Create ShadowNodeFamily inside ComponentDescriptor

Summary:
Changelog: [internal]

1. Creates `ShadowNodeFamily` inside `ComponentDescriptor`.
2. As a side effect of this, we no longer need `ComponentDescriptor::createEventEmitter` so it is removed.

This is a step in order to merge `StateCoordinator` into `ShadowNodeFamily` and use it as target for state updates.

Reviewed By: shergin

Differential Revision: D19514906

fbshipit-source-id: 04ad3c621886be56925acd76f9b35a09d8c5e15a

Author: sammy-SC

ReactCommon/fabric/core/componentdescriptor/ComponentDescriptor.h

@@ -103,14 +103,6 @@ class ComponentDescriptor {
       const SharedProps &props,
       const RawProps &rawProps) const = 0;
 
-  /*
-   * Creates a new `EventEmitter` object compatible with particular type of
-   * shadow nodes.
-   */
-  virtual SharedEventEmitter createEventEmitter(
-      SharedEventTarget eventTarget,
-      const Tag &tag) const = 0;
-
   /*
    * Create an initial State object that represents (and contains) an initial
    * State's data which can be constructed based on initial Props.
@@ -127,6 +119,13 @@ class ComponentDescriptor {
       const State::Shared &previousState,
       const StateData::Shared &data) const = 0;
 
+  /*
+   * Creates a shadow node family for particular node.
+   */
+  virtual ShadowNodeFamily::Shared createFamily(
+      ShadowNodeFamilyFragment const &fragment,
+      SharedEventTarget eventTarget) const = 0;
+
  protected:
   EventDispatcher::Weak eventDispatcher_;
   ContextContainer::Shared contextContainer_;

ReactCommon/fabric/core/componentdescriptor/ConcreteComponentDescriptor.h

@@ -118,13 +118,6 @@ class ConcreteComponentDescriptor : public ComponentDescriptor {
     return ShadowNodeT::Props(rawProps, props);
   };
 
-  virtual SharedEventEmitter createEventEmitter(
-      SharedEventTarget eventTarget,
-      const Tag &tag) const override {
-    return std::make_shared<ConcreteEventEmitter>(
-        std::move(eventTarget), tag, eventDispatcher_);
-  }
-
   virtual State::Shared createInitialState(
       ShadowNodeFragment const &fragment,
       SurfaceId const surfaceId) const override {
@@ -157,6 +150,17 @@ class ConcreteComponentDescriptor : public ComponentDescriptor {
         *std::static_pointer_cast<const ConcreteState>(previousState));
   }
 
+  virtual ShadowNodeFamily::Shared createFamily(
+      ShadowNodeFamilyFragment const &fragment,
+      SharedEventTarget eventTarget) const override {
+    auto eventEmitter = std::make_shared<ConcreteEventEmitter const>(
+        std::move(eventTarget), fragment.tag, eventDispatcher_);
+    return std::make_shared<ShadowNodeFamily>(
+        ShadowNodeFamilyFragment{
+            fragment.tag, fragment.surfaceId, eventEmitter},
+        *this);
+  }
+
  protected:
   virtual void adopt(UnsharedShadowNode shadowNode) const {
     // Default implementation does nothing.

ReactCommon/fabric/core/tests/ComponentDescriptorTest.cpp

@@ -23,9 +23,14 @@ TEST(ComponentDescriptorTest, createShadowNode) {
 
   const auto &raw = RawProps(folly::dynamic::object("nativeID", "abc"));
   SharedProps props = descriptor->cloneProps(nullptr, raw);
-  auto family = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{9, 1, descriptor->createEventEmitter(0, 9)},
-      *descriptor);
+
+  auto family = descriptor->createFamily(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 9,
+          /* .surfaceId = */ 1,
+          /* .eventEmitter = */ nullptr,
+      },
+      nullptr);
 
   SharedShadowNode node = descriptor->createShadowNode(
       ShadowNodeFragment{
@@ -49,9 +54,13 @@ TEST(ComponentDescriptorTest, cloneShadowNode) {
 
   const auto &raw = RawProps(folly::dynamic::object("nativeID", "abc"));
   SharedProps props = descriptor->cloneProps(nullptr, raw);
-  auto family = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{9, 1, descriptor->createEventEmitter(0, 9)},
-      *descriptor);
+  auto family = descriptor->createFamily(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 9,
+          /* .surfaceId = */ 1,
+          /* .eventEmitter = */ nullptr,
+      },
+      nullptr);
   SharedShadowNode node = descriptor->createShadowNode(
       ShadowNodeFragment{
           /* .props = */ props,
@@ -73,25 +82,37 @@ TEST(ComponentDescriptorTest, appendChild) {
 
