From 06485f3624df1ec75a20a9ccf8024f8e60d7c582 Mon Sep 17 00:00:00 2001
From: Matt Carroll <matthew-carroll@users.noreply.github.com>
Date: Wed, 12 Jun 2019 14:57:13 -0700
Subject: [PATCH 1/6] Android Embedding Refactor PR 31: Integrated
 PlatformViewsController in the new embedding.

---
 .../embedding/android/FlutterActivity.java    | 25 ++++++-
 .../embedding/android/FlutterFragment.java    | 71 ++++++++++++++++---
 .../embedding/android/FlutterView.java        | 64 ++++++++++++-----
 .../embedding/engine/FlutterEngine.java       |  3 +
 .../engine/FlutterEnginePluginRegistry.java   | 69 +++++++++---------
 .../activity/ActivityControlSurface.java      | 14 +++-
 .../activity/ActivityPluginBinding.java       |  8 +++
 .../plugins/shim/ShimPluginRegistry.java      | 38 +---------
 .../engine/plugins/shim/ShimRegistrar.java    |  2 +-
 .../platform/PlatformViewRegistryImpl.java    |  4 ++
 .../platform/PlatformViewsController.java     |  2 +-
 11 files changed, 196 insertions(+), 104 deletions(-)

diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java b/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java
index 3341db91c7569..3e04584805ab3 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java
@@ -16,6 +16,7 @@
 import android.os.Bundle;
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
+import android.support.v4.app.Fragment;
 import android.support.v4.app.FragmentActivity;
 import android.support.v4.app.FragmentManager;
 import android.util.TypedValue;
@@ -66,7 +67,10 @@
  * {@code Fragment}.
  */
 // TODO(mattcarroll): explain each call forwarded to Fragment (first requires resolution of PluginRegistry API).
-public class FlutterActivity extends FragmentActivity implements OnFirstFrameRenderedListener {
+public class FlutterActivity extends FragmentActivity
+    implements FlutterFragment.FlutterEngineProvider,
+    FlutterFragment.FlutterEngineConfigurator,
+    OnFirstFrameRenderedListener {
   private static final String TAG = "FlutterActivity";
 
   // Meta-data arguments, processed from manifest XML.
@@ -365,6 +369,25 @@ protected boolean shouldAttachEngineToActivity() {
     return true;
   }
 
+  /**
+   * Hook for subclasses to easily provide a custom {@code FlutterEngine}.
+   */
+  @Nullable
+  @Override
+  public FlutterEngine provideFlutterEngine(@NonNull Context context) {
+    // No-op. Hook for subclasses.
+    return null;
+  }
+
+  /**
+   * Hook for subclasses to easily configure a {@code FlutterEngine}, e.g., register
+   * plugins.
+   */
+  @Override
+  public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
+    // No-op. Hook for subclasses.
+  }
+
   @Override
   public void onPostResume() {
     super.onPostResume();
diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java b/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java
index 59d9719dc940d..cecbfb211fa71 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java
@@ -6,6 +6,8 @@
 
 import static android.content.ComponentCallbacks2.TRIM_MEMORY_RUNNING_LOW;
 
+import android.app.Activity;
+import android.arch.lifecycle.Lifecycle;
 import android.content.Context;
 import android.content.Intent;
 import android.os.Build;
@@ -27,6 +29,7 @@
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.renderer.OnFirstFrameRenderedListener;
 import io.flutter.plugin.platform.PlatformPlugin;
+import io.flutter.plugin.platform.PlatformViewsController;
 import io.flutter.view.FlutterMain;
 
 /**
@@ -296,6 +299,8 @@ public <T extends FlutterFragment> T build() {
   private FlutterView flutterView;
   @Nullable
   private PlatformPlugin platformPlugin;
+  @NonNull
+  private final PlatformViewsController platformViewsController = new PlatformViewsController();
 
   private final OnFirstFrameRenderedListener onFirstFrameRenderedListener = new OnFirstFrameRenderedListener() {
     @Override
@@ -359,8 +364,14 @@ public void onAttach(@NonNull Context context) {
       // sync with the Activity. We use the Fragment's Lifecycle because it is possible that the
       // attached Activity is not a LifecycleOwner.
       Log.d(TAG, "Attaching FlutterEngine to the Activity that owns this Fragment.");
-      flutterEngine.getActivityControlSurface().attachToActivity(getActivity(), getLifecycle());
+      flutterEngine.getActivityControlSurface().attachToActivity(
+          getActivity(),
+          getLifecycle(),
+          platformViewsController
+      );
     }
+
+    configureFlutterEngine(flutterEngine);
   }
 
   private void initializeFlutter(@NonNull Context context) {
@@ -401,11 +412,11 @@ private void setupFlutterEngine() {
       // Defer to the Activity that owns us to provide a FlutterEngine.
       Log.d(TAG, "Deferring to attached Activity to provide a FlutterEngine.");
       FlutterEngineProvider flutterEngineProvider = (FlutterEngineProvider) attachedActivity;
-      flutterEngine = flutterEngineProvider.getFlutterEngine(getContext());
+      flutterEngine = flutterEngineProvider.provideFlutterEngine(getContext());
       if (flutterEngine != null) {
         isFlutterEngineFromActivity = true;
+        return;
       }
-      return;
     }
 
     // Neither our subclass, nor our owning Activity wanted to provide a custom FlutterEngine.
@@ -434,11 +445,34 @@ protected FlutterEngine createFlutterEngine(@NonNull Context context) {
     return null;
   }
 
+  /**
+   * Configures a {@link FlutterEngine} after its creation.
+   * <p>
+   * This method is called after the given {@link FlutterEngine} has been attached to the
+   * owning {@code FragmentActivity}. See
+   * {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface#attachToActivity(Activity, Lifecycle, PlatformViewsController)}.
+   * <p>
+   * It is possible that the owning {@code FragmentActivity} opted not to connect itself as
+   * an {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface}. In that
+   * case, any configuration, e.g., plugins, must not expect or depend upon an available
+   * {@code Activity} at the time that this method is invoked.
+   * <p>
+   * The default behavior of this method is to defer to the owning {@code FragmentActivity}
+   * as a {@link FlutterEngineConfigurator}. Subclasses can override this method if the
+   * subclass needs to override the {@code FragmentActivity}'s behavior, or add to it.
+   */
+  protected void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
+    FragmentActivity attachedActivity = getActivity();
+    if (attachedActivity instanceof FlutterEngineConfigurator) {
+      ((FlutterEngineConfigurator) attachedActivity).configureFlutterEngine(flutterEngine);
+    }
+  }
+
   @Nullable
   @Override
-  public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
+  public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
     Log.v(TAG, "Creating FlutterView.");
-    flutterView = new FlutterView(getContext(), getRenderMode(), getTransparencyMode());
+    flutterView = new FlutterView(getActivity(), getRenderMode(), getTransparencyMode());
     flutterView.addOnFirstFrameRenderedListener(onFirstFrameRenderedListener);
     return flutterView;
   }
@@ -546,7 +580,7 @@ public void onStart() {
       @Override
       public void run() {
         Log.v(TAG, "Attaching FlutterEngine to FlutterView.");
-        flutterView.attachToFlutterEngine(flutterEngine);
+        flutterView.attachToFlutterEngine(flutterEngine, platformViewsController);
 
