Problème keyListener lorsque la fenêtre est masquée

import javax.swing.*;
import java.awt.*;
import java.io.*;
import javax.swing.event.CaretListener;
import javax.swing.event.CaretEvent;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.KeyListener;
import java.awt.event.KeyEvent;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;


public class IG_Screen extends JFrame implements ActionListener, KeyListener{
 JButton btnCommentaire = new JButton("Masquer");
 public IG_Screen(){
  super("Screen");
  this.setSize(150, 100);
  this.setVisible(true);
  btnCommentaire.addActionListener(this);
  addKeyListener(this);
  btnCommentaire.setBounds(10, 10, 120, 25);
  this.add(btnCommentaire);	
  addWindowListener(new WindowAdapter(){
	public void windowOpened(WindowEvent e) { 
	requestFocus(false);	
	}
  });
 } 
 public void keyPressed(KeyEvent evt){}
 public void keyReleased(KeyEvent evt){} 

 public void keyTyped(KeyEvent evt) {
 if (evt.getKeyChar() == 'r'){
 	 System.out.println("r cliked");
     this.setVisible(true);
 }
}
  
 public void actionPerformed(ActionEvent e) {
  if (e.getSource() == btnCommentaire){
   this.setVisible(false);
   }
 } 
 
 public static void main(String[] args) {
 	JFrame f = new IG_Screen(); 
    f.setLayout(null);
    f.setVisible(true); 
 }
}