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 char vroot_rcsid[] = "$Id: vroot.h,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke $";
62 #endif
63
64 #include <X11/X.h>
65 #include <X11/Xatom.h>
66 #include <X11/Xlib.h>
67
68 static Window
VirtualRootWindowOfScreen(screen)69 VirtualRootWindowOfScreen(screen)
70 Screen *screen;
71 {
72 static Screen *save_screen = (Screen *)0;
73 static Window root = (Window)0;
74
75 if (screen != save_screen) {
76 Display *dpy = DisplayOfScreen(screen);
77 Atom __SWM_VROOT = None;
78 int i;
79 Window rootReturn, parentReturn, *children;
80 unsigned int numChildren;
81
82 root = RootWindowOfScreen(screen);
83
84 /* go look for a virtual root */
85 __SWM_VROOT = XInternAtom(dpy, "__SWM_VROOT", False);
86 if (XQueryTree(dpy, root, &rootReturn, &parentReturn,
87 &children, &numChildren)) {
88 for (i = 0; i < numChildren; i++) {
89 Atom actual_type;
90 int actual_format;
91 unsigned long nitems, bytesafter;
92 Window *newRoot = (Window *)0;
93
94 if (XGetWindowProperty(dpy, children[i],
95 __SWM_VROOT, 0, 1, False, XA_WINDOW,
96 &actual_type, &actual_format,
97 &nitems, &bytesafter,
98 (unsigned char **) &newRoot) == Success
99 && newRoot) {
100 root = *newRoot;
101 break;
102 }
103 }
104 if (children)
105 XFree((char *)children);
106 }
107
108 save_screen = screen;
109 }
110
111 return root;
112 }
113
114 #undef RootWindowOfScreen
115 #define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s)
116
117 #undef RootWindow
118 #define RootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen))
119
120 #undef DefaultRootWindow
121 #define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy))
122
123 #endif /* _VROOT_H_ */
124