import java.awt.event.*;
import java.awt.*;
import java.lang.Math;

class TrasladarHandler implements ActionListener
{
  private Dibujo dibujo;
  private Point previo;
  
  public TrasladarHandler(Dibujo dib)
    {
      dibujo = dib;
    }
  
  public void actionPerformed(ActionEvent e)
    {
      dibujo.changeMouseListener(new MouseHandler());
      dibujo.changeMouseMotionListener(new MouseMotionHandler());
    }

  class MouseHandler extends MouseAdapter
  {
    public void mousePressed (MouseEvent event)
      {
        previo = event.getPoint();
      }
  }
  
  class MouseMotionHandler extends MouseMotionAdapter
  {
    public void mouseDragged(MouseEvent event)
      {
        Point p = event.getPoint();
        double deltaX = p.getX()-previo.getX();
        double deltaY = p.getY()-previo.getY();
        dibujo.trasladar(deltaX, deltaY);
        previo = p;
      }
  }  
}