         // TODO(mattcarroll): the following call should exist here, but the plugin system needs to be revamped.
         //                    The existing attach() method does not know how to handle this kind of FlutterView.
@@ -788,7 +822,7 @@ protected void onFirstFrameRendered() {}
    * {@link FlutterActivity}s and/or {@code FlutterFragments}.
    * <p>
    * If the {@link FragmentActivity} that owns this {@code FlutterFragment} implements
-   * {@code FlutterEngineProvider}, that {@link FlutterActivity} will be given an opportunity
+   * {@code FlutterEngineProvider}, that {@link FragmentActivity} will be given an opportunity
    * to provide a {@link FlutterEngine} instead of the {@code FlutterFragment} creating a
    * new one. The {@link FragmentActivity} can provide an existing, pre-warmed {@link FlutterEngine},
    * if desired.
@@ -804,6 +838,27 @@ public interface FlutterEngineProvider {
      * to provide its own {@code FlutterEngine} instance.
      */
     @Nullable
-    FlutterEngine getFlutterEngine(@NonNull Context context);
+    FlutterEngine provideFlutterEngine(@NonNull Context context);
+  }
+
+  /**
+   * Configures a {@link FlutterEngine} after it is created, e.g., adds plugins.
+   * <p>
+   * This interface may be applied to a {@link FragmentActivity} that owns a {@code FlutterFragment}.
+   */
+  public interface FlutterEngineConfigurator {
+    /**
+     * Configures the given {@link FlutterEngine}.
+     * <p>
+     * This method is called after the given {@link FlutterEngine} has been attached to the
+     * owning {@code FragmentActivity}. See
+     * {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface#attachToActivity(Activity, Lifecycle, PlatformViewsController)}.
+     * <p>
+     * It is possible that the owning {@code FragmentActivity} opted not to connect itself as
+     * an {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface}. In that
+     * case, any configuration, e.g., plugins, must not expect or depend upon an available
+     * {@code Activity} at the time that this method is invoked.
+     */
+    void configureFlutterEngine(@NonNull FlutterEngine flutterEngine);
   }
 }
diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterView.java b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
index 45ad7515effed..3f3e74d7f18f3 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterView.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
@@ -5,6 +5,7 @@
 package io.flutter.embedding.android;
 
 import android.annotation.TargetApi;
+import android.app.Activity;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.graphics.Rect;
@@ -36,6 +37,7 @@
 import io.flutter.embedding.engine.renderer.FlutterRenderer;
 import io.flutter.embedding.engine.renderer.OnFirstFrameRenderedListener;
 import io.flutter.plugin.editing.TextInputPlugin;
+import io.flutter.plugin.platform.PlatformViewsController;
 import io.flutter.view.AccessibilityBridge;
 
 /**
@@ -72,6 +74,8 @@ public class FlutterView extends FrameLayout {
   @Nullable
   private FlutterRenderer.RenderSurface renderSurface;
   private boolean didRenderFirstFrame;
+  @Nullable
+  private PlatformViewsController platformViewsController;
 
   // Connections to a Flutter execution context.
   @Nullable
@@ -117,9 +121,11 @@ public void onFirstFrameRendered() {
    *   <li>{@link #renderMode} defaults to {@link RenderMode#surface}.</li>
    *   <li>{@link #transparencyMode} defaults to {@link TransparencyMode#opaque}.</li>
    * </ul>
+   * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
+   * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Context context) {
-    this(context, null, null, null);
+  public FlutterView(@NonNull Activity activity) {
+    this(activity, null, null, null);
   }
 
   /**
@@ -127,38 +133,49 @@ public FlutterView(@NonNull Context context) {
    * and allows selection of a {@link #renderMode}.
    * <p>
    * {@link #transparencyMode} defaults to {@link TransparencyMode#opaque}.
+   * <p>
+   * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
+   * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Context context, @NonNull RenderMode renderMode) {
-    this(context, null, renderMode, null);
+  public FlutterView(@NonNull Activity activity, @NonNull RenderMode renderMode) {
+    this(activity, null, renderMode, null);
   }
 
   /**
    * Constructs a {@code FlutterView} programmatically, without any XML attributes,
    * assumes the use of {@link RenderMode#surface}, and allows selection of a {@link #transparencyMode}.
+   * <p>
+   * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
+   * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Context context, @NonNull TransparencyMode transparencyMode) {
-    this(context, null, RenderMode.surface, transparencyMode);
+  public FlutterView(@NonNull Activity activity, @NonNull TransparencyMode transparencyMode) {
+    this(activity, null, RenderMode.surface, transparencyMode);
   }
 
   /**
    * Constructs a {@code FlutterView} programmatically, without any XML attributes, and allows
    * a selection of {@link #renderMode} and {@link #transparencyMode}.
+   * <p>
+   * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
+   * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Context context, @NonNull RenderMode renderMode, @NonNull TransparencyMode transparencyMode) {
-    this(context, null, renderMode, transparencyMode);
+  public FlutterView(@NonNull Activity activity, @NonNull RenderMode renderMode, @NonNull TransparencyMode transparencyMode) {
+    this(activity, null, renderMode, transparencyMode);
   }
 
   /**
    * Constructs a {@code FlutterSurfaceView} in an XML-inflation-compliant manner.
-   *
-   * // TODO(mattcarroll): expose renderMode in XML when build system supports R.attr
+   * <p>
+   * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
+   * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Context context, @Nullable AttributeSet attrs) {
-    this(context, attrs, null, null);
+   // TODO(mattcarroll): expose renderMode in XML when build system supports R.attr
+  public FlutterView(@NonNull Activity activity, @Nullable AttributeSet attrs) {
+    this(activity, attrs, null, null);
   }
 
-  private FlutterView(@NonNull Context context, @Nullable AttributeSet attrs, @Nullable RenderMode renderMode, @Nullable TransparencyMode transparencyMode) {
-    super(context, attrs);
+  private FlutterView(@NonNull Activity activity, @Nullable AttributeSet attrs, @Nullable RenderMode renderMode, @Nullable TransparencyMode transparencyMode) {
+    super(activity, attrs);
 
     this.renderMode = renderMode == null ? RenderMode.surface : renderMode;
     this.transparencyMode = transparencyMode != null ? transparencyMode : TransparencyMode.opaque;
@@ -511,7 +528,10 @@ private void resetWillNotDraw(boolean isAccessibilityEnabled, boolean isTouchExp
    * See {@link #detachFromFlutterEngine()} for information on how to detach from a
    * {@link FlutterEngine}.
    */
-  public void attachToFlutterEngine(@NonNull FlutterEngine flutterEngine) {
+  public void attachToFlutterEngine(
+      @NonNull FlutterEngine flutterEngine,
+      @NonNull PlatformViewsController platformViewsController
+  ) {
     Log.d(TAG, "Attaching to a FlutterEngine: " + flutterEngine);
     if (isAttachedToFlutterEngine()) {
       if (flutterEngine == this.flutterEngine) {
@@ -527,6 +547,7 @@ public void attachToFlutterEngine(@NonNull FlutterEngine flutterEngine) {
     }
 
     this.flutterEngine = flutterEngine;
+    this.platformViewsController = platformViewsController;
 
