Remove EventHandler type (#40866)

Summary:
Pull Request resolved: https://github.com/facebook/react-native/pull/40866

This type doesn't do anything, and we can replace it with a `jsi::Function` inside `UIManagerBinding`.

Changelog: [Internal]

Reviewed By: rubennorte

Differential Revision: D50176084

fbshipit-source-id: 1c782f3e4d212f1d956451fd650d3ed5ed8f0d71

packages/react-native/ReactCommon/react/renderer/core/EventHandler.h

@@ -1,28 +0,0 @@
-/*
- * Copyright (c) Meta Platforms, Inc. and 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 <memory>
-
-namespace facebook::react {
-
-/*
- * We need this types only to ensure type-safety when we deal with them.
- * Conceptually, they are opaque pointers to some types that derived from those
- * classes.
- *
- * `EventHandler` is managed as a `unique_ptr`, so it must have a *virtual*
- * destructor to allow proper deallocation having only a pointer
- * to the base (`EventHandler`) class.
- */
-struct EventHandler {
-  virtual ~EventHandler() = default;
-};
-using UniqueEventHandler = std::unique_ptr<const EventHandler>;
-
-} // namespace facebook::react

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

@@ -155,15 +155,14 @@ void UIManagerBinding::dispatchEventToJS(
     LOG(WARNING) << "instanceHandle is null, event will be dropped";
   }
 
-  auto& eventHandlerWrapper =
-      static_cast<const EventHandlerWrapper&>(*eventHandler_);
-
   currentEventPriority_ = priority;
-  eventHandlerWrapper.callback.call(
-      runtime,
-      {std::move(instanceHandle),
-       jsi::String::createFromUtf8(runtime, type),
-       std::move(payload)});
+  if (eventHandler_) {
+    eventHandler_->call(
+        runtime,
+        std::move(instanceHandle),
+        jsi::String::createFromUtf8(runtime, type),
+        std::move(payload));
+  }
   currentEventPriority_ = ReactEventPriority::Default;
 }
 
@@ -545,7 +544,7 @@ jsi::Value UIManagerBinding::get(
           auto eventHandler =
               arguments[0].getObject(runtime).getFunction(runtime);
           eventHandler_ =
-              std::make_unique<EventHandlerWrapper>(std::move(eventHandler));
+              std::make_unique<jsi::Function>(std::move(eventHandler));
           return jsi::Value::undefined();
         });
   }

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

@@ -84,7 +84,7 @@ class UIManagerBinding : public jsi::HostObject {
       const EventPayload& payload) const;
 
   std::shared_ptr<UIManager> uiManager_;
-  std::unique_ptr<const EventHandler> eventHandler_;
+  std::unique_ptr<jsi::Function> eventHandler_;
   mutable PointerEventsProcessor pointerEventsProcessor_;
   mutable ReactEventPriority currentEventPriority_;
 };

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

@@ -12,7 +12,6 @@
 #include <jsi/jsi.h>
 #include <react/debug/react_native_assert.h>
 #include <react/renderer/components/text/RawTextShadowNode.h>
-#include <react/renderer/core/EventHandler.h>
 #include <react/renderer/core/LayoutMetrics.h>
 #include <react/renderer/core/ShadowNode.h>
 #include <react/renderer/core/TraitCast.h>
@@ -23,13 +22,6 @@ namespace facebook::react {
 using BackgroundExecutor =
     std::function<void(std::function<void()>&& callback)>;
 
-struct EventHandlerWrapper : public EventHandler {
-  EventHandlerWrapper(jsi::Function eventHandler)
-      : callback(std::move(eventHandler)) {}
-
-  jsi::Function callback;
-};
-
 struct ShadowNodeListWrapper : public jsi::NativeState {
   ShadowNodeListWrapper(ShadowNode::UnsharedListOfShared shadowNodeList)
       : shadowNodeList(std::move(shadowNodeList)) {}