import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
 
class Temp implements ActionListener{
 
    JFrame frame = new JFrame("Temp");
    Container cp = frame.getContentPane();
    
    JPanel p = new JPanel();
    JPanel p1 = new JPanel();
    JPanel p2 = new JPanel();
    
    CheckboxGroup cbg = new CheckboxGroup();
    
    Button b1 = new Button("b1");
    Button b2 = new Button("b2");
    Button b3 = new Button("b3");
    Button b4 = new Button("b4");
    
    public Temp() {
	frame.addWindowListener(new WindowAdapter() {
		public void windowClosing(WindowEvent e) {
		    frame.dispose();
		    System.exit(0);
		}
	    });
	
	p1.setBackground(Color.BLACK);
	p2.setBackground(Color.BLUE);
	
	p1.add(b1);
	p1.add(new Checkbox("a", cbg, true));
	p1.add(new Checkbox("b", cbg, false));
	p2.add(b2);
	p2.add(p1);
	p1.setVisible(false);
	
	cp.add(p);
	p.add(p2);
	p.add(b3);
	p.add(b4);
	
	b1.addActionListener(this);
	b2.addActionListener(this);
	b3.addActionListener(this);
	b4.addActionListener(this);
	
	frame.setVisible(true);
	frame.setResizable(true);
	frame.pack();
    }
    private void setV(Container c,boolean v){
	Component[] components = c.getComponents();
	for(int y=0;y<components.length;y++){
	    components[y].setVisible(v);	   
	    if(components[y] instanceof Container){
		setV((Container)components[y],v);
	    }
	}	
    }
    
 
    public void actionPerformed(ActionEvent e) {
	if(e.getSource() == b3) {
	    //p1.setVisible(false);
	    setV(p1,false);
	    frame.pack();
	} else if(e.getSource() == b4) {
	    //p1.setVisible(true);
	    setV(p1,true);
	    frame.pack();
	    
	}
    }
    
 
    public static void main(String [] args) {
	new Temp();
    }
}