stolcke@ICSI.Berkeley.EDU (Andreas Stolcke) (09/08/90)
I started using tvtwm and was truely thrilled by it. The one major drawback
was that all those nifty programs manipulating the root window stopped
working. So I hacked up this little header file (which I call "vroot.h")
that magically gets things going again. Just #include it after any X headers
and recompile. NB: This little hack almost certainly leaves room for
improvement, so any suggestions are welcome.
Enjoy.
--
Andreas Stolcke
International Computer Science Institute stolcke@icsi.Berkeley.EDU
1957 Center St., Suite 600, Berkeley, CA 94704 (415) 642-4274 ext. 126
----cut here----
/*
* 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 "vroot.h"
*
* after all the X11 header files. It has been tested on such popular
* X clients as xphoon, xfroot, xloadimage, and xaqua.
*
* Andreas Stolcke (stolcke@ICSI.Berkeley.EDU), 9/7/90
*/
#include <X11/X.h>
#include <X11/Xatom.h>
static Window
VirtualRootWindow(dpy, screen)
Display *dpy;
{
static Display *save_dpy = (Display *)NULL;
static int save_screen = -1;
static Window root = (Window)NULL;
Atom __SWM_VROOT = None;
int i;
Window rootReturn, parentReturn, *children;
unsigned int numChildren;
if ( dpy != save_dpy || screen != save_screen ) {
root = RootWindow(dpy, screen);
/* go look for a virtual root */
__SWM_VROOT = XInternAtom(dpy, "__SWM_VROOT", False);
XQueryTree(dpy, root, &rootReturn, &parentReturn,
&children, &numChildren);
for (i = 0; i < numChildren; i++) {
Atom actual_type;
int actual_format;
long nitems, bytesafter;
Window *newRoot = NULL;
if (XGetWindowProperty(dpy, children[i], __SWM_VROOT,
0, 1, False, XA_WINDOW,
&actual_type, &actual_format,
&nitems, &bytesafter,
(unsigned char **) &newRoot) == Success
&& newRoot) {
root = *newRoot;
break;
}
}
save_dpy = dpy;
save_screen = screen;
}
return root;
}
#undef DefaultRootWindow
#define DefaultRootWindow(dpy) RootWindow(dpy, DefaultScreen(dpy))
#undef RootWindow
#define RootWindow(dpy,screen) VirtualRootWindow(dpy,screen)