/* -*- 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
* window managers.
* 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
*
* #include <X11/vroot.h>
*
* 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
* - use ANSI C
*
* 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
* - fixed that last fix.
*/
#ifndef _VROOT_H_
#define _VROOT_H_
#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 #";
#endif
#include <X11/X.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>
static Window
#ifdef __STDC__ /* ANSIfication added by jwz, to avoid superfluous warnings. */
VirtualRootWindowOfScreen(Screen *screen)
#else /* !__STDC__ */
VirtualRootWindowOfScreen(screen) Screen *screen;
#endif /* !__STDC__ */
{
static Screen *save_screen = (Screen *)0;
static Window root = (Window)0;
if (screen != save_screen) {
Display *dpy = DisplayOfScreen(screen);
Atom __SWM_VROOT = None;
unsigned int i;
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 (xss_id && *xss_id) {
unsigned long id = 0;
char c;
if (1 == sscanf (xss_id, " 0x%lx %c", &id, &c) ||
1 == sscanf (xss_id, " %lu %c", &id, &c)) {
root = (Window) id;
save_screen = screen;
return root;
}
}
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++) {
Atom actual_type;
int actual_format;
unsigned long nitems, bytesafter;
unsigned char *newRoot = 0;
if (XGetWindowProperty(dpy, children[i],
__SWM_VROOT, 0, 1, False, XA_WINDOW,
&actual_type, &actual_format,
&nitems, &bytesafter,
&newRoot) == Success
&& newRoot) {
root = *((Window *) newRoot);
break;
}
}
if (children)
XFree((char *)children);
}
save_screen = screen;
}
return root;
}
#undef RootWindowOfScreen
#define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s)
#undef RootWindow
#define RootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen))
#undef DefaultRootWindow
#define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))
#endif /* _VROOT_H_ */
