[android] Remove the FlutterView casting, add a @NonNull and fix code style

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

@@ -1193,7 +1193,7 @@ public void detachFromFlutterEngine() {
     flutterEngine.getPlatformViewsController().detachFromView();
 
     // Disconnect the FlutterEngine's PlatformViewsController from the AccessibilityBridge.
-    flutterEngine.getPlatformViewsController().detachAccessibiltyBridge();
+    flutterEngine.getPlatformViewsController().detachAccessibilityBridge();
 
     // Disconnect and clean up the AccessibilityBridge.
     accessibilityBridge.release();

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

@@ -68,7 +68,7 @@ default void onFlutterViewDetached() {}
    */
   // Default interface methods are supported on all min SDK versions of Android.
   @SuppressLint("NewApi")
-  default void onInputConnectionLocked() {};
+  default void onInputConnectionLocked() {}
 
   /**
    * Callback fired when the platform input connection has been unlocked. See also {@link
@@ -79,5 +79,5 @@ default void onFlutterViewDetached() {}
    */
   // Default interface methods are supported on all min SDK versions of Android.
   @SuppressLint("NewApi")
-  default void onInputConnectionUnlocked() {};
+  default void onInputConnectionUnlocked() {}
 }

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

@@ -32,5 +32,5 @@ public interface PlatformViewsAccessibilityDelegate {
    * <p>Any accessibility events sent by platform views belonging to this delegate will be ignored
    * until a new accessibility bridge is attached.
    */
-  void detachAccessibiltyBridge();
+  void detachAccessibilityBridge();
 }

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

@@ -41,8 +41,9 @@
 /**
  * Manages platform views.
  *
- * <p>Each {@link io.flutter.app.FlutterPluginRegistry} has a single platform views controller. A
- * platform views controller can be attached to at most one Flutter view.
+ * <p>Each {@link io.flutter.embedding.engine.FlutterEngine} or {@link
+ * io.flutter.app.FlutterPluginRegistry} has a single platform views controller. A platform views
+ * controller can be attached to at most one Flutter view.
  */
 public class PlatformViewsController implements PlatformViewsAccessibilityDelegate {
   private static final String TAG = "PlatformViewsController";
@@ -55,8 +56,7 @@ public class PlatformViewsController implements PlatformViewsAccessibilityDelega
   private Context context;
 
   // The View currently rendering the Flutter UI associated with these platform views.
-  // TODO(egarciad): Investigate if this can be downcasted to `FlutterView`.
-  private View flutterView;
+  private FlutterView flutterView;
 
   // The texture registry maintaining the textures into which the embedded views will be rendered.
   @Nullable private TextureRegistry textureRegistry;
@@ -111,10 +111,10 @@ public class PlatformViewsController implements PlatformViewsAccessibilityDelega
   private boolean synchronizeToNativeViewHierarchy = true;
 
   // Overlay layer IDs that were displayed since the start of the current frame.
-  private HashSet<Integer> currentFrameUsedOverlayLayerIds;
+  private final HashSet<Integer> currentFrameUsedOverlayLayerIds;
 
   // Platform view IDs that were displayed since the start of the current frame.
-  private HashSet<Integer> currentFrameUsedPlatformViewIds;
+  private final HashSet<Integer> currentFrameUsedPlatformViewIds;
 
   // Used to acquire the original motion events using the motionEventIds.
   private final MotionEventTracker motionEventTracker;
@@ -290,12 +290,9 @@ public void resizePlatformView(
           vdController.resize(
               physicalWidth,
               physicalHeight,
-              new Runnable() {
-                @Override
-                public void run() {
-                  unlockInputConnection(vdController);
-                  onComplete.run();
-                }
+              () -> {
+                unlockInputConnection(vdController);
+                onComplete.run();
               });
         }
 
@@ -483,7 +480,7 @@ public void detach() {
    * This {@code PlatformViewsController} and its {@code FlutterEngine} is now attached to an
    * Android {@code View} that renders a Flutter UI.
    */
-  public void attachToView(@NonNull View flutterView) {
+  public void attachToView(@NonNull FlutterView flutterView) {
     this.flutterView = flutterView;
 
     // Inform all existing platform views that they are now associated with
@@ -518,7 +515,7 @@ public void attachAccessibilityBridge(AccessibilityBridge accessibilityBridge) {
   }
 
   @Override
-  public void detachAccessibiltyBridge() {
+  public void detachAccessibilityBridge() {
     accessibilityEventsDelegate.setAccessibilityBridge(null);
   }
 
