react · bartlomiejbloniarz · Dec 2, 2025
diff --git a/packages/react-native/Libraries/Animated/__tests__/AnimatedBackend-itest.js b/packages/react-native/Libraries/Animated/__tests__/AnimatedBackend-itest.js
@@ -17,6 +17,7 @@ import ensureInstance from '../../../src/private/__tests__/utilities/ensureInsta
 import * as Fantom from '@react-native/fantom';
 import {createRef} from 'react';
 import {Animated, useAnimatedValue} from 'react-native';
+import {allowStyleProp} from 'react-native/Libraries/Animated/NativeAnimatedAllowlist';
 import ReactNativeElement from 'react-native/src/private/webapis/dom/nodes/ReactNativeElement';
 
 test('animated opacity', () => {
@@ -73,3 +74,60 @@ test('animated opacity', () => {
     <rn-view opacity="0" />,
   );
 });
+
+test('animate layout props', () => {
+  const viewRef = createRef<HostInstance>();
+  allowStyleProp('height');
+
+  let _animatedHeight;
+  let _heightAnimation;
+
+  function MyApp() {
+    const animatedHeight = useAnimatedValue(0);
+    _animatedHeight = animatedHeight;
+    return (
+      <Animated.View
+        ref={viewRef}
+        style={[
+          {
+            width: 100,
+            height: animatedHeight,
+          },
+        ]}
+      />
+    );
+  }
+
+  const root = Fantom.createRoot();
+
+  Fantom.runTask(() => {
+    root.render(<MyApp />);
+  });
+
+  Fantom.runTask(() => {
+    _heightAnimation = Animated.timing(_animatedHeight, {
+      toValue: 100,
+      duration: 200,
+      useNativeDriver: true,
+    }).start();
+  });
+
+  Fantom.unstable_produceFramesForDuration(100);
+
+  // TODO: getFabricUpdateProps is not working with the cloneMutliple method
+  // expect(Fantom.unstable_getFabricUpdateProps(viewElement).height).toBe(100);
+  expect(root.getRenderedOutput({props: ['height']}).toJSX()).toEqual(
+    <rn-view height="50.000000" />,
+  );
+
+  Fantom.unstable_produceFramesForDuration(100);
+
+  // TODO: this shouldn't be neccessary since animation should be stopped after duration
+  Fantom.runTask(() => {
+    _heightAnimation?.stop();
+  });
+
+  expect(root.getRenderedOutput({props: ['height']}).toJSX()).toEqual(
+    <rn-view height="100.000000" />,
+  );
+});
diff --git a/packages/react-native/Libraries/Animated/nodes/AnimatedProps.js b/packages/react-native/Libraries/Animated/nodes/AnimatedProps.js
@@ -14,7 +14,9 @@ import type {AnimatedNodeConfig} from './AnimatedNode';
 import type {AnimatedStyleAllowlist} from './AnimatedStyle';
 
 import NativeAnimatedHelper from '../../../src/private/animated/NativeAnimatedHelper';
+import * as ReactNativeFeatureFlags from '../../../src/private/featureflags/ReactNativeFeatureFlags';
 import {findNodeHandle} from '../../ReactNative/RendererProxy';
+import {getNodeFromPublicInstance} from '../../ReactPrivate/ReactNativePrivateInterface';
 import flattenStyle from '../../StyleSheet/flattenStyle';
 import {AnimatedEvent} from '../AnimatedEvent';
 import AnimatedNode from './AnimatedNode';
@@ -251,7 +253,9 @@ export default class AnimatedProps extends AnimatedNode {
       super.__setPlatformConfig(platformConfig);
 
       if (this._target != null) {
-        this.#connectAnimatedView(this._target);
+        const target = this._target;
+        this.#connectAnimatedView(target);
+        this.#connectShadowNode(target);
       }
     }
   }
@@ -260,9 +264,10 @@ export default class AnimatedProps extends AnimatedNode {
     if (this._target?.instance === instance) {
       return;
     }
-    this._target = {instance, connectedViewTag: null};
+    const target = (this._target = {instance, connectedViewTag: null});
     if (this.__isNative) {
-      this.#connectAnimatedView(this._target);
+      this.#connectAnimatedView(target);
+      this.#connectShadowNode(target);
     }
   }
 
@@ -283,6 +288,27 @@ export default class AnimatedProps extends AnimatedNode {
     target.connectedViewTag = viewTag;
   }
 
