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


 Name

    XSetInputFocus - control input focus

 Syntax


    XSetInputFocus(display, focus, revert_to, time)
          Display *display;
          Window focus;
          int revert_to;
          Time time;

    XGetInputFocus(display, focus_return, revert_to_return)
          Display *display;
          Window *focus_return;
          int *revert_to_return;


 Arguments


    display        Specifies the connection to the X server.

    focus          Specifies the window, PointerRoot, or None.

    focusreturn   Returns the focus window, PointerRoot, or None.

    revertto      Specifies where the input focus reverts to if the window
                   becomes not viewable.  You can pass RevertToParent,
                   RevertToPointerRoot, or RevertToNone.

    reverttoreturn
                   Returns the current focus state (RevertToParent, RevertTo-
                   PointerRoot, or RevertToNone).

    time           Specifies the time.  You can pass either a timestamp or
                   CurrentTime.

 Description

    The XSetInputFocus function changes the input focus and the last-focus-
    change time.  It has no effect if the specified time is earlier than the
    current last-focus-change time or is later than the current X server
    time.  Otherwise, the last-focus-change time is set to the specified time
    (CurrentTime is replaced by the current X server time).  XSetInputFocus
    causes the X server to generate FocusIn and FocusOut events.

    Depending on the focus argument, the following occurs:

    +  If focus is None, all keyboard events are discarded until a new focus
       window is set, and the revertto argument is ignored.

    +  If focus is a window, it becomes the keyboard's focus window.  If a
       generated keyboard event would normally be reported to this window or
       one of its inferiors, the event is reported as usual.  Otherwise, the
       event is reported relative to the focus window.

    +  If focus is PointerRoot, the focus window is dynamically taken to be
       the root window of whatever screen the pointer is on at each keyboard
       event.  In this case, the revertto argument is ignored.

    The specified focus window must be viewable at the time XSetInputFocus is
    called, or a ``BadMatch'' error results.  If the focus window later
    becomes not viewable, the X server evaluates the revertto argument to
    determine the new focus window as follows:

    +  If revertto is RevertToParent, the focus reverts to the parent (or
       the closest viewable ancestor), and the new revertto value is taken
       to be RevertToNone.

    +  If revertto is RevertToPointerRoot or RevertToNone, the focus reverts
       to PointerRoot or None, respectively.  When the focus reverts, the X
       server generates FocusIn and FocusOut events, but the last-focus-
       change time is not affected.

    XSetInputFocus can generate ``BadMatch'', ``BadValue'', and ``BadWindow''
    errors.

    The XGetInputFocus function returns the focus window and the current
    focus state.

 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

    XWarpPointer(XS)
    Xlib - C Language X Interface