Fabric: Using RootComponentDescriptor to manage RootShadowNode in ShadowTree

Summary: We need this change to migrate away `cloneFunction` (to a pointer to ComponentDescriptor) inside ShadowNode.

Reviewed By: mdvacca

Differential Revision: D14249197

fbshipit-source-id: 773edcf40e17989886e2c5d3955823a0dbf3857a

ReactCommon/fabric/components/root/RootComponentDescriptor.h

@@ -0,0 +1,19 @@
+/**
+ * Copyright (c) Facebook, Inc. and its affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <react/components/root/RootShadowNode.h>
+#include <react/core/ConcreteComponentDescriptor.h>
+
+namespace facebook {
+namespace react {
+
+using RootComponentDescriptor = ConcreteComponentDescriptor<RootShadowNode>;
+
+} // namespace react
+} // namespace facebook

ReactCommon/fabric/components/root/RootProps.cpp

@@ -32,6 +32,11 @@ static YGStyle yogaStyleFromLayoutConstraints(
   return yogaStyle;
 }
 
+RootProps::RootProps(const RootProps &sourceProps, const RawProps &rawProps) {
+  // `RootProps` cannot be constructed from `RawProps`.
+  assert(false);
+}
+
 RootProps::RootProps(
     const RootProps &sourceProps,
     const LayoutConstraints &layoutConstraints,

ReactCommon/fabric/components/root/RootProps.h

@@ -23,6 +23,7 @@ using SharedRootProps = std::shared_ptr<const RootProps>;
 class RootProps final : public ViewProps {
  public:
   RootProps() = default;
+  RootProps(const RootProps &sourceProps, const RawProps &rawProps);
   RootProps(
       const RootProps &sourceProps,
       const LayoutConstraints &layoutConstraints,

ReactCommon/fabric/uimanager/Scheduler.cpp

@@ -62,6 +62,9 @@ Scheduler::Scheduler(
   componentDescriptorRegistry_ =
       buildRegistryFunction(eventDispatcher, contextContainer);
 
+  rootComponentDescriptor_ =
+      std::make_unique<const RootComponentDescriptor>(eventDispatcher);
+
   uiManagerRef.setDelegate(this);
   uiManagerRef.setShadowTreeRegistry(&shadowTreeRegistry_);
   uiManagerRef.setComponentDescriptorRegistry(componentDescriptorRegistry_);
@@ -83,8 +86,8 @@ void Scheduler::startSurface(
     const LayoutContext &layoutContext) const {
   SystraceSection s("Scheduler::startSurface");
 
-  auto shadowTree =
-      std::make_unique<ShadowTree>(surfaceId, layoutConstraints, layoutContext);
+  auto shadowTree = std::make_unique<ShadowTree>(
+      surfaceId, layoutConstraints, layoutContext, *rootComponentDescriptor_);
   shadowTree->setDelegate(this);
 
   shadowTreeRegistry_.add(std::move(shadowTree));

ReactCommon/fabric/uimanager/Scheduler.h

@@ -8,6 +8,7 @@
 #include <memory>
 #include <mutex>
 
+#include <react/components/root/RootComponentDescriptor.h>
 #include <react/config/ReactNativeConfig.h>
 #include <react/core/ComponentDescriptor.h>
 #include <react/core/LayoutConstraints.h>
@@ -99,6 +100,7 @@ class Scheduler final : public UIManagerDelegate, public ShadowTreeDelegate {
  private:
   SchedulerDelegate *delegate_;
   SharedComponentDescriptorRegistry componentDescriptorRegistry_;
+  std::unique_ptr<const RootComponentDescriptor> rootComponentDescriptor_;
   ShadowTreeRegistry shadowTreeRegistry_;
   RuntimeExecutor runtimeExecutor_;
   std::shared_ptr<UIManagerBinding> uiManagerBinding_;

ReactCommon/fabric/uimanager/ShadowTree.cpp

@@ -5,6 +5,7 @@
 
 #include "ShadowTree.h"
 
+#include <react/components/root/RootComponentDescriptor.h>
 #include <react/core/LayoutContext.h>
 #include <react/core/LayoutPrimitives.h>
 #include <react/debug/SystraceSection.h>
@@ -79,7 +80,8 @@ static void updateMountedFlag(
 ShadowTree::ShadowTree(
     SurfaceId surfaceId,
     const LayoutConstraints &layoutConstraints,
-    const LayoutContext &layoutContext)
+    const LayoutContext &layoutContext,
+    const RootComponentDescriptor &rootComponentDescriptor)
     : surfaceId_(surfaceId) {
   const auto noopEventEmitter = std::make_shared<const ViewEventEmitter>(
       nullptr, -1, std::shared_ptr<const EventDispatcher>());
@@ -87,16 +89,13 @@ ShadowTree::ShadowTree(
   const auto props = std::make_shared<const RootProps>(
       *RootShadowNode::defaultSharedProps(), layoutConstraints, layoutContext);
 
-  rootShadowNode_ = std::make_shared<RootShadowNode>(
-      ShadowNodeFragment{
+  rootShadowNode_ = std::static_pointer_cast<const RootShadowNode>(
+      rootComponentDescriptor.createShadowNode(ShadowNodeFragment{
           .tag = surfaceId,
           .rootTag = surfaceId,
           .props = props,
           .eventEmitter = noopEventEmitter,
-      },
-      [](const ShadowNode &shadowNode, const ShadowNodeFragment &fragment) {
-        return std::make_shared<RootShadowNode>(shadowNode, fragment);
-      });
+      }));
 }
 
 ShadowTree::~ShadowTree() {

ReactCommon/fabric/uimanager/ShadowTree.h

@@ -9,6 +9,7 @@
 #include <memory>
 #include <shared_mutex>
 
+#include <react/components/root/RootComponentDescriptor.h>
 #include <react/components/root/RootShadowNode.h>
 #include <react/core/LayoutConstraints.h>
 #include <react/core/ReactPrimitives.h>
@@ -33,7 +34,8 @@ class ShadowTree final {
   ShadowTree(
       SurfaceId surfaceId,
       const LayoutConstraints &layoutConstraints,
-      const LayoutContext &layoutContext);
+      const LayoutContext &layoutContext,
+      const RootComponentDescriptor &rootComponentDescriptor);
 
   ~ShadowTree();