Synchronize bubble activity rendering status and its visibility change.

- Add an API ITaskStackListener.onSingleTaskDisplayDrawn() to notifity contents
  are drawn for the first time on a display which can only contain one task.
- BubbleController updates contents visibility (actually alpha value) of
  the Surface in a ActivityView.

Bug: 130442248
Test: atest WmTests:TaskStackChangedListenerTest
Change-Id: Ie5aed373996419b059935889b564ca91c2e3cf23

1 files changed, 11 insertions, 0 deletions

diff --git a/core/java/android/app/ActivityView.java b/core/java/android/app/ActivityView.java
index 4771f9f6ad04..3bf659b663b0 100644
--- a/core/java/android/app/ActivityView.java
+++ b/core/java/android/app/ActivityView.java
@@ -120,6 +120,7 @@ public class ActivityView extends ViewGroup {
 
         mActivityTaskManager = ActivityTaskManager.getService();
         mSurfaceView = new SurfaceView(context);
+        mSurfaceView.setAlpha(0f);
         mSurfaceCallback = new SurfaceCallback();
         mSurfaceView.getHolder().addCallback(mSurfaceCallback);
         addView(mSurfaceView);
@@ -347,6 +348,16 @@ public class ActivityView extends ViewGroup {
     }
 
     @Override
+    public void setAlpha(float alpha) {
+        mSurfaceView.setAlpha(alpha);
+    }
+
+    @Override
+    public float getAlpha() {
+        return mSurfaceView.getAlpha();
+    }
+
+    @Override
     public boolean gatherTransparentRegion(Region region) {
         // The tap exclude region may be affected by any view on top of it, so we detect the
         // possible change by monitoring this function.