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. */ import java.awt.Dimension; import java.awt.Point; import java.awt.Toolkit; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import java.awt.event.KeyEvent; import java.awt.event.WindowAdapter; import java.awt.event.WindowEvent; import javax.swing.JFrame; import javax.swing.JMenu; import javax.swing.JMenuBar; import javax.swing.JMenuItem; import javax.swing.JOptionPane; /* Framework.java requires no other files. */ public class Framework extends WindowAdapter { public int numWindows = 0; private Point lastLocation = null; private int maxX = 500; private int maxY = 500; public Framework() { Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize(); maxX = screenSize.width - 50; maxY = screenSize.height - 50; makeNewWindow(); } public void makeNewWindow() { JFrame frame = new MyFrame(this); numWindows++; System.out.println("Number of windows: " + numWindows); if (lastLocation != null) { // Move the window over and down 40 pixels. lastLocation.translate(40, 40); if ((lastLocation.x > maxX) || (lastLocation.y > maxY)) { lastLocation.setLocation(0, 0); } frame.setLocation(lastLocation); } else { lastLocation = frame.getLocation(); } System.out.println("Frame location: " + lastLocation); frame.setVisible(true); } // This method must be evoked from the event-dispatching thread. public void quit(JFrame frame) { if (quitConfirmed(frame)) { System.out.println("Quitting."); System.exit(0); } System.out.println("Quit operation not confirmed; staying alive."); } private boolean quitConfirmed(JFrame frame) { String s1 = "Quit"; String s2 = "Cancel"; Object[] options = { s1, s2 }; int n = JOptionPane.showOptionDialog(frame, "Windows are still open.\nDo you really want to quit?", "Quit Confirmation", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE, null, options, s1); if (n == JOptionPane.YES_OPTION) { return true; } else { return false; } } public void windowClosed(WindowEvent e) { numWindows--; System.out.println("Number of windows = " + numWindows); if (numWindows <= 0) { System.out.println("All windows gone. Bye bye!"); System.exit(0); } } /** * Create the GUI and show it. For thread safety, this method should be * invoked from the event-dispatching thread. */ private static void createAndShowGUI() { Framework framework = new Framework(); } 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(); } }); } class MyFrame extends JFrame { protected Dimension defaultSize = new Dimension(200, 200); protected Framework framework = null; public MyFrame(Framework controller) { super("New Frame"); framework = controller; setDefaultCloseOperation(DISPOSE_ON_CLOSE); addWindowListener(framework); JMenu menu = new JMenu("Window"); menu.setMnemonic(KeyEvent.VK_W); JMenuItem item = null; // close item = new JMenuItem("Close"); item.setMnemonic(KeyEvent.VK_C); item.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.out.println("Close window"); MyFrame.this.setVisible(false); MyFrame.this.dispose(); } }); menu.add(item); // new item = new JMenuItem("New"); item.setMnemonic(KeyEvent.VK_N); item.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.out.println("New window"); framework.makeNewWindow(); } }); menu.add(item); // quit item = new JMenuItem("Quit"); item.setMnemonic(KeyEvent.VK_Q); item.addActionListener(new ActionListener() { public void actionPerformed(ActionEvent e) { System.out.println("Quit request"); framework.quit(MyFrame.this); } }); menu.add(item); JMenuBar menuBar = new JMenuBar(); menuBar.add(menu); setJMenuBar(menuBar); setSize(defaultSize); } } }