Fling][Android] Add synchronous event support (#44489)

Summary: Pull Request resolved: #44489 Changelog: [internal] Integrate a synchronous event API to trigger synchronous scroll events in Android. The API will be changed in the future, this is exposed only for experimentation. Reviewed By: sammy-SC Differential Revision: D56886403 fbshipit-source-id: 337277c735c0943ce4ba29bb2d646a72fe101ede
facebook · May 8, 2024 · dbc0334 · dbc0334
1 parent c913196
commit dbc0334
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Showing 13 changed files with 183 additions and 20 deletions.
diff --git a/packages/react-native/ReactAndroid/api/ReactAndroid.api b/packages/react-native/ReactAndroid/api/ReactAndroid.api
@@ -2569,7 +2569,7 @@ public final class com/facebook/react/fabric/FabricSoLoader {
 	public static final fun staticInit ()V
 }
 
-public class com/facebook/react/fabric/FabricUIManager : com/facebook/react/bridge/LifecycleEventListener, com/facebook/react/bridge/UIManager, com/facebook/react/fabric/interop/UIBlockViewResolver {
+public class com/facebook/react/fabric/FabricUIManager : com/facebook/react/bridge/LifecycleEventListener, com/facebook/react/bridge/UIManager, com/facebook/react/fabric/interop/UIBlockViewResolver, com/facebook/react/uimanager/events/SynchronousEventReceiver {
 	public static final field ENABLE_FABRIC_LOGS Z
 	public static final field ENABLE_FABRIC_PERF_LOGS Z
 	public static final field IS_DEVELOPMENT_ENVIRONMENT Z
@@ -2603,6 +2603,7 @@ public class com/facebook/react/fabric/FabricUIManager : com/facebook/react/brid
 	public fun profileNextBatch ()V
 	public fun receiveEvent (IILjava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
 	public fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;I)V
+	public fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;IZ)V
 	public fun receiveEvent (ILjava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
 	public fun removeUIManagerEventListener (Lcom/facebook/react/bridge/UIManagerListener;)V
 	public fun resolveCustomDirectEventName (Ljava/lang/String;)Ljava/lang/String;
@@ -2680,6 +2681,7 @@ public final class com/facebook/react/fabric/events/EventBeatManager : com/faceb
 public class com/facebook/react/fabric/events/EventEmitterWrapper {
 	public fun destroy ()V
 	public fun dispatch (Ljava/lang/String;Lcom/facebook/react/bridge/WritableMap;I)V
+	public fun dispatchEventSynchronously (Ljava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
 	public fun dispatchUnique (Ljava/lang/String;Lcom/facebook/react/bridge/WritableMap;)V
 }
 
@@ -5537,6 +5539,7 @@ public abstract class com/facebook/react/uimanager/events/Event {
 	public fun coalesce (Lcom/facebook/react/uimanager/events/Event;)Lcom/facebook/react/uimanager/events/Event;
 	public fun dispatch (Lcom/facebook/react/uimanager/events/RCTEventEmitter;)V
 	public fun dispatchModern (Lcom/facebook/react/uimanager/events/RCTModernEventEmitter;)V
+	protected fun experimental_isSynchronous ()Z
 	public fun getCoalescingKey ()S
 	public fun getEventAnimationDriverMatchSpec ()Lcom/facebook/react/uimanager/events/Event$EventAnimationDriverMatchSpec;
 	protected fun getEventCategory ()I
@@ -5711,6 +5714,10 @@ public abstract interface class com/facebook/react/uimanager/events/RCTModernEve
 	public abstract fun receiveTouches (Lcom/facebook/react/uimanager/events/TouchEvent;)V
 }
 
