Adds feature flag for onLayout event coalescing

Summary:
In the old architecture, Android coalesced onLayout events, ensuring that when the JS thread was busy, intermediate onLayout results were ignored.

This adds a feature flag to experiment with a similar coalescing behavior for the new architecture.

Differential Revision: D62297082

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlags.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<6cc52570dd571ddc792a0fd842c05dd9>>
+ * @generated SignedSource<<f6470a89519ac47c09bca5dd9353a1e4>>
  */
 
 /**
@@ -46,6 +46,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun batchRenderingUpdatesInEventLoop(): Boolean = accessor.batchRenderingUpdatesInEventLoop()
 
+  /**
+   * When enabled, the Fabric onLayout event will be coalesced by dispatching with dispatchUniqueEvent.
+   */
+  @JvmStatic
+  public fun coalesceOnLayoutEvents(): Boolean = accessor.coalesceOnLayoutEvents()
+
   /**
    * Do not wait for a main-thread dispatch to complete init to start executing work on the JS thread on Android
    */

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<eca842a1b1c823b72136c625b3bfd16e>>
+ * @generated SignedSource<<7f020c68199644e4ffa8b01bb40659d4>>
  */
 
 /**
@@ -23,6 +23,7 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
   private var commonTestFlagCache: Boolean? = null
   private var allowRecursiveCommitsWithSynchronousMountOnAndroidCache: Boolean? = null
   private var batchRenderingUpdatesInEventLoopCache: Boolean? = null
+  private var coalesceOnLayoutEventsCache: Boolean? = null
   private var completeReactInstanceCreationOnBgThreadOnAndroidCache: Boolean? = null
   private var destroyFabricSurfacesInReactInstanceManagerCache: Boolean? = null
   private var enableAlignItemsBaselineOnFabricIOSCache: Boolean? = null
@@ -96,6 +97,15 @@ public class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAccesso
     return cached
   }
 
+  override fun coalesceOnLayoutEvents(): Boolean {
+    var cached = coalesceOnLayoutEventsCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.coalesceOnLayoutEvents()
+      coalesceOnLayoutEventsCache = cached
+    }
+    return cached
+  }
+
   override fun completeReactInstanceCreationOnBgThreadOnAndroid(): Boolean {
     var cached = completeReactInstanceCreationOnBgThreadOnAndroidCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsCxxInterop.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<ad54375c4ae3be2f377260887ae5aaf9>>
+ * @generated SignedSource<<ea9374ed3adaf5d41a8a1cd0569c35ac>>
  */
 
 /**
@@ -34,6 +34,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun batchRenderingUpdatesInEventLoop(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun coalesceOnLayoutEvents(): Boolean
+
   @DoNotStrip @JvmStatic public external fun completeReactInstanceCreationOnBgThreadOnAndroid(): Boolean
 
   @DoNotStrip @JvmStatic public external fun destroyFabricSurfacesInReactInstanceManager(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsDefaults.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<2a0cd5a4875a54bb724e5765ffe7753e>>
+ * @generated SignedSource<<353196c285c62f4304d612a57417cb6a>>
  */
 
 /**
@@ -29,6 +29,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun batchRenderingUpdatesInEventLoop(): Boolean = false
 
+  override fun coalesceOnLayoutEvents(): Boolean = false
+
   override fun completeReactInstanceCreationOnBgThreadOnAndroid(): Boolean = false
 
   override fun destroyFabricSurfacesInReactInstanceManager(): Boolean = false

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsLocalAccessor.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<d02af2a8ef015c57d45aba8280539606>>
+ * @generated SignedSource<<3016538257cf64e360de0e6a0ed45ba2>>
  */
 
 /**
@@ -27,6 +27,7 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
   private var commonTestFlagCache: Boolean? = null
   private var allowRecursiveCommitsWithSynchronousMountOnAndroidCache: Boolean? = null
   private var batchRenderingUpdatesInEventLoopCache: Boolean? = null
+  private var coalesceOnLayoutEventsCache: Boolean? = null
   private var completeReactInstanceCreationOnBgThreadOnAndroidCache: Boolean? = null
   private var destroyFabricSurfacesInReactInstanceManagerCache: Boolean? = null
   private var enableAlignItemsBaselineOnFabricIOSCache: Boolean? = null
@@ -103,6 +104,16 @@ public class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun coalesceOnLayoutEvents(): Boolean {
+    var cached = coalesceOnLayoutEventsCache
+    if (cached == null) {
+      cached = currentProvider.coalesceOnLayoutEvents()
+      accessedFeatureFlags.add("coalesceOnLayoutEvents")
+      coalesceOnLayoutEventsCache = cached
+    }
+    return cached
+  }
+
   override fun completeReactInstanceCreationOnBgThreadOnAndroid(): Boolean {
     var cached = completeReactInstanceCreationOnBgThreadOnAndroidCache
     if (cached == null) {

