/* -*- Mode: C; tab-width: 2 -*- */
/*****************************************************************************/
/** Copyright 1991 by Andreas Stolcke **/
/** Copyright 1990 by Solbourne Computer Inc. **/
/** Longmont, Colorado **/
/** All Rights Reserved **/
/** Permission to use, copy, modify, and distribute this software and **/
/** its documentation for any purpose and without fee is hereby **/
/** granted, provided that the above copyright notice appear in all **/
/** copies and that both that copyright notice and this permis- **/
/** sion notice appear in supporting documentation, and that the **/
/** name of Solbourne not be used in advertising **/
/** in publicity pertaining to distribution of the software without **/
/** specific, written prior permission. **/
/** ANDREAS STOLCKE AND SOLBOURNE COMPUTER INC. DISCLAIMS ALL WARRANTIES **/
/** WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF **/
/** MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL ANDREAS STOLCKE **/
/** OR SOLBOURNE BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL **/
/** DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA **/
/** OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER **/
/** TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE **/
/** OR PERFORMANCE OF THIS SOFTWARE. **/
/*****************************************************************************/
* vroot.h -- Virtual Root Window handling header file
* This header file redefines the X11 macros RootWindow and DefaultRootWindow,
* making them look for a virtual root window as provided by certain `virtual'
* window managers like swm and tvtwm. If none is found, the ordinary root
* window is returned, thus retaining backward compatibility with standard
* The function implementing the virtual root lookup remembers the result of
* its last invocation to avoid overhead in the case of repeated calls
* on the same display and screen arguments.
* The lookup code itself is taken from Tom LaStrange's ssetroot program.
* Most simple root window changing X programs can be converted to using
* virtual roots by just including
* after all the X11 header files. It has been tested on such popular
* X clients as xphoon, xfroot, xloadimage, and xaqua.
* It also works with the core clients xprop, xwininfo, xwd, and editres
* (and is necessary to get those clients working under tvtwm).
* It does NOT work with xsetroot; get the xsetroot replacement included in
* the tvtwm distribution instead.
* Andreas Stolcke <stolcke@ICSI.Berkeley.EDU>, 9/7/90
* - replaced all NULL's with properly cast 0's, 5/6/91
* - free children list (suggested by Mark Martin <mmm@cetia.fr>), 5/16/91
* - include X11/Xlib.h and support RootWindowOfScreen, too 9/17/91
* Jamie Zawinski <jwz@jwz.org>, 28-Apr-1997
* Jamie Zawinski <jwz@jwz.org>, 3-Sep-2003
* - if the environment variable "XSCREENSAVER_WINDOW" is set, use that
* as the root window instead of searching for __SWM_VROOT.
* Jamie Zawinski <jwz@jwz.org>, 14-Aug-2004
* - changes to get gcc to stop whining about "type punning".
* Jamie Zawinski <jwz@jwz.org>, 16-Dec-2004
#define _XSCREENSAVER_VROOT_H_
#if !defined(lint) && !defined(SABER)
static const char vroot_rcsid
[] =
"#Id: vroot.h,v 1.8 2004/12/16 05:33:54 jwz Exp #" "\n"
"#Id: vroot.h,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke #";
#ifdef __STDC__ /* ANSIfication added by jwz, to avoid superfluous warnings. */
VirtualRootWindowOfScreen(Screen
*screen
)
VirtualRootWindowOfScreen(screen
) Screen
*screen
;
static Screen
*save_screen
= (Screen
*)0;
static Window root
= (Window
)0;
if (screen
!= save_screen
) {
Display
*dpy
= DisplayOfScreen(screen
);
Window rootReturn
, parentReturn
, *children
;
unsigned int numChildren
;
/* first check for a hex or decimal window ID in the environment */
const char *xss_id
= getenv("XSCREENSAVER_WINDOW");
if (1 == sscanf (xss_id
, " 0x%lx %c", &id
, &c
) ||
1 == sscanf (xss_id
, " %lu %c", &id
, &c
)) {
root
= RootWindowOfScreen(screen
);
/* go look for a virtual root */
__SWM_VROOT
= XInternAtom(dpy
, "__SWM_VROOT", False
);
if (XQueryTree(dpy
, root
, &rootReturn
, &parentReturn
,
&children
, &numChildren
)) {
for (i
= 0; i
< numChildren
; i
++) {
unsigned long nitems
, bytesafter
;
unsigned char *newRoot
= 0;
if (XGetWindowProperty(dpy
, children
[i
],
__SWM_VROOT
, 0, 1, False
, XA_WINDOW
,
&actual_type
, &actual_format
,
root
= *((Window
*) newRoot
);
#undef RootWindowOfScreen
#define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s)
#define RootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen))
#define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))