import java.awt.Color;

import java.awt.GridLayout;

import java.awt.event.ActionEvent;

import java.awt.event.ActionListener;

import javax.swing.BoxLayout;

import javax.swing.JButton;

import javax.swing.JFrame;

import javax.swing.JMenuBar;

import javax.swing.JMenu;

import javax.swing.JMenuItem;

import javax.swing.JPanel;

public class ColorBox extends JFrame implements ActionListener {

JPanel colorPanel;

public ColorBox() {

super("Color, Box, and Nesting Demo");

// Set up button panel

JButton redButton = new JButton("Red");

redButton.addActionListener(this);

redButton.setEnabled(false);

JButton whiteButton = new JButton("White");

whiteButton.addActionListener(this);

JButton blueButton = new JButton("Blue");

blueButton.addActionListener(this);

JPanel buttonPanel = new JPanel();

buttonPanel.setLayout(new BoxLayout(buttonPanel, BoxLayout.Y_AXIS));

buttonPanel.add(redButton);

buttonPanel.add(whiteButton);

buttonPanel.add(blueButton);

// Set up color panel

colorPanel = new JPanel();

colorPanel.setSize(200, 200);

// Set up main application frame

setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

setLayout(new GridLayout(1, 2));

add(buttonPanel);

add(colorPanel);

JMenuBar menuBar = createJMenuBar();

setJMenuBar(menuBar);

}

private JMenuBar createJMenuBar() {

JMenuItem redMenuItem = new JMenuItem("Rot");

redMenuItem.addActionListener(this);

redMenuItem.setActionCommand("Red");

JMenuItem whiteMenuItem = new JMenuItem("Weiss");

whiteMenuItem.addActionListener(this);

JMenuItem blueMenuItem = new JMenuItem("Blau");

blueMenuItem.addActionListener(this);

JMenu colorMenu = new JMenu("Color");

colorMenu.add(redMenuItem);

colorMenu.add(whiteMenuItem);

colorMenu.add(blueMenuItem);

JMenuBar menuBar = new JMenuBar();

menuBar.add(colorMenu);

return menuBar;

}

private JButton createButton(String label, ActionListener listener) {

JButton button = new JButton(label);

button.addActionListener(listener);

return button;

}

public void actionPerformed(ActionEvent e) {

String button = e.getActionCommand();

if (button == "Red") {

colorPanel.setBackground(Color.RED);

} else if (button == "White") {

colorPanel.setBackground(Color.WHITE);

} else if (button == "Blue") {

colorPanel.setBackground(Color.BLUE);

}

}

public static void main(String[] args) {

ColorBox cb = new ColorBox();

cb.pack();

cb.setVisible(true);

}

}