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. */ // v 1.3 import java.awt.BorderLayout; import java.awt.GridLayout; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.BorderFactory; import javax.swing.ImageIcon; import javax.swing.JButton; import javax.swing.JFrame; import javax.swing.JLabel; import javax.swing.JPanel; import javax.swing.JTextField; import javax.swing.SwingConstants; import javax.swing.UIManager; // This example demonstrates the use of JButton, JTextField and JLabel. public class CelsiusConverter2 implements ActionListener { JFrame converterFrame; JPanel converterPanel; JTextField tempCelsius; JLabel celsiusLabel, fahrenheitLabel; JButton convertTemp; // Constructor public CelsiusConverter2() { // Create the frame and container. converterFrame = new JFrame("Convert Celsius to Fahrenheit"); converterPanel = new JPanel(); converterPanel.setLayout(new GridLayout(2, 2)); // Add the widgets. addWidgets(); // Add the panel to the frame. converterFrame.getContentPane().add(converterPanel, BorderLayout.CENTER); // Exit when the window is closed. converterFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // Show the converter. converterFrame.pack(); converterFrame.setVisible(true); } // Create and add the widgets for converter. private void addWidgets() { // Create widgets. ImageIcon icon = new ImageIcon("images/convert.gif", "Convert temperature"); tempCelsius = new JTextField(2); celsiusLabel = new JLabel("Celsius", SwingConstants.LEFT); convertTemp = new JButton(icon); fahrenheitLabel = new JLabel("Fahrenheit", SwingConstants.LEFT); celsiusLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5)); fahrenheitLabel.setBorder(BorderFactory.createEmptyBorder(5, 5, 5, 5)); // Listen to events from Convert button. convertTemp.addActionListener(this); // Add widgets to container. converterPanel.add(tempCelsius); converterPanel.add(celsiusLabel); converterPanel.add(convertTemp); converterPanel.add(fahrenheitLabel); } // Implementation of ActionListener interface. public void actionPerformed(ActionEvent event) { // Parse degrees Celsius as a double and convert to Fahrenheit. int tempFahr = (int) ((Double.parseDouble(tempCelsius.getText())) * 1.8 + 32); // Set fahrenheitLabel to new value and set font color based on the // temperature. if (tempFahr <= 32) { fahrenheitLabel.setText("<html><Font Color=blue>" + tempFahr + "° </Font><Font Color=black> Fahrenheit</font></html>"); } else if (tempFahr <= 80) { fahrenheitLabel.setText("<html><Font Color=green>" + tempFahr + "° </Font><Font Color=black> Fahrenheit </Font></html>"); } else { fahrenheitLabel.setText("<html><Font Color=red>" + tempFahr + "° </Font><Font Color=black> Fahrenheit</Font></html>"); } } // main method public static void main(String[] args) { // set the look and feel try { UIManager.setLookAndFeel(UIManager.getCrossPlatformLookAndFeelClassName()); } catch (Exception e) { } CelsiusConverter2 converter = new CelsiusConverter2(); } }