Introduce EventBeatManager and enable events

Summary: This diff introduces the concept of EventBeatManager, this is a class that acts as a proxy between the list of EventBeats registered in C++ and the Android side.

Reviewed By: shergin

Differential Revision: D10127857

fbshipit-source-id: a1956ca42d4c470fbc11cc9f30336a182fe7910c

ReactAndroid/src/main/java/com/facebook/react/fabric/FabricBinding.java

@@ -1,37 +1,31 @@
 /**
  * Copyright (c) Facebook, Inc. and its affiliates.
  *
- * This source code is licensed under the MIT license found in the
- * LICENSE file in the root directory of this source tree.
+ * <p>This source code is licensed under the MIT license found in the LICENSE file in the root
+ * directory of this source tree.
  */
-
 package com.facebook.react.fabric;
 
 import com.facebook.react.bridge.JavaScriptContextHolder;
 import com.facebook.react.bridge.NativeMap;
-import com.facebook.react.bridge.UIManager;
 
 public interface FabricBinding {
 
-  void installFabric(JavaScriptContextHolder jsContext, FabricBinder fabricBinder);
+  // TODO: T31905686 change types of UIManager and EventBeatManager when moving to OSS
+  void installFabric(
+      JavaScriptContextHolder jsContext, FabricBinder fabricBinder, Object eventBeatManager);
 
   void releaseEventTarget(long jsContextNativePointer, long eventTargetPointer);
 
   void releaseEventHandler(long jsContextNativePointer, long eventHandlerPointer);
 
   void dispatchEventToEmptyTarget(
-    long jsContextNativePointer,
-    long eventHandlerPointer,
-    String type,
-    NativeMap payload
-  );
+      long jsContextNativePointer, long eventHandlerPointer, String type, NativeMap payload);
 
   void dispatchEventToTarget(
-    long jsContextNativePointer,
-    long eventHandlerPointer,
-    long eventTargetPointer,
-    String type,
-    NativeMap payload
-  );
-
+      long jsContextNativePointer,
+      long eventHandlerPointer,
+      long eventTargetPointer,
+      String type,
+      NativeMap payload);
 }

ReactAndroid/src/main/java/com/facebook/react/uimanager/events/BatchEventDispatchedListener.java

@@ -0,0 +1,16 @@
+/**
+ * Copyright (c) 2014-present, Facebook, Inc.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+package com.facebook.react.uimanager.events;
+
+public interface BatchEventDispatchedListener {
+
+  /**
+   * Called after a batch of low priority events has been dispatched.
+   */
+  void onBatchEventDispatched();
+
+}

ReactAndroid/src/main/java/com/facebook/react/uimanager/events/EventDispatcher.java

@@ -20,6 +20,7 @@ import com.facebook.systrace.Systrace;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.Comparator;
+import java.util.List;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicInteger;
 import javax.annotation.Nullable;
@@ -90,6 +91,7 @@ public class EventDispatcher implements LifecycleEventListener {
   private final DispatchEventsRunnable mDispatchEventsRunnable = new DispatchEventsRunnable();
   private final ArrayList<Event> mEventStaging = new ArrayList<>();
   private final ArrayList<EventDispatcherListener> mListeners = new ArrayList<>();
+  private final List<BatchEventDispatchedListener> mPostEventDispatchListeners = new ArrayList<>();
   private final ScheduleDispatchFrameCallback mCurrentFrameCallback =
     new ScheduleDispatchFrameCallback();
   private final AtomicInteger mHasDispatchScheduledCount = new AtomicInteger();
@@ -149,6 +151,14 @@ public class EventDispatcher implements LifecycleEventListener {
     mListeners.remove(listener);
   }
 
+  public void addBatchEventDispatchedListener(BatchEventDispatchedListener listener) {
+    mPostEventDispatchListeners.add(listener);
+  }
+
+  public void removeBatchEventDispatchedListener(BatchEventDispatchedListener listener) {
+    mPostEventDispatchListeners.remove(listener);
+  }
+
   @Override
   public void onHostResume() {
     mCurrentFrameCallback.maybePostFromNonUI();
@@ -355,6 +365,9 @@ public class EventDispatcher implements LifecycleEventListener {
             event.dispatch(mReactEventEmitter);
             event.dispose();
           }
+          for (BatchEventDispatchedListener listener : mPostEventDispatchListeners) {
+            listener.onBatchEventDispatched();
+          }
           clearEventsToDispatch();
           mEventCookieToLastEventIdx.clear();
         }

ReactAndroid/src/main/java/com/facebook/react/uimanager/events/ReactEventEmitter.java

@@ -9,7 +9,6 @@ package com.facebook.react.uimanager.events;
 
 import static com.facebook.react.uimanager.events.TouchesHelper.TARGET_KEY;
 
-import android.util.Log;
 import android.util.SparseArray;
 import com.facebook.infer.annotation.Assertions;
 import com.facebook.react.bridge.ReactApplicationContext;
@@ -17,8 +16,6 @@ import com.facebook.react.bridge.WritableArray;
 import com.facebook.react.bridge.WritableMap;
 import com.facebook.react.uimanager.common.UIManagerType;
 import com.facebook.react.uimanager.common.ViewUtil;
-import java.io.Closeable;
-import java.io.IOException;
 import javax.annotation.Nullable;
 
 public class ReactEventEmitter implements RCTEventEmitter {