@@ -720,7 +717,7 @@ private void flushAllViews() {
 
   private void initializeRootImageViewIfNeeded() {
     if (synchronizeToNativeViewHierarchy && !flutterViewConvertedToImageView) {
-      ((FlutterView) flutterView).convertToImageView();
+      flutterView.convertToImageView();
       flutterViewConvertedToImageView = true;
     }
   }
@@ -764,7 +761,7 @@ void initializePlatformViewIfNeeded(int viewId) {
 
     platformViewParent.put(viewId, parentView);
     parentView.addView(platformView.getView());
-    ((FlutterView) flutterView).addView(parentView);
+    flutterView.addView(parentView);
   }
 
   public void attachToFlutterRenderer(FlutterRenderer flutterRenderer) {
@@ -829,7 +826,7 @@ public void onDisplayOverlaySurface(int id, int x, int y, int width, int height)
 
     final FlutterImageView overlayView = overlayLayerViews.get(id);
     if (overlayView.getParent() == null) {
-      ((FlutterView) flutterView).addView(overlayView);
+      flutterView.addView(overlayView);
     }
 
     FrameLayout.LayoutParams layoutParams = new FrameLayout.LayoutParams((int) width, (int) height);
@@ -852,14 +849,13 @@ public void onBeginFrame() {
    * <p>This member is not intended for public use, and is only visible for testing.
    */
   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.
     //
     // Otherwise, acquire the latest image.
     if (flutterViewConvertedToImageView && currentFrameUsedPlatformViewIds.isEmpty()) {
       flutterViewConvertedToImageView = false;
-      view.revertImageView(
+      flutterView.revertImageView(
           () -> {
             // Destroy overlay surfaces once the surface reversion is completed.
             finishFrame(false);
@@ -876,7 +872,7 @@ public void onEndFrame() {
     // dropped.
     // For example, a toolbar widget painted by Flutter may not be rendered.
     final boolean isFrameRenderedUsingImageReaders =
-        flutterViewConvertedToImageView && view.acquireLatestImageViewFrame();
+        flutterViewConvertedToImageView && flutterView.acquireLatestImageViewFrame();
     finishFrame(isFrameRenderedUsingImageReaders);
   }
 
@@ -886,7 +882,7 @@ private void finishFrame(boolean isFrameRenderedUsingImageReaders) {
       final FlutterImageView overlayView = overlayLayerViews.valueAt(i);
 
       if (currentFrameUsedOverlayLayerIds.contains(overlayId)) {
-        ((FlutterView) flutterView).attachOverlaySurfaceToRender(overlayView);
+        flutterView.attachOverlaySurfaceToRender(overlayView);
         final boolean didAcquireOverlaySurfaceImage = overlayView.acquireLatestImage();
         isFrameRenderedUsingImageReaders &= didAcquireOverlaySurfaceImage;
       } else {
@@ -970,12 +966,11 @@ public FlutterOverlaySurface createOverlaySurface() {
    */
   public void destroyOverlaySurfaces() {
     for (int i = 0; i < overlayLayerViews.size(); i++) {
-      int overlayId = overlayLayerViews.keyAt(i);
       FlutterImageView overlayView = overlayLayerViews.valueAt(i);
       overlayView.detachFromRenderer();
       overlayView.closeImageReader();
       if (flutterView != null) {
-        ((FlutterView) flutterView).removeView(overlayView);
+        flutterView.removeView(overlayView);
       }
     }
     overlayLayerViews.clear();

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

@@ -4,7 +4,6 @@
 
 package io.flutter.plugin.platform;
 
-import static android.content.Context.INPUT_METHOD_SERVICE;
 import static android.content.Context.WINDOW_SERVICE;
 import static android.view.View.OnFocusChangeListener;
 
@@ -99,7 +98,7 @@ static class PresentationState {
   // presentation.
   private FrameLayout container;
 
-  private PresentationState state;
+  private final PresentationState state;
 
   private boolean startFocused = false;
 

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

@@ -64,7 +64,7 @@ public static VirtualDisplayController create(
   private final OnFocusChangeListener focusChangeListener;
   private VirtualDisplay virtualDisplay;
   @VisibleForTesting SingleViewPresentation presentation;
-  private Surface surface;
+  private final Surface surface;
 
   private VirtualDisplayController(
       Context context,

shell/platform/android/io/flutter/view/AccessibilityBridge.java

@@ -137,8 +137,7 @@ public class AccessibilityBridge extends AccessibilityNodeProvider {
   @NonNull private final AccessibilityViewEmbedder accessibilityViewEmbedder;
 
