/**
   @version 1.00 2019-04-04
   @author Agustín J. González
*/

import java.awt.*;
import java.awt.geom.*;
//import java.util.*;
import java.awt.event.*;
import javax.swing.*;


public class MyOwnGraphicsObject {  
   public static void main(String[] args) {
      SwingUtilities.invokeLater(new Runnable() { // implementación Swing recomendada
         public void run() {
            MyOwnFrame frame = new MyOwnFrame();
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
            frame.setVisible(true);
         } // run ends
      });
   }
}

/**
   A frame with a panel for a simple graphics object
*/
class MyOwnFrame extends JFrame  {
   public MyOwnFrame() {
      setTitle("MyOwnGraphcisObject");
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);

      // add panel to frame
      MyOwnPanel panel = new MyOwnPanel();
      Container contentPane = getContentPane();
      contentPane.add(panel);
   }

   public static final int DEFAULT_WIDTH = 300;
   public static final int DEFAULT_HEIGHT = 300;  
}

/**
   A panel for a simple graphics object.
*/
class MyOwnPanel extends JPanel  { 
   public MyOwnPanel() {  
      sem = new Semaphore(this);
      setFocusable(true);
   }

   public void paintComponent(Graphics g)   {  
      super.paintComponent(g);
      Graphics2D g2 = (Graphics2D)g;
      sem.paintComponent(g2);
   }

   private Semaphore  sem;
}

class Semaphore {
  public Semaphore (JPanel p) {
    panel = p;
    color = Color.RED;
    ellipse = new Ellipse2D.Double(100,100,50,50);
    timer = new Timer(1000, this);
    timer.start();
  }

  public void actionPerformed(ActionEvent event){
    color = (color==Color.RED)?Color.GREEN : Color.RED;
    panel.repaint();
  }
  public void paintComponent(Graphics2D g2d)   {
    g2d.setColor(color);
    g2d.fill(ellipse);
  }
  
  private Timer timer;
  private JPanel panel;
  private Ellipse2D red, yellow;
  private Color color;
  private final int origen_X=150;
  private final int ORIGEN_Y=100;
  private final int LIGHT_RADIO;
}