+public abstract interface class com/facebook/react/uimanager/events/SynchronousEventReceiver {
+	public abstract fun receiveEvent (IILjava/lang/String;ZLcom/facebook/react/bridge/WritableMap;IZ)V
+}
+
 public final class com/facebook/react/uimanager/events/TouchEvent : com/facebook/react/uimanager/events/Event {
 	public static final field Companion Lcom/facebook/react/uimanager/events/TouchEvent$Companion;
 	public static final field UNSET J
@@ -6655,6 +6662,7 @@ public class com/facebook/react/views/scroll/ReactHorizontalScrollView : android
 	public fun setBorderWidth (IF)V
 	public fun setDecelerationRate (F)V
 	public fun setDisableIntervalMomentum (Z)V
+	public fun setEnableSyncOnScroll (Z)V
 	public fun setEndFillColor (I)V
 	public fun setLastScrollDispatchTime (J)V
 	public fun setMaintainVisibleContentPosition (Lcom/facebook/react/views/scroll/MaintainVisibleScrollPositionHelper$Config;)V
@@ -6702,6 +6710,7 @@ public class com/facebook/react/views/scroll/ReactHorizontalScrollViewManager :
 	public fun setContentOffset (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;Lcom/facebook/react/bridge/ReadableMap;)V
 	public fun setDecelerationRate (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;F)V
 	public fun setDisableIntervalMomentum (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;Z)V
+	public fun setEnableSyncOnScroll (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;Z)V
 	public fun setFadingEdgeLength (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;I)V
 	public fun setHorizontal (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;Z)V
 	public fun setMaintainVisibleContentPosition (Lcom/facebook/react/views/scroll/ReactHorizontalScrollView;Lcom/facebook/react/bridge/ReadableMap;)V
@@ -6782,6 +6791,7 @@ public class com/facebook/react/views/scroll/ReactScrollView : android/widget/Sc
 	public fun setContentOffset (Lcom/facebook/react/bridge/ReadableMap;)V
 	public fun setDecelerationRate (F)V
 	public fun setDisableIntervalMomentum (Z)V
+	public fun setEnableSyncOnScroll (Z)V
 	public fun setEndFillColor (I)V
 	public fun setLastScrollDispatchTime (J)V
 	public fun setMaintainVisibleContentPosition (Lcom/facebook/react/views/scroll/MaintainVisibleScrollPositionHelper$Config;)V
@@ -6860,6 +6870,7 @@ public final class com/facebook/react/views/scroll/ReactScrollViewHelper {
 	public static final fun updateFabricScrollState (Landroid/view/ViewGroup;)V
 	public final fun updateFabricScrollState (Landroid/view/ViewGroup;II)V
 	public static final fun updateStateOnScrollChanged (Landroid/view/ViewGroup;FF)V
+	public static final fun updateStateOnScrollChanged (Landroid/view/ViewGroup;FFZ)V
 }
 
 public abstract interface class com/facebook/react/views/scroll/ReactScrollViewHelper$HasFlingAnimator {
@@ -6938,6 +6949,7 @@ public class com/facebook/react/views/scroll/ReactScrollViewManager : com/facebo
 	public fun setContentOffset (Lcom/facebook/react/views/scroll/ReactScrollView;Lcom/facebook/react/bridge/ReadableMap;)V
 	public fun setDecelerationRate (Lcom/facebook/react/views/scroll/ReactScrollView;F)V
 	public fun setDisableIntervalMomentum (Lcom/facebook/react/views/scroll/ReactScrollView;Z)V
+	public fun setEnableSyncOnScroll (Lcom/facebook/react/views/scroll/ReactScrollView;Z)V
 	public fun setFadingEdgeLength (Lcom/facebook/react/views/scroll/ReactScrollView;I)V
 	public fun setHorizontal (Lcom/facebook/react/views/scroll/ReactScrollView;Z)V
 	public fun setIsInvertedVirtualizedList (Lcom/facebook/react/views/scroll/ReactScrollView;Z)V
@@ -6974,13 +6986,13 @@ public final class com/facebook/react/views/scroll/ScrollEvent : com/facebook/re
 	public static final field Companion Lcom/facebook/react/views/scroll/ScrollEvent$Companion;
 	public fun canCoalesce ()Z
 	public fun getEventName ()Ljava/lang/String;
-	public static final fun obtain (IILcom/facebook/react/views/scroll/ScrollEventType;FFFFIIII)Lcom/facebook/react/views/scroll/ScrollEvent;
+	public static final fun obtain (IILcom/facebook/react/views/scroll/ScrollEventType;FFFFIIIIZ)Lcom/facebook/react/views/scroll/ScrollEvent;
 	public static final fun obtain (ILcom/facebook/react/views/scroll/ScrollEventType;FFFFIIII)Lcom/facebook/react/views/scroll/ScrollEvent;
 	public fun onDispose ()V
 }
 
