When a window is first shown only draw once while animating.

On some hardware allocating a new graphics buffer is quite
expensive, which blocks updates to the UI.  This can cause
glitches when performing window animations.

To reduce these glitches, the view hierarchy will now only
allow itself to be drawn once if its window is being shown
while the window manager is animating, not resuming draws
until it is told that the animation is done.

Change-Id: Ie15192f6fddbd0931b022a72c76ddd55ca266d84

1 files changed, 24 insertions, 2 deletions

diff --git a/services/java/com/android/server/wm/WindowManagerService.java b/services/java/com/android/server/wm/WindowManagerService.java
index b270cee..276bc5b 100755
--- a/services/java/com/android/server/wm/WindowManagerService.java
+++ b/services/java/com/android/server/wm/WindowManagerService.java
@@ -424,6 +424,12 @@ public class WindowManagerService extends IWindowManager.Stub
             = new ArrayList<Pair<WindowState, IRemoteCallback>>();
 
     /**
+     * Windows that have called relayout() while we were running animations,
+     * so we need to tell when the animation is done.
+     */
+    final ArrayList<WindowState> mRelayoutWhileAnimating = new ArrayList<WindowState>();
+
+    /**
      * Used when rebuilding window list to keep track of windows that have
      * been removed.
      */
@@ -2647,6 +2653,7 @@ public class WindowManagerService extends IWindowManager.Stub
         boolean inTouchMode;
         boolean configChanged;
         boolean surfaceChanged = false;
+        boolean animating;
 
         // if they don't have this permission, mask out the status bar bits
         int systemUiVisibility = 0;
@@ -2946,7 +2953,11 @@ public class WindowManagerService extends IWindowManager.Stub
                 TAG, "Relayout of " + win + ": focusMayChange=" + focusMayChange);
 
             inTouchMode = mInTouchMode;
-            
+            animating = mAnimator.mAnimating;
+            if (animating && !mRelayoutWhileAnimating.contains(win)) {
+                mRelayoutWhileAnimating.add(win);
+            }
+
             mInputMonitor.updateInputWindowsLw(true /*force*/);
         }
 
@@ -2958,7 +2969,8 @@ public class WindowManagerService extends IWindowManager.Stub
 
         return (inTouchMode ? WindowManagerImpl.RELAYOUT_RES_IN_TOUCH_MODE : 0)
                 | (displayed ? WindowManagerImpl.RELAYOUT_RES_FIRST_TIME : 0)
-                | (surfaceChanged ? WindowManagerImpl.RELAYOUT_RES_SURFACE_CHANGED : 0);
+                | (surfaceChanged ? WindowManagerImpl.RELAYOUT_RES_SURFACE_CHANGED : 0)
+                | (animating ? WindowManagerImpl.RELAYOUT_RES_ANIMATING : 0);
     }
 
     public void performDeferredDestroyWindow(Session session, IWindow client) {
@@ -8579,6 +8591,16 @@ public class WindowManagerService extends IWindowManager.Stub
             mToBottomApps.clear();
         }
 
+        if (!mAnimator.mAnimating && mRelayoutWhileAnimating.size() > 0) {
+            for (int j=mRelayoutWhileAnimating.size()-1; j>=0; j--) {
+                try {
+                    mRelayoutWhileAnimating.get(j).mClient.doneAnimating();
+                } catch (RemoteException e) {
+                }
+            }
+            mRelayoutWhileAnimating.clear();
+        }
+
         if (wallpaperDestroyed) {
             mLayoutNeeded |= adjustWallpaperWindowsLocked() != 0;
         }