XGrabKeyboard(XS) X Version 11 (Release 5) 6 January 1993  XGrabKeyboard(XS)


 Name

    XGrabKeyboard - 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.

    grabwindow    Specifies the grab window.

    keyboardmode  Specifies further processing of keyboard events.  You can
                   pass GrabModeSync or GrabModeAsync.

    ownerevents   Specifies a Boolean value that indicates whether the key-
                   board events are to be reported as usual.

    pointermode   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 ownerevents is False, all generated key events
    are reported with respect to grabwindow.  If ownerevents 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
    grabwindow.  Both KeyPress and KeyRelease events are always reported,
    independent of any event selection made by the client.

    If the keyboardmode 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 keyboardmode
    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 pointermode is GrabModeAsync, pointer event processing is unaffected
    by activation of the grab.  If pointermode 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 grabwindow 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.  Other-
    wise, the last-keyboard-grab time is set to the specified time (Current-
    Time 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 UngrabKey-
    board 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 defined Win-
                   dow.

 See also

    XAllowEvents(XS), XGrabButton(XS), XGrabKey(XS), XGrabPointer(XS)
    Xlib - C Language X Interface