View: Expose gatherTransparentRegion

Recently exposed ViewRoot API requires requestTransparentRegion for
many of the use cases we want to support. requestTransparentRegion is
already public API, however the documentation and definition is a little
confusing and arguably it shouldn't do anything unless we also implement
gatherTransparentRegion. gatherTransparentRegion is already made public
through SurfaceView, and so exposing it properly on View seems like
a non disruptive option.

Bug: 179647628
Test: android.view.cts.ViewRootSyncTest
Change-Id: I72fb2744bc03cdd26d64547dbebeb12751a33a2a

1 files changed, 2 insertions, 4 deletions

diff --git a/core/java/android/view/View.java b/core/java/android/view/View.java
index bed5eea2d199..afba492ba192 100644
--- a/core/java/android/view/View.java
+++ b/core/java/android/view/View.java
@@ -26115,7 +26115,7 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
     }
 
     /**
-     * This is used by the RootView to perform an optimization when
+     * This is used by the ViewRoot to perform an optimization when
      * the view hierarchy contains one or several SurfaceView.
      * SurfaceView is always considered transparent, but its children are not,
      * therefore all View objects remove themselves from the global transparent
@@ -26127,10 +26127,8 @@ public class View implements Drawable.Callback, KeyEvent.Callback,
      * point is opaque, regardless of the transparent region; returns false
      * if it is possible for underlying windows to be seen behind the view.
      *
-     * {@hide}
      */
-    @UnsupportedAppUsage
-    public boolean gatherTransparentRegion(Region region) {
+    public boolean gatherTransparentRegion(@Nullable Region region) {
         final AttachInfo attachInfo = mAttachInfo;
         if (region != null && attachInfo != null) {
             final int pflags = mPrivateFlags;