xcb_grab_key - Man Page

#include <xcb/xproto.h>

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.

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.

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.

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.

xcb-requests(3), xcb_grab_keyboard(3)

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

xcb_key_press_event_t(3), xcb_motion_notify_event_t(3), xcb_ungrab_key(3).

The man page xcb_grab_key_checked(3) is an alias of xcb_grab_key(3).