import javax.swing.JPanel;
import javax.swing.JFrame;
import javax.swing.JLabel;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Dimension;
import java.awt.GridLayout;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;


class Ardoise extends JPanel {
  Ardoise() {
      setPreferredSize(new Dimension(100, 100));
      setForeground(Color.RED);
    }

  public  void paintComponent(Graphics g) {
    int largeur = getSize().width;
    int hauteur = getSize().height;

    super.paintComponent(g);
    g.fillOval(10, 10, largeur - 20, hauteur - 20);
  }
}

public class Touches extends JFrame implements KeyListener {
  Ardoise ardoise = new Ardoise();
  JLabel labelR = new JLabel(" touche r : ovale rouge");
  JLabel labelB = new JLabel(" touche b : ovale bleu");
  JLabel labelV = new JLabel(" touche v : ovale vert");
  JLabel labelE = new JLabel(" touche e : effacer");
  JPanel indications = new JPanel();
  
  Touches() {
      indications.setLayout(new GridLayout(4, 1));
      indications.add(labelR);
      indications.add(labelB);
      indications.add(labelV);
      indications.add(labelE);
      add(indications, BorderLayout.NORTH);
      add(ardoise, BorderLayout.CENTER);
      addKeyListener (this);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      addWindowListener(new WindowAdapter() {
	      public void windowOpened(WindowEvent e) { 		       
		  requestFocus();	
	      }
	  });
      pack();
      setVisible(true);
    }

  public void keyPressed(KeyEvent evt){}

  public void keyReleased(KeyEvent evt){}  

  public void keyTyped(KeyEvent evt) {
      if (evt.getKeyChar() == 'r')
	ardoise.setForeground(Color.RED);
      else if (evt.getKeyChar() == 'b')
	ardoise.setForeground(Color.BLUE);
      else if (evt.getKeyChar() == 'v')
	ardoise.setForeground(Color.GREEN);
      else if (evt.getKeyChar() == 'e')
	ardoise.setForeground(ardoise.getBackground());
      repaint();
    }
}

class EssaiTouches {  
  public static void main(String[] argv) {
	new Touches();
    }
}