Manual pages › X Window and screen libraries (3X)

XGrKey(3X)

grab keyboard keys

From the original Amiga UNIX 2.1 manual. Some things it mentions may not be in this release.

NAME

XGrabKey, XUngrabKey - grab keyboard keys

SYNTAX

XGrabKey(display, keycode, modifiers, grab_window,
owner_events, pointer_mode,
             keyboard_mode)
      Display *display;
      int keycode;
      unsigned int modifiers;
      Window grab_window;
      Bool owner_events;
      int pointer_mode, keyboard_mode;

XUngrabKey(display, keycode, modifiers, grab_window)
      Display *display;
      int keycode;
      unsigned int modifiers;
      Window grab_window;

ARGUMENTS

display   Specifies the connection to the XWIN 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 key-
          mask bits.

owner_events
          Specifies a Boolean value that indicates whether
          the pointer events are to be reported as usual or
          reported with respect to the grab window if
          selected by the event mask.

pointer_mode
          Specifies further processing of pointer events.
          You can pass GrabModeSync or GrabModeAsync.

DESCRIPTION

     The XGrabKey function establishes a passive grab on the key-
     board.  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

XWIN 3.0               Last change: 9/1/88                 .ie t

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).

     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 (includ-
     ing the combination of no modifiers). It is not required
     that all modifiers specified have currently assigned Key-
     Codes.  A keycode argument of AnyKey is equivalent to issu-
     ing 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 com-
     pletely, and a BadAccess error results (no grabs are esta-
     blished) 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.

XWIN 3.0               Last change: 9/1/88                 .ie t

XUngrabKey can generate BadValue and BadWindow error.

DIAGNOSTICS

BadAccess A client attempted to grab a key/button combina-
          tion 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 gen-
          erate this error.

BadWindow A value for a Window argument does not name a