am 91283969: Merge "Fixing crash in recents window transition. (Bug 18246975, 18159006)" into lmp-mr1-dev

* commit '9128396982233d6af49613231100f1bc4b6c477b':
  Fixing crash in recents window transition.  (Bug 18246975, 18159006)

services/core/java/com/android/server/wm/AppTransition.java

@@ -691,8 +691,10 @@ public class AppTransition implements Dump {
                 throw new RuntimeException("Invalid thumbnail transition state");
         }
 
-        return prepareThumbnailAnimationWithDuration(a, appWidth, appHeight,
+        int duration = Math.max(THUMBNAIL_APP_TRANSITION_ALPHA_DURATION,
-                THUMBNAIL_APP_TRANSITION_DURATION, mThumbnailFastOutSlowInInterpolator);
+                THUMBNAIL_APP_TRANSITION_DURATION);
+        return prepareThumbnailAnimationWithDuration(a, appWidth, appHeight, duration,
+                mThumbnailFastOutSlowInInterpolator);
     }
 
     /**

services/core/java/com/android/server/wm/AppWindowAnimator.java

@@ -58,7 +58,9 @@ public class AppWindowAnimator {
     // the state changes.
     boolean allDrawn;
 
-    // Special surface for thumbnail animation.
+    // Special surface for thumbnail animation.  If deferThumbnailDestruction is enabled, then we
+    // will make sure that the thumbnail is destroyed after the other surface is completed.  This
+    // requires that the duration of the two animations are the same.
     SurfaceControl thumbnail;
     int thumbnailTransactionSeq;
     int thumbnailX;
@@ -68,13 +70,12 @@ public class AppWindowAnimator {
     Animation thumbnailAnimation;
     final Transformation thumbnailTransformation = new Transformation();
     // This flag indicates that the destruction of the thumbnail surface is synchronized with
-    // another animation, so do not pre-emptively destroy the thumbnail surface when the animation
+    // another animation, so defer the destruction of this thumbnail surface for a single frame
-    // completes
+    // after the secondary animation completes.
     boolean deferThumbnailDestruction;
-    // This is the thumbnail surface that has been bestowed upon this animator, and when the
+    // This flag is set if the animator has deferThumbnailDestruction set and has reached the final
-    // surface for this animator's animation is complete, we will destroy the thumbnail surface
+    // frame of animation.  It will extend the animation by one frame and then clean up afterwards.
-    // as well.  Do not animate or do anything with this surface.
+    boolean deferFinalFrameCleanup;
-    SurfaceControl deferredThumbnail;
 
     /** WindowStateAnimator from mAppAnimator.allAppWindows as of last performLayout */
     ArrayList<WindowStateAnimator> mAllAppWinAnimators = new ArrayList<WindowStateAnimator>();
@@ -134,9 +135,7 @@ public class AppWindowAnimator {
             animation = null;
             animating = true;
         }
-        if (!deferThumbnailDestruction) {
         clearThumbnail();
-        }
         if (mAppToken.deferClearAllDrawn) {
             mAppToken.allDrawn = false;
             mAppToken.deferClearAllDrawn = false;
@@ -148,13 +147,7 @@ public class AppWindowAnimator {
             thumbnail.destroy();
             thumbnail = null;
         }
-    }
+        deferThumbnailDestruction = false;
-
-    public void clearDeferredThumbnail() {
-        if (deferredThumbnail != null) {
-            deferredThumbnail.destroy();
-            deferredThumbnail = null;
-        }
     }
 
     void updateLayers() {
@@ -223,19 +216,26 @@ public class AppWindowAnimator {
             return false;
         }
         transformation.clear();
-        final boolean more = animation.getTransformation(currentTime, transformation);
+        boolean hasMoreFrames = animation.getTransformation(currentTime, transformation);
+        if (!hasMoreFrames) {
+            if (deferThumbnailDestruction && !deferFinalFrameCleanup) {
+                // We are deferring the thumbnail destruction, so extend the animation for one more
+                // (dummy) frame before we clean up
+                deferFinalFrameCleanup = true;
+                hasMoreFrames = true;
+            } else {
                 if (false && WindowManagerService.DEBUG_ANIM) Slog.v(
-            TAG, "Stepped animation in " + mAppToken + ": more=" + more + ", xform=" + transformation);
+                        TAG, "Stepped animation in " + mAppToken + ": more=" + hasMoreFrames +
-        if (!more) {
+                                ", xform=" + transformation);
+                deferFinalFrameCleanup = false;
                 animation = null;
-            if (!deferThumbnailDestruction) {
                 clearThumbnail();
-            }
                 if (WindowManagerService.DEBUG_ANIM) Slog.v(
                         TAG, "Finished animation in " + mAppToken + " @ " + currentTime);
             }
-        hasTransformation = more;
+        }
-        return more;
+        hasTransformation = hasMoreFrames;
+        return hasMoreFrames;
     }
 
     // This must be called while inside a transaction.

services/core/java/com/android/server/wm/WindowManagerService.java

@@ -9244,12 +9244,6 @@ public class WindowManagerService extends IWindowManager.Stub
                                 topClosingLayer);
                         openingAppAnimator.deferThumbnailDestruction =
                                 !mAppTransition.isNextThumbnailTransitionScaleUp();
-                        if (openingAppAnimator.deferThumbnailDestruction) {
-                            if (closingAppAnimator != null &&
-                                    closingAppAnimator.animation != null) {
-                                closingAppAnimator.deferredThumbnail = surfaceControl;
-                            }
-                        }
                     } else {
                         anim = mAppTransition.createThumbnailScaleAnimationLocked(
                                 displayInfo.appWidth, displayInfo.appHeight, transit);

services/core/java/com/android/server/wm/WindowStateAnimator.java

@@ -975,11 +975,6 @@ class WindowStateAnimator {
             mWin.mHasSurface = false;
             mDrawState = NO_SURFACE;
         }
-
-        // Destroy any deferred thumbnail surfaces
-        if (mAppAnimator != null) {
-            mAppAnimator.clearDeferredThumbnail();
-        }
     }
 
     void destroyDeferredSurfaceLocked() {