in src/protocols/rdp/keyboard.c [641:706]
int guac_rdp_keyboard_update_keysym(guac_rdp_keyboard* keyboard,
int keysym, int pressed, guac_rdp_key_source source) {
/* Synchronize lock keys states, if this has not yet been done */
if (!keyboard->synchronized) {
guac_client* client = keyboard->client;
guac_rdp_client* rdp_client = (guac_rdp_client*) client->data;
/* Synchronize remote lock key states with local state */
guac_rdp_send_synchronize_event(rdp_client, keyboard->lock_flags);
keyboard->synchronized = 1;
}
guac_rdp_key* key = guac_rdp_keyboard_get_key(keyboard, keysym);
/* Update tracking of client-side keyboard state but only for keys which
* are tracked server-side, as well (to ensure that the key count remains
* correct, even if a user sends extra unbalanced or excessive press and
* release events) */
if (source == GUAC_RDP_KEY_SOURCE_CLIENT && key != NULL) {
if (pressed && !key->user_pressed) {
keyboard->user_pressed_keys++;
key->user_pressed = 1;
}
else if (!pressed && key->user_pressed) {
keyboard->user_pressed_keys--;
key->user_pressed = 0;
}
}
/* Send events and update server-side lock state only if server-side key
* state is changing (or if server-side state of this key is untracked) */
if (key == NULL || (pressed && key->pressed == NULL) || (!pressed && key->pressed != NULL)) {
/* Toggle locks on keydown */
if (pressed)
keyboard->lock_flags ^= guac_rdp_keyboard_lock_flag(keysym);
/* If key is known, update state and attempt to send using normal RDP key
* events */
const guac_rdp_keysym_desc* definition = NULL;
if (key != NULL) {
definition = guac_rdp_keyboard_send_defined_key(keyboard, key, pressed);
key->pressed = pressed ? definition : NULL;
}
/* Fall back to dead keys or Unicode events if otherwise undefined inside
* current keymap (note that we only handle "pressed" here, as neither
* Unicode events nor dead keys can have a pressed/released state) */
if (definition == NULL && pressed) {
guac_rdp_keyboard_send_missing_key(keyboard, keysym);
}
}
/* Reset RDP server keyboard state (releasing any automatically
* pressed keys) once all keys have been released on the client
* side */
if (source == GUAC_RDP_KEY_SOURCE_CLIENT && keyboard->user_pressed_keys == 0)
guac_rdp_keyboard_reset(keyboard);
return 0;
}