151 lines
3.9 KiB
C++
151 lines
3.9 KiB
C++
// =====================================================================================================================
|
|
// Copyright 2024 Medusa Slockbower
|
|
// Licensed under the Apache License, Version 2.0 (the "License");
|
|
// you may not use this file except in compliance with the License.
|
|
// You may obtain a copy of the License at
|
|
//
|
|
// http://www.apache.org/licenses/LICENSE-2.0
|
|
//
|
|
// Unless required by applicable law or agreed to in writing, software
|
|
// distributed under the License is distributed on an "AS IS" BASIS,
|
|
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
// See the License for the specific language governing permissions and
|
|
// limitations under the License.
|
|
// =====================================================================================================================
|
|
|
|
#ifndef ENGINE_EVENTSYSTEM_H
|
|
#define ENGINE_EVENTSYSTEM_H
|
|
|
|
#include <open-cpp-utils/unique_id.h>
|
|
|
|
#include <cstdint>
|
|
#include <list>
|
|
#include <mutex>
|
|
|
|
|
|
#define MAX_EVENT_TYPES 256
|
|
|
|
namespace ocu = open_cpp_utils;
|
|
|
|
namespace OpenShaderDesigner
|
|
{
|
|
|
|
/**
|
|
* \brief Base Event class for sending events to the Engine.
|
|
*/
|
|
struct Event
|
|
{
|
|
template<typename T>
|
|
static uint8_t TypeOf() { return static_cast<uint8_t>(ocu::unique_id<uint8_t, T>()); }
|
|
|
|
/**
|
|
* \brief Get the Event's type ID.
|
|
* \return A pointer to the Event type ID.
|
|
*/
|
|
virtual inline uint8_t GetID() const = 0;
|
|
};
|
|
|
|
|
|
/**
|
|
* \brief Base EventHandler for abstraction.
|
|
*/
|
|
class _ImplEventHandler
|
|
{
|
|
virtual bool _HandleEvent(const Event* event) = 0;
|
|
|
|
friend class EventSystem;
|
|
};
|
|
|
|
/**
|
|
* \brief EventHandler interface for creating custom EventHandlers
|
|
* \tparam EventType The ComponentType of Event handled by the EventHandler
|
|
*/
|
|
template<typename EventType>
|
|
class EventHandler : private _ImplEventHandler
|
|
{
|
|
public:
|
|
using HandledType = EventType; //!< The type handled by the EventHandler
|
|
|
|
/**
|
|
* \brief Virtual function for custom EventHandler implementations.
|
|
* \param event The Event being handled.
|
|
*/
|
|
virtual bool HandleEvent(const HandledType* event) = 0;
|
|
private:
|
|
|
|
/**
|
|
* \brief Override for abstraction.
|
|
* \param event The Event being handled.
|
|
*/
|
|
bool _HandleEvent(const Event* event) override;
|
|
};
|
|
|
|
/**
|
|
* \brief EventSystem for posting Events to be handled.
|
|
*/
|
|
class EventSystem
|
|
{
|
|
public:
|
|
/**
|
|
* \brief Post an Event to be Handled.
|
|
*/
|
|
static void PostEvent(const Event*);
|
|
|
|
/**
|
|
* \brief Register an EventHandler with the EventSystem.
|
|
* \tparam T ComponentType of Event handled by the EventHandler.
|
|
*/
|
|
template<typename T>
|
|
static void RegisterHandler(EventHandler<T>*);
|
|
|
|
/**
|
|
* \brief Unregister an EventHandler with the EventSystem.
|
|
* \tparam T ComponentType of Event handled by the EventHandler.
|
|
*/
|
|
template<typename T>
|
|
static void UnregisterHandler(EventHandler<T>*);
|
|
|
|
private:
|
|
inline static std::list<_ImplEventHandler*> HandlerMap_[MAX_EVENT_TYPES];
|
|
inline static std::mutex Lock_;
|
|
|
|
EventSystem(const EventSystem&) = delete;
|
|
EventSystem(EventSystem&&) = delete;
|
|
};
|
|
|
|
template<typename T>
|
|
void EventSystem::UnregisterHandler(EventHandler<T>* handler)
|
|
{
|
|
// Thread safe
|
|
std::lock_guard guard(Lock_);
|
|
const uint8_t index = T::ID;
|
|
std::erase(HandlerMap_[index], reinterpret_cast<_ImplEventHandler*>(handler));
|
|
}
|
|
|
|
template<typename T>
|
|
void EventSystem::RegisterHandler(EventHandler<T>* handler)
|
|
{
|
|
// Thread safe
|
|
std::lock_guard guard(Lock_);
|
|
const uint8_t index = T::ID;
|
|
HandlerMap_[index].push_back(reinterpret_cast<_ImplEventHandler*>(handler));
|
|
}
|
|
|
|
template<typename EventType>
|
|
bool EventHandler<EventType>::_HandleEvent(const Event *event)
|
|
{
|
|
if(EventType::ID != event->GetID()) return false;
|
|
return HandleEvent(reinterpret_cast<const EventType*>(event));
|
|
}
|
|
|
|
}
|
|
|
|
#define BeginEvent(EVENT) struct EVENT : OpenShaderDesigner::Event \
|
|
{ \
|
|
static inline const uint8_t ID = Event::TypeOf<EVENT>(); \
|
|
inline uint8_t GetID() const override { return ID; }
|
|
|
|
#define EndEvent };
|
|
|
|
#endif //ENGINE_EVENTSYSTEM_H
|