static Rectangle boundsOnScreen(Component c) {
  if (c == null) null;
  if (c.getParent() instanceof JViewport
    && c.getParent().getParent() instanceof JScrollPane)
    c = c.getParent().getParent();
  try { 
    ret new Rectangle(c.getLocationOnScreen(), c.getSize());
  } catch (IllegalComponentStateException e) {
    null;
  }
}