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.Container; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.ItemEvent; import java.awt.event.ItemListener; import java.awt.event.KeyEvent; import javax.swing.ButtonGroup; import javax.swing.ImageIcon; import javax.swing.JCheckBoxMenuItem; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JPanel; import javax.swing.JRadioButtonMenuItem; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.KeyStroke; import javax.swing.MenuElement; import javax.swing.MenuSelectionManager; import javax.swing.Timer; /* * MenuSelectionManagerDemo.java is a 1.4 application that requires * images/middle.gif. */ /* * This class is just like MenuDemo, except every second (thanks to a Timer) the * selected path of the menu is printed in the text area. */ public class MenuSelectionManagerDemo implements ActionListener, ItemListener { JTextArea output; JScrollPane scrollPane; String newline = "\n"; public final static int ONE_SECOND = 1000; public JMenuBar createMenuBar() { JMenuBar menuBar; JMenu menu, submenu; JMenuItem menuItem; JRadioButtonMenuItem rbMenuItem; JCheckBoxMenuItem cbMenuItem; //Create the menu bar. menuBar = new JMenuBar(); //Build the first menu. menu = new JMenu("A Menu"); menu.setMnemonic(KeyEvent.VK_A); menu.getAccessibleContext().setAccessibleDescription("The only menu in this program that has menu items"); menuBar.add(menu); //a group of JMenuItems menuItem = new JMenuItem("A text-only menu item", KeyEvent.VK_T); //menuItem.setMnemonic(KeyEvent.VK_T); //used constructor instead menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_1, ActionEvent.ALT_MASK)); menuItem.getAccessibleContext().setAccessibleDescription("This doesn't really do anything"); menuItem.addActionListener(this); menu.add(menuItem); ImageIcon icon = createImageIcon("1.gif"); menuItem = new JMenuItem("Both text and icon", icon); menuItem.setMnemonic(KeyEvent.VK_B); menuItem.addActionListener(this); menu.add(menuItem); menuItem = new JMenuItem(icon); menuItem.setMnemonic(KeyEvent.VK_D); menuItem.addActionListener(this); menu.add(menuItem); //a group of radio button menu items menu.addSeparator(); ButtonGroup group = new ButtonGroup(); rbMenuItem = new JRadioButtonMenuItem("A radio button menu item"); rbMenuItem.setSelected(true); rbMenuItem.setMnemonic(KeyEvent.VK_R); group.add(rbMenuItem); rbMenuItem.addActionListener(this); menu.add(rbMenuItem); rbMenuItem = new JRadioButtonMenuItem("Another one"); rbMenuItem.setMnemonic(KeyEvent.VK_O); group.add(rbMenuItem); rbMenuItem.addActionListener(this); menu.add(rbMenuItem); //a group of check box menu items menu.addSeparator(); cbMenuItem = new JCheckBoxMenuItem("A check box menu item"); cbMenuItem.setMnemonic(KeyEvent.VK_C); cbMenuItem.addItemListener(this); menu.add(cbMenuItem); cbMenuItem = new JCheckBoxMenuItem("Another one"); cbMenuItem.setMnemonic(KeyEvent.VK_H); cbMenuItem.addItemListener(this); menu.add(cbMenuItem); //a submenu menu.addSeparator(); submenu = new JMenu("A submenu"); submenu.setMnemonic(KeyEvent.VK_S); menuItem = new JMenuItem("An item in the submenu"); menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_2, ActionEvent.ALT_MASK)); menuItem.addActionListener(this); submenu.add(menuItem); menuItem = new JMenuItem("Another item"); menuItem.addActionListener(this); submenu.add(menuItem); menu.add(submenu); //Build second menu in the menu bar. menu = new JMenu("Another Menu"); menu.setMnemonic(KeyEvent.VK_N); menu.getAccessibleContext().setAccessibleDescription("This menu does nothing"); menuBar.add(menu); Timer timer = new Timer(ONE_SECOND, new ActionListener() { public void actionPerformed(ActionEvent evt) { MenuElement[] path = MenuSelectionManager.defaultManager().getSelectedPath(); for (int i = 0; i < path.length; i++) { if (path[i].getComponent() instanceof javax.swing.JMenuItem) { JMenuItem mi = (JMenuItem) path[i].getComponent(); if ("".equals(mi.getText())) { output.append("ICON-ONLY MENU ITEM > "); } else { output.append(mi.getText() + " > "); } } } if (path.length > 0) output.append(newline); } }); timer.start(); return menuBar; } public Container createContentPane() { //Create the content-pane-to-be. JPanel contentPane = new JPanel(new BorderLayout()); contentPane.setOpaque(true); //Create a scrolled text area. output = new JTextArea(5, 30); output.setEditable(false); scrollPane = new JScrollPane(output); //Add the text area to the content pane. contentPane.add(scrollPane, BorderLayout.CENTER); return contentPane; } public void actionPerformed(ActionEvent e) { JMenuItem source = (JMenuItem) (e.getSource()); String s = "Action event detected." + newline + " Event source: " + source.getText() + " (an instance of " + getClassName(source) + ")"; output.append(s + newline); output.setCaretPosition(output.getDocument().getLength()); } public void itemStateChanged(ItemEvent e) { JMenuItem source = (JMenuItem) (e.getSource()); String s = "Item event detected." + newline + " Event source: " + source.getText() + " (an instance of " + getClassName(source) + ")" + newline + " New state: " + ((e.getStateChange() == ItemEvent.SELECTED) ? "selected" : "unselected"); output.append(s + newline); output.setCaretPosition(output.getDocument().getLength()); } // Returns just the class name -- no package info. protected String getClassName(Object o) { String classString = o.getClass().getName(); int dotIndex = classString.lastIndexOf("."); return classString.substring(dotIndex + 1); } /** Returns an ImageIcon, or null if the path was invalid. */ protected static ImageIcon createImageIcon(String path) { java.net.URL imgURL = MenuSelectionManagerDemo.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("MenuSelectionManagerDemo"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. MenuSelectionManagerDemo demo = new MenuSelectionManagerDemo(); frame.setJMenuBar(demo.createMenuBar()); frame.setContentPane(demo.createContentPane()); //Display the window. frame.setSize(450, 260); 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(); } }); } }