/*
 * CDE - Common Desktop Environment
 *
 * Copyright (c) 1993-2012, The Open Group. All rights reserved.
 *
 * These libraries and programs are free software; you can
 * redistribute them and/or modify them under the terms of the GNU
 * Lesser General Public License as published by the Free Software
 * Foundation; either version 2 of the License, or (at your option)
 * any later version.
 *
 * These libraries and programs are distributed in the hope that
 * they will be useful, but WITHOUT ANY WARRANTY; without even the
 * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
 * PURPOSE. See the GNU Lesser General Public License for more
 * details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with these libraries and programs; if not, write
 * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
 * Floor, Boston, MA 02110-1301 USA
 */
/*****************************************************************************/
/**                   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
 */

#ifndef _VROOT_H_
#define _VROOT_H_

#if !defined(lint) && !defined(SABER)
static const char vroot_rcsid[] = "$XConsortium: vroot.h /main/3 1996/06/11 16:30:45 cde-hal $";
#endif

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

#if 0
static Window
VirtualRootWindowOfScreen(Screen *screen)
{
  static Screen *save_screen = NULL;
  static Window root = None;

  if (screen != save_screen)
    {
      Display *dpy = DisplayOfScreen(screen);
      Atom __SWM_VROOT = None;
      unsigned int i;
      Window rootReturn, parentReturn, *children;
      unsigned int numChildren;

      root = RootWindowOfScreen(screen);

      /* go look for a virtual root */
      /* we're in deep shit if a window dies during this loop */
      __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;
	      Window *newRoot = NULL;
	      int status;

	      status =
		XGetWindowProperty(dpy, children[i],
				   __SWM_VROOT, 0, 1, False, XA_WINDOW,
				   &actual_type, &actual_format,
				   &nitems, &bytesafter,
				   (unsigned char **) &newRoot);

	      if (status == Success && newRoot != NULL)
		{
		  root = *newRoot;
		  break;
		}
	    }
	  if (children != NULL)
	    XFree((char *) children);
	}

      save_screen = screen;
    }

  return (root);
}
#endif


/* Need original macros to figure out if there is a virtual root. */
  
#if 0
#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))

#else

#define VRootWindowOfScreen(s) VirtualRootWindowOfScreen(s)

#define VRootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen))

#define VDefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))
#endif

#endif /* _VROOT_H_ */
