Java tutorial
/* * Copyright (c) 1995 - 2008 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: * * - Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * - Redistributions 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 nor the names of its * contributors may be used to endorse or promote products derived * from this software without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS * IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. */ /* * WindowEventDemo */ 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.JFrame; import javax.swing.JScrollPane; import javax.swing.JTextArea; import javax.swing.Timer; import javax.swing.UIManager; import javax.swing.UnsupportedLookAndFeelException; public class WindowEventDemo extends JFrame implements WindowListener, WindowFocusListener, WindowStateListener { static final String newline = System.getProperty("line.separator"); static final String space = " "; static WindowEventDemo frame = new WindowEventDemo("WindowEventDemo"); JTextArea display; public static void main(String[] args) { /* Use an appropriate Look and Feel */ try { // UIManager.setLookAndFeel("com.sun.java.swing.plaf.windows.WindowsLookAndFeel"); // UIManager.setLookAndFeel("com.sun.java.swing.plaf.gtk.GTKLookAndFeel"); UIManager.setLookAndFeel("javax.swing.plaf.metal.MetalLookAndFeel"); } catch (UnsupportedLookAndFeelException ex) { ex.printStackTrace(); } catch (IllegalAccessException ex) { ex.printStackTrace(); } catch (InstantiationException ex) { ex.printStackTrace(); } catch (ClassNotFoundException ex) { ex.printStackTrace(); } /* Turn off metal's use of bold fonts */ UIManager.put("swing.boldMetal", Boolean.FALSE); // Schedule a job for the event dispatch thread: // creating and showing this application's GUI. javax.swing.SwingUtilities.invokeLater(new Runnable() { public void run() { createAndShowGUI(); } }); } /** * Create the GUI and show it. For thread safety, this method should be * invoked from the event-dispatching thread. */ private static void createAndShowGUI() { // Create and set up the window. frame.setDefaultCloseOperation(JFrame.DO_NOTHING_ON_CLOSE); // Set up the content pane. frame.addComponentsToPane(); // Display the window. frame.pack(); frame.setVisible(true); } private void addComponentsToPane() { display = new JTextArea(); display.setEditable(false); JScrollPane scrollPane = new JScrollPane(display); scrollPane.setPreferredSize(new Dimension(500, 450)); getContentPane().add(scrollPane, BorderLayout.CENTER); addWindowListener(this); addWindowFocusListener(this); addWindowStateListener(this); checkWM(); } public WindowEventDemo(String name) { super(name); } // Some window managers don't support all window states. public void checkWM() { Toolkit tk = frame.getToolkit(); if (!(tk.isFrameStateSupported(Frame.ICONIFIED))) { displayMessage("Your window manager doesn't support ICONIFIED."); } else displayMessage("Your window manager supports ICONIFIED."); if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_VERT))) { displayMessage("Your window manager doesn't support MAXIMIZED_VERT."); } else displayMessage("Your window manager supports MAXIMIZED_VERT."); if (!(tk.isFrameStateSupported(Frame.MAXIMIZED_HORIZ))) { displayMessage("Your window manager doesn't support MAXIMIZED_HORIZ."); } else displayMessage("Your window manager supports 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 (frame.isDisplayable()) { alreadyDisposed = true; frame.dispose(); } } }; Timer timer = new Timer(500, task); // fire every half second timer.setInitialDelay(2000); // first delay 2 seconds timer.setRepeats(false); 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); } private void displayMessage(String msg) { display.append(msg + newline); System.out.println(msg); } private 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); displayMessage(msg); } private String convertStateToString(int state) { if (state == Frame.NORMAL) { return "NORMAL"; } String strState = " "; if ((state & Frame.ICONIFIED) != 0) { strState += "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) { strState += "MAXIMIZED_BOTH"; } else { if ((state & Frame.MAXIMIZED_VERT) != 0) { strState += "MAXIMIZED_VERT"; } if ((state & Frame.MAXIMIZED_HORIZ) != 0) { strState += "MAXIMIZED_HORIZ"; } } if (" ".equals(strState)) { strState = "UNKNOWN"; } return strState.trim(); } }