XGrabKeyboard(3X11) XLIB FUNCTIONS XGrabKeyboard(3X11)NAME
XGrabKeyboard, XUngrabKeyboard - grab the keyboard
SYNTAX
int XGrabKeyboard(display, grab_window, owner_events,
pointer_mode, keyboard_mode, time)
Display *display;
Window grab_window;
Bool owner_events;
int pointer_mode, keyboard_mode;
Time time;
XUngrabKeyboard(display, time)
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 CurrentTime.
DESCRIPTION
The XGrabKeyboard function actively grabs control of the
keyboard and generates FocusIn and FocusOut events. Fur-
ther key events are reported only to the grabbing client.
XGrabKeyboard overrides any active keyboard 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 nor-
mally; 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 processing continues as usual. If the keyboard is
currently frozen by this client, then processing of
X Version 11 Release 6.4 1
XGrabKeyboard(3X11) XLIB FUNCTIONS XGrabKeyboard(3X11)
keyboard events is resumed. If the keyboard_mode argu-
ment is GrabModeSync, the state of the keyboard (as seen
by client applications) appears to freeze, and the X
server generates 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 unaffected 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
keyboard grab is released. Actual pointer changes are not
lost while the pointer is frozen; they are simply queued
in the server for later processing.
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 (Current-
Time 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 gen-
erates FocusIn and FocusOut events. The X server automat-
ically 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 spe-
cific 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.
X Version 11 Release 6.4 2
XGrabKeyboard(3X11) XLIB FUNCTIONS XGrabKeyboard(3X11)SEE ALSOXAllowEvents(3X11), XGrabButton(3X11), XGrabKey(3X11),
XGrabPointer(3X11)
Xlib - C Language X Interface
X Version 11 Release 6.4 3