Fire PlatformViewController FlutterView callbacks (#13015)

Fixes a bug where `PlatformViewController` was not being notified of `FlutterView` attachment changes.

shell/platform/android/BUILD.gn

@@ -417,6 +417,7 @@ action("robolectric_tests") {
     "test/io/flutter/embedding/android/FlutterActivityAndFragmentDelegateTest.java",
     "test/io/flutter/embedding/android/FlutterActivityTest.java",
     "test/io/flutter/embedding/android/FlutterFragmentTest.java",
+    "test/io/flutter/embedding/android/FlutterViewTest.java",
     "test/io/flutter/embedding/engine/FlutterEngineCacheTest.java",
     "test/io/flutter/embedding/engine/FlutterJNITest.java",
     "test/io/flutter/embedding/engine/RenderingComponentTest.java",

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

@@ -633,6 +633,8 @@ public class FlutterView extends FrameLayout {
     sendLocalesToFlutter(getResources().getConfiguration());
     sendViewportMetricsToFlutter();
 
+    flutterEngine.getPlatformViewsController().attachToView(this);
+
     // Notify engine attachment listeners of the attachment.
     for (FlutterEngineAttachmentListener listener : flutterEngineAttachmentListeners) {
       listener.onFlutterEngineAttachedToFlutterView(flutterEngine);
@@ -668,6 +670,8 @@ public class FlutterView extends FrameLayout {
       listener.onFlutterEngineDetachedFromFlutterView();
     }
 
+    flutterEngine.getPlatformViewsController().detachFromView();
+
     // Disconnect the FlutterEngine's PlatformViewsController from the AccessibilityBridge.
     flutterEngine.getPlatformViewsController().detachAccessibiltyBridge();
 

shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java

@@ -143,14 +143,19 @@ public class FlutterEngine implements LifecycleOwner {
    * and {@link FlutterLoader#ensureInitializationComplete(Context, String[])}.
    */
   public FlutterEngine(@NonNull Context context) {
-    this(context, FlutterLoader.getInstance());
+    this(context, FlutterLoader.getInstance(), new FlutterJNI());
   }
 
-  /* package */ FlutterEngine(@NonNull Context context, @NonNull FlutterLoader flutterLoader) {
+  /**
+   * Constructs a new {@code FlutterEngine}. See {@link #FlutterEngine(Context)}.
+   *
+   * {@code flutterJNI} should be a new instance that has never been attached to an engine before.
+   */
+  public FlutterEngine(@NonNull Context context, @NonNull FlutterLoader flutterLoader, @NonNull FlutterJNI flutterJNI) {
+    this.flutterJNI = flutterJNI;
     flutterLoader.startInitialization(context);
     flutterLoader.ensureInitializationComplete(context, null);
 
-    this.flutterJNI = new FlutterJNI();
     flutterJNI.addEngineLifecycleListener(engineLifecycleListener);
     attachToJni();
 

shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java

@@ -121,7 +121,7 @@ public class FlutterJNI {
 
   // TODO(mattcarroll): add javadocs
   @UiThread
-  public static native boolean nativeGetIsSoftwareRenderingEnabled();
+  public native boolean nativeGetIsSoftwareRenderingEnabled();
 
   @Nullable
   // TODO(mattcarroll): add javadocs

shell/platform/android/io/flutter/embedding/engine/renderer/FlutterRenderer.java

@@ -281,7 +281,7 @@ public class FlutterRenderer implements TextureRegistry {
 
   // TODO(mattcarroll): describe the native behavior that this invokes
   public boolean isSoftwareRenderingEnabled() {
-    return FlutterJNI.nativeGetIsSoftwareRenderingEnabled();
+    return flutterJNI.nativeGetIsSoftwareRenderingEnabled();
   }
 