     // Instruct our FlutterRenderer that we are now its designated RenderSurface.
     didRenderFirstFrame = false;
@@ -537,7 +558,7 @@ public void attachToFlutterEngine(@NonNull FlutterEngine flutterEngine) {
     textInputPlugin = new TextInputPlugin(
         this,
         this.flutterEngine.getDartExecutor(),
-        null
+        platformViewsController
     );
     androidKeyProcessor = new AndroidKeyProcessor(
         this.flutterEngine.getKeyEventChannel(),
@@ -549,9 +570,7 @@ public void attachToFlutterEngine(@NonNull FlutterEngine flutterEngine) {
         flutterEngine.getAccessibilityChannel(),
         (AccessibilityManager) getContext().getSystemService(Context.ACCESSIBILITY_SERVICE),
         getContext().getContentResolver(),
-        // TODO(mattcaroll): plumb the platform views controller to the accessibility bridge.
-        // https://github.com/flutter/flutter/issues/29618
-        null
+        platformViewsController
     );
     accessibilityBridge.setOnAccessibilityChangeListener(onAccessibilityChangeListener);
     resetWillNotDraw(
@@ -559,6 +578,10 @@ public void attachToFlutterEngine(@NonNull FlutterEngine flutterEngine) {
         accessibilityBridge.isTouchExplorationEnabled()
     );
 
+    // Connect AccessibilityBridge to the PlatformViewsController within the FlutterEngine.
+    // This allows platform Views to hook into Flutter's overall accessibility system.
+    platformViewsController.attachAccessibilityBridge(accessibilityBridge);
+
     // Inform the Android framework that it should retrieve a new InputConnection
     // now that an engine is attached.
     // TODO(mattcarroll): once this is proven to work, move this line ot TextInputPlugin
@@ -597,6 +620,9 @@ public void detachFromFlutterEngine() {
       listener.onFlutterEngineDetachedFromFlutterView();
     }
 
+    // Disconnect the FlutterEngine's PlatformViewsController from the AccessibilityBridge.
+    platformViewsController.detachAccessibiltyBridge();
+
     // Disconnect and clean up the AccessibilityBridge.
     accessibilityBridge.release();
     accessibilityBridge = null;
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java b/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
index 08ed9f75004f7..f79224247f8af 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
@@ -29,6 +29,8 @@
 import io.flutter.embedding.engine.systemchannels.SettingsChannel;
 import io.flutter.embedding.engine.systemchannels.SystemChannel;
 import io.flutter.embedding.engine.systemchannels.TextInputChannel;
+import io.flutter.plugin.platform.PlatformViewsAccessibilityDelegate;
+import io.flutter.plugin.platform.PlatformViewsController;
 
 /**
  * A single Flutter execution environment.
@@ -139,6 +141,7 @@ public FlutterEngine(@NonNull Context context) {
     textInputChannel = new TextInputChannel(dartExecutor);
 
     androidLifecycle = new FlutterEngineAndroidLifecycle(this);
+
     this.pluginRegistry = new FlutterEnginePluginRegistry(
       context.getApplicationContext(),
       this,
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java b/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java
index 370ac44605e49..82b89cbf52b3a 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java
@@ -34,13 +34,14 @@
 import io.flutter.embedding.engine.plugins.service.ServiceAware;
 import io.flutter.embedding.engine.plugins.service.ServiceControlSurface;
 import io.flutter.embedding.engine.plugins.service.ServicePluginBinding;
+import io.flutter.plugin.platform.PlatformViewsController;
 
 class FlutterEnginePluginRegistry implements PluginRegistry,
     ActivityControlSurface,
     ServiceControlSurface,
     BroadcastReceiverControlSurface,
     ContentProviderControlSurface {
-  private static final String TAG = "EnginePluginRegistry";
+  private static final String TAG = "FlutterEnginePluginRegistry";
 
   // PluginRegistry
   @NonNull
@@ -277,16 +278,32 @@ private boolean isAttachedToActivity() {
   }
 
   @Override
-  public void attachToActivity(@NonNull Activity activity, @NonNull Lifecycle lifecycle) {
+  public void attachToActivity(
+      @NonNull Activity activity,
+      @NonNull Lifecycle lifecycle,
+      @NonNull PlatformViewsController platformViewsController
+  ) {
     Log.v(TAG, "Attaching to an Activity: " + activity + "."
         + (isWaitingForActivityReattachment ? " This is after a config change." : ""));
     // If we were already attached to an Android component, detach from it.
     detachFromAndroidComponent();
 
     this.activity = activity;
-    this.activityPluginBinding = new FlutterEngineActivityPluginBinding(activity);
+    this.activityPluginBinding = new FlutterEngineActivityPluginBinding(
+        activity,
+        platformViewsController
+    );
     this.flutterEngineAndroidLifecycle.setBackingLifecycle(lifecycle);
 
+    // Activate the PlatformViewsController. This must happen before any plugins attempt
+    // to use it, otherwise an error strack trace will appear that says there is no
+    // flutter/platform_views channel.
+    platformViewsController.attach(
+        activity,
+        pluginBinding.getFlutterEngine().getRenderer(),
+        pluginBinding.getFlutterEngine().getDartExecutor()
+    );
+
     // Notify all ActivityAware plugins that they are now attached to a new Activity.
     for (ActivityAware activityAware : activityAwarePlugins.values()) {
       if (isWaitingForActivityReattachment) {
@@ -308,6 +325,9 @@ public void detachFromActivityForConfigChanges() {
         activityAware.onDetachedFromActivityForConfigChanges();
       }
 
+      // Deactivate PlatformViewsController.
+      activityPluginBinding.platformViewsController.detach();
+
       flutterEngineAndroidLifecycle.setBackingLifecycle(null);
       activity = null;
       activityPluginBinding = null;
@@ -504,6 +524,8 @@ private static class FlutterEngineActivityPluginBinding implements ActivityPlugi
     @NonNull
     private final Activity activity;
     @NonNull
+    private final PlatformViewsController platformViewsController;
+    @NonNull
     private final Set<io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener> onRequestPermissionsResultListeners = new HashSet<>();
     @NonNull
     private final Set<io.flutter.plugin.common.PluginRegistry.ActivityResultListener> onActivityResultListeners = new HashSet<>();
@@ -512,32 +534,28 @@ private static class FlutterEngineActivityPluginBinding implements ActivityPlugi
     @NonNull
     private final Set<io.flutter.plugin.common.PluginRegistry.UserLeaveHintListener> onUserLeaveHintListeners = new HashSet<>();
 
-    public FlutterEngineActivityPluginBinding(@NonNull Activity activity) {
+    public FlutterEngineActivityPluginBinding(@NonNull Activity activity, @NonNull PlatformViewsController platformViewsController) {
       this.activity = activity;
+      this.platformViewsController = platformViewsController;
     }
 
-    /**
-     * Returns the {@link Activity} that is currently attached to the {@link FlutterEngine} that
-     * owns this {@code ActivityPluginBinding}.
-     */
     @Override
     @NonNull
     public Activity getActivity() {
       return activity;
     }
 
-    /**
-     * Adds a listener that is invoked whenever the associated {@link Activity}'s
-     * {@code onRequestPermissionsResult(...)} method is invoked.
-     */
+    @NonNull
+    @Override
+    public PlatformViewsController getPlatformViewsController() {
+      return platformViewsController;
+    }
+
     @Override
     public void addRequestPermissionsResultListener(@NonNull io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener listener) {
       onRequestPermissionsResultListeners.add(listener);
     }
 
-    /**
-     * Removes a listener that was added in {@link #addRequestPermissionsResultListener(io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener)}.
-     */
     @Override
     public void removeRequestPermissionsResultListener(@NonNull io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener listener) {
       onRequestPermissionsResultListeners.remove(listener);
@@ -555,18 +573,11 @@ boolean onRequestPermissionsResult(int requestCode, @NonNull String[] permission
       return didConsumeResult;
     }
 
