Provide access to a mirror of WallpaperEngine SurfaceControl

Bug: 179127643
Test: manual: tested behavior of wallpaper preview in older
WallpaperPicker apk and new version

Change-Id: I3b66cbdf2198228e990fae6400d019da91bc93c9

2 files changed, 20 insertions, 13 deletions

diff --git a/core/java/android/service/wallpaper/IWallpaperEngine.aidl b/core/java/android/service/wallpaper/IWallpaperEngine.aidl
index fbb449d3875e..81af6a220444 100644
--- a/core/java/android/service/wallpaper/IWallpaperEngine.aidl
+++ b/core/java/android/service/wallpaper/IWallpaperEngine.aidl
@@ -21,27 +21,29 @@ import android.app.WallpaperColors;
 import android.graphics.Rect;
 import android.graphics.RectF;
 import android.view.MotionEvent;
+import android.view.SurfaceControl;
 import android.os.Bundle;
 
 /**
  * @hide
  */
-oneway interface IWallpaperEngine {
-    void setDesiredSize(int width, int height);
-    void setDisplayPadding(in Rect padding);
+interface IWallpaperEngine {
+    oneway void setDesiredSize(int width, int height);
+    oneway void setDisplayPadding(in Rect padding);
     @UnsupportedAppUsage
-    void setVisibility(boolean visible);
-    void setInAmbientMode(boolean inAmbientDisplay, long animationDuration);
+    oneway void setVisibility(boolean visible);
+    oneway void setInAmbientMode(boolean inAmbientDisplay, long animationDuration);
     @UnsupportedAppUsage
-    void dispatchPointer(in MotionEvent event);
+    oneway void dispatchPointer(in MotionEvent event);
     @UnsupportedAppUsage
-    void dispatchWallpaperCommand(String action, int x, int y,
+    oneway void dispatchWallpaperCommand(String action, int x, int y,
             int z, in Bundle extras);
-    void requestWallpaperColors();
+    oneway void requestWallpaperColors();
     @UnsupportedAppUsage
-    void destroy();
-    void setZoomOut(float scale);
-    void scalePreview(in Rect positionInWindow);
-    void removeLocalColorsAreas(in List<RectF> regions);
-    void addLocalColorsAreas(in List<RectF> regions);
+    oneway void destroy();
+    oneway void setZoomOut(float scale);
+    oneway void scalePreview(in Rect positionInWindow);
+    oneway void removeLocalColorsAreas(in List<RectF> regions);
+    oneway void addLocalColorsAreas(in List<RectF> regions);
+    SurfaceControl mirrorSurfaceControl();
 }
diff --git a/core/java/android/service/wallpaper/WallpaperService.java b/core/java/android/service/wallpaper/WallpaperService.java
index 71784ef0b4d6..d89c29a5a360 100644
--- a/core/java/android/service/wallpaper/WallpaperService.java
+++ b/core/java/android/service/wallpaper/WallpaperService.java
@@ -1982,6 +1982,11 @@ public abstract class WallpaperService extends Service {
             mCaller.sendMessage(msg);
         }
 
+        @Nullable
+        public SurfaceControl mirrorSurfaceControl() {
+            return mEngine == null ? null : SurfaceControl.mirrorSurface(mEngine.mSurfaceControl);
+        }
+
         private void doDetachEngine() {
             mActiveEngines.remove(mEngine);
             mEngine.detach();