This example demonstrates the use of JButton, JTextField and JLabel

/* 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
              + "&#176 </Font><Font Color=black> Fahrenheit</font></html>");
    } else if (tempFahr <= 80) {
      fahrenheitLabel
          .setText("<html><Font Color=green>"
              + tempFahr
              + "&#176 </Font><Font Color=black> Fahrenheit </Font></html>");
    } else {
      fahrenheitLabel
          .setText("<html><Font Color=red>"
              + tempFahr
              + "&#176 </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();

  }
}

Related examples in the same category

1.	Separating GUI logic and business objects
2.	Creates two JPanels (opaque), one containing another opaque JPanel, and the other containing a non-opaque JPanel
3.	The revalidate method to dynamically update the
4.	Swing Application
5.	CelsiusConverter: the use of JButton, JTextField and JLabel
6.	GUI invoked from the event-dispatching thread
7.	Standalone GUI program that shows paint, repaint, and update
8.	LunarPhases: the use of JButton, JTextField and JLabel
9.	Hello World Swing

This example demonstrates the use of JButton, JTextField and JLabel : Basics « Swing JFC « Java

Related examples in the same category