Writing Classes - Java Software Solutions: Foundations of Program Design - page 198

LISTING 4.13
//********************************************************************
// FahrenheitPanel.java Author: Lewis/Loftus
//
// Demonstrates the use of text fields.
//********************************************************************
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class FahrenheitPanel extends JPanel
{
private JLabel inputLabel, outputLabel, resultLabel;
private JTextField fahrenheit;
//-----------------------------------------------------------------
// Constructor: Sets up the main GUI components.
//-----------------------------------------------------------------
public FahrenheitPanel()
{
inputLabel = new JLabel ("Enter Fahrenheit temperature:");
outputLabel = new JLabel ("Temperature in Celsius: ");
resultLabel = new JLabel ("---");
fahrenheit = new JTextField (5);
fahrenheit.addActionListener ( new TempListener());
add (inputLabel);
add (fahrenheit);
add (outputLabel);
add (resultLabel);
setPreferredSize ( new Dimension(300, 75));
setBackground (Color.yellow);
}
//*****************************************************************
// Represents an action listener for the temperature input field.
//*****************************************************************
private class TempListener implements ActionListener