scrcpy/app/src/hid/hid_keyboard.h
Romain Vimont 91485e2863 Extract keyboard HID handling
Split the keyboard implementation using AOA and the code handling HID
events, so that HID events can be reused for another protocol (UHID).

PR #4473 <https://github.com/Genymobile/scrcpy/pull/4473>
2024-03-01 00:51:37 +01:00

49 lines
1.6 KiB
C

#ifndef SC_HID_KEYBOARD_H
#define SC_HID_KEYBOARD_H
#include "common.h"
#include <stdbool.h>
#include "hid/hid_event.h"
#include "input_events.h"
// See "SDL2/SDL_scancode.h".
// Maybe SDL_Keycode is used by most people, but SDL_Scancode is taken from USB
// HID protocol.
// 0x65 is Application, typically AT-101 Keyboard ends here.
#define SC_HID_KEYBOARD_KEYS 0x66
extern const uint8_t SC_HID_KEYBOARD_REPORT_DESC[];
extern const size_t SC_HID_KEYBOARD_REPORT_DESC_LEN;
/**
* HID keyboard events are sequence-based, every time keyboard state changes
* it sends an array of currently pressed keys, the host is responsible for
* compare events and determine which key becomes pressed and which key becomes
* released. In order to convert SDL_KeyboardEvent to HID events, we first use
* an array of keys to save each keys' state. And when a SDL_KeyboardEvent was
* emitted, we updated our state, and then we use a loop to generate HID
* events. The sequence of array elements is unimportant and when too much keys
* pressed at the same time (more than report count), we should generate
* phantom state. Don't forget that modifiers should be updated too, even for
* phantom state.
*/
struct sc_hid_keyboard {
bool keys[SC_HID_KEYBOARD_KEYS];
};
void
sc_hid_keyboard_init(struct sc_hid_keyboard *hid);
bool
sc_hid_keyboard_event_from_key(struct sc_hid_keyboard *hid,
struct sc_hid_event *hid_event,
const struct sc_key_event *event);
bool
sc_hid_keyboard_event_from_mods(struct sc_hid_event *event,
uint16_t mods_state);
#endif