#ifndef _VROOT_H_
#define _VROOT_H_

#if !defined( lint ) && !defined( SABER )
/* #ident	"@(#)vroot.h	4.14 99/06/17 xlockmore" */

#endif

/*****************************************************************************/
/**                   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
 */

#include <X11/X.h>
#include <X11/Xatom.h>
#include <X11/Xlib.h>

static      Window
VirtualRootWindowOfScreen(Screen * s)
{
	static Screen *save_screen = (Screen *) 0;
	static Window root = (Window) 0;

	if (s != save_screen) {

		root = RootWindowOfScreen(s);

		/* go look for a virtual root */
#if 0
/*-
 * I forget why I put this here....
 * With this it screws up the mouse focus with xscreensaver.
 */
		if (inroot)
#endif
		{
			Display    *dpy = DisplayOfScreen(s);
			Atom        __SWM_VROOT = None;
			int         i;
			Window      rootReturn, parentReturn, *children;
			unsigned int numChildren;

			__SWM_VROOT = XInternAtom(dpy, "__SWM_VROOT", False);
			if (XQueryTree(dpy, root, &rootReturn, &parentReturn,
				       &children, &numChildren)) {
				for (i = 0; i < (int) numChildren; i++) {
					Atom        actual_type;
					int         actual_format;
					unsigned long nitems, bytesafter;
					Window     *newRoot = (Window *) 0;

					if (XGetWindowProperty(dpy, children[i],
					 __SWM_VROOT, 0, 1, False, XA_WINDOW,
						&actual_type, &actual_format,
							&nitems, &bytesafter,
							       (unsigned char **) &newRoot) == Success && newRoot) {
						root = *newRoot;
						break;
					}
				}
				if (children)
					XFree((caddr_t) children);
			}
		}
		save_screen = s;
	}
	return root;
}

#undef RootWindowOfScreen
#define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s)

#undef RootWindow
#define RootWindow(dpy,s) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,s))

#undef DefaultRootWindow
#define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))

#endif /* _VROOT_H_ */
