Java tutorial
/* * Copyright (c) 1995, 2008, Oracle and/or its affiliates. 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 Oracle or 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. */ package QandE; /* * Beeper2.java is a version of the 1.4 Beeper.java example * that allows the user to select from 1 to 10 beeps and then * beeps that many times when the ClickMe button is pressed. * This solution uses a JSpinner to select the number of beeps. * Your solution could use a different widget, such as a combo * box or a group of radio buttons. */ import java.awt.*; import javax.swing.*; import java.awt.event.*; public class Beeper2 extends JPanel implements ActionListener { JButton button; SpinnerNumberModel beepsModel; javax.swing.Timer timer; final static String BUTTON_CMD = "Button"; int beepsRemaining; public Beeper2() { super(new BorderLayout()); //Create and set up the spinner. String numBeepsString = "Number of Beeps: "; beepsModel = new SpinnerNumberModel(1, 1, 10, 1); JLabel numBeepsLabel = new JLabel(numBeepsString); add(numBeepsLabel, BorderLayout.PAGE_START); JSpinner spinner = new JSpinner(beepsModel); numBeepsLabel.setLabelFor(spinner); add(spinner, BorderLayout.CENTER); button = new JButton("Click Me"); button.setPreferredSize(new Dimension(200, 80)); add(button, BorderLayout.PAGE_END); button.setActionCommand(BUTTON_CMD); button.addActionListener(this); } public void actionPerformed(ActionEvent e) { if (BUTTON_CMD.equals(e.getActionCommand())) { startBeeping(beepsModel.getNumber().intValue()); } else { //called by the Timer Toolkit.getDefaultToolkit().beep(); if (--beepsRemaining < 1) { timer.stop(); } } } private void startBeeping(int numBeeps) { Toolkit.getDefaultToolkit().beep(); if (numBeeps > 1) { if (timer == null) { timer = new Timer(500, this); } beepsRemaining = numBeeps - 1; timer.start(); } } /** * 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. JFrame frame = new JFrame("Beeper2"); frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //Create and set up the content pane. JComponent newContentPane = new Beeper2(); 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(); } }); } }