificationPanel.java
@@ -147,7 +147,7 @@ public class NotificationPanel extends RelativeLayout implements StatusBarPanel,
         public boolean onPreDraw() {
             getViewTreeObserver().removeOnPreDrawListener(this);
             mChoreo.startAnimation(true);
-            return true;
+            return false;
         }
     };