[PATCH 1/3] Add vroot.h.

[Corbin Simpson]

Part of #7968.

I'm not perfect, but I think the legalese is equivalent to the package
license? If not, we can always hack around it.
---
 vroot.h |  138 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 files changed, 138 insertions(+), 0 deletions(-)
 create mode 100644 vroot.h

diff --git a/vroot.h b/vroot.h
new file mode 100644
index 0000000..6925bb2
--- /dev/null
+++ b/vroot.h
@@ -0,0 +1,138 @@
+/* -*- Mode: C; tab-width: 2 -*-                                             */
+/*****************************************************************************/
+/**                   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
+ *
+ * The function VirtualRootWindowOfScreen returns the 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.
+ *
+ * Andreas Stolcke <stolcke at 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 at cetia.fr>), 5/16/91
+ * - include X11/Xlib.h and support RootWindowOfScreen, too 9/17/91
+ *
+ * Jamie Zawinski <jwz at jwz.org>, 28-Apr-1997
+ * - use ANSI C
+ *
+ * Jamie Zawinski <jwz at jwz.org>, 3-Sep-2003
+ * - if the environment variable "XSCREENSAVER_WINDOW" is set, use that
+ *   as the root window instead of searching for __SWM_VROOT.
+ *
+ * Jamie Zawinski <jwz at jwz.org>, 14-Aug-2004
+ * - changes to get gcc to stop whining about "type punning".
+ *
+ * Jamie Zawinski <jwz at jwz.org>, 16-Dec-2004
+ * - fixed that last fix.
+ *
+ * Eugene St Leger <grimrc at yahoo.com> 23/8/2006
+ * - removed the macros and included in xdpyinfo
+ */
+
+#ifndef _VROOT_H_
+#define _VROOT_H_
+#define _XSCREENSAVER_VROOT_H_
+
+#if !defined(lint) && !defined(SABER)
+static const char vroot_rcsid[] =
+ "#Id: vroot.h,v 1.8 2004/12/16 05:33:54 jwz Exp #" "\n"
+ "#Id: vroot.h,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke #";
+#endif
+
+#include <X11/X.h>
+#include <X11/Xatom.h>
+#include <X11/Xlib.h>
+
+static Window
+#ifdef __STDC__ /* ANSIfication added by jwz, to avoid superfluous warnings. */
+VirtualRootWindowOfScreen(Screen *screen)
+#else /* !__STDC__ */
+VirtualRootWindowOfScreen(screen) Screen *screen;
+#endif /* !__STDC__ */
+{
+	static Screen *save_screen = (Screen *)0;
+	static Window root = (Window)0;
+
+	if (screen != save_screen) {
+		Display *dpy = DisplayOfScreen(screen);
+		Atom __SWM_VROOT = None;
+		int i;
+		Window rootReturn, parentReturn, *children;
+		unsigned int numChildren;
+
+    /* first check for a hex or decimal window ID in the environment */
+    const char *xss_id = getenv("XSCREENSAVER_WINDOW");
+    if (xss_id && *xss_id) {
+      unsigned long id = 0;
+      char c;
+      if (1 == sscanf (xss_id, " 0x%lx %c", &id, &c) ||
+          1 == sscanf (xss_id, " %lu %c",   &id, &c)) {
+        root = (Window) id;
+        save_screen = screen;
+        return root;
+      }
+    }
+
+		root = RootWindowOfScreen(screen);
+
+		/* go look for a virtual root */
+		__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;
+				unsigned char *newRoot = 0;
+
+				if (XGetWindowProperty(dpy, children[i],
+					__SWM_VROOT, 0, 1, False, XA_WINDOW,
+					&actual_type, &actual_format,
+					&nitems, &bytesafter,
+					&newRoot) == Success
+				    && newRoot) {
+				    root = *((Window *) newRoot);
+				    break;
+				}
+			}
+			if (children)
+				XFree((char *)children);
+		}
+
+		save_screen = screen;
+	}
+
+	return root;
+}
+
+#endif /* _VROOT_H_ */
-- 
1.6.6.1