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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 contains 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  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