 public final class com/facebook/react/views/scroll/ScrollEvent$Companion {
-	public final fun obtain (IILcom/facebook/react/views/scroll/ScrollEventType;FFFFIIII)Lcom/facebook/react/views/scroll/ScrollEvent;
+	public final fun obtain (IILcom/facebook/react/views/scroll/ScrollEventType;FFFFIIIIZ)Lcom/facebook/react/views/scroll/ScrollEvent;
 	public final fun obtain (ILcom/facebook/react/views/scroll/ScrollEventType;FFFFIIII)Lcom/facebook/react/views/scroll/ScrollEvent;
 }
 

diff --git a/...es/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java b/...es/react-native/ReactAndroid/src/main/java/com/facebook/react/fabric/FabricUIManager.java
@@ -85,6 +85,7 @@
 import com.facebook.react.uimanager.events.EventDispatcher;
 import com.facebook.react.uimanager.events.FabricEventDispatcher;
 import com.facebook.react.uimanager.events.RCTEventEmitter;
+import com.facebook.react.uimanager.events.SynchronousEventReceiver;
 import com.facebook.react.views.text.TextLayoutManager;
 import java.util.ArrayList;
 import java.util.HashMap;
@@ -99,7 +100,8 @@
  */
 @SuppressLint("MissingNativeLoadLibrary")
 @DoNotStripAny
-public class FabricUIManager implements UIManager, LifecycleEventListener, UIBlockViewResolver {
+public class FabricUIManager
+    implements UIManager, LifecycleEventListener, UIBlockViewResolver, SynchronousEventReceiver {
   public static final String TAG = FabricUIManager.class.getSimpleName();
 
   // The IS_DEVELOPMENT_ENVIRONMENT variable is used to log extra data when running fabric in a
@@ -955,6 +957,19 @@ public void receiveEvent(
       boolean canCoalesceEvent,
       @Nullable WritableMap params,
       @EventCategoryDef int eventCategory) {
+    receiveEvent(surfaceId, reactTag, eventName, canCoalesceEvent, params, eventCategory, false);
+  }
+
+  @Override
+  public void receiveEvent(
+      int surfaceId,
+      int reactTag,
+      String eventName,
+      boolean canCoalesceEvent,
+      @Nullable WritableMap params,
+      @EventCategoryDef int eventCategory,
+      boolean experimental_isSynchronous) {
+
     if (ReactBuildConfig.DEBUG && surfaceId == View.NO_ID) {
       FLog.d(TAG, "Emitted event without surfaceId: [%d] %s", reactTag, eventName);
     }
@@ -979,10 +994,14 @@ public void receiveEvent(
       return;
     }
 
-    if (canCoalesceEvent) {
-      eventEmitter.dispatchUnique(eventName, params);
+    if (experimental_isSynchronous) {
+      eventEmitter.dispatchEventSynchronously(eventName, params);
     } else {
-      eventEmitter.dispatch(eventName, params, eventCategory);
+      if (canCoalesceEvent) {
+        eventEmitter.dispatchUnique(eventName, params);
+      } else {
+        eventEmitter.dispatch(eventName, params, eventCategory);
+      }
     }
   }
 

diff --git a/...tive/ReactAndroid/src/main/java/com/facebook/react/fabric/events/EventEmitterWrapper.java b/...tive/ReactAndroid/src/main/java/com/facebook/react/fabric/events/EventEmitterWrapper.java
@@ -58,6 +58,14 @@ public synchronized void dispatch(
     dispatchEvent(eventName, (NativeMap) params, eventCategory);
   }
 
+  public synchronized void dispatchEventSynchronously(
+      String eventName, @Nullable WritableMap params) {
+    if (!isValid()) {
+      return;
+    }
+    dispatchEventSynchronously(eventName, (NativeMap) params);
+  }
+
   /**
    * Invokes the execution of the C++ EventEmitter. C++ will coalesce events sent to the same
    * target.

