XGrabKey(3) XLIB FUNCTIONS XGrabKey(3)

NAME

XGrabKey, XUngrabKey - grab keyboard keys

SYNTAX

int XGrabKey(Display *display, int keycode, unsigned int modifiers,
Window grab_window, Bool owner_events, int pointer_mode, int
keyboard_mode);

int XUngrabKey(Display *display, int keycode, unsigned int modifiers,
Window grab_window);

ARGUMENTS

display Specifies the connection to the X server.

grab_window
Specifies the grab window.

keyboard_mode
Specifies further processing of keyboard events. You can
pass GrabModeSync or GrabModeAsync.

keycode Specifies the KeyCode or AnyKey.

modifiers Specifies the set of keymasks or AnyModifier. The mask is
the bitwise inclusive OR of the valid keymask bits.

owner_events
Specifies a Boolean value that indicates whether the
keyboard events are to be reported as usual.

pointer_mode
Specifies further processing of pointer events. You can
pass GrabModeSync or GrabModeAsync.

DESCRIPTION

The XGrabKey function establishes a passive grab on the keyboard. In
the future, the keyboard is actively grabbed (as for XGrabKeyboard),
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:

+o 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.

+o 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.

+o 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.

XGrabKey can generate BadAccess, BadValue, and BadWindow errors.

The XUngrabKey function releases the key combination on the specified
window if it was grabbed by this client. It has no effect on an
active grab. A modifiers of AnyModifier is equivalent to issuing the
request for all possible modifier combinations (including the
combination of no modifiers). A keycode argument of AnyKey is
equivalent to issuing the request for all possible key codes.

XUngrabKey can generate BadValue and BadWindow error.

DIAGNOSTICS

BadAccess A client attempted to grab a key/button combination already
grabbed by another client.

BadValue Some numeric value falls outside the range of values
accepted by the request. Unless a specific range is
specified for an argument, the full range defined by the
argument's type is accepted. Any argument defined as a set
of alternatives can generate this error.

BadWindow A value for a Window argument does not name a defined
Window.

SEE ALSO

XAllowEvents(3), XGrabButton(3), XGrabKeyboard(3), XGrabPointer(3)
Xlib - C Language X Interface

X Version 11 libX11 1.8.10 XGrabKey(3)