Return only view manager names from bridgeless UIManager.getConstants()

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<<6b457b1b41a17fa2065720edc82939e3>>
+ * @generated SignedSource<<34a4beae0933f13de477fdf344bb2c8a>>
  */
 
 /**
@@ -294,6 +294,12 @@ public object ReactNativeFeatureFlags {
   @JvmStatic
   public fun enableLayoutAnimationsOnIOS(): Boolean = accessor.enableLayoutAnimationsOnIOS()
 
+  /**
+   * When enabled, UIManager.getConstants() in bridgeless mode on Android returns only the view manager names. JS gets the constants of each view manager on first use.
+   */
+  @JvmStatic
+  public fun enableLazyViewManagerConstantsAndroid(): Boolean = accessor.enableLazyViewManagerConstantsAndroid()
+
   /**
    * Enable NSNull conversion when handling module arguments on iOS
    */

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<<0fdae97a0b469d01bad69d0d05c79121>>
+ * @generated SignedSource<<83eea4dd516167329e06efcf51194e3c>>
  */
 
 /**
@@ -64,6 +64,7 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
   private var enableKeyEventsCache: Boolean? = null
   private var enableLayoutAnimationsOnAndroidCache: Boolean? = null
   private var enableLayoutAnimationsOnIOSCache: Boolean? = null
+  private var enableLazyViewManagerConstantsAndroidCache: Boolean? = null
   private var enableModuleArgumentNSNullConversionIOSCache: Boolean? = null
   private var enableMountingCoordinatorPullModelAndroidCache: Boolean? = null
   private var enableMutationObserverByDefaultCache: Boolean? = null
@@ -515,6 +516,15 @@ internal class ReactNativeFeatureFlagsCxxAccessor : ReactNativeFeatureFlagsAcces
     return cached
   }
 
+  override fun enableLazyViewManagerConstantsAndroid(): Boolean {
+    var cached = enableLazyViewManagerConstantsAndroidCache
+    if (cached == null) {
+      cached = ReactNativeFeatureFlagsCxxInterop.enableLazyViewManagerConstantsAndroid()
+      enableLazyViewManagerConstantsAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun enableModuleArgumentNSNullConversionIOS(): Boolean {
     var cached = enableModuleArgumentNSNullConversionIOSCache
     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<<e7d0d9416b8e1fa2a9f6246050cc06b0>>
+ * @generated SignedSource<<c33234fb0e4ac72412cc27c6c99c5756>>
  */
 
 /**
@@ -116,6 +116,8 @@ public object ReactNativeFeatureFlagsCxxInterop {
 
   @DoNotStrip @JvmStatic public external fun enableLayoutAnimationsOnIOS(): Boolean
 
+  @DoNotStrip @JvmStatic public external fun enableLazyViewManagerConstantsAndroid(): Boolean
+
   @DoNotStrip @JvmStatic public external fun enableModuleArgumentNSNullConversionIOS(): Boolean
 
   @DoNotStrip @JvmStatic public external fun enableMountingCoordinatorPullModelAndroid(): 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<<92e293070f5407d0096ab7f3fd208d45>>
+ * @generated SignedSource<<4c80bc66f090ad8f55507910d93e2035>>
  */
 
 /**
@@ -111,6 +111,8 @@ public open class ReactNativeFeatureFlagsDefaults : ReactNativeFeatureFlagsProvi
 
   override fun enableLayoutAnimationsOnIOS(): Boolean = true
 
+  override fun enableLazyViewManagerConstantsAndroid(): Boolean = false
+
   override fun enableModuleArgumentNSNullConversionIOS(): Boolean = false
 
   override fun enableMountingCoordinatorPullModelAndroid(): 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<<17a4a2a29b0480e06ed3e8ed71fd908f>>
+ * @generated SignedSource<<81cb1a9c3708f7ba054cdfa68619ab52>>
  */
 
 /**
@@ -68,6 +68,7 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
   private var enableKeyEventsCache: Boolean? = null
   private var enableLayoutAnimationsOnAndroidCache: Boolean? = null
   private var enableLayoutAnimationsOnIOSCache: Boolean? = null
+  private var enableLazyViewManagerConstantsAndroidCache: Boolean? = null
   private var enableModuleArgumentNSNullConversionIOSCache: Boolean? = null
   private var enableMountingCoordinatorPullModelAndroidCache: Boolean? = null
   private var enableMutationObserverByDefaultCache: Boolean? = null
@@ -563,6 +564,16 @@ internal class ReactNativeFeatureFlagsLocalAccessor : ReactNativeFeatureFlagsAcc
     return cached
   }
 
