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:
· 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 con‐
tains 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 applica‐
tions) 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 combina‐
tion 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. Other‐
wise, the specified keycode must be in the range specified by min_key‐
code and max_keycode in the connection setup, or a BadValue error
results.
If some other client has issued a XGrabKey with the same key combina‐
tion on the same window, a BadAccess error results. When using AnyMod‐
ifier 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 ALSOXAllowAccess(3), XGrabButton(3), XGrabKeyboard(3), XGrabPointer(3)
Xlib - C Language X Interface
X Version 11 libX11 1.3.3 XGrabKey(3)
