scrcpy/app/src/controlevent.h

#ifndef CONTROL_EVENT_H
#define CONTROL_EVENT_H

#include <SDL2/SDL_mutex.h>
#include <SDL2/SDL_stdinc.h>

#include "android/input.h"
#include "android/keycodes.h"

#define CONTROL_EVENT_QUEUE_SIZE 64
#define SERIALIZED_EVENT_MAX_SIZE 33
#define TEXT_MAX_LENGTH 31

enum control_event_type {
    CONTROL_EVENT_TYPE_KEYCODE,
    CONTROL_EVENT_TYPE_TEXT,
    CONTROL_EVENT_TYPE_MOUSE,
    CONTROL_EVENT_TYPE_SCROLL,
};

struct control_event {
    enum control_event_type type;
    union {
        struct {
            enum android_keyevent_action action;
            enum android_keycode keycode;
            enum android_metastate metastate;
        } keycode_event;
        struct {
            char text[TEXT_MAX_LENGTH + 1]; // nul-terminated string
        } text_event;
        struct {
            enum android_motionevent_action action;
            enum android_motionevent_buttons buttons;
            Sint32 x;
            Sint32 y;
        } mouse_event;
        struct {
            Sint32 x;
            Sint32 y;
            Sint32 hscroll;
            Sint32 vscroll;
        } scroll_event;
    };
};

struct control_event_queue {
    struct control_event data[CONTROL_EVENT_QUEUE_SIZE];
    int head;
    int tail;
};

// buf size must be at least SERIALIZED_EVENT_MAX_SIZE
int control_event_serialize(const struct control_event *event, unsigned char *buf);

SDL_bool control_event_queue_init(struct control_event_queue *queue);
void control_event_queue_destroy(struct control_event_queue *queue);

SDL_bool control_event_queue_is_empty(const struct control_event_queue *queue);
SDL_bool control_event_queue_is_full(const struct control_event_queue *queue);

// event is copied, the queue does not use the event after the function returns
SDL_bool control_event_queue_push(struct control_event_queue *queue, const struct control_event *event);
SDL_bool control_event_queue_take(struct control_event_queue *queue, struct control_event *event);

#endif