#include <X11/Xlib.h>
#include <X11/extensions/Xcomposite.h>
#include <stdlib.h>
#include <stdio.h>

/*
 * Thie program demonstrates that windows that have had
 * XcompositeRedirectSubwindows() called on them will
 * not have their background drawn at all.
 *
 * This is correct according to the composite spec, but I don't see any
 * good (API) reason for this behavior. The right
 * behavior in my opinion is to only have the background
 * painting turned off it is moving a redirected window that
 * causes the expose/paintbackground. Ie,. basically when the
 * expose is real, it should be processed.
 *
 * Think of an application for example that has a manual redirect
 * of the subwindows of its own toplevel window.
 */
static int comp_event;
static int comp_error;

static void
disaster (const char *what)
{
    fprintf (stderr, "Error: %s\n", what);
    exit (0);
}

int
main (int argc, char **argv)
{
    Display *dpy;
    Window main_window;

    dpy = XOpenDisplay (NULL);
    if (!XCompositeQueryExtension (dpy, &comp_event, &comp_error))
	disaster ("No composite extension found\n");

    /* Create main window */
    
    main_window = XCreateSimpleWindow (dpy, XDefaultRootWindow (dpy),
				       100, 100, 600, 400, 0, 0, 0xffffffff);
    XMapWindow (dpy, main_window);

    XCompositeRedirectSubwindows (dpy,
				  main_window,
				  CompositeRedirectManual);

    XFlush (dpy);

    sleep (100);
}