Ubuntu Manpage: xcb_grab_keyboard

NAME

       xcb_grab_keyboard - Grab the keyboard

SYNOPSIS

       #include <xcb/xproto.h>

   Request function

       xcb_grab_keyboard_cookie_t xcb_grab_keyboard(xcb_connection_t *conn, uint8_t owner_events,
              xcb_window_t grab_window, xcb_timestamp_t time, uint8_t pointer_mode, uint8_t keyboard_mode);

   Reply datastructure
       typedef struct xcb_grab_keyboard_reply_t {
           uint8_t  response_type;
           uint8_t  status;
           uint16_t sequence;
           uint32_t length;
       } xcb_grab_keyboard_reply_t;

   Reply function

       xcb_grab_keyboard_reply_t *xcb_grab_keyboard_reply(xcb_connection_t *conn,
              xcb_grab_keyboard_cookie_t cookie, xcb_generic_error_t **e);

REQUEST ARGUMENTS

conn The XCB connection to X11.

owner_events
If 1, the grab_window will still get the pointer events. If 0, events are not reported to the
grab_window.

grab_window
Specifies the window on which the pointer should be grabbed.

time Timestamp to avoid race conditions when running X over the network.

The special value XCB_CURRENT_TIME will be replaced with the current server time.

pointer_mode
One of the following values:

XCB_GRAB_MODE_SYNC
The state of the keyboard appears to freeze: No further keyboard events are generated
by the server until the grabbing client issues a releasing AllowEvents request or un‐
til the keyboard grab is released.

XCB_GRAB_MODE_ASYNC
Keyboard event processing continues normally.

keyboard_mode
One of the following values:

XCB_GRAB_MODE_ASYNC
Keyboard event processing continues normally.

REPLY FIELDS

       response_type
                 The type of this reply, in this case XCB_GRAB_KEYBOARD. This  field  is  also  present  in  the
                 xcb_generic_reply_t and can be used to tell replies apart from each other.

       sequence  The sequence number of the last request processed by the X11 server.

       length    The length of the reply, in words (a word is 4 bytes).

       status    One of the following values:

                 XCB_GRAB_STATUS_SUCCESS
                           TODO: NOT YET DOCUMENTED.

                 XCB_GRAB_STATUS_ALREADY_GRABBED
                           TODO: NOT YET DOCUMENTED.

                 XCB_GRAB_STATUS_INVALID_TIME
                           TODO: NOT YET DOCUMENTED.

                 XCB_GRAB_STATUS_NOT_VIEWABLE
                           TODO: NOT YET DOCUMENTED.

                 XCB_GRAB_STATUS_FROZEN
                           TODO: NOT YET DOCUMENTED.
                 TODO: NOT YET DOCUMENTED.

DESCRIPTION

       Actively  grabs control of the keyboard and generates FocusIn and FocusOut events. Further key events are
       reported only to the grabbing client.

       Any active keyboard grab by this client is overridden. If the keyboard is actively grabbed by some  other
       client,  AlreadyGrabbed  is returned. If grab_window is not viewable, GrabNotViewable is returned. If the
       keyboard is frozen by an active grab of another client, GrabFrozen is returned. If the specified time  is
       earlier  than the last-keyboard-grab time or later than the current X server time, GrabInvalidTime is re‐
       turned. Otherwise, the last-keyboard-grab time is set to the specified time.

RETURN VALUE

       Returns an xcb_grab_keyboard_cookie_t. Errors  have  to  be  handled  when  calling  the  reply  function
       xcb_grab_keyboard_reply.

       If  you  want  to  handle  errors in the event loop instead, use xcb_grab_keyboard_unchecked. See xcb-re‐
       quests(3) for details.

ERRORS

       xcb_value_error_t
                 TODO: reasons?

       xcb_window_error_t
                 The specified window does not exist.

EXAMPLE

       /*
        * Grabs the keyboard actively
        *
        */
       void my_example(xcb_connection_t *conn, xcb_screen_t *screen) {
           xcb_grab_keyboard_cookie_t cookie;
           xcb_grab_keyboard_reply_t *reply;

           cookie = xcb_grab_keyboard(
               conn,
               true,                /* report events */
               screen->root,        /* grab the root window */
               XCB_CURRENT_TIME,
               XCB_GRAB_MODE_ASYNC, /* process events as normal, do not require sync */
               XCB_GRAB_MODE_ASYNC
           );

           if ((reply = xcb_grab_keyboard_reply(conn, cookie, NULL))) {
               if (reply->status == XCB_GRAB_STATUS_SUCCESS)
                   printf("successfully grabbed the keyboard\n");

               free(reply);
           }
       }

AUTHOR

       Generated from xproto.xml. Contact xcb@lists.freedesktop.org for corrections and improvements.

X Version 11                                       libxcb 1.14                              xcb_grab_keyboard(3)