[This file is in the public domain.]

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
  Benefits:
	- can be included even ahead of X header files
	- supports RootWindowOfScreen, thus working with editres
	- has RCS string compiled in, so client binaries can be checked with
	  `ident' for vroot functionality

- The Imakefile now supports an `includes' target. After customizing TOPDIR
this will create a link to vroot.h in the mit source directory.  I find
this convenient for recompiling some of the MIT clients (xprop, xwd, xwininfo)
in their original source directories.  9/19/91

[$Id: README,v 1.4 1991/09/30 19:23:16 stolcke Exp stolcke $]
