Fabric: ShadowTree::completeByReplacingShadowNode was moved to RootShadowNode

Summary:
Removing additional complexity from ShadowTree should help with maintainability. Now, this class is "tricky", but short at least.
With new `commit` API, it's much more simple and expected this way.

Reviewed By: sahrens

Differential Revision: D13615365

fbshipit-source-id: 1fe851c1a2d3bdc7ac2f4a570cf0170eae3c4c67

ReactCommon/fabric/components/root/RootShadowNode.cpp

@@ -35,5 +35,34 @@ UnsharedRootShadowNode RootShadowNode::clone(
   return newRootShadowNode;
 }
 
+UnsharedRootShadowNode RootShadowNode::clone(
+    const SharedShadowNode &oldShadowNode,
+    const SharedShadowNode &newShadowNode) const {
+  std::vector<std::reference_wrapper<const ShadowNode>> ancestors;
+  oldShadowNode->constructAncestorPath(*this, ancestors);
+
+  if (ancestors.size() == 0) {
+    return UnsharedRootShadowNode{nullptr};
+  }
+
+  auto oldChild = oldShadowNode;
+  auto newChild = newShadowNode;
+
+  SharedShadowNodeUnsharedList sharedChildren;
+
+  for (const auto &ancestor : ancestors) {
+    auto children = ancestor.get().getChildren();
+    std::replace(children.begin(), children.end(), oldChild, newChild);
+
+    sharedChildren = std::make_shared<SharedShadowNodeList>(children);
+
+    oldChild = ancestor.get().shared_from_this();
+    newChild = oldChild->clone(ShadowNodeFragment{.children = sharedChildren});
+  }
+
+  return std::make_shared<RootShadowNode>(
+      *this, ShadowNodeFragment{.children = sharedChildren});
+}
+
 } // namespace react
 } // namespace facebook

ReactCommon/fabric/components/root/RootShadowNode.h

@@ -46,6 +46,16 @@ class RootShadowNode final
       const LayoutConstraints &layoutConstraints,
       const LayoutContext &layoutContext) const;
 
+  /*
+   * Clones the node replacing a given old shadow node with a new one in the
+   * tree by cloning all nodes on the path to the root node and then complete
+   * the tree. Returns `nullptr` if the operation cannot be finished
+   * successfully.
+   */
+  UnsharedRootShadowNode clone(
+      const SharedShadowNode &oldShadowNode,
+      const SharedShadowNode &newShadowNode) const;
+
  private:
   using YogaLayoutableShadowNode::layout;
 };

ReactCommon/fabric/uimanager/Scheduler.cpp

@@ -151,8 +151,9 @@ Size Scheduler::measureSurface(
 
   Size size;
   shadowTreeRegistry_.visit(surfaceId, [&](const ShadowTree &shadowTree) {
-    shadowTree.commit([&] (const SharedRootShadowNode &oldRootShadowNode) {
-      auto rootShadowNode = oldRootShadowNode->clone(layoutConstraints, layoutContext);
+    shadowTree.commit([&](const SharedRootShadowNode &oldRootShadowNode) {
+      auto rootShadowNode =
+          oldRootShadowNode->clone(layoutConstraints, layoutContext);
       rootShadowNode->layout();
       size = rootShadowNode->getLayoutMetrics().frame.size;
       return nullptr;
@@ -168,9 +169,11 @@ void Scheduler::constraintSurfaceLayout(
   SystraceSection s("Scheduler::constraintSurfaceLayout");
 
   shadowTreeRegistry_.visit(surfaceId, [&](const ShadowTree &shadowTree) {
-    shadowTree.commit([&] (const SharedRootShadowNode &oldRootShadowNode) {
-      return oldRootShadowNode->clone(layoutConstraints, layoutContext);
-    }, std::numeric_limits<int>::max());
+    shadowTree.commit(
+        [&](const SharedRootShadowNode &oldRootShadowNode) {
+          return oldRootShadowNode->clone(layoutConstraints, layoutContext);
+        },
+        std::numeric_limits<int>::max());
   });
 }
 

ReactCommon/fabric/uimanager/ShadowTree.cpp

@@ -55,38 +55,6 @@ SharedRootShadowNode ShadowTree::getRootShadowNode() const {
   return rootShadowNode_;
 }
 
-bool ShadowTree::completeByReplacingShadowNode(
-    const SharedShadowNode &oldShadowNode,
-    const SharedShadowNode &newShadowNode) const {
-  return commit([&](const SharedRootShadowNode &oldRootShadowNode) {
-    std::vector<std::reference_wrapper<const ShadowNode>> ancestors;
-    oldShadowNode->constructAncestorPath(*oldRootShadowNode, ancestors);
-
-    if (ancestors.size() == 0) {
-      return UnsharedRootShadowNode{nullptr};
-    }
-
-    auto oldChild = oldShadowNode;
-    auto newChild = newShadowNode;
-
-    SharedShadowNodeUnsharedList sharedChildren;
-
-    for (const auto &ancestor : ancestors) {
-      auto children = ancestor.get().getChildren();
-      std::replace(children.begin(), children.end(), oldChild, newChild);
-
-      sharedChildren = std::make_shared<SharedShadowNodeList>(children);
-
-      oldChild = ancestor.get().shared_from_this();
-      newChild =
-          oldChild->clone(ShadowNodeFragment{.children = sharedChildren});
-    }
-
-    return std::make_shared<RootShadowNode>(
-        *oldRootShadowNode, ShadowNodeFragment{.children = sharedChildren});
-  });
-}
-
 bool ShadowTree::commit(
     std::function<UnsharedRootShadowNode(
         const SharedRootShadowNode &oldRootShadowNode)> transaction,

ReactCommon/fabric/uimanager/ShadowTree.h

@@ -54,16 +54,6 @@ class ShadowTree final {
       int attempts = 1,
       int *revision = nullptr) const;
 
-  /*
-   * Replaces a given old shadow node with a new one in the tree by cloning all
-   * nodes on the path to the root node and then complete the tree.
-   * Can be called from any thread.
-   * Returns `true` if the operation finished successfully.
-   */
-  bool completeByReplacingShadowNode(
-      const SharedShadowNode &oldShadowNode,
-      const SharedShadowNode &newShadowNode) const;
-
   /*
    * Returns a root shadow node that represents the last committed three.
    */

ReactCommon/fabric/uimanager/UIManager.cpp

@@ -86,7 +86,9 @@ void UIManager::setNativeProps(
 
   shadowTreeRegistry_->visit(
       shadowNode->getRootTag(), [&](const ShadowTree &shadowTree) {
-        shadowTree.completeByReplacingShadowNode(shadowNode, newShadowNode);
+        shadowTree.commit([&](const SharedRootShadowNode &oldRootShadowNode) {
+          return oldRootShadowNode->clone(shadowNode, newShadowNode);
+        });
       });
 }