Add direct AnimatedProps update path for iOS

Summary:
Add an iOS-optimized code path that passes typed AnimatedProps directly through the delegate chain, avoiding the folly::dynamic serialization round-trip. Android and CxxPlatform get no-op stubs. Gated behind the `optimizedAnimatedPropUpdates` feature flag.

Changelog:
[iOS][Added] - Add a direct AnimatedProps update path through `RCTScheduler` / `RCTMountingManager` that bypasses the folly::dynamic serialization round-trip (gated by `optimizedAnimatedPropUpdates`)

Differential Revision: D101157449

Author: Bartlomiej Bloniarz

packages/react-native/React/Fabric/Mounting/RCTMountingManager.h

@@ -69,6 +69,8 @@ NS_ASSUME_NONNULL_BEGIN
 - (void)synchronouslyUpdateViewOnUIThread:(ReactTag)reactTag
                              changedProps:(folly::dynamic)props
                       componentDescriptor:(const facebook::react::ComponentDescriptor &)componentDescriptor;
+
+- (void)synchronouslyUpdateViewOnUIThread:(ReactTag)reactTag withProps:(facebook::react::Props::Shared)newProps;
 @end
 
 NS_ASSUME_NONNULL_END

packages/react-native/React/Fabric/Mounting/RCTMountingManager.mm

@@ -330,6 +330,41 @@ - (void)synchronouslyUpdateViewOnUIThread:(ReactTag)reactTag
   [componentView finalizeUpdates:RNComponentViewUpdateMaskProps];
 }
 
+- (void)synchronouslyUpdateViewOnUIThread:(ReactTag)reactTag withProps:(Props::Shared)newProps
+{
+  RCTAssertMainQueue();
+
+  UIView<RCTComponentViewProtocol> *componentView = [_componentViewRegistry findComponentViewWithTag:reactTag];
+  if (!componentView) {
+    RCTLogWarn(@"Attempted to update view with tag %ld, but it no longer exists", (long)reactTag);
+    return;
+  }
+
+  NSSet<NSString *> *propKeys = componentView.propKeysManagedByAnimated_DO_NOT_USE_THIS_IS_BROKEN ?: [NSSet new];
+
+  Props::Shared oldProps = [componentView props];
+
+  componentView.propKeysManagedByAnimated_DO_NOT_USE_THIS_IS_BROKEN = nil;
+  [componentView updateProps:newProps oldProps:oldProps];
+  componentView.propKeysManagedByAnimated_DO_NOT_USE_THIS_IS_BROKEN = propKeys;
+
+  const auto &newViewProps = static_cast<const ViewProps &>(*newProps);
+
+  if (componentView.layer.opacity != (float)newViewProps.opacity) {
+    componentView.layer.opacity = newViewProps.opacity;
+  }
+
+  auto layoutMetrics = LayoutMetrics();
+  layoutMetrics.frame.size.width = componentView.layer.bounds.size.width;
+  layoutMetrics.frame.size.height = componentView.layer.bounds.size.height;
+  CATransform3D newTransform = RCTCATransform3DFromTransformMatrix(newViewProps.resolveTransform(layoutMetrics));
+  if (!CATransform3DEqualToTransform(newTransform, componentView.layer.transform)) {
+    componentView.layer.transform = newTransform;
+  }
+
+  [componentView finalizeUpdates:RNComponentViewUpdateMaskProps];
+}
+
 - (void)synchronouslyDispatchCommandOnUIThread:(ReactTag)reactTag
                                    commandName:(NSString *)commandName
                                           args:(NSArray *)args

packages/react-native/React/Fabric/RCTScheduler.h

@@ -19,6 +19,10 @@
 #import <react/renderer/uimanager/UIManager.h>
 #import <react/utils/ContextContainer.h>
 
+namespace facebook::react {
+struct AnimatedProps;
+} // namespace facebook::react
+
 NS_ASSUME_NONNULL_BEGIN
 
 /**
@@ -45,6 +49,11 @@ NS_ASSUME_NONNULL_BEGIN
                        forShadowView:(const facebook::react::ShadowView &)shadowView;
 
