event.hpp

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#pragma once
 
#include <functional>
#include <unordered_map>
#include <vector>
#include <typeindex>
#include <memory>
 
namespace Engine::Core {
    class Event {
        public:
            virtual ~Event() = default;
    };

    class EventDispatcher {
        private:
            using RawCallback = std::function<void(Event&)>;
            std::unordered_map<std::type_index, std::vector<RawCallback>> mListeners;
            
        public:
            template<typename EventType>
            using EventCallback = std::function<void(EventType&)>;

            template<typename EventType>
            void Subscribe(EventCallback<EventType> callback) {
                auto& listeners = mListeners[typeid(EventType)];
                listeners.push_back([cb = std::move(callback)](Event& e) {
                    cb(static_cast<EventType&>(e));
                });
            }

            template<typename EventType>
            void Emit(EventType* event) const {
                auto it = mListeners.find(typeid(EventType));
                if (it != mListeners.end()) {
                    for (const auto& listener : it->second) {
                        listener(*event);
                    }
                }
            }
    };
}