workspace/kscreensaver/libkscreensaver/kscreensaver_vroot.h

   1 /*****************************************************************************/
   2 /**                   Copyright 1991 by Andreas Stolcke                     **/
   3 /**               Copyright 1990 by Solbourne Computer Inc.                 **/
   4 /**                          Longmont, Colorado                             **/
   5 /**                                                                         **/
   6 /**                           All Rights Reserved                           **/
   7 /**                                                                         **/
   8 /**    Permission to use, copy, modify, and distribute this software and    **/
   9 /**    its documentation  for  any  purpose  and  without  fee is hereby    **/
  10 /**    granted, provided that the above copyright notice appear  in  all    **/
  11 /**    copies and that both  that  copyright  notice  and  this  permis-    **/
  12 /**    sion  notice appear in supporting  documentation,  and  that  the    **/
  13 /**    name of Solbourne not be used in advertising                         **/
  14 /**    in publicity pertaining to distribution of the  software  without    **/
  15 /**    specific, written prior permission.                                  **/
  16 /**                                                                         **/
  17 /**    ANDREAS STOLCKE AND SOLBOURNE COMPUTER INC. DISCLAIMS ALL WARRANTIES **/
  18 /**    WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF    **/
  19 /**    MERCHANTABILITY  AND  FITNESS,  IN  NO  EVENT SHALL ANDREAS STOLCKE  **/
  20 /**    OR SOLBOURNE BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL    **/
  21 /**    DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA   **/
  22 /**    OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER    **/
  23 /**    TORTIOUS ACTION, ARISING OUT OF OR IN  CONNECTION  WITH  THE  USE    **/
  24 /**    OR PERFORMANCE OF THIS SOFTWARE.                                     **/
  25 /*****************************************************************************/
  26 /*
  27  * vroot.h -- Virtual Root Window handling header file
  28  *
  29  * This header file redefines the X11 macros RootWindow and DefaultRootWindow,
  30  * making them look for a virtual root window as provided by certain `virtual'
  31  * window managers like swm and tvtwm. If none is found, the ordinary root
  32  * window is returned, thus retaining backward compatibility with standard
  33  * window managers.
  34  * The function implementing the virtual root lookup remembers the result of
  35  * its last invocation to avoid overhead in the case of repeated calls
  36  * on the same display and screen arguments.
  37  * The lookup code itself is taken from Tom LaStrange's ssetroot program.
  38  *
  39  * Most simple root window changing X programs can be converted to using
  40  * virtual roots by just including
  41  *
  42  * #include <X11/vroot.h>
  43  *
  44  * after all the X11 header files.  It has been tested on such popular
  45  * X clients as xphoon, xfroot, xloadimage, and xaqua.
  46  * It also works with the core clients xprop, xwininfo, xwd, and editres
  47  * (and is necessary to get those clients working under tvtwm).
  48  * It does NOT work with xsetroot; get the xsetroot replacement included in
  49  * the tvtwm distribution instead.
  50  *
  51  * Andreas Stolcke <stolcke@ICSI.Berkeley.EDU>, 9/7/90
  52  * - replaced all NULL's with properly cast 0's, 5/6/91
  53  * - free children list (suggested by Mark Martin <mmm@cetia.fr>), 5/16/91
  54  * - include X11/Xlib.h and support RootWindowOfScreen, too 9/17/91
  55  */
  56
  57 #ifndef _VROOT_H_
  58 #define _VROOT_H_
  59
  60 #if !defined(lint) && !defined(SABER)
  61 static const char vroot_rcsid[] = "#Id: vroot.h,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke #";
  62 #endif
  63
  64 #include <QtGui/QWidget>
  65 #ifdef Q_WS_X11
  66 #include <X11/X.h>
  67 #include <X11/Xatom.h>
  68 #include <X11/Xlib.h>
  69 #include <fixx11h.h>
  70
  71 static Window
  72 #if defined(__STDC__) || defined(__cplusplus) /* ANSIfication added by jwz, to avoid superfluous warnings. */
  73 VirtualRootWindowOfScreen(Screen *screen)
  74 #else /* !__STDC__ */
  75 VirtualRootWindowOfScreen(screen) Screen *screen;
  76 #endif /* !__STDC__ */
  77 {
  78         static Screen *save_screen = (Screen *)0;
  79         static Window root = (Window)0;
  80
  81         if (screen != save_screen) {
  82                 Display *dpy = DisplayOfScreen(screen);
  83                 Atom __SWM_VROOT = None;
  84                 uint i;
  85                 Window rootReturn, parentReturn, *children;
  86                 unsigned int numChildren;
  87
  88                 root = RootWindowOfScreen(screen);
  89
  90                 /* go look for a virtual root */
  91                 __SWM_VROOT = XInternAtom(dpy, "__SWM_VROOT", False);
  92                 if (XQueryTree(dpy, root, &rootReturn, &parentReturn,
  93                                  &children, &numChildren)) {
  94                         for (i = 0; i < numChildren; i++) {
  95                                 Atom actual_type;
  96                                 int actual_format;
  97                                 unsigned long nitems, bytesafter;
  98                                 unsigned char *newRoot = 0;
  99
 100                                 if (XGetWindowProperty(dpy, children[i],
 101                                         __SWM_VROOT, 0, 1, False, XA_WINDOW,
 102                                         &actual_type, &actual_format,
 103                                         &nitems, &bytesafter,
 104                                         &newRoot) == Success
 105                                     && newRoot) {
 106                                     void* tmpRoot = (void*) newRoot;
 107                                     root = *((Window *) tmpRoot);
 108                                     XFree((char*) newRoot);
 109                                     break;
 110                                 }
 111                         }
 112                         if (children)
 113                                 XFree((char *)children);
 114                 }
 115
 116                 save_screen = screen;
 117         }
 118
 119         return root;
 120 }
 121
 122 #undef RootWindowOfScreen
 123 #define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s)
 124
 125 #undef RootWindow
 126 #define RootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen))
 127
 128 #undef DefaultRootWindow
 129 #define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))
 130 #endif
 131
 132 #endif /* _VROOT_H_ */