+  #connectShadowNode(target: TargetView): void {
+    if (
+      !ReactNativeFeatureFlags.cxxNativeAnimatedEnabled() ||
+      //eslint-disable-next-line
+      !ReactNativeFeatureFlags.useSharedAnimatedBackend()
+    ) {
+      return;
+    }
+
+    invariant(this.__isNative, 'Expected node to be marked as "native"');
+    // $FlowExpectedError[incompatible-type] - target.instance may be an HTMLElement but we need ReactNativeElement for Fabric
+    const shadowNode = getNodeFromPublicInstance(target.instance);
+    if (shadowNode == null) {
+      return;
+    }
+    NativeAnimatedHelper.API.connectAnimatedNodeToShadowNodeFamily(
+      this.__getNativeTag(),
+      shadowNode,
+    );
+  }
+
   #disconnectAnimatedView(target: TargetView): void {
     invariant(this.__isNative, 'Expected node to be marked as "native"');
     const viewTag = target.connectedViewTag;

diff --git a/packages/react-native/Libraries/NativeAnimation/RCTNativeAnimatedTurboModule.mm b/packages/react-native/Libraries/NativeAnimation/RCTNativeAnimatedTurboModule.mm
@@ -10,6 +10,7 @@
 #import <React/RCTInitializing.h>
 #import <React/RCTNativeAnimatedNodesManager.h>
 #import <React/RCTNativeAnimatedTurboModule.h>
+#import <react/debug/react_native_assert.h>
 #import <react/featureflags/ReactNativeFeatureFlags.h>
 
 #import "RCTAnimationPlugins.h"
@@ -165,6 +166,12 @@ - (void)setSurfacePresenter:(id<RCTSurfacePresenterStub>)surfacePresenter
   }];
 }
 
+RCT_EXPORT_METHOD(connectAnimatedNodeToShadowNodeFamily : (double)nodeTag shadowNode : (NSDictionary *)shadowNode)
+{
+  // This method should only be called when using CxxNativeAnimated
+  react_native_assert(false);
+}
+
 RCT_EXPORT_METHOD(disconnectAnimatedNodeFromView : (double)nodeTag viewTag : (double)viewTag)
 {
   [self queueOperationBlock:^(RCTNativeAnimatedNodesManager *nodesManager) {

diff --git a/packages/react-native/Libraries/NativeAnimation/React-RCTAnimation.podspec b/packages/react-native/Libraries/NativeAnimation/React-RCTAnimation.podspec
@@ -48,6 +48,7 @@ Pod::Spec.new do |s|
   add_dependency(s, "ReactCommon", :subspec => "turbomodule/core", :additional_framework_paths => ["react/nativemodule/core"])
   add_dependency(s, "React-NativeModulesApple")
   add_dependency(s, "React-featureflags")
+  add_dependency(s, "React-debug")
 
   add_rn_third_party_dependencies(s)
   add_rncore_dependency(s)

diff --git a/packages/react-native/ReactCommon/react/renderer/animated/AnimatedModule.cpp b/packages/react-native/ReactCommon/react/renderer/animated/AnimatedModule.cpp
@@ -9,9 +9,9 @@
 
 #include <glog/logging.h>
 #include <jsi/JSIDynamic.h>
+#include <react/renderer/bridging/bridging.h>
 
 namespace facebook::react {
-
 AnimatedModule::AnimatedModule(
     std::shared_ptr<CallInvoker> jsInvoker,
     std::shared_ptr<NativeAnimatedNodesManagerProvider> nodesManagerProvider)
@@ -160,6 +160,19 @@ void AnimatedModule::connectAnimatedNodeToView(
       ConnectAnimatedNodeToViewOp{.nodeTag = nodeTag, .viewTag = viewTag});
 }
 
+void AnimatedModule::connectAnimatedNodeToShadowNodeFamily(
+    jsi::Runtime& rt,
+    Tag nodeTag,
+    jsi::Object shadowNodeObj) {
+  const auto& shadowNode = Bridging<std::shared_ptr<const ShadowNode>>::fromJs(
+      rt, jsi::Value(rt, shadowNodeObj));
+
+  operations_.emplace_back(
+      ConnectAnimatedNodeToShadowNodeFamilyOp{
+          .nodeTag = nodeTag,
+          .shadowNodeFamily = shadowNode->getFamilyShared()});
+}
+
 void AnimatedModule::disconnectAnimatedNodeFromView(
     jsi::Runtime& /*rt*/,
     Tag nodeTag,
@@ -282,6 +295,11 @@ void AnimatedModule::executeOperation(
                                    DisconnectAnimatedNodeFromViewOp>) {
             nodesManager->disconnectAnimatedNodeFromView(
                 op.nodeTag, op.viewTag);
+          } else if constexpr (std::is_same_v<
+                                   T,
+                                   ConnectAnimatedNodeToShadowNodeFamilyOp>) {
+            nodesManager->connectAnimatedNodeToShadowNodeFamily(
+                op.nodeTag, op.shadowNodeFamily);
           } else if constexpr (std::is_same_v<T, RestoreDefaultValuesOp>) {
             nodesManager->restoreDefaultValues(op.nodeTag);
           } else if constexpr (std::is_same_v<T, DropAnimatedNodeOp>) {

