Fabric: Introducting ShadowNode.sourceNode, the node used in copy-constructor

Summary: We will need this later in the diffing alogrithm.

Reviewed By: fkgozali

Differential Revision: D7330337

fbshipit-source-id: 3da44a62e4d5f30deed28b18a5779544153244f3

ReactCommon/fabric/core/shadownode/ShadowNode.cpp

@@ -41,7 +41,8 @@ ShadowNode::ShadowNode(
   tag_(shadowNode->tag_),
   instanceHandle_(shadowNode->instanceHandle_),
   props_(props ? props : shadowNode->props_),
-  children_(children ? children : shadowNode->children_) {}
+  children_(children ? children : shadowNode->children_),
+  sourceNode_(shadowNode) {}
 
 #pragma mark - Getters
 
@@ -57,7 +58,9 @@ Tag ShadowNode::getTag() const {
   return tag_;
 }
 
-#pragma mark - Mutating Methods
+SharedShadowNode ShadowNode::getSourceNode() const {
+  return sourceNode_;
+}
 
 void ShadowNode::sealRecursive() const {
   if (getSealed()) {
@@ -73,6 +76,8 @@ void ShadowNode::sealRecursive() const {
   }
 }
 
+#pragma mark - Mutating Methods
+
 void ShadowNode::appendChild(const SharedShadowNode &child) {
   ensureUnsealed();
 
@@ -95,6 +100,11 @@ void ShadowNode::replaceChild(const SharedShadowNode &oldChild, const SharedShad
   children_ = std::make_shared<const SharedShadowNodeList>(nonConstChildrenCopy);
 }
 
+void ShadowNode::clearSourceNode() {
+  ensureUnsealed();
+  sourceNode_ = nullptr;
+}
+
 #pragma mark - DebugStringConvertible
 
 std::string ShadowNode::getDebugName() const {
@@ -127,6 +137,13 @@ SharedDebugStringConvertibleList ShadowNode::getDebugProps() const {
     list.push_back(std::make_shared<DebugStringConvertibleItem>("handle", std::to_string((size_t)instanceHandle_)));
   }
 
+  if (sourceNode_) {
+    list.push_back(std::make_shared<DebugStringConvertibleItem>(
+      "source",
+      sourceNode_->getDebugDescription({.maximumDepth = 1, .format = false})
+    ));
+  }
+
   SharedDebugStringConvertibleList propsList = props_->getDebugProps();
   std::move(propsList.begin(), propsList.end(), std::back_inserter(list));
   return list;

ReactCommon/fabric/core/shadownode/ShadowNode.h

@@ -55,13 +55,14 @@ public:
   SharedShadowNodeSharedList getChildren() const;
   SharedProps getProps() const;
   Tag getTag() const;
+  SharedShadowNode getSourceNode() const;
+  void sealRecursive() const;
 
 #pragma mark - Mutating Methods
 
-  void sealRecursive() const;
-
   void appendChild(const SharedShadowNode &child);
   void replaceChild(const SharedShadowNode &oldChild, const SharedShadowNode &newChild);
+  void clearSourceNode();
 
 #pragma mark - DebugStringConvertible
 
@@ -76,6 +77,7 @@ protected:
   InstanceHandle instanceHandle_;
   SharedProps props_;
   SharedShadowNodeSharedList children_;
+  SharedShadowNode sourceNode_;
 };
 
 } // namespace react