Replace Flutter surface only after all platform views are destroyed (f…

…lutter#24363)

shell/platform/android/io/flutter/embedding/android/FlutterView.java

@@ -999,6 +999,12 @@ public void detachFromFlutterEngine() {
     flutterEngine = null;
   }
 
+  @VisibleForTesting
+  @NonNull
+  public RenderSurface getRenderSurface() {
+    return renderSurface;
+  }
+
   @VisibleForTesting
   @NonNull
   public FlutterImageView createImageView() {

shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java

@@ -784,11 +784,11 @@ public void onBeginFrame() {
 
   public void onEndFrame() {
     final FlutterView view = (FlutterView) flutterView;
-    // If there are no platform views in the current frame,
-    // then revert the image view surface and use the previous surface.
+    // If there are no platform views, then revert the image view surface,
+    // and use the previous surface.
     //
     // Otherwise, acquire the latest image.
-    if (flutterViewConvertedToImageView && currentFrameUsedPlatformViewIds.isEmpty()) {
+    if (flutterViewConvertedToImageView && platformViews.size() == 0) {
       flutterViewConvertedToImageView = false;
       view.revertImageView(
           () -> {

shell/platform/android/test/io/flutter/plugin/platform/PlatformViewsControllerTest.java

@@ -415,6 +415,7 @@ public void onEndFrame__destroysOverlaySurfaceAfterFrameOnFlutterSurfaceView() {
 
     // Produce a frame that doesn't display platform views.
     platformViewsController.onBeginFrame();
+    disposePlatformView(jni, platformViewsController, platformViewId);
     platformViewsController.onEndFrame();
 
     verify(overlayImageView, never()).detachFromRenderer();
@@ -485,17 +486,80 @@ public void onEndFrame__removesPlatformViewParent() {
 
     // Simulate create call from the framework.
     createPlatformView(jni, platformViewsController, platformViewId, "testType");
-    platformViewsController.initializePlatformViewIfNeeded(platformViewId);
-    assertEquals(flutterView.getChildCount(), 2);
+    assertEquals(flutterView.getChildCount(), 1);
+    assertEquals(flutterView.getChildAt(0).getClass().getSimpleName(), "FlutterSurfaceView");
 
     // Simulate first frame from the framework.
     jni.onFirstFrame();
     platformViewsController.onBeginFrame();
+    platformViewsController.onDisplayPlatformView(
+        platformViewId, 0, 0, 100, 100, 200, 200, new FlutterMutatorsStack());
+    assertEquals(flutterView.getChildCount(), 3);
+    assertEquals(flutterView.getChildAt(0).getClass().getSimpleName(), "FlutterSurfaceView");
+    assertTrue(flutterView.getChildAt(1).getClass().getSimpleName().startsWith("FlutterImageView"));
+
     platformViewsController.onEndFrame();
+    assertEquals(flutterView.getChildCount(), 3);
+    assertEquals(flutterView.getChildAt(0).getClass().getSimpleName(), "FlutterSurfaceView");
+    assertTrue(flutterView.getChildAt(1).getClass().getSimpleName().startsWith("FlutterImageView"));
 
     // Simulate dispose call from the framework.
     disposePlatformView(jni, platformViewsController, platformViewId);
+    assertEquals(flutterView.getChildCount(), 2);
+    assertEquals(flutterView.getChildAt(0).getClass().getSimpleName(), "FlutterSurfaceView");
+    assertTrue(flutterView.getChildAt(1).getClass().getSimpleName().startsWith("FlutterImageView"));
+  }
+
+  @Test
+  @Config(shadows = {ShadowFlutterSurfaceView.class, ShadowFlutterJNI.class})
+  public void onEndFrame__revertsFlutterSurface() {
+    final PlatformViewsController platformViewsController = new PlatformViewsController();
+
+    final int platformViewId = 0;
+    assertNull(platformViewsController.getPlatformViewById(platformViewId));
+
+    final PlatformViewFactory viewFactory = mock(PlatformViewFactory.class);
+    final PlatformView platformView = mock(PlatformView.class);
+    final View androidView = mock(View.class);
+    when(platformView.getView()).thenReturn(androidView);
+    when(viewFactory.create(any(), eq(platformViewId), any())).thenReturn(platformView);
+
+    platformViewsController.getRegistry().registerViewFactory("testType", viewFactory);
+
+    final FlutterJNI jni = new FlutterJNI();
+    jni.attachToNative(false);
+
+    final FlutterView flutterView = attach(jni, platformViewsController);
+
+    jni.onFirstFrame();
+
+    // Simulate create call from the framework.
+    createPlatformView(jni, platformViewsController, platformViewId, "testType");
     assertEquals(flutterView.getChildCount(), 1);
+    assertEquals(flutterView.getChildAt(0).getClass().getSimpleName(), "FlutterSurfaceView");
+
+    // Simulate first frame from the framework.
+    jni.onFirstFrame();
+    platformViewsController.onBeginFrame();
+    platformViewsController.onDisplayPlatformView(
+        platformViewId, 0, 0, 100, 100, 200, 200, new FlutterMutatorsStack());
+    assertTrue(
+        flutterView.getRenderSurface().getClass().getSimpleName().contains("FlutterImageView"));
+
+    platformViewsController.onEndFrame();
+    assertTrue(
+        flutterView.getRenderSurface().getClass().getSimpleName().contains("FlutterImageView"));
+
+    platformViewsController.onBeginFrame();
+    platformViewsController.onEndFrame();
+    assertTrue(
+        flutterView.getRenderSurface().getClass().getSimpleName().contains("FlutterImageView"));
+
+    platformViewsController.onBeginFrame();
+    // Dispose the platform view is sufficient to flip the Flutter surface.
+    disposePlatformView(jni, platformViewsController, platformViewId);
+    platformViewsController.onEndFrame();
+    assertEquals(flutterView.getRenderSurface().getClass().getSimpleName(), "FlutterSurfaceView");
   }
 
   @Test
@@ -556,8 +620,6 @@ private static FlutterView attach(
         new FlutterView(context, FlutterView.RenderMode.surface) {
           @Override
           public FlutterImageView createImageView() {
-            final FlutterImageView view = mock(FlutterImageView.class);
-            when(view.acquireLatestImage()).thenReturn(true);
             return mock(FlutterImageView.class);
           }
         };