XGrabKeyboard(3) XLIB FUNCTIONS XGrabKeyboard(3)
NAME
XGrabKeyboard, XUngrabKeyboard - grab the keyboard
SYNTAX
int XGrabKeyboard(Display *display, Window grab_window, Bool
owner_events, int pointer_mode, int keyboard_mode, Time time);
int XUngrabKeyboard(Display *display, Time time);
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.
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.
time Specifies the time. You can pass either a timestamp or Cur-
rentTime.
DESCRIPTION
The XGrabKeyboard function actively grabs control of the keyboard and
generates FocusIn and FocusOut events. Further key events are reported
only to the grabbing client. XGrabKeyboard overrides any active key-
board grab by this client. If owner_events is False, all generated key
events are reported with respect to grab_window. If owner_events is
True and if a generated key event would normally be reported to this
client, it is reported normally; otherwise, the event is reported with
respect to the grab_window. Both KeyPress and KeyRelease events are
always reported, independent of any event selection made by the client.
If the keyboard_mode argument is GrabModeAsync, keyboard event process-
ing continues as usual. If the keyboard is currently frozen by this
client, then processing of keyboard events is resumed. If the key-
board_mode argument is GrabModeSync, the state of the keyboard (as
seen by client applications) appears to freeze, and the X server gener-
ates no further keyboard events until the grabbing client issues a
releasing XAllowEvents call or until the keyboard grab is released.
Actual keyboard changes are not lost while the keyboard is frozen; they
are simply queued in the server for later processing.
If pointer_mode is GrabModeAsync, pointer event processing is unaf-
fected by activation of the grab. If pointer_mode is GrabModeSync, the
state of the pointer (as seen by client applications) appears to
freeze, and the X server generates no further pointer events until the
grabbing client issues a releasing XAllowEvents call or until the key-
board grab is released. Actual pointer changes are not lost while the
pointer is frozen; they are simply queued in the server for later pro-
cessing.
If the keyboard is actively grabbed by some other client, XGrabKeyboard
fails and returns AlreadyGrabbed. If grab_window is not viewable, it
fails and returns GrabNotViewable. If the keyboard is frozen by an
active grab of another client, it fails and returns GrabFrozen. If the
specified time is earlier than the last-keyboard-grab time or later
than the current X server time, it fails and returns GrabInvalidTime.
Otherwise, the last-keyboard-grab time is set to the specified time
(CurrentTime is replaced by the current X server time).
XGrabKeyboard can generate BadValue and BadWindow errors.
The XUngrabKeyboard function releases the keyboard and any queued
events if this client has it actively grabbed from either XGrabKeyboard
or XGrabKey. XUngrabKeyboard does not release the keyboard and any
queued events if the specified time is earlier than the last-keyboard-
grab time or is later than the current X server time. It also gener-
ates FocusIn and FocusOut events. The X server automatically performs
an UngrabKeyboard request if the event window for an active keyboard
grab becomes not viewable.
DIAGNOSTICS
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), XGrabKey(3), XGrabPointer(3)
Xlib - C Language X Interface
X Version 11 libX11 1.7.1 XGrabKeyboard(3)
xorg-libX11 1.7.1 - Generated Wed May 19 09:19:31 CDT 2021