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. */ /* * WindowEventDemo.java is a 1.4 example that requires no other files. */ import java.awt.BorderLayout; import java.awt.Dimension; import java.awt.Frame; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.WindowEvent; import java.awt.event.WindowFocusListener; import java.awt.event.WindowListener; import java.awt.event.WindowStateListener; import javax.swing.JComponent; import javax.swing.JFrame; import javax.swing.JPanel; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.Timer; public class WindowEventDemo extends JPanel implements WindowListener, WindowFocusListener, WindowStateListener { final static String newline = "\n"; final static String space = " "; static JFrame frame; JTextArea display; public WindowEventDemo() { super(new BorderLayout()); display = new JTextArea(); display.setEditable(false); JScrollPane scrollPane = new JScrollPane(display); scrollPane.setPreferredSize(new Dimension(500, 450)); add(scrollPane, BorderLayout.CENTER); frame.addWindowListener(this); frame.addWindowFocusListener(this); frame.addWindowStateListener(this); checkWM(); } //Some window managers don't support all window states. //For example, dtwm doesn't support true maximization, //but mimics it by resizing the window to be the size //of the screen. In this case the window does not fire //the MAXIMIZED_ constants on the window's state listener. //Microsoft Windows supports MAXIMIZED_BOTH, but not //MAXIMIZED_VERT or MAXIMIZED_HORIZ. public void checkWM() { Toolkit tk = frame.getToolkit(); if (!(tk.isFrameStateSupported(Frame.ICONIFIED))) { displayMessage("Your window manager doesn't support ICONIFIED."); } if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_VERT))) { displayMessage("Your window manager doesn't support MAXIMIZED_VERT."); } if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_HORIZ))) { displayMessage("Your window manager doesn't support MAXIMIZED_HORIZ."); } if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_BOTH))) { displayMessage("Your window manager doesn't support MAXIMIZED_BOTH."); } else { displayMessage("Your window manager supports MAXIMIZED_BOTH."); } } public void windowClosing(WindowEvent e) { displayMessage("WindowListener method called: windowClosing."); //A pause so user can see the message before //the window actually closes. ActionListener task = new ActionListener() { boolean alreadyDisposed = false; public void actionPerformed(ActionEvent e) { if (!alreadyDisposed) { alreadyDisposed = true; frame.dispose(); } else { //make sure the program exits System.exit(0); } } }; Timer timer = new Timer(500, task); //fire every half second timer.setInitialDelay(2000); //first delay 2 seconds timer.start(); } public void windowClosed(WindowEvent e) { //This will only be seen on standard output. displayMessage("WindowListener method called: windowClosed."); } public void windowOpened(WindowEvent e) { displayMessage("WindowListener method called: windowOpened."); } public void windowIconified(WindowEvent e) { displayMessage("WindowListener method called: windowIconified."); } public void windowDeiconified(WindowEvent e) { displayMessage("WindowListener method called: windowDeiconified."); } public void windowActivated(WindowEvent e) { displayMessage("WindowListener method called: windowActivated."); } public void windowDeactivated(WindowEvent e) { displayMessage("WindowListener method called: windowDeactivated."); } public void windowGainedFocus(WindowEvent e) { displayMessage("WindowFocusListener method called: windowGainedFocus."); } public void windowLostFocus(WindowEvent e) { displayMessage("WindowFocusListener method called: windowLostFocus."); } public void windowStateChanged(WindowEvent e) { displayStateMessage("WindowStateListener method called: windowStateChanged.", e); } void displayMessage(String msg) { display.append(msg + newline); System.out.println(msg); } void displayStateMessage(String prefix, WindowEvent e) { int state = e.getNewState(); int oldState = e.getOldState(); String msg = prefix + newline + space + "New state: " + convertStateToString(state) + newline + space + "Old state: " + convertStateToString(oldState); display.append(msg + newline); System.out.println(msg); } String convertStateToString(int state) { if (state == Frame.NORMAL) { return "NORMAL"; } if ((state & Frame.ICONIFIED) != 0) { return "ICONIFIED"; } //MAXIMIZED_BOTH is a concatenation of two bits, so //we need to test for an exact match. if ((state & Frame.MAXIMIZED_BOTH) == Frame.MAXIMIZED_BOTH) { return "MAXIMIZED_BOTH"; } if ((state & Frame.MAXIMIZED_VERT) != 0) { return "MAXIMIZED_VERT"; } if ((state & Frame.MAXIMIZED_HORIZ) != 0) { return "MAXIMIZED_HORIZ"; } return "UNKNOWN"; } /** * 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. frame = new JFrame("WindowEventDemo"); frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); //Create and set up the content pane. JComponent newContentPane = new WindowEventDemo(); 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(); } }); } }