xcb_grab_key(3) XCB Requests xcb_grab_key(3)

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 combinations.

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 until the
keyboard grab is released.

XCB_GRAB_MODE_ASYNC
Keyboard event processing continues normally.


keyboard_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 until the
keyboard grab is released.

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 transmitted 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 automatically 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 window.

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 combinations (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 results (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.

SEE ALSO

xcb-requests(3), xcb_grab_keyboard(3)

AUTHOR

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

X Version 11 libxcb 1.16.1 xcb_grab_key(3)