serenity/LibGUI/GEventLoop.h

#pragma once

#include "GEvent.h"
#include <AK/HashMap.h>
#include <AK/OwnPtr.h>
#include <AK/Vector.h>

class GObject;
class GWindow;
struct GUI_Event;

class GEventLoop {
public:
    GEventLoop();
    ~GEventLoop();

    int exec();

    void post_event(GObject* receiver, OwnPtr<GEvent>&&);

    static GEventLoop& main();

    static void initialize();

    bool running() const { return m_running; }

    int register_timer(GObject&, int milliseconds, bool should_reload);
    bool unregister_timer(int timer_id);

private:
    void wait_for_event();
    void handle_paint_event(const GUI_Event&, GWindow&);
    void handle_mouse_event(const GUI_Event&, GWindow&);
    void handle_key_event(const GUI_Event&, GWindow&);
    void handle_window_activation_event(const GUI_Event&, GWindow&);

    void get_next_timer_expiration(timeval&);

    struct QueuedEvent {
        GObject* receiver { nullptr };
        OwnPtr<GEvent> event;
    };
    Vector<QueuedEvent> m_queued_events;

    int m_event_fd { -1 };
    bool m_running { false };

    int m_next_timer_id { 1 };

    struct EventLoopTimer {
        int timer_id { 0 };
        int interval { 0 };
        timeval fire_time;
        bool should_reload { false };
        GObject* owner { nullptr };

        void reload();
        bool has_expired() const;
    };

    HashMap<int, OwnPtr<EventLoopTimer>> m_timers;
};