 - (void)schedulerDidSynchronouslyUpdateViewOnUIThread:(facebook::react::Tag)reactTag props:(folly::dynamic)props;
+
+- (void)schedulerDidSynchronouslyUpdateViewWithAnimatedPropsOnUIThread:(facebook::react::Tag)reactTag
+                                                             surfaceId:(facebook::react::SurfaceId)surfaceId
+                                                         animatedProps:
+                                                             (const facebook::react::AnimatedProps &)animatedProps;
 @end
 
 /**

packages/react-native/React/Fabric/RCTScheduler.mm

@@ -10,6 +10,7 @@
 #import <QuartzCore/CADisplayLink.h>
 #import <cxxreact/TraceSection.h>
 #import <react/featureflags/ReactNativeFeatureFlags.h>
+#import <react/renderer/animationbackend/AnimatedProps.h>
 #import <react/renderer/animations/LayoutAnimationDriver.h>
 #import <react/renderer/componentregistry/ComponentDescriptorFactory.h>
 #import <react/renderer/scheduler/Scheduler.h>
@@ -83,7 +84,12 @@ void schedulerShouldSynchronouslyUpdateAnimatedPropsOnUIThread(
       SurfaceId surfaceId,
       const std::unordered_map<Tag, AnimatedProps> &updates) override
   {
-    // Not implemented on iOS yet -- filled in by a later commit.
+    RCTScheduler *scheduler = (__bridge RCTScheduler *)scheduler_;
+    for (const auto &[tag, animatedProps] : updates) {
+      [scheduler.delegate schedulerDidSynchronouslyUpdateViewWithAnimatedPropsOnUIThread:tag
+                                                                               surfaceId:surfaceId
+                                                                           animatedProps:animatedProps];
+    }
   }
 
   void schedulerDidUpdateShadowTree(const std::unordered_map<Tag, folly::dynamic> &tagToProps) override

packages/react-native/React/Fabric/RCTSurfacePresenter.mm

@@ -28,8 +28,10 @@
 #import <react/utils/FollyConvert.h>
 
 #import <react/featureflags/ReactNativeFeatureFlags.h>
+#import <react/renderer/animationbackend/AnimatedProps.h>
 #import <react/renderer/componentregistry/ComponentDescriptorFactory.h>
 #import <react/renderer/components/text/BaseTextProps.h>
+#import <react/renderer/components/view/BaseViewProps.h>
 #import <react/renderer/runtimescheduler/RuntimeScheduler.h>
 #import <react/renderer/scheduler/SchedulerToolbox.h>
 #import <react/utils/ContextContainer.h>
@@ -416,6 +418,44 @@ - (void)schedulerDidSetIsJSResponder:(BOOL)isJSResponder
   [_mountingManager setIsJSResponder:isJSResponder blockNativeResponder:blockNativeResponder forShadowView:shadowView];
 }
 
+- (void)schedulerDidSynchronouslyUpdateViewWithAnimatedPropsOnUIThread:(Tag)tag
+                                                             surfaceId:(SurfaceId)surfaceId
+                                                         animatedProps:(const AnimatedProps &)animatedProps
+{
+  RCTScheduler *scheduler = [self scheduler];
+  if (!scheduler) {
+    return;
+  }
+
+  UIView<RCTComponentViewProtocol> *componentView =
+      [_mountingManager.componentViewRegistry findComponentViewWithTag:tag];
+  if (componentView == nil) {
+    return;
+  }
+  ComponentHandle handle = [[componentView class] componentDescriptorProvider].handle;
+  auto *componentDescriptor = [scheduler findComponentDescriptorByHandle_DO_NOT_USE_THIS_IS_BROKEN:handle];
+  if (!componentDescriptor) {
+    return;
+  }
+
+  Props::Shared oldProps = [componentView props];
+  PropsParserContext propsParserContext{surfaceId, *[self contextContainer]};
+
+  Props::Shared newProps;
+  if (animatedProps.rawProps) {
+    newProps = componentDescriptor->cloneProps(propsParserContext, oldProps, RawProps(*animatedProps.rawProps));
+  } else {
+    newProps = componentDescriptor->cloneProps(propsParserContext, oldProps, RawProps{});
+  }
+
+  auto viewProps = std::const_pointer_cast<BaseViewProps>(std::static_pointer_cast<const BaseViewProps>(newProps));
+  for (auto &animatedProp : animatedProps.props) {
+    cloneProp(*viewProps, *animatedProp);
+  }
+
+  [_mountingManager synchronouslyUpdateViewOnUIThread:tag withProps:newProps];
+}
+
 - (void)addObserver:(id<RCTSurfacePresenterObserver>)observer
 {
   std::unique_lock lock(_observerListMutex);