diff --git a/packages/react-native/ReactCommon/react/renderer/animated/AnimatedModule.h b/packages/react-native/ReactCommon/react/renderer/animated/AnimatedModule.h
@@ -87,6 +87,11 @@ class AnimatedModule : public NativeAnimatedModuleCxxSpec<AnimatedModule>, publi
     Tag viewTag{};
   };
 
+  struct ConnectAnimatedNodeToShadowNodeFamilyOp {
+    Tag nodeTag{};
+    std::shared_ptr<const ShadowNodeFamily> shadowNodeFamily{};
+  };
+
   struct DisconnectAnimatedNodeFromViewOp {
     Tag nodeTag{};
     Tag viewTag{};
@@ -124,6 +129,7 @@ class AnimatedModule : public NativeAnimatedModuleCxxSpec<AnimatedModule>, publi
       SetAnimatedNodeOffsetOp,
       SetAnimatedNodeValueOp,
       ConnectAnimatedNodeToViewOp,
+      ConnectAnimatedNodeToShadowNodeFamilyOp,
       DisconnectAnimatedNodeFromViewOp,
       RestoreDefaultValuesOp,
       FlattenAnimatedNodeOffsetOp,
@@ -176,6 +182,8 @@ class AnimatedModule : public NativeAnimatedModuleCxxSpec<AnimatedModule>, publi
 
   void connectAnimatedNodeToView(jsi::Runtime &rt, Tag nodeTag, Tag viewTag);
 
+  void connectAnimatedNodeToShadowNodeFamily(jsi::Runtime &rt, Tag nodeTag, jsi::Object shadowNode);
+
   void disconnectAnimatedNodeFromView(jsi::Runtime &rt, Tag nodeTag, Tag viewTag);
 
   void restoreDefaultValues(jsi::Runtime &rt, Tag nodeTag);

diff --git a/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.cpp b/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.cpp
@@ -238,6 +238,20 @@ void NativeAnimatedNodesManager::connectAnimatedNodeToView(
   }
 }
 
+void NativeAnimatedNodesManager::connectAnimatedNodeToShadowNodeFamily(
+    Tag propsNodeTag,
+    std::shared_ptr<const ShadowNodeFamily> family) noexcept {
+  react_native_assert(propsNodeTag);
+  auto node = getAnimatedNode<PropsAnimatedNode>(propsNodeTag);
+  if (node != nullptr && family != nullptr) {
+    std::lock_guard<std::mutex> lock(tagToShadowNodeFamilyMutex_);
+    tagToShadowNodeFamily_[family->getTag()] = family;
+  } else {
+    LOG(WARNING)
+        << "Cannot ConnectAnimatedNodeToShadowNodeFamily, animated node has to be props type";
+  }
+}
+
 void NativeAnimatedNodesManager::disconnectAnimatedNodeFromView(
     Tag propsNodeTag,
     Tag viewTag) noexcept {
@@ -251,6 +265,10 @@ void NativeAnimatedNodesManager::disconnectAnimatedNodeFromView(
       std::lock_guard<std::mutex> lock(connectedAnimatedNodesMutex_);
       connectedAnimatedNodes_.erase(viewTag);
     }
+    {
+      std::lock_guard<std::mutex> lock(tagToShadowNodeFamilyMutex_);
+      tagToShadowNodeFamily_.erase(viewTag);
+    }
     updatedNodeTags_.insert(node->tag());
 
     onManagedPropsRemoved(viewTag);
@@ -989,15 +1007,47 @@ AnimationMutations NativeAnimatedNodesManager::pullAnimationMutations() {
       }
 
