final Arrow arrow = new Arrow();
frame.add(arrow, BorderLayout.CENTER);
frame.setSize(640, 480);
frame.setResizable(false);
frame.setVisible(true);
frame.getContentPane().addMouseMotionListener(new MouseMotionListener() {
public void mouseMoved (MouseEvent e) {
arrow.setArrowLocation(320, 240, e.getX(), e.getY());
}
public void mouseDragged (MouseEvent e) {