scripts/cxx-api/api-snapshots/ReactAndroidDebugCxx.api

@@ -1560,7 +1560,8 @@ class facebook::react::AnimationBackend : public facebook::react::UIManagerAnima
   public virtual void trigger() override;
   public void commitUpdates(facebook::react::SurfaceId surfaceId, facebook::react::SurfaceUpdates& surfaceUpdates);
   public void requestAsyncFlushForSurfaces(const std::set<facebook::react::SurfaceId>& surfaces);
-  public void synchronouslyUpdateProps(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdateProps(facebook::react::SurfaceId surfaceId, const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdatePropsUnbuffered(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
 }
 
 class facebook::react::AnimationBackendCommitHook : public facebook::react::UIManagerCommitHook {

scripts/cxx-api/api-snapshots/ReactAndroidReleaseCxx.api

@@ -1559,7 +1559,8 @@ class facebook::react::AnimationBackend : public facebook::react::UIManagerAnima
   public virtual void trigger() override;
   public void commitUpdates(facebook::react::SurfaceId surfaceId, facebook::react::SurfaceUpdates& surfaceUpdates);
   public void requestAsyncFlushForSurfaces(const std::set<facebook::react::SurfaceId>& surfaces);
-  public void synchronouslyUpdateProps(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdateProps(facebook::react::SurfaceId surfaceId, const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdatePropsUnbuffered(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
 }
 
 class facebook::react::AnimationBackendCommitHook : public facebook::react::UIManagerCommitHook {

scripts/cxx-api/api-snapshots/ReactAppleDebugCxx.api

@@ -1595,6 +1595,7 @@ interface RCTMountingManager : public NSObject {
   public virtual void setContextContainer:(std::shared_ptr<const facebook::react::ContextContainer> contextContainer);
   public virtual void setIsJSResponder:blockNativeResponder:forShadowView:(BOOL isJSResponder, BOOL blockNativeResponder, const facebook::react::ShadowView& shadowView);
   public virtual void synchronouslyUpdateViewOnUIThread:changedProps:componentDescriptor:(ReactTag reactTag, folly::dynamic props, const facebook::react::ComponentDescriptor& componentDescriptor);
+  public virtual void synchronouslyUpdateViewOnUIThread:withProps:(ReactTag reactTag, facebook::react::Props::Shared newProps);
 }
 
 interface RCTMultilineTextInputView : public RCTBaseTextInputView {
@@ -3387,6 +3388,7 @@ protocol RCTSchedulerDelegate {
   public virtual void schedulerDidSendAccessibilityEvent:eventType:(const facebook::react::ShadowView& shadowView, const std::string& eventType);
   public virtual void schedulerDidSetIsJSResponder:blockNativeResponder:forShadowView:(BOOL isJSResponder, BOOL blockNativeResponder, const facebook::react::ShadowView& shadowView);
   public virtual void schedulerDidSynchronouslyUpdateViewOnUIThread:props:(facebook::react::Tag reactTag, folly::dynamic props);
+  public virtual void schedulerDidSynchronouslyUpdateViewWithAnimatedPropsOnUIThread:surfaceId:animatedProps:(facebook::react::Tag reactTag, facebook::react::SurfaceId surfaceId, const facebook::react::AnimatedProps& animatedProps);
   public virtual void schedulerShouldMergeReactRevision:(facebook::react::SurfaceId surfaceId);
   public virtual void schedulerShouldRenderTransactions:(std::shared_ptr<const facebook::react::MountingCoordinator> mountingCoordinator);
 }
@@ -4535,7 +4537,8 @@ class facebook::react::AnimationBackend : public facebook::react::UIManagerAnima
   public virtual void trigger() override;
   public void commitUpdates(facebook::react::SurfaceId surfaceId, facebook::react::SurfaceUpdates& surfaceUpdates);
   public void requestAsyncFlushForSurfaces(const std::set<facebook::react::SurfaceId>& surfaces);
-  public void synchronouslyUpdateProps(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdateProps(facebook::react::SurfaceId surfaceId, const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdatePropsUnbuffered(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
 }
 
