Create PlatformView instance right after method channel call from Dart (flutter#20500)

Author: Emmanuel Garcia

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

@@ -79,7 +79,6 @@ public class PlatformViewsController implements PlatformViewsAccessibilityDelega
   // it is associated with(e.g if a platform view creates other views in the same virtual display.
   private final HashMap<Context, View> contextToPlatformView;
 
-  private final SparseArray<PlatformViewsChannel.PlatformViewCreationRequest> platformViewRequests;
   private final SparseArray<View> platformViews;
   private final SparseArray<FlutterMutatorView> mutatorViews;
 
@@ -107,18 +106,45 @@ public class PlatformViewsController implements PlatformViewsAccessibilityDelega
         @Override
         public void createAndroidViewForPlatformView(
             @NonNull PlatformViewsChannel.PlatformViewCreationRequest request) {
-          // API level 19 is required for android.graphics.ImageReader.
+          // API level 19 is required for `android.graphics.ImageReader`.
           ensureValidAndroidVersion(Build.VERSION_CODES.KITKAT);
-          platformViewRequests.put(request.viewId, request);
+
+          if (!validateDirection(request.direction)) {
+            throw new IllegalStateException(
+                "Trying to create a view with unknown direction value: "
+                    + request.direction
+                    + "(view id: "
+                    + request.viewId
+                    + ")");
+          }
+
+          final PlatformViewFactory factory = registry.getFactory(request.viewType);
+          if (factory == null) {
+            throw new IllegalStateException(
+                "Trying to create a platform view of unregistered type: " + request.viewType);
+          }
+
+          Object createParams = null;
+          if (request.params != null) {
+            createParams = factory.getCreateArgsCodec().decodeMessage(request.params);
+          }
+
+          final PlatformView platformView = factory.create(context, request.viewId, createParams);
+          final View view = platformView.getView();
+          if (view == null) {
+            throw new IllegalStateException(
+                "PlatformView#getView() returned null, but an Android view reference was expected.");
+          }
+          if (view.getParent() != null) {
+            throw new IllegalStateException(
+                "The Android view returned from PlatformView#getView() was already added to a parent view.");
+          }
+          platformViews.put(request.viewId, view);
         }
 
         @Override
         public void disposeAndroidViewForPlatformView(int viewId) {
           // Hybrid view.
-          if (platformViewRequests.get(viewId) != null) {
-            platformViewRequests.remove(viewId);
-          }
-
           final View platformView = platformViews.get(viewId);
           if (platformView != null) {
             final FlutterMutatorView mutatorView = mutatorViews.get(viewId);
@@ -378,7 +404,6 @@ public PlatformViewsController() {
     currentFrameUsedOverlayLayerIds = new HashSet<>();
     currentFrameUsedPlatformViewIds = new HashSet<>();
 
-    platformViewRequests = new SparseArray<>();
     platformViews = new SparseArray<>();
     mutatorViews = new SparseArray<>();
 
@@ -651,50 +676,15 @@ private void initializeRootImageViewIfNeeded() {
 
   @VisibleForTesting
   void initializePlatformViewIfNeeded(int viewId) {
-    if (platformViews.get(viewId) != null) {
-      return;
-    }
-
-    PlatformViewsChannel.PlatformViewCreationRequest request = platformViewRequests.get(viewId);
-    if (request == null) {
-      throw new IllegalStateException(
-          "Platform view hasn't been initialized from the platform view channel.");
-    }
-
-    if (!validateDirection(request.direction)) {
-      throw new IllegalStateException(
-          "Trying to create a view with unknown direction value: "
-              + request.direction
-              + "(view id: "
-              + viewId
-              + ")");
-    }
-
-    PlatformViewFactory factory = registry.getFactory(request.viewType);
-    if (factory == null) {
-      throw new IllegalStateException(
-          "Trying to create a platform view of unregistered type: " + request.viewType);
-    }
-
-    Object createParams = null;
-    if (request.params != null) {
-      createParams = factory.getCreateArgsCodec().decodeMessage(request.params);
-    }
-
-    PlatformView platformView = factory.create(context, viewId, createParams);
-    View view = platformView.getView();
-
+    final View view = platformViews.get(viewId);
     if (view == null) {
       throw new IllegalStateException(
-          "PlatformView#getView() returned null, but an Android view reference was expected.");
+          "Platform view hasn't been initialized from the platform view channel.");
     }
-    if (view.getParent() != null) {
-      throw new IllegalStateException(
-          "The Android view returned from PlatformView#getView() was already added to a parent view.");
+    if (mutatorViews.get(viewId) != null) {
+      return;
     }
-    platformViews.put(viewId, view);
-
-    FlutterMutatorView mutatorView =
+    final FlutterMutatorView mutatorView =
         new FlutterMutatorView(
             context, context.getResources().getDisplayMetrics().density, androidTouchProcessor);
     mutatorViews.put(viewId, mutatorView);

