Ecouter un objet quelconque

import java.awt.Color;
import java.awt.Component;
import java.awt.Graphics;
import java.awt.Point;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;

import javax.swing.JFrame;
import javax.swing.JRadioButton;

public class SommetDeplacable extends Component
{    
    private final transient Point tmp = new Point();
    
    private class Mouse implements MouseListener
    {
        @Override
        public void mouseClicked(MouseEvent e)
        {
            tmp.setLocation(e.getX(),e.getY());
        }

        @Override
        public void mouseEntered(MouseEvent e)
        {
        }

        @Override
        public void mouseExited(MouseEvent e)
        {
        }

        @Override
        public void mousePressed(MouseEvent e)
        {
        }

        @Override
        public void mouseReleased(MouseEvent e)
        {
        }
    }
    
    private class MouseMotion implements MouseMotionListener
    {
        @Override
        public void mouseDragged(MouseEvent e)
        {
            Point pos = SommetDeplacable.this.getLocation();
            
            SommetDeplacable.this.setLocation
            (
                pos.x + e.getX() - tmp.x,
                pos.y + e.getY() - tmp.y
            );
        }

        @Override
        public void mouseMoved(MouseEvent e)
        {
        }
    }

    public SommetDeplacable(int x, int y)
    {
        setLocation(x, y);
        setSize(20,20);
        addMouseListener(new Mouse());
        addMouseMotionListener(new MouseMotion());
    }
    
    @Override
    public void paint(Graphics g)
    {
        g.setColor(Color.BLACK);
        g.fillOval(0,0,getWidth(),getHeight());
    }
    
    public static void main(String[] args)
    {
        JFrame frame = new JFrame();
        frame.setLayout(null);
        frame.setSize(500,500);
        frame.add(new SommetDeplacable(100,100));
        frame.add(new SommetDeplacable(200,200));
        frame.setVisible(true);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    }
}