feat: add new hook shadowTreeDidCommit

Author: paradowstack

packages/react-native/ReactCommon/react/renderer/mounting/ShadowTree.cpp

@@ -463,6 +463,9 @@ CommitStatus ShadowTree::tryCommit(
     }
   }
 
+  delegate_.shadowTreeDidCommit(
+      *this, newRevision.rootShadowNode, affectedLayoutableNodes);
+
   emitLayoutEvents(affectedLayoutableNodes);
 
   if (isReactBranch) {

packages/react-native/ReactCommon/react/renderer/mounting/ShadowTreeDelegate.h

@@ -11,6 +11,7 @@
 
 namespace facebook::react {
 
+class LayoutableShadowNode;
 class ShadowTree;
 struct ShadowTreeCommitOptions;
 
@@ -49,6 +50,16 @@ class ShadowTreeDelegate {
    */
   virtual void shadowTreeDidPromoteReactRevision(const ShadowTree &shadowTree) const = 0;
 
+  /*
+   * Called right after a Shadow Tree commits a new tree, reporting the nodes
+   * whose layout changed in this commit.
+   */
+  virtual void shadowTreeDidCommit(
+      const ShadowTree& shadowTree,
+      const RootShadowNode::Shared& rootShadowNode,
+      const std::vector<const LayoutableShadowNode*>& affectedLayoutableNodes)
+      const noexcept {}
+
   virtual ~ShadowTreeDelegate() noexcept = default;
 };
 

packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.cpp

@@ -670,6 +670,21 @@ void UIManager::shadowTreeDidPromoteReactRevision(
   }
 }
 
+void UIManager::shadowTreeDidCommit(
+    const ShadowTree& shadowTree,
+    const RootShadowNode::Shared& rootShadowNode,
+    const std::vector<const LayoutableShadowNode*>& affectedLayoutableNodes)
+    const noexcept {
+  TraceSection s("UIManager::shadowTreeDidCommit");
+
+  std::shared_lock lock(commitHookMutex_);
+
+  for (auto* commitHook : commitHooks_) {
+    commitHook->shadowTreeDidCommit(
+        shadowTree, rootShadowNode, affectedLayoutableNodes);
+  }
+}
+
 void UIManager::reportMount(SurfaceId surfaceId) const {
   TraceSection s("UIManager::reportMount");
 

packages/react-native/ReactCommon/react/renderer/uimanager/UIManager.h

@@ -146,6 +146,12 @@ class UIManager final : public ShadowTreeDelegate {
 
   void shadowTreeDidPromoteReactRevision(const ShadowTree &shadowTree) const override;
 
+  void shadowTreeDidCommit(
+      const ShadowTree& shadowTree,
+      const RootShadowNode::Shared& rootShadowNode,
+      const std::vector<const LayoutableShadowNode*>& affectedLayoutableNodes)
+      const noexcept override;
+
   std::shared_ptr<ShadowNode> createNode(
       Tag tag,
       const std::string &componentName,

packages/react-native/ReactCommon/react/renderer/uimanager/UIManagerCommitHook.h

@@ -11,6 +11,7 @@
 
 namespace facebook::react {
 
+class LayoutableShadowNode;
 class ShadowTree;
 struct ShadowTreeCommitOptions;
 class UIManager;
@@ -54,6 +55,16 @@ class UIManagerCommitHook {
     return newRootShadowNode;
   }
 
+  /*
+   * Called right after a `ShadowTree` commits a new tree.
+   * The semantic of the method corresponds to a method of the same name
+   * from `ShadowTreeDelegate`.
+   */
+  virtual void shadowTreeDidCommit(
+      const ShadowTree& /*shadowTree*/,
+      const RootShadowNode::Shared& /*rootShadowNode*/,
+      const std::vector<const LayoutableShadowNode*>& /*affectedLayoutableNodes*/) noexcept {}
+
   virtual ~UIManagerCommitHook() noexcept = default;
 };