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

@@ -7,6 +7,7 @@
 
 import android.content.Context;
 import android.content.res.AssetManager;
+import android.util.SparseArray;
 import android.view.MotionEvent;
 import android.view.Surface;
 import android.view.SurfaceHolder;
@@ -28,7 +29,9 @@
 import io.flutter.embedding.engine.systemchannels.MouseCursorChannel;
 import io.flutter.embedding.engine.systemchannels.SettingsChannel;
 import io.flutter.embedding.engine.systemchannels.TextInputChannel;
+import io.flutter.plugin.common.FlutterException;
 import io.flutter.plugin.common.MethodCall;
+import io.flutter.plugin.common.StandardMessageCodec;
 import io.flutter.plugin.common.StandardMethodCodec;
 import io.flutter.plugin.localization.LocalizationPlugin;
 import java.nio.ByteBuffer;
@@ -242,7 +245,29 @@ public void getPlatformViewById__hybridComposition() {
 
   @Test
   @Config(shadows = {ShadowFlutterJNI.class})
-  public void initializePlatformViewIfNeeded__throwsIfViewIsNull() {
+  public void createPlatformViewMessage__initializesAndroidView() {
+    PlatformViewsController platformViewsController = new PlatformViewsController();
+
+    int platformViewId = 0;
+    assertNull(platformViewsController.getPlatformViewById(platformViewId));
+
+    PlatformViewFactory viewFactory = mock(PlatformViewFactory.class);
+    PlatformView platformView = mock(PlatformView.class);
+    when(platformView.getView()).thenReturn(mock(View.class));
+    when(viewFactory.create(any(), eq(platformViewId), any())).thenReturn(platformView);
+    platformViewsController.getRegistry().registerViewFactory("testType", viewFactory);
+
+    FlutterJNI jni = new FlutterJNI();
+    attach(jni, platformViewsController);
+
+    // Simulate create call from the framework.
+    createPlatformView(jni, platformViewsController, platformViewId, "testType");
+    verify(platformView, times(1)).getView();
+  }
+
+  @Test
+  @Config(shadows = {ShadowFlutterJNI.class})
+  public void createPlatformViewMessage__throwsIfViewIsNull() {
     PlatformViewsController platformViewsController = new PlatformViewsController();
 
     int platformViewId = 0;
@@ -259,22 +284,28 @@ public void initializePlatformViewIfNeeded__throwsIfViewIsNull() {
 
     // Simulate create call from the framework.
     createPlatformView(jni, platformViewsController, platformViewId, "testType");
+    assertEquals(ShadowFlutterJNI.getResponses().size(), 1);
 
+    final ByteBuffer responseBuffer = ShadowFlutterJNI.getResponses().get(0);
+    responseBuffer.rewind();
+
+    StandardMethodCodec methodCodec = new StandardMethodCodec(new StandardMessageCodec());
     try {
-      platformViewsController.initializePlatformViewIfNeeded(platformViewId);
-    } catch (Exception exception) {
-      assertTrue(exception instanceof IllegalStateException);
-      assertEquals(
-          exception.getMessage(),
-          "PlatformView#getView() returned null, but an Android view reference was expected.");
+      methodCodec.decodeEnvelope(responseBuffer);
+    } catch (FlutterException exception) {
+      assertTrue(
+          exception
+              .getMessage()
+              .contains(
+                  "PlatformView#getView() returned null, but an Android view reference was expected."));
       return;
     }
-    assertTrue(false);
+    assertFalse(true);
   }
 
   @Test
   @Config(shadows = {ShadowFlutterJNI.class})
-  public void initializePlatformViewIfNeeded__throwsIfViewHasParent() {
+  public void createPlatformViewMessage__throwsIfViewHasParent() {
     PlatformViewsController platformViewsController = new PlatformViewsController();
 
     int platformViewId = 0;
@@ -293,16 +324,23 @@ public void initializePlatformViewIfNeeded__throwsIfViewHasParent() {
 
     // Simulate create call from the framework.
     createPlatformView(jni, platformViewsController, platformViewId, "testType");
+    assertEquals(ShadowFlutterJNI.getResponses().size(), 1);
+
+    final ByteBuffer responseBuffer = ShadowFlutterJNI.getResponses().get(0);
+    responseBuffer.rewind();
+
+    StandardMethodCodec methodCodec = new StandardMethodCodec(new StandardMessageCodec());
     try {
-      platformViewsController.initializePlatformViewIfNeeded(platformViewId);
-    } catch (Exception exception) {
-      assertTrue(exception instanceof IllegalStateException);
-      assertEquals(
-          exception.getMessage(),
-          "The Android view returned from PlatformView#getView() was already added to a parent view.");
+      methodCodec.decodeEnvelope(responseBuffer);
+    } catch (FlutterException exception) {
+      assertTrue(
+          exception
+              .getMessage()
+              .contains(
+                  "The Android view returned from PlatformView#getView() was already added to a parent view."));
       return;
     }
-    assertTrue(false);
+    assertFalse(true);
   }
 
   @Test
@@ -481,6 +519,7 @@ public FlutterImageView createImageView() {
 
   @Implements(FlutterJNI.class)
   public static class ShadowFlutterJNI {
+    private static SparseArray<ByteBuffer> replies = new SparseArray<>();
 
     public ShadowFlutterJNI() {}
 
@@ -527,7 +566,13 @@ public void setViewportMetrics(
 
     @Implementation
     public void invokePlatformMessageResponseCallback(
-        int responseId, ByteBuffer message, int position) {}
+        int responseId, ByteBuffer message, int position) {
+      replies.put(responseId, message);
+    }
+
+    public static SparseArray<ByteBuffer> getResponses() {
+      return replies;
+    }
   }
 
   @Implements(SurfaceView.class)