   // TODO(mattcarroll): describe the native behavior that this invokes

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

@@ -38,7 +38,6 @@ import android.view.inputmethod.InputConnection;
 import android.view.inputmethod.InputMethodManager;
 
 import java.nio.ByteBuffer;
-import java.nio.ByteOrder;
 import java.util.ArrayList;
 import java.util.List;
 import java.util.Locale;
@@ -162,7 +161,7 @@ public class FlutterView extends SurfaceView implements BinaryMessenger, Texture
 
         dartExecutor = mNativeView.getDartExecutor();
         flutterRenderer = new FlutterRenderer(mNativeView.getFlutterJNI());
-        mIsSoftwareRenderingEnabled = FlutterJNI.nativeGetIsSoftwareRenderingEnabled();
+        mIsSoftwareRenderingEnabled = mNativeView.getFlutterJNI().nativeGetIsSoftwareRenderingEnabled();
         mMetrics = new ViewportMetrics();
         mMetrics.devicePixelRatio = context.getResources().getDisplayMetrics().density;
         setFocusable(true);

shell/platform/android/test/io/flutter/FlutterTestSuite.java

@@ -10,6 +10,7 @@ import org.junit.runners.Suite.SuiteClasses;
 
 import io.flutter.embedding.android.FlutterActivityTest;
 import io.flutter.embedding.android.FlutterFragmentTest;
+import io.flutter.embedding.android.FlutterViewTest;
 import io.flutter.embedding.engine.FlutterEngineCacheTest;
 import io.flutter.embedding.engine.FlutterJNITest;
 import io.flutter.embedding.engine.RenderingComponentTest;
@@ -28,6 +29,7 @@ import io.flutter.util.PreconditionsTest;
     FlutterFragmentTest.class,
     FlutterJNITest.class,
     FlutterRendererTest.class,
+    FlutterViewTest.class,
     PlatformChannelTest.class,
     PreconditionsTest.class,
     RenderingComponentTest.class,

shell/platform/android/test/io/flutter/embedding/android/FlutterViewTest.java

+package io.flutter.embedding.android;
+
+import static org.mockito.Mockito.spy;
+import static org.mockito.Mockito.times;
+import static org.mockito.Mockito.verify;
+import static org.mockito.Mockito.when;
+
+import io.flutter.embedding.engine.FlutterJNI;
+import io.flutter.embedding.engine.loader.FlutterLoader;
+import io.flutter.plugin.platform.PlatformViewsController;
+import org.junit.Before;
+import org.junit.Test;
+import org.junit.runner.RunWith;
+import org.mockito.Mock;
+import org.mockito.MockitoAnnotations;
+import org.mockito.Spy;
+import org.robolectric.RobolectricTestRunner;
+import org.robolectric.RuntimeEnvironment;
+import org.robolectric.annotation.Config;
+
+import io.flutter.embedding.engine.FlutterEngine;
+
+@Config(manifest = Config.NONE)
+@RunWith(RobolectricTestRunner.class)
+public class FlutterViewTest {
+  @Mock FlutterJNI mockFlutterJni;
+  @Mock FlutterLoader mockFlutterLoader;
+  @Spy PlatformViewsController platformViewsController;
+
+  @Before
+  public void setUp() {
+    MockitoAnnotations.initMocks(this);
+    when(mockFlutterJni.isAttached()).thenReturn(true);
+  }
+
+  @Test
+  public void attachToFlutterEngine_alertsPlatformViews() {
+    FlutterView flutterView = new FlutterView(RuntimeEnvironment.application);
+    FlutterEngine flutterEngine = spy(new FlutterEngine(RuntimeEnvironment.application, mockFlutterLoader, mockFlutterJni));
+    when(flutterEngine.getPlatformViewsController()).thenReturn(platformViewsController);
+
+    flutterView.attachToFlutterEngine(flutterEngine);
+
+    verify(platformViewsController, times(1)).attachToView(flutterView);
+  }
+
+   @Test
+   public void detachFromFlutterEngine_alertsPlatformViews() {
+     FlutterView flutterView = new FlutterView(RuntimeEnvironment.application);
+     FlutterEngine flutterEngine = spy(new FlutterEngine(RuntimeEnvironment.application, mockFlutterLoader, mockFlutterJni));
+     when(flutterEngine.getPlatformViewsController()).thenReturn(platformViewsController);
+
+     flutterView.attachToFlutterEngine(flutterEngine);
+     flutterView.detachFromFlutterEngine();
+
+     verify(platformViewsController, times(1)).detachFromView();
+   }
+}