+  override fun enableLazyViewManagerConstantsAndroid(): Boolean {
+    var cached = enableLazyViewManagerConstantsAndroidCache
+    if (cached == null) {
+      cached = currentProvider.enableLazyViewManagerConstantsAndroid()
+      accessedFeatureFlags.add("enableLazyViewManagerConstantsAndroid")
+      enableLazyViewManagerConstantsAndroidCache = cached
+    }
+    return cached
+  }
+
   override fun enableModuleArgumentNSNullConversionIOS(): Boolean {
     var cached = enableModuleArgumentNSNullConversionIOSCache
     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<<3c3e22fe0cffa5498750e91ad05df9a8>>
+ * @generated SignedSource<<8a0dcd5fddadda04dfb4b161e9cdf86a>>
  */
 
 /**
@@ -111,6 +111,8 @@ public interface ReactNativeFeatureFlagsProvider {
 
   @DoNotStrip public fun enableLayoutAnimationsOnIOS(): Boolean
 
+  @DoNotStrip public fun enableLazyViewManagerConstantsAndroid(): Boolean
+
   @DoNotStrip public fun enableModuleArgumentNSNullConversionIOS(): Boolean
 
   @DoNotStrip public fun enableMountingCoordinatorPullModelAndroid(): Boolean

packages/react-native/ReactAndroid/src/main/java/com/facebook/react/runtime/ReactInstance.kt

@@ -223,12 +223,6 @@ internal class ReactInstance(
       UIConstantsProviderBinding.install(
           // Use unbuffered RuntimeExecutor to install binding
           unbufferedRuntimeExecutor,
-          // Here we are construncting the return value for UManager.getConstants call.
-          // The old architectre relied on the constatnts struct to contain:
-          // 1. Eagerly loaded view configs for all native components.
-          // 2. genericBubblingEventTypes.
-          // 3. genericDirectEventTypes.
-          // We want to match this beahavior.
           { Arguments.makeNativeMap(UIManagerModuleConstantsHelper.defaultExportableEventTypes) },
           ConstantsForViewManagerProvider { viewManagerName: String ->
             val viewManager =
@@ -237,16 +231,27 @@ internal class ReactInstance(
             getConstantsForViewManager(viewManager, customDirectEvents)
           },
           {
-            val viewManagers: List<ViewManager<*, *>> =
-                ArrayList(viewManagerResolver.eagerViewManagerMap.values)
-            val constants = createConstants(viewManagers, customDirectEvents)
-
-            val lazyViewManagers = viewManagerResolver.lazyViewManagerNames
-            if (!lazyViewManagers.isEmpty()) {
-              constants["ViewManagerNames"] = ArrayList(lazyViewManagers)
-              constants["LazyViewManagersEnabled"] = true
+            if (ReactNativeFeatureFlags.enableLazyViewManagerConstantsAndroid()) {
+              // Names only: each view config is built on first use.
+              Arguments.makeNativeMap(createConstants(viewManagerResolver))
+            } else {
+              // Here we are construncting the return value for UManager.getConstants call.
+              // The old architectre relied on the constatnts struct to contain:
+              // 1. Eagerly loaded view configs for all native components.
+              // 2. genericBubblingEventTypes.
+              // 3. genericDirectEventTypes.
+              // We want to match this beahavior.
+              val viewManagers: List<ViewManager<*, *>> =
+                  ArrayList(viewManagerResolver.eagerViewManagerMap.values)
+              val constants = createConstants(viewManagers, customDirectEvents)
+
+              val lazyViewManagers = viewManagerResolver.lazyViewManagerNames
+              if (!lazyViewManagers.isEmpty()) {
+                constants["ViewManagerNames"] = ArrayList(lazyViewManagers)
+                constants["LazyViewManagersEnabled"] = true
+              }
+              Arguments.makeNativeMap(constants)
             }
-            Arguments.makeNativeMap(constants)
           },
       )
     }
@@ -584,6 +589,19 @@ internal class ReactInstance(
       SoLoader.loadLibrary("rninstance")
     }
 