   // The delegate for interacting with embedded platform views. Used to embed accessibility data for
-  // an embedded
-  // view in the accessibility tree.
+  // an embedded view in the accessibility tree.
   @NonNull private final PlatformViewsAccessibilityDelegate platformViewsAccessibilityDelegate;
 
   // Android's {@link ContentResolver}, which is used to observe the global
@@ -386,11 +385,7 @@ public AccessibilityBridge(
       @NonNull AccessibilityChannel accessibilityChannel,
       @NonNull AccessibilityManager accessibilityManager,
       @NonNull ContentResolver contentResolver,
-      // This should be @NonNull once the plumbing for
-      // io.flutter.embedding.engine.android.FlutterView is done.
-      // TODO(mattcarrol): Add the annotation once the plumbing is done.
-      // https://github.com/flutter/flutter/issues/29618
-      PlatformViewsAccessibilityDelegate platformViewsAccessibilityDelegate) {
+      @NonNull PlatformViewsAccessibilityDelegate platformViewsAccessibilityDelegate) {
     this(
         rootAccessibilityView,
         accessibilityChannel,
@@ -407,11 +402,7 @@ public AccessibilityBridge(
       @NonNull AccessibilityManager accessibilityManager,
       @NonNull ContentResolver contentResolver,
       @NonNull AccessibilityViewEmbedder accessibilityViewEmbedder,
-      // This should be @NonNull once the plumbing for
-      // io.flutter.embedding.engine.android.FlutterView is done.
-      // TODO(mattcarrol): Add the annotation once the plumbing is done.
-      // https://github.com/flutter/flutter/issues/29618
-      PlatformViewsAccessibilityDelegate platformViewsAccessibilityDelegate) {
+      @NonNull PlatformViewsAccessibilityDelegate platformViewsAccessibilityDelegate) {
     this.rootAccessibilityView = rootAccessibilityView;
     this.accessibilityChannel = accessibilityChannel;
     this.accessibilityManager = accessibilityManager;
@@ -464,13 +455,7 @@ public void onTouchExplorationStateChanged(boolean isTouchExplorationEnabled) {
       this.contentResolver.registerContentObserver(transitionUri, false, animationScaleObserver);
     }
 
-    // platformViewsAccessibilityDelegate should be @NonNull once the plumbing
-    // for io.flutter.embedding.engine.android.FlutterView is done.
-    // TODO(mattcarrol): Remove the null check once the plumbing is done.
-    // https://github.com/flutter/flutter/issues/29618
-    if (platformViewsAccessibilityDelegate != null) {
-      platformViewsAccessibilityDelegate.attachAccessibilityBridge(this);
-    }
+    platformViewsAccessibilityDelegate.attachAccessibilityBridge(this);
   }
 
   /**
@@ -482,13 +467,7 @@ public void onTouchExplorationStateChanged(boolean isTouchExplorationEnabled) {
    */
   public void release() {
     isReleased = true;
-    // platformViewsAccessibilityDelegate should be @NonNull once the plumbing
-    // for io.flutter.embedding.engine.android.FlutterView is done.
-    // TODO(mattcarrol): Remove the null check once the plumbing is done.
-    // https://github.com/flutter/flutter/issues/29618
-    if (platformViewsAccessibilityDelegate != null) {
-      platformViewsAccessibilityDelegate.detachAccessibiltyBridge();
-    }
+    platformViewsAccessibilityDelegate.detachAccessibilityBridge();
     setOnAccessibilityChangeListener(null);
     accessibilityManager.removeAccessibilityStateChangeListener(accessibilityStateChangeListener);
     if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.KITKAT) {

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

@@ -59,7 +59,7 @@ public class PlatformViewsControllerTest {
   public void itNotifiesVirtualDisplayControllersOfViewAttachmentAndDetachment() {
     // Setup test structure.
     // Create a fake View that represents the View that renders a Flutter UI.
-    View fakeFlutterView = new View(RuntimeEnvironment.systemContext);
+    FlutterView fakeFlutterView = new FlutterView(RuntimeEnvironment.systemContext);
 
     // Create fake VirtualDisplayControllers. This requires internal knowledge of
     // PlatformViewsController. We know that all PlatformViewsController does is