Defer detach until animations are complete.

Allowing the detach of ActivityStack from DisplayContent to happen
immediately was causing all sorts of problems associated with not
having a Display to complete the animations.

Waiting for animations to complete before either the detach or the
display removal fixes those problems.

Change-Id: I8a5663bfac5c3c1084ff4fcc451e0e38e8080265

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

@@ -102,6 +102,10 @@ class DisplayContent {
 
     final WindowManagerService mService;
 
+    static final int DEFER_DETACH = 1;
+    static final int DEFER_REMOVAL = 2;
+    int mDeferredActions;
+
     /**
      * @param display May not be null.
      * @param service You know.

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

@@ -137,6 +137,21 @@ public class TaskStack {
         return mBounds.isEmpty();
     }
 
+    boolean isAnimating() {
+        for (int taskNdx = mTasks.size() - 1; taskNdx >= 0; --taskNdx) {
+            final ArrayList<AppWindowToken> activities = mTasks.get(taskNdx).mAppTokens;
+            for (int activityNdx = activities.size() - 1; activityNdx >= 0; --activityNdx) {
+                final ArrayList<WindowState> windows = activities.get(activityNdx).allAppWindows;
+                for (int winNdx = windows.size() - 1; winNdx >= 0; --winNdx) {
+                    if (windows.get(winNdx).mWinAnimator.isAnimating()) {
+                        return true;
+                    }
+                }
+            }
+        }
+        return false;
+    }
+
     void resizeBounds(float oldWidth, float oldHeight, float newWidth, float newHeight) {
         if (oldWidth == newWidth && oldHeight == newHeight) {
             return;
@@ -351,6 +366,19 @@ public class TaskStack {
         mAnimationBackgroundSurface.mDimSurface.destroy();
     }
 
+    void checkForDeferredDetach() {
+        if (mDisplayContent != null &&
+                (mDisplayContent.mDeferredActions & DisplayContent.DEFER_DETACH) != 0 &&
+                !isAnimating()) {
+            mDisplayContent.mDeferredActions &= ~DisplayContent.DEFER_DETACH;
+            mService.detachStack(mStackId);
+            if ((mDisplayContent.mDeferredActions & DisplayContent.DEFER_REMOVAL) != 0) {
+                mDisplayContent.mDeferredActions &= ~DisplayContent.DEFER_REMOVAL;
+                mService.onDisplayRemoved(mDisplayContent.getDisplayId());
+            }
+        }
+    }
+
     public void dump(String prefix, PrintWriter pw) {
         pw.print(prefix); pw.print("mStackId="); pw.println(mStackId);
         for (int taskNdx = 0; taskNdx < mTasks.size(); ++taskNdx) {

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

@@ -64,7 +64,7 @@ public class WindowAnimator {
     Object mLastWindowFreezeSource;
 
     SparseArray<DisplayContentsAnimator> mDisplayContentsAnimators =
-            new SparseArray<WindowAnimator.DisplayContentsAnimator>(2);
+            new SparseArray<DisplayContentsAnimator>(2);
 
     boolean mInitialized = false;
 
@@ -451,11 +451,6 @@ public class WindowAnimator {
         }
     }
 
-    private void performAnimationsLocked(final int displayId) {
-        updateWindowsLocked(displayId);
-        updateWallpaperLocked(displayId);
-    }
-
 
     /** Locked on mService.mWindowMap. */
     private void animateLocked() {
@@ -496,7 +491,8 @@ public class WindowAnimator {
 
                 // Update animations of all applications, including those
                 // associated with exiting/removed apps
-                performAnimationsLocked(displayId);
+                updateWindowsLocked(displayId);
+                updateWallpaperLocked(displayId);
 
                 final WindowList windows = mService.getWindowListLocked(displayId);
                 final int N = windows.size();

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

@@ -4917,6 +4917,10 @@ public class WindowManagerService extends IWindowManager.Stub
             if (stack != null) {
                 final DisplayContent displayContent = stack.getDisplayContent();
                 if (displayContent != null) {
+                    if (stack.isAnimating()) {
+                        displayContent.mDeferredActions |= DisplayContent.DEFER_DETACH;
+                        return;
+                    }
                     displayContent.detachStack(stack);
                     stack.detachDisplay();
                 }
@@ -10848,6 +10852,10 @@ public class WindowManagerService extends IWindowManager.Stub
     private void handleDisplayRemovedLocked(int displayId) {
         final DisplayContent displayContent = getDisplayContentLocked(displayId);
         if (displayContent != null) {
+            if ((displayContent.mDeferredActions & DisplayContent.DEFER_DETACH) != 0) {
+                displayContent.mDeferredActions |= DisplayContent.DEFER_REMOVAL;
+                return;
+            }
             mDisplayContents.delete(displayId);
             displayContent.close();
             if (displayId == Display.DEFAULT_DISPLAY) {

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

@@ -416,6 +416,7 @@ class WindowStateAnimator {
             mService.mPendingRemove.add(mWin);
             mWin.mRemoveOnExit = false;
         }
+        mWin.getStack().checkForDeferredDetach();
         mAnimator.hideWallpapersLocked(mWin);
     }