-    /**
-     * Adds a listener that is invoked whenever the associated {@link Activity}'s
-     * {@code onActivityResult(...)} method is invoked.
-     */
     @Override
     public void addActivityResultListener(@NonNull io.flutter.plugin.common.PluginRegistry.ActivityResultListener listener) {
       onActivityResultListeners.add(listener);
     }
 
-    /**
-     * Removes a listener that was added in {@link #addActivityResultListener(io.flutter.plugin.common.PluginRegistry.ActivityResultListener)}.
-     */
     @Override
     public void removeActivityResultListener(@NonNull io.flutter.plugin.common.PluginRegistry.ActivityResultListener listener) {
       onActivityResultListeners.remove(listener);
@@ -584,18 +595,11 @@ boolean onActivityResult(int requestCode, int resultCode, @Nullable Intent data)
       return didConsumeResult;
     }
 
-    /**
-     * Adds a listener that is invoked whenever the associated {@link Activity}'s
-     * {@code onNewIntent(...)} method is invoked.
-     */
     @Override
     public void addOnNewIntentListener(@NonNull io.flutter.plugin.common.PluginRegistry.NewIntentListener listener) {
       onNewIntentListeners.add(listener);
     }
 
-    /**
-     * Removes a listener that was added in {@link #addOnNewIntentListener(io.flutter.plugin.common.PluginRegistry.NewIntentListener)}.
-     */
     @Override
     public void removeOnNewIntentListener(@NonNull io.flutter.plugin.common.PluginRegistry.NewIntentListener listener) {
       onNewIntentListeners.remove(listener);
@@ -611,18 +615,11 @@ void onNewIntent(@Nullable Intent intent) {
       }
     }
 
-    /**
-     * Adds a listener that is invoked whenever the associated {@link Activity}'s
-     * {@code onUserLeaveHint()} method is invoked.
-     */
     @Override
     public void addOnUserLeaveHintListener(@NonNull io.flutter.plugin.common.PluginRegistry.UserLeaveHintListener listener) {
       onUserLeaveHintListeners.add(listener);
     }
 
-    /**
-     * Removes a listener that was added in {@link #addOnUserLeaveHintListener(io.flutter.plugin.common.PluginRegistry.UserLeaveHintListener)}.
-     */
     @Override
     public void removeOnUserLeaveHintListener(@NonNull io.flutter.plugin.common.PluginRegistry.UserLeaveHintListener listener) {
       onUserLeaveHintListeners.remove(listener);
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java
index c5833eca7ce67..19ec3d1354271 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java
@@ -10,6 +10,8 @@
 import android.support.annotation.NonNull;
 import android.support.annotation.Nullable;
 
+import io.flutter.plugin.platform.PlatformViewsController;
+
 /**
  * Control surface through which an {@link Activity} attaches to a {@link FlutterEngine}.
  * <p>
@@ -46,8 +48,11 @@ public interface ActivityControlSurface {
    * executing Dart code, the {@link Activity} should invoke this method. At that point the
    * {@link FlutterEngine} is considered "attached" to the {@link Activity} and all
    * {@link ActivityAware} plugins are given access to the {@link Activity}.
+   * <p>
+   * Flutter expects that platform views are supported whenever a Flutter UI is available,
+   * therefore, a {@link PlatformViewsController} is required when attaching to an {@code Activity}.
    */
-  void attachToActivity(@NonNull Activity activity, @NonNull Lifecycle lifecycle);
+  void attachToActivity(@NonNull Activity activity, @NonNull Lifecycle lifecycle, @NonNull PlatformViewsController platformViewsController);
 
   /**
    * Call this method from the {@link Activity} that is attached to this {@code ActivityControlSurfaces}'s
@@ -56,7 +61,11 @@ public interface ActivityControlSurface {
    * <p>
    * This method gives each {@link ActivityAware} plugin an opportunity to clean up its references
    * before the {@link Activity is destroyed}.
+   * <p>
+   * This method does NOT detach the {@link PlatformViewsController} that was provided in the
+   * {@link #attachToActivity(Activity, Lifecycle, PlatformViewsController)} method.
    */
+   // TODO(mattcarroll): once platform views are fully updated for lifecycle purposes, reconsider detaching PlatformViewsController here.
   void detachFromActivityForConfigChanges();
 
   /**
@@ -66,6 +75,9 @@ public interface ActivityControlSurface {
    * <p>
    * This method gives each {@link ActivityAware} plugin an opportunity to clean up its references
    * before the {@link Activity is destroyed}.
+   * <p>
+   * Invocation of this method also detaches the {@link PlatformViewsController} that was provided
+   * in the {@link #attachToActivity(Activity, Lifecycle, PlatformViewsController)} method.
    */
   void detachFromActivity();
 
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java
index 9420c43c57b10..c9b0df3e2338c 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java
@@ -8,6 +8,7 @@
 import android.support.annotation.NonNull;
 
 import io.flutter.plugin.common.PluginRegistry;
+import io.flutter.plugin.platform.PlatformViewsController;
 
 /**
  * Binding that gives {@link ActivityAware} plugins access to an associated {@link Activity} and
@@ -22,6 +23,13 @@ public interface ActivityPluginBinding {
   @NonNull
   Activity getActivity();
 
+  /**
+   * Returns the {@link PlatformViewsController} that is currently connected to the Flutter UI
+   * being displayed in the given {@code Activity}.
+   */
+  @NonNull
+  PlatformViewsController getPlatformViewsController();
+
   /**
    * Adds a listener that is invoked whenever the associated {@link Activity}'s
    * {@code onRequestPermissionsResult(...)} method is invoked.
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimPluginRegistry.java b/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimPluginRegistry.java
index ce85eb0f37c90..011eea303bab1 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimPluginRegistry.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimPluginRegistry.java
@@ -4,7 +4,6 @@
 
 package io.flutter.embedding.engine.plugins.shim;
 
-import android.app.Activity;
 import android.support.annotation.NonNull;
 
 import java.util.HashMap;
@@ -18,8 +17,6 @@
 import io.flutter.embedding.engine.plugins.activity.ActivityAware;
 import io.flutter.embedding.engine.plugins.activity.ActivityPluginBinding;
 import io.flutter.plugin.common.PluginRegistry;
-import io.flutter.plugin.platform.PlatformViewsController;
-import io.flutter.view.FlutterView;
 
 /**
  * A {@link PluginRegistry} that is shimmed to use the new Android embedding and plugin API behind
@@ -41,24 +38,11 @@ public class ShimPluginRegistry implements PluginRegistry {
   private static final String TAG = "ShimPluginRegistry";
 
   private final FlutterEngine flutterEngine;
-  private final PlatformViewsController platformViewsController;
   private final Map<String, Object> pluginMap = new HashMap<>();
   private final ShimRegistrarAggregate shimRegistrarAggregate;
-  private final FlutterEngine.EngineLifecycleListener engineLifecycleListener = new FlutterEngine.EngineLifecycleListener() {
-    @Override
-    public void onPreEngineRestart() {
-      Log.v(TAG, "onPreEngineRestart()");
-      ShimPluginRegistry.this.onPreEngineRestart();
-    }
-  };
 
