Ubuntu Manpage: xcb_grab_key - Grab keyboard key(s)

NAME

       xcb_grab_key - Grab keyboard key(s)

SYNOPSIS

       #include <xcb/xproto.h>

   Request function

       xcb_void_cookie_t xcb_grab_key(xcb_connection_t *conn, uint8_t owner_events, xcb_window_t grab_window,
              uint16_t modifiers, xcb_keycode_t key, uint8_t pointer_mode, uint8_t keyboard_mode);

REQUEST ARGUMENTS

conn The XCB connection to X11.

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

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

modifiers The modifiers to grab.

Using the special value XCB_MOD_MASK_ANY means grab the key with all possible modifier combina‐
tions.

key The keycode of the key to grab.

The special value XCB_GRAB_ANY means grab any key.

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.

DESCRIPTION

Establishes a passive grab on the keyboard. In the future, the keyboard is actively grabbed (as for
GrabKeyboard), the last-keyboard-grab time is set to the time at which the key was pressed (as transmit‐
ted in the KeyPress event), and the KeyPress event is reported if all of the following conditions are
true:

The keyboard is not grabbed and the specified key (which can itself be a modifier key) is logically
pressed when the specified modifier keys are logically down, and no other modifier keys are logically
down.

Either the grab_window is an ancestor of (or is) the focus window, or the grab_window is a descendant of
the focus window and contains the pointer.

A passive grab on the same key combination does not exist on any ancestor of grab_window.

The interpretation of the remaining arguments is as for XGrabKeyboard. The active grab is terminated au‐
tomatically when the logical state of the keyboard has the specified key released (independent of the
logical state of the modifier keys), at which point a KeyRelease event is reported to the grabbing win‐
dow.

Note that the logical state of a device (as seen by client applications) may lag the physical state if
device event processing is frozen.

A modifiers argument of AnyModifier is equivalent to issuing the request for all possible modifier combi‐
nations (including the combination of no modifiers). It is not required that all modifiers specified
have currently assigned KeyCodes. A keycode argument of AnyKey is equivalent to issuing the request for
all possible KeyCodes. Otherwise, the specified keycode must be in the range specified by min_keycode
and max_keycode in the connection setup, or a BadValue error results.

If some other client has issued a XGrabKey with the same key combination on the same window, a BadAccess
error results. When using AnyModifier or AnyKey, the request fails completely, and a BadAccess error re‐
sults (no grabs are established) if there is a conflicting grab for any combination.

RETURN VALUE

       Returns an xcb_void_cookie_t. Errors (if any) have to be handled in the event loop.

       If  you want to handle errors directly with xcb_request_check instead, use xcb_grab_key_checked. See xcb-
       requests(3) for details.

ERRORS

       xcb_access_error_t
                 Another client has already issued a GrabKey with the same button/key combination  on  the  same
                 window.

       xcb_value_error_t
                 The  key  is  not XCB_GRAB_ANY and not in the range specified by min_keycode and max_keycode in
                 the connection setup.

       xcb_window_error_t
                 The specified window does not exist.

AUTHOR

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

X Version 11                                      libxcb 1.17.0                                  xcb_grab_key(3)