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/internal/featureflags/ReactNativeFeatureFlagsProvider.kt

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<92b1214e3a526d7c67dcc7b0c2a131de>>
+ * @generated SignedSource<<34af2926e822628b1c6f3313b25db9fe>>
  */
 
 /**
@@ -29,6 +29,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun batchRenderingUpdatesInEventLoop(): Boolean
 
+  @DoNotStrip public fun coalesceOnLayoutEvents(): Boolean
+
   @DoNotStrip public fun completeReactInstanceCreationOnBgThreadOnAndroid(): Boolean
 
   @DoNotStrip public fun destroyFabricSurfacesInReactInstanceManager(): Boolean

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c23b21fca18699470580e54b99de1126>>
+ * @generated SignedSource<<9a874be28601d8847c998cbd77a0159b>>
  */
 
 /**
@@ -57,6 +57,12 @@ class ReactNativeFeatureFlagsProviderHolder
     return method(javaProvider_);
   }
 
+  bool coalesceOnLayoutEvents() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("coalesceOnLayoutEvents");
+    return method(javaProvider_);
+  }
+
   bool completeReactInstanceCreationOnBgThreadOnAndroid() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("completeReactInstanceCreationOnBgThreadOnAndroid");
@@ -346,6 +352,11 @@ bool JReactNativeFeatureFlagsCxxInterop::batchRenderingUpdatesInEventLoop(
   return ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::coalesceOnLayoutEvents(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::coalesceOnLayoutEvents();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::completeReactInstanceCreationOnBgThreadOnAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::completeReactInstanceCreationOnBgThreadOnAndroid();
@@ -597,6 +608,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "batchRenderingUpdatesInEventLoop",
         JReactNativeFeatureFlagsCxxInterop::batchRenderingUpdatesInEventLoop),
+      makeNativeMethod(
+        "coalesceOnLayoutEvents",
+        JReactNativeFeatureFlagsCxxInterop::coalesceOnLayoutEvents),
       makeNativeMethod(
         "completeReactInstanceCreationOnBgThreadOnAndroid",
         JReactNativeFeatureFlagsCxxInterop::completeReactInstanceCreationOnBgThreadOnAndroid),

packages/react-native/ReactAndroid/src/main/jni/react/featureflags/JReactNativeFeatureFlagsCxxInterop.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<89d0da3b2bb56a4ee3c887e6c57491b2>>
+ * @generated SignedSource<<1d8cfaa9b86400f61db540a2f8d25ebc>>
  */
 
 /**
@@ -39,6 +39,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool batchRenderingUpdatesInEventLoop(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool coalesceOnLayoutEvents(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool completeReactInstanceCreationOnBgThreadOnAndroid(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.cpp

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<6139aa47aac3e5682a453a416bc10236>>
+ * @generated SignedSource<<8987cb4c07891b8b5716d6ac18677a11>>
  */
 
 /**
@@ -33,6 +33,10 @@ bool ReactNativeFeatureFlags::batchRenderingUpdatesInEventLoop() {
   return getAccessor().batchRenderingUpdatesInEventLoop();
 }
 
+bool ReactNativeFeatureFlags::coalesceOnLayoutEvents() {
+  return getAccessor().coalesceOnLayoutEvents();
+}
+
 bool ReactNativeFeatureFlags::completeReactInstanceCreationOnBgThreadOnAndroid() {
   return getAccessor().completeReactInstanceCreationOnBgThreadOnAndroid();
 }

packages/react-native/ReactCommon/react/featureflags/ReactNativeFeatureFlags.h

@@ -4,7 +4,7 @@
  * This source code is licensed under the MIT license found in the
  * LICENSE file in the root directory of this source tree.
  *
- * @generated SignedSource<<c8266eb27ec23aaa856fa95275503a81>>
+ * @generated SignedSource<<b891ab975bd5d25e6334f52be6b5ace2>>
  */
 
 /**
@@ -52,6 +52,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool batchRenderingUpdatesInEventLoop();
 
+  /**
+   * When enabled, the Fabric onLayout event will be coalesced by dispatching with dispatchUniqueEvent.
+   */
+  RN_EXPORT static bool coalesceOnLayoutEvents();
+
   /**
    * Do not wait for a main-thread dispatch to complete init to start executing work on the JS thread on Android
    */