-  public ShimPluginRegistry(
-      @NonNull FlutterEngine flutterEngine,
-      @NonNull PlatformViewsController platformViewsController
-  ) {
+  public ShimPluginRegistry(@NonNull FlutterEngine flutterEngine) {
     this.flutterEngine = flutterEngine;
-    this.flutterEngine.addEngineLifecycleListener(engineLifecycleListener);
-    this.platformViewsController = platformViewsController;
     this.shimRegistrarAggregate = new ShimRegistrarAggregate();
     this.flutterEngine.getPlugins().add(shimRegistrarAggregate);
   }
@@ -86,26 +70,6 @@ public <T> T valuePublishedByPlugin(String pluginKey) {
     return (T) pluginMap.get(pluginKey);
   }
 
-  //----- From FlutterPluginRegistry that aren't in the PluginRegistry interface ----//
-  public void attach(FlutterView flutterView, Activity activity) {
-    Log.v(TAG, "Attaching to a FlutterView and an Activity.");
-    platformViewsController.attach(activity, flutterEngine.getRenderer(), flutterEngine.getDartExecutor());
-  }
-
-  public void detach() {
-    Log.v(TAG, "Detaching from a FlutterView and an Activity.");
-    platformViewsController.detach();
-    platformViewsController.onFlutterViewDestroyed();
-  }
-
-  private void onPreEngineRestart() {
-    platformViewsController.onPreEngineRestart();
-  }
-
-  public PlatformViewsController getPlatformViewsController() {
-    return platformViewsController;
-  }
-
   /**
    * Aggregates all {@link ShimRegistrar}s within one single {@link FlutterPlugin}.
    * <p>
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java b/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java
index e6bb8e50c7860..813353275b3af 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java
@@ -74,7 +74,7 @@ public TextureRegistry textures() {
 
   @Override
   public PlatformViewRegistry platformViewRegistry() {
-    return null;
+    return activityPluginBinding != null ? activityPluginBinding.getPlatformViewsController().getRegistry() : null;
   }
 
   @Override
diff --git a/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java b/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java
index 5c303034c764f..87ffcfc001abe 100644
--- a/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java
+++ b/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java
@@ -7,6 +7,8 @@
 import java.util.HashMap;
 import java.util.Map;
 
+import io.flutter.Log;
+
 class PlatformViewRegistryImpl implements PlatformViewRegistry {
 
     PlatformViewRegistryImpl() {
@@ -20,11 +22,13 @@ class PlatformViewRegistryImpl implements PlatformViewRegistry {
     public boolean registerViewFactory(String viewTypeId, PlatformViewFactory factory) {
         if (viewFactories.containsKey(viewTypeId))
             return false;
+        Log.d("REPRO", "Registering " + viewTypeId + " -> " + factory + ", this: " + this);
         viewFactories.put(viewTypeId, factory);
         return true;
     }
 
     PlatformViewFactory getFactory(String viewTypeId) {
+        Log.d("REPRO", "Being asked for factory for " + viewTypeId + "... -> " + viewFactories.get(viewTypeId) + ", this: " + this);
         return viewFactories.get(viewTypeId);
     }
 }
diff --git a/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java b/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
index 201cfcb631066..d0c0bfbd1392d 100644
--- a/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
+++ b/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
@@ -263,7 +263,7 @@ public PlatformViewsController() {
      * Attaches this platform views controller to its input and output channels.
      *
      * @param context The base context that will be passed to embedded views created by this controller.
-     *                This should be the context of the Activity hosting the Flutter application.
+     *                This should be the {@code Application} {@code Context}.
      * @param textureRegistry The texture registry which provides the output textures into which the embedded views
      *                        will be rendered.
      * @param dartExecutor The dart execution context, which is used to setup a system channel.

From 94e260d90ffd0ff77fc8536fdb7eeaad9128769e Mon Sep 17 00:00:00 2001
From: Matt Carroll <matthew-carroll@users.noreply.github.com>
Date: Thu, 13 Jun 2019 23:43:56 -0700
Subject: [PATCH 2/6] PR Updates.

---
 .../android/io/flutter/embedding/engine/FlutterEngine.java    | 3 ---
 .../io/flutter/plugin/platform/PlatformViewRegistryImpl.java  | 4 ----
 .../io/flutter/plugin/platform/PlatformViewsController.java   | 2 +-
 3 files changed, 1 insertion(+), 8 deletions(-)

diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java b/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
index f79224247f8af..08ed9f75004f7 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
@@ -29,8 +29,6 @@
 import io.flutter.embedding.engine.systemchannels.SettingsChannel;
 import io.flutter.embedding.engine.systemchannels.SystemChannel;
 import io.flutter.embedding.engine.systemchannels.TextInputChannel;
-import io.flutter.plugin.platform.PlatformViewsAccessibilityDelegate;
-import io.flutter.plugin.platform.PlatformViewsController;
 
 /**
  * A single Flutter execution environment.
@@ -141,7 +139,6 @@ public FlutterEngine(@NonNull Context context) {
     textInputChannel = new TextInputChannel(dartExecutor);
 
     androidLifecycle = new FlutterEngineAndroidLifecycle(this);
-
     this.pluginRegistry = new FlutterEnginePluginRegistry(
       context.getApplicationContext(),
       this,
diff --git a/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java b/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java
index 87ffcfc001abe..5c303034c764f 100644
--- a/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java
+++ b/shell/platform/android/io/flutter/plugin/platform/PlatformViewRegistryImpl.java
@@ -7,8 +7,6 @@
 import java.util.HashMap;
 import java.util.Map;
 
-import io.flutter.Log;
-
 class PlatformViewRegistryImpl implements PlatformViewRegistry {
 
     PlatformViewRegistryImpl() {
@@ -22,13 +20,11 @@ class PlatformViewRegistryImpl implements PlatformViewRegistry {
     public boolean registerViewFactory(String viewTypeId, PlatformViewFactory factory) {
         if (viewFactories.containsKey(viewTypeId))
             return false;
-        Log.d("REPRO", "Registering " + viewTypeId + " -> " + factory + ", this: " + this);
         viewFactories.put(viewTypeId, factory);
         return true;
     }
 
     PlatformViewFactory getFactory(String viewTypeId) {
-        Log.d("REPRO", "Being asked for factory for " + viewTypeId + "... -> " + viewFactories.get(viewTypeId) + ", this: " + this);
         return viewFactories.get(viewTypeId);
     }
 }
diff --git a/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java b/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
index d0c0bfbd1392d..201cfcb631066 100644
--- a/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
+++ b/shell/platform/android/io/flutter/plugin/platform/PlatformViewsController.java
@@ -263,7 +263,7 @@ public PlatformViewsController() {
      * Attaches this platform views controller to its input and output channels.
      *
      * @param context The base context that will be passed to embedded views created by this controller.
-     *                This should be the {@code Application} {@code Context}.
+     *                This should be the context of the Activity hosting the Flutter application.
      * @param textureRegistry The texture registry which provides the output textures into which the embedded views
      *                        will be rendered.
      * @param dartExecutor The dart execution context, which is used to setup a system channel.

From 64219fa7ee9acece22854524d511da1b30c57c64 Mon Sep 17 00:00:00 2001
From: Matt Carroll <matthew-carroll@users.noreply.github.com>
Date: Thu, 13 Jun 2019 23:51:52 -0700
Subject: [PATCH 3/6] PR Updates.