diff --git a/...es/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/Event.java b/...es/react-native/ReactAndroid/src/main/java/com/facebook/react/uimanager/events/Event.java
@@ -184,6 +184,10 @@ protected int getEventCategory() {
     return EventCategoryDef.UNSPECIFIED;
   }
 
+  protected boolean experimental_isSynchronous() {
+    return false;
+  }
+
   /**
    * Dispatch this event to JS using a V2 EventEmitter. If surfaceId is not -1 and `getEventData` is
    * non-null, this will use the RCTModernEventEmitter API. Otherwise, it falls back to the

diff --git a/...ReactAndroid/src/main/java/com/facebook/react/uimanager/events/FabricEventDispatcher.java b/...ReactAndroid/src/main/java/com/facebook/react/uimanager/events/FabricEventDispatcher.java
@@ -11,8 +11,12 @@
 import com.facebook.infer.annotation.Nullsafe;
 import com.facebook.react.bridge.LifecycleEventListener;
 import com.facebook.react.bridge.ReactApplicationContext;
+import com.facebook.react.bridge.ReactNoCrashSoftException;
+import com.facebook.react.bridge.ReactSoftExceptionLogger;
+import com.facebook.react.bridge.UIManager;
 import com.facebook.react.bridge.UiThreadUtil;
 import com.facebook.react.modules.core.ReactChoreographer;
+import com.facebook.react.uimanager.UIManagerHelper;
 import com.facebook.react.uimanager.common.UIManagerType;
 import com.facebook.systrace.Systrace;
 import java.util.concurrent.CopyOnWriteArrayList;
@@ -43,12 +47,43 @@ public void dispatchEvent(Event event) {
     for (EventDispatcherListener listener : mListeners) {
       listener.onEventDispatch(event);
     }
-    event.dispatchModern(mReactEventEmitter);
+    if (event.experimental_isSynchronous()) {
+      dispatchSynchronous(event);
+    } else {
+      event.dispatchModern(mReactEventEmitter);
+    }
 
     event.dispose();
     maybePostFrameCallbackFromNonUI();
   }
 
+  private void dispatchSynchronous(Event event) {
+    Systrace.beginSection(
+        Systrace.TRACE_TAG_REACT_JAVA_BRIDGE,
+        "FabricEventDispatcher.dispatchSynchronous('" + event.getEventName() + "')");
+    try {
+      UIManager fabricUIManager = UIManagerHelper.getUIManager(mReactContext, UIManagerType.FABRIC);
+      if (fabricUIManager instanceof SynchronousEventReceiver) {
+        ((SynchronousEventReceiver) fabricUIManager)
+            .receiveEvent(
+                event.getSurfaceId(),
+                event.getViewTag(),
+                event.getEventName(),
+                event.canCoalesce(),
+                event.getEventData(),
+                event.getEventCategory(),
+                true);
+      } else {
+        ReactSoftExceptionLogger.logSoftException(
+            "FabricEventDispatcher",
+            new ReactNoCrashSoftException(
+                "Fabric UIManager expected to implement SynchronousEventReceiver."));
+      }
+    } finally {
+      Systrace.endSection(Systrace.TRACE_TAG_REACT_JAVA_BRIDGE);
+    }
+  }
+
   public void dispatchAllEvents() {
     maybePostFrameCallbackFromNonUI();
   }

diff --git a/...eactAndroid/src/main/java/com/facebook/react/uimanager/events/SynchronousEventReceiver.kt b/...eactAndroid/src/main/java/com/facebook/react/uimanager/events/SynchronousEventReceiver.kt
@@ -0,0 +1,23 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * 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
+
+import com.facebook.react.bridge.WritableMap
+
+@Deprecated("Experimental")
+public interface SynchronousEventReceiver {
+  public fun receiveEvent(
+      surfaceId: Int,
+      reactTag: Int,
+      eventName: String,
+      canCoalesceEvent: Boolean,
+      params: WritableMap?,
+      @EventCategoryDef eventCategory: Int,
+      experimental_isSynchronous: Boolean
+  ): Unit
+}
diff --git a/...ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java b/...ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollView.java
@@ -92,6 +92,8 @@ public class ReactHorizontalScrollView extends HorizontalScrollView
   private @Nullable Runnable mPostTouchRunnable;
   private boolean mRemoveClippedSubviews;
   private boolean mScrollEnabled = true;
+  private boolean mPreventReentry = false;
+  private boolean mEnableSyncOnScroll = false;
   private boolean mSendMomentumEvents;
   private @Nullable FpsListener mFpsListener = null;
   private @Nullable String mScrollPerfTag;
@@ -220,6 +222,10 @@ public void setScrollEnabled(boolean scrollEnabled) {
     mScrollEnabled = scrollEnabled;
   }
 
