Java tutorial
/* From http://java.sun.com/docs/books/tutorial/index.html */ /* * Copyright (c) 2006 Sun Microsystems, Inc. All Rights Reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions are met: * * -Redistribution of source code must retain the above copyright notice, this * list of conditions and the following disclaimer. * * -Redistribution in binary form must reproduce the above copyright notice, * this list of conditions and the following disclaimer in the documentation * and/or other materials provided with the distribution. * * Neither the name of Sun Microsystems, Inc. or the names of contributors may * be used to endorse or promote products derived from this software without * specific prior written permission. * * This software is provided "AS IS," without a warranty of any kind. ALL * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES, INCLUDING * ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE * OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN MIDROSYSTEMS, INC. ("SUN") * AND ITS LICENSORS SHALL NOT BE LIABLE FOR ANY DAMAGES SUFFERED BY LICENSEE * AS A RESULT OF USING, MODIFYING OR DISTRIBUTING THIS SOFTWARE OR ITS * DERIVATIVES. IN NO EVENT WILL SUN OR ITS LICENSORS BE LIABLE FOR ANY LOST * REVENUE, PROFIT OR DATA, OR FOR DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, * INCIDENTAL OR PUNITIVE DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY * OF LIABILITY, ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, * EVEN IF SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES. * * You acknowledge that this software is not designed, licensed or intended * for use in the design, construction, operation or maintenance of any * nuclear facility. */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import javax.swing.BorderFactory; import javax.swing.ButtonGroup; import javax.swing.ImageIcon; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JRadioButton; /* * RadioButtonDemo.java is a 1.4 application that requires these files: * images/Bird.gif images/Cat.gif images/Dog.gif images/Rabbit.gif * images/Pig.gif */ public class RadioButtonDemo extends JPanel implements ActionListener { static String birdString = "Bird"; static String catString = "Cat"; static String dogString = "Dog"; static String rabbitString = "Rabbit"; static String pigString = "Pig"; JLabel picture; public RadioButtonDemo() { super(new BorderLayout()); //Create the radio buttons. JRadioButton birdButton = new JRadioButton(birdString); birdButton.setMnemonic(KeyEvent.VK_B); birdButton.setActionCommand(birdString); birdButton.setSelected(true); JRadioButton catButton = new JRadioButton(catString); catButton.setMnemonic(KeyEvent.VK_C); catButton.setActionCommand(catString); JRadioButton dogButton = new JRadioButton(dogString); dogButton.setMnemonic(KeyEvent.VK_D); dogButton.setActionCommand(dogString); JRadioButton rabbitButton = new JRadioButton(rabbitString); rabbitButton.setMnemonic(KeyEvent.VK_R); rabbitButton.setActionCommand(rabbitString); JRadioButton pigButton = new JRadioButton(pigString); pigButton.setMnemonic(KeyEvent.VK_P); pigButton.setActionCommand(pigString); //Group the radio buttons. ButtonGroup group = new ButtonGroup(); group.add(birdButton); group.add(catButton); group.add(dogButton); group.add(rabbitButton); group.add(pigButton); //Register a listener for the radio buttons. birdButton.addActionListener(this); catButton.addActionListener(this); dogButton.addActionListener(this); rabbitButton.addActionListener(this); pigButton.addActionListener(this); //Set up the picture label. picture = new JLabel(createImageIcon("images/" + birdString + ".gif")); //The preferred size is hard-coded to be the width of the //widest image and the height of the tallest image. //A real program would compute this. picture.setPreferredSize(new Dimension(177, 122)); //Put the radio buttons in a column in a panel. JPanel radioPanel = new JPanel(new GridLayout(0, 1)); radioPanel.add(birdButton); radioPanel.add(catButton); radioPanel.add(dogButton); radioPanel.add(rabbitButton); radioPanel.add(pigButton); add(radioPanel, BorderLayout.LINE_START); add(picture, BorderLayout.CENTER); setBorder(BorderFactory.createEmptyBorder(20, 20, 20, 20)); } /** Listens to the radio buttons. */ public void actionPerformed(ActionEvent e) { picture.setIcon(createImageIcon("images/" + e.getActionCommand() + ".gif")); } /** Returns an ImageIcon, or null if the path was invalid. */ protected static ImageIcon createImageIcon(String path) { java.net.URL imgURL = RadioButtonDemo.class.getResource(path); if (imgURL != null) { return new ImageIcon(imgURL); } else { System.err.println("Couldn't find file: " + path); return null; } } /** * 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("RadioButtonDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. JComponent newContentPane = new RadioButtonDemo(); newContentPane.setOpaque(true); //content panes must be opaque frame.setContentPane(newContentPane); //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(); } }); } }