+    private fun createConstants(viewManagerResolver: ViewManagerResolver): Map<String, Any> {
+      ReactMarker.logMarker(ReactMarkerConstants.CREATE_UI_MANAGER_MODULE_CONSTANTS_START)
+      SystraceMessage.beginSection(Systrace.TRACE_TAG_REACT, "CreateUIManagerConstants")
+          .arg("Lazy", true)
+          .flush()
+      try {
+        return UIManagerModuleConstantsHelper.createConstants(viewManagerResolver)
+      } finally {
+        Systrace.endSection(Systrace.TRACE_TAG_REACT)
+        ReactMarker.logMarker(ReactMarkerConstants.CREATE_UI_MANAGER_MODULE_CONSTANTS_END)
+      }
+    }
+
     private fun createConstants(
         viewManagers: List<ViewManager<in Nothing, in Nothing>>,
         customDirectEvents: MutableMap<String, Any>?,

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<<f9c238d577cf696d9baed365741d3d5a>>
+ * @generated SignedSource<<6053c059e59bf5c869e232f375331a34>>
  */
 
 /**
@@ -303,6 +303,12 @@ class ReactNativeFeatureFlagsJavaProvider
     return method(javaProvider_);
   }
 
+  bool enableLazyViewManagerConstantsAndroid() override {
+    static const auto method =
+        getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableLazyViewManagerConstantsAndroid");
+    return method(javaProvider_);
+  }
+
   bool enableModuleArgumentNSNullConversionIOS() override {
     static const auto method =
         getReactNativeFeatureFlagsProviderJavaClass()->getMethod<jboolean()>("enableModuleArgumentNSNullConversionIOS");
@@ -851,6 +857,11 @@ bool JReactNativeFeatureFlagsCxxInterop::enableLayoutAnimationsOnIOS(
   return ReactNativeFeatureFlags::enableLayoutAnimationsOnIOS();
 }
 
+bool JReactNativeFeatureFlagsCxxInterop::enableLazyViewManagerConstantsAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
+  return ReactNativeFeatureFlags::enableLazyViewManagerConstantsAndroid();
+}
+
 bool JReactNativeFeatureFlagsCxxInterop::enableModuleArgumentNSNullConversionIOS(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop> /*unused*/) {
   return ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS();
@@ -1284,6 +1295,9 @@ void JReactNativeFeatureFlagsCxxInterop::registerNatives() {
       makeNativeMethod(
         "enableLayoutAnimationsOnIOS",
         JReactNativeFeatureFlagsCxxInterop::enableLayoutAnimationsOnIOS),
+      makeNativeMethod(
+        "enableLazyViewManagerConstantsAndroid",
+        JReactNativeFeatureFlagsCxxInterop::enableLazyViewManagerConstantsAndroid),
       makeNativeMethod(
         "enableModuleArgumentNSNullConversionIOS",
         JReactNativeFeatureFlagsCxxInterop::enableModuleArgumentNSNullConversionIOS),

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<<8d25ec35055628073cf8cd61f8cc838e>>
+ * @generated SignedSource<<5ccb6e1392e43f84eaedddb7bb244240>>
  */
 
 /**
@@ -162,6 +162,9 @@ class JReactNativeFeatureFlagsCxxInterop
   static bool enableLayoutAnimationsOnIOS(
     facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
 
+  static bool enableLazyViewManagerConstantsAndroid(
+    facebook::jni::alias_ref<JReactNativeFeatureFlagsCxxInterop>);
+
   static bool enableModuleArgumentNSNullConversionIOS(
     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<<e9243c6d351c49208f0cdac358527d43>>
+ * @generated SignedSource<<e8a2096cee73a029293468260dfc51eb>>
  */
 
 /**
@@ -202,6 +202,10 @@ bool ReactNativeFeatureFlags::enableLayoutAnimationsOnIOS() {
   return getAccessor().enableLayoutAnimationsOnIOS();
 }
 
+bool ReactNativeFeatureFlags::enableLazyViewManagerConstantsAndroid() {
+  return getAccessor().enableLazyViewManagerConstantsAndroid();
+}
+
 bool ReactNativeFeatureFlags::enableModuleArgumentNSNullConversionIOS() {
   return getAccessor().enableModuleArgumentNSNullConversionIOS();
 }

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<<dc12cb4c1ebd82d842a8e7698fc6c746>>
+ * @generated SignedSource<<226f8736887b225621437a435ca9fe33>>
  */
 
 /**
@@ -261,6 +261,11 @@ class ReactNativeFeatureFlags {
    */
   RN_EXPORT static bool enableLayoutAnimationsOnIOS();
 
+  /**
+   * When enabled, UIManager.getConstants() in bridgeless mode on Android returns only the view manager names. JS gets the constants of each view manager on first use.
+   */
+  RN_EXPORT static bool enableLazyViewManagerConstantsAndroid();
+
   /**
    * Enable NSNull conversion when handling module arguments on iOS
    */