WindowAdapter

The program has been expanded with more blanks for you to fill code that does those three things.

import java.awt.*; 
import java.awt.event.*;
import javax.swing.*; 

public class TwoButtons extends JFrame implements ActionListener
{
  JButton redButton ;
  JButton grnButton ;

  // constructor for TwoButtons
  public TwoButtons()                           
  {
    redButton = new JButton("Red");
    grnButton = new JButton("Green");
    getContentPane().setLayout( new FlowLayout() ); 
    getContentPane().add( redButton );                      
    getContentPane().add( grnButton );
  }

   . . . . more code will go here . . . . 

  public static void main ( String[] args )
  {
    TwoButtons demo  = new TwoButtons() ;
    
    ____________wquit = new ____________(); // 2 
    demo.____________( wquit ); // 3 
    
    demo.setSize( 200, 150 );     
    demo.setVisible( true );      

  }
}

class  ___________  extends ___________  // 1 
{
  public void windowClosing( WindowEvent e )
  {
    System.______________( 0 );  
  }
}