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

XGrKeybrd(3X)

grab the keyboard

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

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 XWIN 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 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.

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.  XGrab-
     Keyboard 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, indepen-
     dent of any event selection made by the client.

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

     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 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 XWIN server gen-
     erates 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 XWIN server gen-
     erates 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 GrabNot-
     Viewable.  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 XWIN 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 XWIN 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 XWIN server time.  It also generates Focu-
sIn and FocusOut events.  The XWIN server automatically per-
forms 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.

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

     BadWindow A value for a Window argument does not name a