/* * CardLayoutDemo.java is a 1.4 application that requires no other files. */import java.awt.*;import java.awt.event.*;import javax.swing.*;public class CardLayoutDemo implements ItemListener {    JPanel cards; //a panel that uses CardLayout    final static String BUTTONPANEL = "JPanel with JButtons";    final static String TEXTPANEL = "JPanel with JTextField";    public void addComponentToPane(Container pane) {        //Put the JComboBox in a JPanel to get a nicer look.        JPanel comboBoxPane = new JPanel(); //use FlowLayout        String comboBoxItems[] = { BUTTONPANEL, TEXTPANEL };        JComboBox cb = new JComboBox(comboBoxItems);        cb.setEditable(false);        cb.addItemListener(this);        comboBoxPane.add(cb);        //Create the "cards".        JPanel card1 = new JPanel();        card1.add(new JButton("Button 1"));        card1.add(new JButton("Button 2"));        card1.add(new JButton("Button 3"));        JPanel card2 = new JPanel();        card2.add(new JTextField("TextField", 20));        //Create the panel that contains the "cards".        cards = new JPanel(new CardLayout());        cards.add(card1, BUTTONPANEL);        cards.add(card2, TEXTPANEL);        pane.add(comboBoxPane, BorderLayout.PAGE_START);        pane.add(cards, BorderLayout.CENTER);    }    public void itemStateChanged(ItemEvent evt) {        CardLayout cl = (CardLayout)(cards.getLayout());        cl.show(cards, (String)evt.getItem());    }    /**     * Create the GUI and show it.  For thread safety,     * this method should be invoked from the     * event-dispatching thread.     */    private static void createAndShowGUI() {        //Make sure we have nice window decorations.        JFrame.setDefaultLookAndFeelDecorated(true);        //Create and set up the window.        JFrame frame = new JFrame("CardLayoutDemo");        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);        //Create and set up the content pane.        CardLayoutDemo demo = new CardLayoutDemo();        demo.addComponentToPane(frame.getContentPane());        //Display the window.        frame.pack();        frame.setVisible(true);    }    public static void main(String[] args) {        //Schedule a job for the event-dispatching thread:        //creating and showing this application's GUI.        javax.swing.SwingUtilities.invokeLater(new Runnable() {            public void run() {                createAndShowGUI();            }        });    }}