EventDistributor.hh

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#ifndef EVENTDISTRIBUTOR_HH
#define EVENTDISTRIBUTOR_HH
 
#include "Event.hh"
 
#include <array>
#include <condition_variable>
#include <mutex>
#include <vector>
#include <utility>
 
namespace openmsx {
 
class Reactor;
class EventListener;
 
class EventDistributor
{
public:
        enum class Priority {
                OTHER,
                HOTKEY_HIGH, // above IMGUI
                IMGUI,
                HOTKEY_LOW, // below IMGUI
                MSX,
                LOWEST, // should only be used internally in EventDistributor
        };
        friend auto operator<=>(Priority x, Priority y) { return std::to_underlying(x) <=> std::to_underlying(y); }
 
        explicit EventDistributor(Reactor& reactor);
 
        void registerEventListener(EventType type, EventListener& listener,
                                   Priority priority = Priority::OTHER);
 
        void unregisterEventListener(EventType type, EventListener& listener);
 
        void distributeEvent(Event&& event);
 
        void deliverEvents();
 
        bool sleep(unsigned us);
 
private:
        [[nodiscard]] bool isRegistered(EventType type, EventListener* listener) const;
 
private:
        Reactor& reactor;
 
        struct Entry {
                Priority priority;
                EventListener* listener;
        };
        using PriorityMap = std::vector<Entry>; // sorted on priority
        std::array<PriorityMap, size_t(EventType::NUM_EVENT_TYPES)> listeners;
        using EventQueue = std::vector<Event>;
        EventQueue scheduledEvents;
        std::mutex mutex; // lock data structures
        std::mutex cvMutex; // lock condition_variable
        std::condition_variable condition;
};
 
} // namespace openmsx
 
#endif