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; /* * This is a 1.3 version (thanks to JFrame.EXIT_ON_CLOSE) * but could easily be converted to work in earlier releases. * There are many valid ways to implement the exercise. */ import javax.swing.*; import java.awt.*; import java.awt.event.*; public class SwingApp2 { JButton startButton, stopButton; JLabel label; public SwingApp2() { JFrame f = new JFrame("SwingApp2"); f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //1.3+ createGUI(f); initListeners(); f.pack(); f.setVisible(true); } void initListeners() { ActionListener al = new MyActionListener(); startButton.addActionListener(al); stopButton.addActionListener(al); } class MyActionListener implements ActionListener { public void actionPerformed(ActionEvent e) { if (e.getSource() == startButton) { startButton.setEnabled(false); stopButton.setEnabled(true); label.setText("Press Stop."); } else { // e.getSource() == stopButton stopButton.setEnabled(false); startButton.setEnabled(true); label.setText("Press Start."); } } } void createGUI(JFrame f) { startButton = new JButton("Start"); stopButton = new JButton("Stop"); stopButton.setEnabled(false); label = new JLabel("Press Start.", JLabel.CENTER); Container c = f.getContentPane(); //Use the content pane's default BorderLayout layout manager. c.add(startButton, BorderLayout.WEST); c.add(stopButton, BorderLayout.EAST); c.add(label, BorderLayout.SOUTH); } public static void main(String[] args) { new SwingApp2(); } }