---
 .../embedding/android/FlutterView.java        | 24 +++++++++----------
 1 file changed, 12 insertions(+), 12 deletions(-)

diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterView.java b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
index 3f3e74d7f18f3..38608a25d749a 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterView.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
@@ -124,8 +124,8 @@ public void onFirstFrameRendered() {
    * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
    * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Activity activity) {
-    this(activity, null, null, null);
+  public FlutterView(@NonNull Context context) {
+    this(context, null, null, null);
   }
 
   /**
@@ -137,8 +137,8 @@ public FlutterView(@NonNull Activity activity) {
    * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
    * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Activity activity, @NonNull RenderMode renderMode) {
-    this(activity, null, renderMode, null);
+  public FlutterView(@NonNull Context context, @NonNull RenderMode renderMode) {
+    this(context, null, renderMode, null);
   }
 
   /**
@@ -148,8 +148,8 @@ public FlutterView(@NonNull Activity activity, @NonNull RenderMode renderMode) {
    * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
    * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Activity activity, @NonNull TransparencyMode transparencyMode) {
-    this(activity, null, RenderMode.surface, transparencyMode);
+  public FlutterView(@NonNull Context context, @NonNull TransparencyMode transparencyMode) {
+    this(context, null, RenderMode.surface, transparencyMode);
   }
 
   /**
@@ -159,8 +159,8 @@ public FlutterView(@NonNull Activity activity, @NonNull TransparencyMode transpa
    * {@code FlutterView} requires an {@code Activity} instead of a generic {@code Context}
    * to be compatible with {@link PlatformViewsController}.
    */
-  public FlutterView(@NonNull Activity activity, @NonNull RenderMode renderMode, @NonNull TransparencyMode transparencyMode) {
-    this(activity, null, renderMode, transparencyMode);
+  public FlutterView(@NonNull Context context, @NonNull RenderMode renderMode, @NonNull TransparencyMode transparencyMode) {
+    this(context, null, renderMode, transparencyMode);
   }
 
   /**
@@ -170,12 +170,12 @@ public FlutterView(@NonNull Activity activity, @NonNull RenderMode renderMode, @
    * to be compatible with {@link PlatformViewsController}.
    */
    // TODO(mattcarroll): expose renderMode in XML when build system supports R.attr
-  public FlutterView(@NonNull Activity activity, @Nullable AttributeSet attrs) {
-    this(activity, attrs, null, null);
+  public FlutterView(@NonNull Context context, @Nullable AttributeSet attrs) {
+    this(context, attrs, null, null);
   }
 
-  private FlutterView(@NonNull Activity activity, @Nullable AttributeSet attrs, @Nullable RenderMode renderMode, @Nullable TransparencyMode transparencyMode) {
-    super(activity, attrs);
+  private FlutterView(@NonNull Context context, @Nullable AttributeSet attrs, @Nullable RenderMode renderMode, @Nullable TransparencyMode transparencyMode) {
+    super(context, attrs);
 
     this.renderMode = renderMode == null ? RenderMode.surface : renderMode;
     this.transparencyMode = transparencyMode != null ? transparencyMode : TransparencyMode.opaque;

From e878c19a3fe5b0c04595ead88f86afa4b245774c Mon Sep 17 00:00:00 2001
From: Matt Carroll <matthew-carroll@users.noreply.github.com>
Date: Fri, 28 Jun 2019 14:50:04 -0700
Subject: [PATCH 4/6] PR Updates.

---
 .../android/io/flutter/embedding/android/FlutterActivity.java   | 2 ++
 .../android/io/flutter/embedding/engine/FlutterJNI.java         | 1 +
 2 files changed, 3 insertions(+)

diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java b/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java
index 3e04584805ab3..f9eabc5015cd4 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterActivity.java
@@ -382,6 +382,8 @@ public FlutterEngine provideFlutterEngine(@NonNull Context context) {
   /**
    * Hook for subclasses to easily configure a {@code FlutterEngine}, e.g., register
    * plugins.
+   * <p>
+   * This method is called after {@link #provideFlutterEngine(Context)}.
    */
   @Override
   public void configureFlutterEngine(@NonNull FlutterEngine flutterEngine) {
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
index 9dca768d8fdb9..c478cea46ab0a 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterJNI.java
@@ -419,6 +419,7 @@ private native void nativeDispatchPointerDataPacket(long nativePlatformViewId,
    * See {@link AccessibilityBridge} for an example of an {@link AccessibilityDelegate} and the
    * surrounding responsibilities.
    */
+  // TODO(mattcarroll): move AccessibilityDelegate definition into FlutterJNI. FlutterJNI should be the basis of dependencies, not the other way round.
   @UiThread
   public void setAccessibilityDelegate(@Nullable AccessibilityDelegate accessibilityDelegate) {
     ensureRunningOnMainThread();

From 7b3009522373481c2f6e0f0c8c8736b091d99d18 Mon Sep 17 00:00:00 2001
From: Matt Carroll <matthew-carroll@users.noreply.github.com>
Date: Mon, 1 Jul 2019 02:03:55 -0700
Subject: [PATCH 5/6] PR Updates.

---
 .../embedding/android/FlutterFragment.java    | 16 +++--------
 .../embedding/android/FlutterView.java        | 15 ++++------
 .../embedding/engine/FlutterEngine.java       | 17 +++++++++++
 .../engine/FlutterEnginePluginRegistry.java   | 28 ++++++-------------
 .../activity/ActivityControlSurface.java      | 12 +-------
 .../activity/ActivityPluginBinding.java       |  7 -----
 .../engine/plugins/shim/ShimRegistrar.java    |  2 +-
 7 files changed, 37 insertions(+), 60 deletions(-)

diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java b/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java
index cecbfb211fa71..4893002a5f280 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterFragment.java
@@ -29,7 +29,6 @@
 import io.flutter.embedding.engine.dart.DartExecutor;
 import io.flutter.embedding.engine.renderer.OnFirstFrameRenderedListener;
 import io.flutter.plugin.platform.PlatformPlugin;
-import io.flutter.plugin.platform.PlatformViewsController;
 import io.flutter.view.FlutterMain;
 
 /**
@@ -299,8 +298,6 @@ public <T extends FlutterFragment> T build() {
   private FlutterView flutterView;
   @Nullable
   private PlatformPlugin platformPlugin;
-  @NonNull
-  private final PlatformViewsController platformViewsController = new PlatformViewsController();
 
   private final OnFirstFrameRenderedListener onFirstFrameRenderedListener = new OnFirstFrameRenderedListener() {
     @Override
@@ -366,8 +363,7 @@ public void onAttach(@NonNull Context context) {
       Log.d(TAG, "Attaching FlutterEngine to the Activity that owns this Fragment.");
       flutterEngine.getActivityControlSurface().attachToActivity(
           getActivity(),
-          getLifecycle(),
-          platformViewsController
+          getLifecycle()
       );
     }
 
