NAME

       XSetInputFocus, XGetInputFocus - control input focus

SYNTAX

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

       int XGetInputFocus(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.

       focus_return
                 Returns the focus window, PointerRoot, or None.

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

       revert_to_return
                 Returns  the  current  focus  state  (RevertToParent,  RevertToPointerRoot,   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 revert_to 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
            revert_to 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 revert_to argument to determine the new focus window as follows:

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

       •    If revert_to 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 Window.

SEE ALSO

       XWarpPointer(3)
       Xlib - C Language X Interface