react-native/ReactCommon/fabric/events/primitives.h

49 lines
1.5 KiB
C++

/**
* 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 <folly/dynamic.h>
namespace facebook {
namespace react {
enum class EventPriority: int {
SynchronousUnbatched,
SynchronousBatched,
AsynchronousUnbatched,
AsynchronousBatched,
Sync = SynchronousUnbatched,
Work = SynchronousBatched,
Interactive = AsynchronousUnbatched,
Deferred = AsynchronousBatched
};
/*
* 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.
*
* `EventTarget` is managed as a `shared_ptr`, so it does not need to have a virtual
* destructor because `shared_ptr` stores a pointer to destructor inside.
*/
struct EventHandler { virtual ~EventHandler() = default; };
using UniqueEventHandler = std::unique_ptr<const EventHandler>;
struct EventTarget {};
using SharedEventTarget = std::shared_ptr<const EventTarget>;
using WeakEventTarget = std::weak_ptr<const EventTarget>;
using EventPipe = std::function<void(const EventTarget *eventTarget, const std::string &type, const folly::dynamic &payload)>;
} // namespace react
} // namespace facebook