@@ -450,7 +446,7 @@ protected FlutterEngine createFlutterEngine(@NonNull Context context) {
    * <p>
    * This method is called after the given {@link FlutterEngine} has been attached to the
    * owning {@code FragmentActivity}. See
-   * {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface#attachToActivity(Activity, Lifecycle, PlatformViewsController)}.
+   * {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface#attachToActivity(Activity, Lifecycle)}.
    * <p>
    * It is possible that the owning {@code FragmentActivity} opted not to connect itself as
    * an {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface}. In that
@@ -580,11 +576,7 @@ public void onStart() {
       @Override
       public void run() {
         Log.v(TAG, "Attaching FlutterEngine to FlutterView.");
-        flutterView.attachToFlutterEngine(flutterEngine, platformViewsController);
-
-        // TODO(mattcarroll): the following call should exist here, but the plugin system needs to be revamped.
-        //                    The existing attach() method does not know how to handle this kind of FlutterView.
-        //flutterEngine.getPlugins().attach(this, getActivity());
+        flutterView.attachToFlutterEngine(flutterEngine);
 
         doInitialFlutterViewRun();
       }
@@ -852,7 +844,7 @@ public interface FlutterEngineConfigurator {
      * <p>
      * This method is called after the given {@link FlutterEngine} has been attached to the
      * owning {@code FragmentActivity}. See
-     * {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface#attachToActivity(Activity, Lifecycle, PlatformViewsController)}.
+     * {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface#attachToActivity(Activity, Lifecycle)}.
      * <p>
      * It is possible that the owning {@code FragmentActivity} opted not to connect itself as
      * an {@link io.flutter.embedding.engine.plugins.activity.ActivityControlSurface}. In that
diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterView.java b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
index 38608a25d749a..b8bc2a44cdab4 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterView.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
@@ -5,7 +5,6 @@
 package io.flutter.embedding.android;
 
 import android.annotation.TargetApi;
-import android.app.Activity;
 import android.content.Context;
 import android.content.res.Configuration;
 import android.graphics.Rect;
@@ -74,8 +73,6 @@ public class FlutterView extends FrameLayout {
   @Nullable
   private FlutterRenderer.RenderSurface renderSurface;
   private boolean didRenderFirstFrame;
-  @Nullable
-  private PlatformViewsController platformViewsController;
 
   // Connections to a Flutter execution context.
   @Nullable
@@ -529,8 +526,7 @@ private void resetWillNotDraw(boolean isAccessibilityEnabled, boolean isTouchExp
    * {@link FlutterEngine}.
    */
   public void attachToFlutterEngine(
-      @NonNull FlutterEngine flutterEngine,
-      @NonNull PlatformViewsController platformViewsController
+      @NonNull FlutterEngine flutterEngine
   ) {
     Log.d(TAG, "Attaching to a FlutterEngine: " + flutterEngine);
     if (isAttachedToFlutterEngine()) {
@@ -547,7 +543,6 @@ public void attachToFlutterEngine(
     }
 
     this.flutterEngine = flutterEngine;
-    this.platformViewsController = platformViewsController;
 
     // Instruct our FlutterRenderer that we are now its designated RenderSurface.
     didRenderFirstFrame = false;
@@ -558,7 +553,7 @@ public void attachToFlutterEngine(
     textInputPlugin = new TextInputPlugin(
         this,
         this.flutterEngine.getDartExecutor(),
-        platformViewsController
+        this.flutterEngine.getPlatformViewsController()
     );
     androidKeyProcessor = new AndroidKeyProcessor(
         this.flutterEngine.getKeyEventChannel(),
@@ -570,7 +565,7 @@ public void attachToFlutterEngine(
         flutterEngine.getAccessibilityChannel(),
         (AccessibilityManager) getContext().getSystemService(Context.ACCESSIBILITY_SERVICE),
         getContext().getContentResolver(),
-        platformViewsController
+        this.flutterEngine.getPlatformViewsController()
     );
     accessibilityBridge.setOnAccessibilityChangeListener(onAccessibilityChangeListener);
     resetWillNotDraw(
@@ -580,7 +575,7 @@ public void attachToFlutterEngine(
 
     // Connect AccessibilityBridge to the PlatformViewsController within the FlutterEngine.
     // This allows platform Views to hook into Flutter's overall accessibility system.
-    platformViewsController.attachAccessibilityBridge(accessibilityBridge);
+    this.flutterEngine.getPlatformViewsController().attachAccessibilityBridge(accessibilityBridge);
 
     // Inform the Android framework that it should retrieve a new InputConnection
     // now that an engine is attached.
@@ -621,7 +616,7 @@ public void detachFromFlutterEngine() {
     }
 
     // Disconnect the FlutterEngine's PlatformViewsController from the AccessibilityBridge.
-    platformViewsController.detachAccessibiltyBridge();
+    flutterEngine.getPlatformViewsController().detachAccessibiltyBridge();
 
     // Disconnect and clean up the AccessibilityBridge.
     accessibilityBridge.release();
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java b/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
index 08ed9f75004f7..3e2fb2b1c2644 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterEngine.java
@@ -29,6 +29,7 @@
 import io.flutter.embedding.engine.systemchannels.SettingsChannel;
 import io.flutter.embedding.engine.systemchannels.SystemChannel;
 import io.flutter.embedding.engine.systemchannels.TextInputChannel;
+import io.flutter.plugin.platform.PlatformViewsController;
 
 /**
  * A single Flutter execution environment.
@@ -88,6 +89,11 @@ public class FlutterEngine implements LifecycleOwner {
   @NonNull
   private final TextInputChannel textInputChannel;
 
+  // Platform Views.
+  @NonNull
+  private final PlatformViewsController platformViewsController;
+
+  // Engine Lifecycle.
   @NonNull
   private final Set<EngineLifecycleListener> engineLifecycleListeners = new HashSet<>();
   @NonNull
@@ -138,6 +144,8 @@ public FlutterEngine(@NonNull Context context) {
     systemChannel = new SystemChannel(dartExecutor);
     textInputChannel = new TextInputChannel(dartExecutor);
 
+    platformViewsController = new PlatformViewsController();
+
     androidLifecycle = new FlutterEngineAndroidLifecycle(this);
     this.pluginRegistry = new FlutterEnginePluginRegistry(
       context.getApplicationContext(),
@@ -300,6 +308,15 @@ public PluginRegistry getPlugins() {
     return pluginRegistry;
   }
 
+  /**
+   * {@code PlatformViewsController}, which controls all platform views running within
+   * this {@code FlutterEngine}.
+   */
+  @NonNull
+  public PlatformViewsController getPlatformViewsController() {
+    return platformViewsController;
+  }
+
   @NonNull
   public ActivityControlSurface getActivityControlSurface() {
     return pluginRegistry;
diff --git a/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java b/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java
index 82b89cbf52b3a..173aa915e663c 100644
--- a/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java
+++ b/shell/platform/android/io/flutter/embedding/engine/FlutterEnginePluginRegistry.java
@@ -280,8 +280,7 @@ private boolean isAttachedToActivity() {
   @Override
   public void attachToActivity(
       @NonNull Activity activity,
-      @NonNull Lifecycle lifecycle,
-      @NonNull PlatformViewsController platformViewsController
+      @NonNull Lifecycle lifecycle
   ) {
     Log.v(TAG, "Attaching to an Activity: " + activity + "."
         + (isWaitingForActivityReattachment ? " This is after a config change." : ""));
@@ -289,16 +288,13 @@ public void attachToActivity(
     detachFromAndroidComponent();
 
     this.activity = activity;
-    this.activityPluginBinding = new FlutterEngineActivityPluginBinding(
-        activity,
-        platformViewsController
-    );
+    this.activityPluginBinding = new FlutterEngineActivityPluginBinding(activity);
     this.flutterEngineAndroidLifecycle.setBackingLifecycle(lifecycle);
 
     // Activate the PlatformViewsController. This must happen before any plugins attempt
-    // to use it, otherwise an error strack trace will appear that says there is no
+    // to use it, otherwise an error stack trace will appear that says there is no
     // flutter/platform_views channel.
-    platformViewsController.attach(
+    pluginBinding.getFlutterEngine().getPlatformViewsController().attach(
         activity,
         pluginBinding.getFlutterEngine().getRenderer(),
         pluginBinding.getFlutterEngine().getDartExecutor()
@@ -326,7 +322,7 @@ public void detachFromActivityForConfigChanges() {
       }
 