   const auto &raw = RawProps(folly::dynamic::object("nativeID", "abc"));
   SharedProps props = descriptor->cloneProps(nullptr, raw);
-  auto family1 = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{1, 1, descriptor->createEventEmitter(0, 9)},
-      *descriptor);
+  auto family1 = descriptor->createFamily(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 1,
+          /* .surfaceId = */ 1,
+          /* .eventEmitter = */ nullptr,
+      },
+      nullptr);
   SharedShadowNode node1 = descriptor->createShadowNode(
       ShadowNodeFragment{
           /* .props = */ props,
       },
       family1);
-  auto family2 = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{2, 1, descriptor->createEventEmitter(0, 2)},
-      *descriptor);
+  auto family2 = descriptor->createFamily(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 2,
+          /* .surfaceId = */ 1,
+          /* .eventEmitter = */ nullptr,
+      },
+      nullptr);
   SharedShadowNode node2 = descriptor->createShadowNode(
       ShadowNodeFragment{
           /* .props = */ props,
       },
       family2);
-  auto family3 = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{3, 1, descriptor->createEventEmitter(0, 3)},
-      *descriptor);
+  auto family3 = descriptor->createFamily(
+      ShadowNodeFamilyFragment{
+          /* .tag = */ 3,
+          /* .surfaceId = */ 1,
+          /* .eventEmitter = */ nullptr,
+      },
+      nullptr);
   SharedShadowNode node3 = descriptor->createShadowNode(
       ShadowNodeFragment{
           /* .props = */ props,

ReactCommon/fabric/element/ComponentBuilder.cpp

@@ -25,13 +25,10 @@ ShadowNode::Shared ComponentBuilder::build(
     children.push_back(build(childFragment));
   }
 
-  auto eventEmitter =
-      componentDescriptor.createEventEmitter(nullptr, elementFragment.tag);
-
-  auto family = std::make_shared<ShadowNodeFamily>(
+  auto family = componentDescriptor.createFamily(
       ShadowNodeFamilyFragment{
-          elementFragment.tag, elementFragment.surfaceId, eventEmitter},
-      componentDescriptor);
+          elementFragment.tag, elementFragment.surfaceId, nullptr},
+      nullptr);
 
   auto shadowNode = componentDescriptor.createShadowNode(
       ShadowNodeFragment{

ReactCommon/fabric/mounting/ShadowTree.cpp

@@ -102,9 +102,9 @@ ShadowTree::ShadowTree(
   const auto props = std::make_shared<const RootProps>(
       *RootShadowNode::defaultSharedProps(), layoutConstraints, layoutContext);
 
-  auto family = std::make_shared<ShadowNodeFamily>(
+  auto family = rootComponentDescriptor.createFamily(
       ShadowNodeFamilyFragment{surfaceId, surfaceId, noopEventEmitter},
-      rootComponentDescriptor);
+      nullptr);
   rootShadowNode_ = std::static_pointer_cast<const RootShadowNode>(
       rootComponentDescriptor.createShadowNode(
           ShadowNodeFragment{

ReactCommon/fabric/uimanager/ComponentDescriptorRegistry.cpp

@@ -172,12 +172,9 @@ SharedShadowNode ComponentDescriptorRegistry::createNode(
   auto unifiedComponentName = componentNameByReactViewName(viewName);
   auto const &componentDescriptor = this->at(unifiedComponentName);
 
-  auto family = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{
-          tag,
-          surfaceId,
-          componentDescriptor.createEventEmitter(std::move(eventTarget), tag)},
-      componentDescriptor);
+  auto family = componentDescriptor.createFamily(
+      ShadowNodeFamilyFragment{tag, surfaceId, nullptr},
+      std::move(eventTarget));
   auto const props =
       componentDescriptor.cloneProps(nullptr, RawProps(propsDynamic));
   auto const state = componentDescriptor.createInitialState(

ReactCommon/fabric/uimanager/UIManager.cpp

@@ -33,12 +33,9 @@ SharedShadowNode UIManager::createNode(
   auto fallbackDescriptor =
       componentDescriptorRegistry_->getFallbackComponentDescriptor();
 
-  auto family = std::make_shared<ShadowNodeFamily>(
-      ShadowNodeFamilyFragment{
-          tag,
-          surfaceId,
-          componentDescriptor.createEventEmitter(std::move(eventTarget), tag)},
-      componentDescriptor);
+  auto family = componentDescriptor.createFamily(
+      ShadowNodeFamilyFragment{tag, surfaceId, nullptr},
+      std::move(eventTarget));
   auto const props = componentDescriptor.cloneProps(nullptr, rawProps);
   auto const state = componentDescriptor.createInitialState(
       ShadowNodeFragment{props}, surfaceId);