x frame extents

frame_extents.c

static void
get_frame_extents(Display *dpy, Window w, int *top) {
  long *extents;
  Atom actual_type;
  int actual_format;
  unsigned long nitems, bytes_after;
  unsigned char *data = NULL;
  int result;

  *top = 0;

  result = XGetWindowProperty(
    dpy, w, XInternAtom(dpy, "_NET_FRAME_EXTENTS", False),
    0, 4, False, AnyPropertyType, 
    &actual_type, &actual_format, 
    &nitems, &bytes_after, &data);

  if (result == Success) {
    printf("nitems: %u, after: %u\n", nitems, bytes_after);
    if ((nitems == 4) && (bytes_after == 0)) {
      extents = (long *)data;
      *top = (int) *(extents + 2);
    }
    XFree(data);
  }
}