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1 | /* -*- Mode: C; tab-width: 2 -*- */ |
2 | /*****************************************************************************/ | |
3 | /** Copyright 1991 by Andreas Stolcke **/ | |
4 | /** Copyright 1990 by Solbourne Computer Inc. **/ | |
5 | /** Longmont, Colorado **/ | |
6 | /** **/ | |
7 | /** All Rights Reserved **/ | |
8 | /** **/ | |
9 | /** Permission to use, copy, modify, and distribute this software and **/ | |
10 | /** its documentation for any purpose and without fee is hereby **/ | |
11 | /** granted, provided that the above copyright notice appear in all **/ | |
12 | /** copies and that both that copyright notice and this permis- **/ | |
13 | /** sion notice appear in supporting documentation, and that the **/ | |
14 | /** name of Solbourne not be used in advertising **/ | |
15 | /** in publicity pertaining to distribution of the software without **/ | |
16 | /** specific, written prior permission. **/ | |
17 | /** **/ | |
18 | /** ANDREAS STOLCKE AND SOLBOURNE COMPUTER INC. DISCLAIMS ALL WARRANTIES **/ | |
19 | /** WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF **/ | |
20 | /** MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL ANDREAS STOLCKE **/ | |
21 | /** OR SOLBOURNE BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL **/ | |
22 | /** DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA **/ | |
23 | /** OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER **/ | |
24 | /** TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE **/ | |
25 | /** OR PERFORMANCE OF THIS SOFTWARE. **/ | |
26 | /*****************************************************************************/ | |
27 | /* | |
28 | * vroot.h -- Virtual Root Window handling header file | |
29 | * | |
30 | * This header file redefines the X11 macros RootWindow and DefaultRootWindow, | |
31 | * making them look for a virtual root window as provided by certain `virtual' | |
32 | * window managers like swm and tvtwm. If none is found, the ordinary root | |
33 | * window is returned, thus retaining backward compatibility with standard | |
34 | * window managers. | |
35 | * The function implementing the virtual root lookup remembers the result of | |
36 | * its last invocation to avoid overhead in the case of repeated calls | |
37 | * on the same display and screen arguments. | |
38 | * The lookup code itself is taken from Tom LaStrange's ssetroot program. | |
39 | * | |
40 | * Most simple root window changing X programs can be converted to using | |
41 | * virtual roots by just including | |
42 | * | |
43 | * #include <X11/vroot.h> | |
44 | * | |
45 | * after all the X11 header files. It has been tested on such popular | |
46 | * X clients as xphoon, xfroot, xloadimage, and xaqua. | |
47 | * It also works with the core clients xprop, xwininfo, xwd, and editres | |
48 | * (and is necessary to get those clients working under tvtwm). | |
49 | * It does NOT work with xsetroot; get the xsetroot replacement included in | |
50 | * the tvtwm distribution instead. | |
51 | * | |
52 | * Andreas Stolcke <stolcke@ICSI.Berkeley.EDU>, 9/7/90 | |
53 | * - replaced all NULL's with properly cast 0's, 5/6/91 | |
54 | * - free children list (suggested by Mark Martin <mmm@cetia.fr>), 5/16/91 | |
55 | * - include X11/Xlib.h and support RootWindowOfScreen, too 9/17/91 | |
56 | * | |
57 | * Jamie Zawinski <jwz@jwz.org>, 28-Apr-1997 | |
