import java.awt.event.*;
import java.awt.*;

class CrearCirculoHandler implements ActionListener
{ private Dibujo dibujo;
  private Circulo circulo;
  private int estado;
  private Point centro;
  private static final int INICIAL=0;
  private static final int AFTER_CREADO=1;
    
  public CrearCirculoHandler(Dibujo dib) {
    dibujo=dib;
    estado=INICIAL;
  }

 public void actionPerformed(ActionEvent e)
    {
      dibujo.changeMouseListener(new MouseHandler());
      dibujo.changeMouseMotionListener(new MouseMotionHandler());
      estado = INICIAL;
     }
  
  class MouseHandler extends MouseAdapter
  {
    public void mousePressed(MouseEvent event)
      {
        if(estado==INICIAL)
        {
          centro = event.getPoint();
          circulo = new Circulo(centro, 0);
          dibujo.incorpore(circulo);
          estado = AFTER_CREADO;
          dibujo.repaint();
         }
      }
    public void mouseReleased(MouseEvent event)
      {
        estado = INICIAL;
       }
  }
  
  class MouseMotionHandler extends MouseMotionAdapter
  {
    public void mouseDragged(MouseEvent event)
      {
        if (estado == AFTER_CREADO) {
          Point p = event.getPoint();
          double a = p.getX()-centro.getX();
          double b = p.getY()-centro.getY();
          double newRadio=Math.sqrt(a*a+b*b);
          circulo.setRadio(newRadio);
          dibujo.repaint();
         }
      }
  }  
}