       // Deactivate PlatformViewsController.
-      activityPluginBinding.platformViewsController.detach();
+      pluginBinding.getFlutterEngine().getPlatformViewsController().detach();
 
       flutterEngineAndroidLifecycle.setBackingLifecycle(null);
       activity = null;
@@ -344,6 +340,9 @@ public void detachFromActivity() {
         activityAware.onDetachedFromActivity();
       }
 
+      // Deactivate PlatformViewsController.
+      pluginBinding.getFlutterEngine().getPlatformViewsController().detach();
+
       flutterEngineAndroidLifecycle.setBackingLifecycle(null);
       activity = null;
       activityPluginBinding = null;
@@ -524,8 +523,6 @@ private static class FlutterEngineActivityPluginBinding implements ActivityPlugi
     @NonNull
     private final Activity activity;
     @NonNull
-    private final PlatformViewsController platformViewsController;
-    @NonNull
     private final Set<io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener> onRequestPermissionsResultListeners = new HashSet<>();
     @NonNull
     private final Set<io.flutter.plugin.common.PluginRegistry.ActivityResultListener> onActivityResultListeners = new HashSet<>();
@@ -534,9 +531,8 @@ private static class FlutterEngineActivityPluginBinding implements ActivityPlugi
     @NonNull
     private final Set<io.flutter.plugin.common.PluginRegistry.UserLeaveHintListener> onUserLeaveHintListeners = new HashSet<>();
 
-    public FlutterEngineActivityPluginBinding(@NonNull Activity activity, @NonNull PlatformViewsController platformViewsController) {
+    public FlutterEngineActivityPluginBinding(@NonNull Activity activity) {
       this.activity = activity;
-      this.platformViewsController = platformViewsController;
     }
 
     @Override
@@ -545,12 +541,6 @@ public Activity getActivity() {
       return activity;
     }
 
-    @NonNull
-    @Override
-    public PlatformViewsController getPlatformViewsController() {
-      return platformViewsController;
-    }
-
     @Override
     public void addRequestPermissionsResultListener(@NonNull io.flutter.plugin.common.PluginRegistry.RequestPermissionsResultListener listener) {
       onRequestPermissionsResultListeners.add(listener);
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java
index 19ec3d1354271..0f51c78d9595f 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityControlSurface.java
@@ -48,11 +48,8 @@ public interface ActivityControlSurface {
    * executing Dart code, the {@link Activity} should invoke this method. At that point the
    * {@link FlutterEngine} is considered "attached" to the {@link Activity} and all
    * {@link ActivityAware} plugins are given access to the {@link Activity}.
-   * <p>
-   * Flutter expects that platform views are supported whenever a Flutter UI is available,
-   * therefore, a {@link PlatformViewsController} is required when attaching to an {@code Activity}.
    */
-  void attachToActivity(@NonNull Activity activity, @NonNull Lifecycle lifecycle, @NonNull PlatformViewsController platformViewsController);
+  void attachToActivity(@NonNull Activity activity, @NonNull Lifecycle lifecycle);
 
   /**
    * Call this method from the {@link Activity} that is attached to this {@code ActivityControlSurfaces}'s
@@ -61,11 +58,7 @@ public interface ActivityControlSurface {
    * <p>
    * This method gives each {@link ActivityAware} plugin an opportunity to clean up its references
    * before the {@link Activity is destroyed}.
-   * <p>
-   * This method does NOT detach the {@link PlatformViewsController} that was provided in the
-   * {@link #attachToActivity(Activity, Lifecycle, PlatformViewsController)} method.
    */
-   // TODO(mattcarroll): once platform views are fully updated for lifecycle purposes, reconsider detaching PlatformViewsController here.
   void detachFromActivityForConfigChanges();
 
   /**
@@ -75,9 +68,6 @@ public interface ActivityControlSurface {
    * <p>
    * This method gives each {@link ActivityAware} plugin an opportunity to clean up its references
    * before the {@link Activity is destroyed}.
-   * <p>
-   * Invocation of this method also detaches the {@link PlatformViewsController} that was provided
-   * in the {@link #attachToActivity(Activity, Lifecycle, PlatformViewsController)} method.
    */
   void detachFromActivity();
 
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java
index c9b0df3e2338c..2958d79a81322 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/activity/ActivityPluginBinding.java
@@ -23,13 +23,6 @@ public interface ActivityPluginBinding {
   @NonNull
   Activity getActivity();
 
-  /**
-   * Returns the {@link PlatformViewsController} that is currently connected to the Flutter UI
-   * being displayed in the given {@code Activity}.
-   */
-  @NonNull
-  PlatformViewsController getPlatformViewsController();
-
   /**
    * Adds a listener that is invoked whenever the associated {@link Activity}'s
    * {@code onRequestPermissionsResult(...)} method is invoked.
diff --git a/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java b/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java
index 813353275b3af..39e5ea5764353 100644
--- a/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java
+++ b/shell/platform/android/io/flutter/embedding/engine/plugins/shim/ShimRegistrar.java
@@ -74,7 +74,7 @@ public TextureRegistry textures() {
 
   @Override
   public PlatformViewRegistry platformViewRegistry() {
-    return activityPluginBinding != null ? activityPluginBinding.getPlatformViewsController().getRegistry() : null;
+    return pluginBinding != null ? pluginBinding.getFlutterEngine().getPlatformViewsController().getRegistry() : null;
   }
 
   @Override

From 6a1f257f970c490f207716f1e376b73527ffa2a5 Mon Sep 17 00:00:00 2001
From: Matt Carroll <matthew-carroll@users.noreply.github.com>
Date: Mon, 1 Jul 2019 15:55:09 -0700
Subject: [PATCH 6/6] Implemented checkInputConnectionProxy in FlutterView.

---
 .../flutter/embedding/android/FlutterView.java   | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/shell/platform/android/io/flutter/embedding/android/FlutterView.java b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
index b8bc2a44cdab4..49b933c03ad44 100644
--- a/shell/platform/android/io/flutter/embedding/android/FlutterView.java
+++ b/shell/platform/android/io/flutter/embedding/android/FlutterView.java
@@ -18,6 +18,7 @@
 import android.util.AttributeSet;
 import android.view.KeyEvent;
 import android.view.MotionEvent;
+import android.view.View;
 import android.view.WindowInsets;
 import android.view.accessibility.AccessibilityManager;
 import android.view.accessibility.AccessibilityNodeProvider;
@@ -381,6 +382,21 @@ public InputConnection onCreateInputConnection(@NonNull EditorInfo outAttrs) {
     return textInputPlugin.createInputConnection(this, outAttrs);
   }
 
+  /**
+   * Allows a {@code View} that is not currently the input connection target to invoke commands on
+   * the {@link android.view.inputmethod.InputMethodManager}, which is otherwise disallowed.
+   * <p>
+   * Returns true to allow non-input-connection-targets to invoke methods on
+   * {@code InputMethodManager}, or false to exclusively allow the input connection target to invoke
+   * such methods.
+   */
+  @Override
+  public boolean checkInputConnectionProxy(View view) {
+    return flutterEngine != null
+        ? flutterEngine.getPlatformViewsController().checkInputConnectionProxy(view)
+        : super.checkInputConnectionProxy(view);
+  }
+
   /**
    * Invoked when key is released.
    *