static Component componentAtScreenLocationInWindow(Window window, int x, int y) {
  if (window == null) null;
  ret swing(func -> Component {
    Point p = new(x, y);
    SwingUtilities.convertPointFromScreen(p, window);
    ret SwingUtilities.getDeepestComponentAt(window, p.x, p.y);
  });
}

static Component componentAtScreenLocationInWindow(Window window, MouseEvent e) {
  Point p = e.getLocationOnScreen();
  ret componentAtScreenLocationInWindow(window, p.x, p.y);
}

Began life as a copy of #1019640