       for (auto& [tag, props] : updateViewPropsDirect_) {
-        // TODO: also handle layout props (updateViewProps_). It is skipped for
-        // now, because the backend requires shadowNodeFamilies to be able to
-        // commit to the ShadowTree
         propsBuilder.storeDynamic(props);
         mutations.push_back(
             AnimationMutation{tag, nullptr, propsBuilder.get()});
         containsChange = true;
       }
-      updateViewPropsDirect_.clear();
+      {
+        std::lock_guard<std::mutex> lock(tagToShadowNodeFamilyMutex_);
+        for (auto& [tag, props] : updateViewProps_) {
+          auto familyIt = tagToShadowNodeFamily_.find(tag);
+          if (familyIt == tagToShadowNodeFamily_.end()) {
+            continue;
+          }
+          if (auto family = familyIt->second.lock()) {
+            // C++ Animated produces props in the form of a folly::dynamic, so
+            // it wouldn't make sense to unpack it here. However, for the
+            // purposes of testing, we want to be able to use the statically
+            // typed AnimationMutation. At a later stage we will instead just
+            // pass the dynamic directly to propsBuilder and the new API could
+            // be used by 3rd party libraries or in the fututre by Animated.
+            if (props.find("width") != props.items().end()) {
+              propsBuilder.setWidth(
+                  yoga::Style::SizeLength::points(props["width"].asDouble()));
+            }
+            if (props.find("height") != props.items().end()) {
+              propsBuilder.setHeight(
+                  yoga::Style::SizeLength::points(props["height"].asDouble()));
+            }
+            mutations.push_back(
+                AnimationMutation{
+                    .tag = tag,
+                    .family = family,
+                    .props = propsBuilder.get(),
+                });
+          }
+          containsChange = true;
+        }
+      }
+      if (containsChange) {
+        updateViewPropsDirect_.clear();
+        updateViewProps_.clear();
+      }
     }
 
     if (!containsChange) {
@@ -1017,16 +1067,38 @@ AnimationMutations NativeAnimatedNodesManager::pullAnimationMutations() {
         }
       }
 
-      // Step 2: update all nodes that are connected to the finished animations.
+      // Step 2: update all nodes that are connected to the finished
+      // animations.
       updateNodes(finishedAnimationValueNodes);
 
       isEventAnimationInProgress_ = false;
 
       for (auto& [tag, props] : updateViewPropsDirect_) {
-        // TODO: handle layout props
         propsBuilder.storeDynamic(props);
         mutations.push_back(
-            AnimationMutation{tag, nullptr, propsBuilder.get()});
+            AnimationMutation{
+                .tag = tag,
+                .family = nullptr,
+                .props = propsBuilder.get(),
+            });
+      }
+      {
+        std::lock_guard<std::mutex> lock(tagToShadowNodeFamilyMutex_);
+        for (auto& [tag, props] : updateViewProps_) {
+          auto familyIt = tagToShadowNodeFamily_.find(tag);
+          if (familyIt == tagToShadowNodeFamily_.end()) {
+            continue;
+          }
+          if (auto family = familyIt->second.lock()) {
+            propsBuilder.storeDynamic(props);
+            mutations.push_back(
+                AnimationMutation{
+                    .tag = tag,
+                    .family = family,
+                    .props = propsBuilder.get(),
+                });
+          }
+        }
       }
     }
   } else {
@@ -1107,7 +1179,8 @@ void NativeAnimatedNodesManager::onRender() {
         }
       }
 
-      // Step 2: update all nodes that are connected to the finished animations.
+      // Step 2: update all nodes that are connected to the finished
+      // animations.
       updateNodes(finishedAnimationValueNodes);
 
       isEventAnimationInProgress_ = false;

diff --git a/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.h b/packages/react-native/ReactCommon/react/renderer/animated/NativeAnimatedNodesManager.h
@@ -21,6 +21,7 @@
 #include <react/renderer/animationbackend/AnimationBackend.h>
 #endif
 #include <react/renderer/core/ReactPrimitives.h>
+#include <react/renderer/core/ShadowNode.h>
 #include <react/renderer/uimanager/UIManagerAnimationBackend.h>
 #include <chrono>
 #include <memory>
@@ -101,6 +102,8 @@ class NativeAnimatedNodesManager {
 
   void connectAnimatedNodeToView(Tag propsNodeTag, Tag viewTag) noexcept;
 
+  void connectAnimatedNodeToShadowNodeFamily(Tag propsNodeTag, std::shared_ptr<const ShadowNodeFamily> family) noexcept;
+
   void disconnectAnimatedNodes(Tag parentTag, Tag childTag) noexcept;
 
   void disconnectAnimatedNodeFromView(Tag propsNodeTag, Tag viewTag) noexcept;
@@ -258,6 +261,9 @@ class NativeAnimatedNodesManager {
   std::unordered_map<Tag, folly::dynamic> updateViewProps_{};
   std::unordered_map<Tag, folly::dynamic> updateViewPropsDirect_{};
 
+  mutable std::mutex tagToShadowNodeFamilyMutex_;
+  std::unordered_map<Tag, std::weak_ptr<const ShadowNodeFamily>> tagToShadowNodeFamily_{};
+
   /*
    * Sometimes a view is not longer connected to a PropsAnimatedNode, but
    * NativeAnimated has previously changed the view's props via direct