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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