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

XSeInFoc(3X)

control input focus

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

NAME

XSetInputFocus, XGetInputFocus - 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 XWIN 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 Revert-
          ToParent, 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 XWIN server time.  Otherwise, the
last-focus-change time is set to the specified time
(CurrentTime is replaced by the current XWIN server time).
XSetInputFocus causes the XWIN 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

XWIN 3.0               Last change: 9/1/88                 .ie t
          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 dynami-
          cally 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 XWIN 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 XWIN server generates Focu-
          sIn 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 gen-
          erate this error.

BadWindow A value for a Window argument does not name a