58 | * - use ANSI C | |
59 | * | |
60 | * Jamie Zawinski <jwz@jwz.org>, 3-Sep-2003 | |
61 | * - if the environment variable "XSCREENSAVER_WINDOW" is set, use that | |
62 | * as the root window instead of searching for __SWM_VROOT. | |
63 | * | |
64 | * Jamie Zawinski <jwz@jwz.org>, 14-Aug-2004 | |
65 | * - changes to get gcc to stop whining about "type punning". | |
66 | * | |
67 | * Jamie Zawinski <jwz@jwz.org>, 16-Dec-2004 | |
68 | * - fixed that last fix. | |
69 | */ | |
70 | ||
71 | #ifndef _VROOT_H_ | |
72 | #define _VROOT_H_ | |
73 | #define _XSCREENSAVER_VROOT_H_ | |
74 | ||
75 | #if !defined(lint) && !defined(SABER) | |
76 | static const char vroot_rcsid[] = | |
77 | "#Id: vroot.h,v 1.8 2004/12/16 05:33:54 jwz Exp #" "\n" | |
78 | "#Id: vroot.h,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke #"; | |
79 | #endif | |
80 | ||
81 | #include <X11/X.h> | |
82 | #include <X11/Xatom.h> | |
83 | #include <X11/Xlib.h> | |
84 | ||
85 | static Window | |
86 | #ifdef __STDC__ /* ANSIfication added by jwz, to avoid superfluous warnings. */ | |
87 | VirtualRootWindowOfScreen(Screen *screen) | |
88 | #else /* !__STDC__ */ | |
89 | VirtualRootWindowOfScreen(screen) Screen *screen; | |
90 | #endif /* !__STDC__ */ | |
91 | { | |
92 | static Screen *save_screen = (Screen *)0; | |
93 | static Window root = (Window)0; | |
94 | ||
95 | if (screen != save_screen) { | |
96 | Display *dpy = DisplayOfScreen(screen); | |
97 | Atom __SWM_VROOT = None; | |
98 | int i; | |
99 | Window rootReturn, parentReturn, *children; | |
100 | unsigned int numChildren; | |
101 | ||
102 | /* first check for a hex or decimal window ID in the environment */ | |
103 | const char *xss_id = getenv("XSCREENSAVER_WINDOW"); | |
104 | if (xss_id && *xss_id) { | |
105 | unsigned long id = 0; | |
106 | char c; | |
107 | if (1 == sscanf (xss_id, " 0x%lx %c", &id, &c) || | |
108 | 1 == sscanf (xss_id, " %lu %c", &id, &c)) { | |
109 | root = (Window) id; | |
110 | save_screen = screen; | |
111 | return root; | |
112 | } | |
113 | } | |
114 | ||
115 | root = RootWindowOfScreen(screen); | |
116 | ||
117 | /* go look for a virtual root */ | |
118 | __SWM_VROOT = XInternAtom(dpy, "__SWM_VROOT", False); | |
119 | if (XQueryTree(dpy, root, &rootReturn, &parentReturn, | |
120 | &children, &numChildren)) { | |
121 | for (i = 0; i < numChildren; i++) { | |
122 | Atom actual_type; | |
123 | int actual_format; | |
124 | unsigned long nitems, bytesafter; | |
125 | unsigned char *newRoot = 0; | |
126 | ||
127 | if (XGetWindowProperty(dpy, children[i], | |
128 | __SWM_VROOT, 0, 1, False, XA_WINDOW, | |
129 | &actual_type, &actual_format, | |
130 | &nitems, &bytesafter, | |
131 | &newRoot) == Success | |
132 | && newRoot) { | |
133 | root = *((Window *) newRoot); | |
134 | break; | |
135 | } | |
136 | } | |
137 | if (children) | |
138 | XFree((char *)children); | |
139 | } | |
140 | ||
141 | save_screen = screen; | |
142 | } | |
143 | ||
144 | return root; | |
145 | } | |
146 | ||
147 | #undef RootWindowOfScreen | |
148 | #define RootWindowOfScreen(s) VirtualRootWindowOfScreen(s) | |
149 | ||
150 | #undef RootWindow | |
151 | #define RootWindow(dpy,screen) VirtualRootWindowOfScreen(ScreenOfDisplay(dpy,screen)) | |
152 | ||
153 | #undef DefaultRootWindow | |
154 | #define DefaultRootWindow(dpy) VirtualRootWindowOfScreen(DefaultScreenOfDisplay(dpy)) | |
155 | ||
156 | #endif /* _VROOT_H_ */ |