+  public void setEnableSyncOnScroll(boolean enableSyncOnScroll) {
+    mEnableSyncOnScroll = enableSyncOnScroll;
+  }
+
   public void setPagingEnabled(boolean pagingEnabled) {
     mPagingEnabled = pagingEnabled;
   }
@@ -470,11 +476,16 @@ protected void onScrollChanged(int x, int y, int oldX, int oldY) {
       if (mRemoveClippedSubviews) {
         updateClippingRect();
       }
-
+      if (mPreventReentry) {
+        return;
+      }
+      mPreventReentry = true;
       ReactScrollViewHelper.updateStateOnScrollChanged(
           this,
           mOnScrollDispatchHelper.getXFlingVelocity(),
-          mOnScrollDispatchHelper.getYFlingVelocity());
+          mOnScrollDispatchHelper.getYFlingVelocity(),
+          mEnableSyncOnScroll);
+      mPreventReentry = false;
     }
   }
 

diff --git a/...droid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java b/...droid/src/main/java/com/facebook/react/views/scroll/ReactHorizontalScrollViewManager.java
@@ -88,6 +88,11 @@ public void setDecelerationRate(ReactHorizontalScrollView view, float decelerati
     view.setDecelerationRate(decelerationRate);
   }
 
+  @ReactProp(name = "enableSyncOnScroll")
+  public void setEnableSyncOnScroll(ReactHorizontalScrollView view, boolean enableSyncOnScroll) {
+    view.setEnableSyncOnScroll(enableSyncOnScroll);
+  }
+
   @ReactProp(name = "disableIntervalMomentum")
   public void setDisableIntervalMomentum(
       ReactHorizontalScrollView view, boolean disableIntervalMomentum) {

diff --git a/...ct-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java b/...ct-native/ReactAndroid/src/main/java/com/facebook/react/views/scroll/ReactScrollView.java
@@ -93,9 +93,11 @@ public class ReactScrollView extends ScrollView
   private @Nullable Runnable mPostTouchRunnable;
   private boolean mRemoveClippedSubviews;
   private boolean mScrollEnabled = true;
+  private boolean mPreventReentry = false;
   private boolean mSendMomentumEvents;
   private @Nullable FpsListener mFpsListener = null;
   private @Nullable String mScrollPerfTag;
+  private boolean mEnableSyncOnScroll = false;
   private @Nullable Drawable mEndBackground;
   private int mEndFillColor = Color.TRANSPARENT;
   private boolean mDisableIntervalMomentum = false;
@@ -201,6 +203,10 @@ public void setScrollPerfTag(@Nullable String scrollPerfTag) {
     mScrollPerfTag = scrollPerfTag;
   }
 
+  public void setEnableSyncOnScroll(boolean enableSyncOnScroll) {
+    mEnableSyncOnScroll = enableSyncOnScroll;
+  }
+
   public void setScrollEnabled(boolean scrollEnabled) {
     mScrollEnabled = scrollEnabled;
   }
@@ -388,11 +394,16 @@ protected void onScrollChanged(int x, int y, int oldX, int oldY) {
       if (mRemoveClippedSubviews) {
         updateClippingRect();
       }
-
+      if (mPreventReentry) {
+        return;
+      }
+      mPreventReentry = true;
       ReactScrollViewHelper.updateStateOnScrollChanged(
           this,
           mOnScrollDispatchHelper.getXFlingVelocity(),
-          mOnScrollDispatchHelper.getYFlingVelocity());
+          mOnScrollDispatchHelper.getYFlingVelocity(),
+          mEnableSyncOnScroll);
+      mPreventReentry = false;
     }
   }