 class facebook::react::AnimationBackendCommitHook : public facebook::react::UIManagerCommitHook {

scripts/cxx-api/api-snapshots/ReactAppleReleaseCxx.api

@@ -1595,6 +1595,7 @@ interface RCTMountingManager : public NSObject {
   public virtual void setContextContainer:(std::shared_ptr<const facebook::react::ContextContainer> contextContainer);
   public virtual void setIsJSResponder:blockNativeResponder:forShadowView:(BOOL isJSResponder, BOOL blockNativeResponder, const facebook::react::ShadowView& shadowView);
   public virtual void synchronouslyUpdateViewOnUIThread:changedProps:componentDescriptor:(ReactTag reactTag, folly::dynamic props, const facebook::react::ComponentDescriptor& componentDescriptor);
+  public virtual void synchronouslyUpdateViewOnUIThread:withProps:(ReactTag reactTag, facebook::react::Props::Shared newProps);
 }
 
 interface RCTMultilineTextInputView : public RCTBaseTextInputView {
@@ -3387,6 +3388,7 @@ protocol RCTSchedulerDelegate {
   public virtual void schedulerDidSendAccessibilityEvent:eventType:(const facebook::react::ShadowView& shadowView, const std::string& eventType);
   public virtual void schedulerDidSetIsJSResponder:blockNativeResponder:forShadowView:(BOOL isJSResponder, BOOL blockNativeResponder, const facebook::react::ShadowView& shadowView);
   public virtual void schedulerDidSynchronouslyUpdateViewOnUIThread:props:(facebook::react::Tag reactTag, folly::dynamic props);
+  public virtual void schedulerDidSynchronouslyUpdateViewWithAnimatedPropsOnUIThread:surfaceId:animatedProps:(facebook::react::Tag reactTag, facebook::react::SurfaceId surfaceId, const facebook::react::AnimatedProps& animatedProps);
   public virtual void schedulerShouldMergeReactRevision:(facebook::react::SurfaceId surfaceId);
   public virtual void schedulerShouldRenderTransactions:(std::shared_ptr<const facebook::react::MountingCoordinator> mountingCoordinator);
 }
@@ -4534,7 +4536,8 @@ class facebook::react::AnimationBackend : public facebook::react::UIManagerAnima
   public virtual void trigger() override;
   public void commitUpdates(facebook::react::SurfaceId surfaceId, facebook::react::SurfaceUpdates& surfaceUpdates);
   public void requestAsyncFlushForSurfaces(const std::set<facebook::react::SurfaceId>& surfaces);
-  public void synchronouslyUpdateProps(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdateProps(facebook::react::SurfaceId surfaceId, const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdatePropsUnbuffered(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
 }
 
 class facebook::react::AnimationBackendCommitHook : public facebook::react::UIManagerCommitHook {

scripts/cxx-api/api-snapshots/ReactCommonDebugCxx.api

@@ -885,7 +885,8 @@ class facebook::react::AnimationBackend : public facebook::react::UIManagerAnima
   public virtual void trigger() override;
   public void commitUpdates(facebook::react::SurfaceId surfaceId, facebook::react::SurfaceUpdates& surfaceUpdates);
   public void requestAsyncFlushForSurfaces(const std::set<facebook::react::SurfaceId>& surfaces);
-  public void synchronouslyUpdateProps(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdateProps(facebook::react::SurfaceId surfaceId, const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
+  public void synchronouslyUpdatePropsUnbuffered(const std::unordered_map<facebook::react::Tag, facebook::react::AnimatedProps>& updates);
 }
 
 class facebook::react::AnimationBackendCommitHook : public facebook::react::UIManagerCommitHook {