XGrabKeyboard(3X11) X Version 11 (Release 5) 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. Further
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 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 processing continues as usual. If the keyboard is
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XGrabKeyboard(3X11) X Version 11 (Release 5) XGrabKeyboard(3X11)
currently frozen by this client, then processing of keyboard
events is resumed. If the keyboard_mode argument 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 (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 generates 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
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XGrabKeyboard(3X11) X Version 11 (Release 5) XGrabKeyboard(3X11)
defined Window.
SEE ALSO
XAllowEvents(3X11), XGrabButton(3X11), XGrabKey(3X11),
XGrabPointer(3X11)
Xlib - C Language X Interface
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