TempConverterGUI

package view;

import java.awt.BorderLayout;
import java.awt.Container;
import java.awt.FlowLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

import model.TempConverter;

/**
 * A event driven program with a graphical user interface that uses class
 * TempConverter to convert F to C and C to F.
 */

public class TempConverterGUI extends JFrame {

	public static void main(String[] args) {
		new TempConverterGUI().setVisible(true);
	}

	public TempConverterGUI() {
		// This is a composed method
		layoutTheGUI();
		registerListeners();
	}

	private JTextField degreesCField;
	private JTextField degreesFField;
	private JButton convertC2F;
	private JButton convertF2C;
	private JPanel topPanel;

	private void layoutTheGUI() {
		setTitle("Temperature Converter");
		setSize(300, 110);
		setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); // shuts off the thread
								// when the frame closes
		topPanel = new JPanel();
		topPanel.setLayout(new FlowLayout());

		// Celsius
		topPanel.add(new JLabel("Celsius:"));
		degreesCField = new JTextField(10);
		topPanel.add(degreesCField);
		convertC2F = new JButton("Convert");
		topPanel.add(convertC2F);

		// Fahrenheit
		topPanel.add(new JLabel("Fahrenheit:"));
		degreesFField = new JTextField(10);
		topPanel.add(degreesFField);
		convertF2C = new JButton("Convert");
		topPanel.add(convertF2C);

		Container contentPane = this.getContentPane();
		contentPane.add(topPanel, BorderLayout.CENTER);
	}

	private void registerListeners() {
		convertC2F.addActionListener(new makeFahrenheit());
		convertF2C.addActionListener(new makeCelsius());
	}

	private class makeFahrenheit implements ActionListener {
		public void actionPerformed(ActionEvent evt) {
			try {
				String input = degreesCField.getText();
				double celsius = Double.parseDouble(input);
				double fahr = TempConverter.C2F(celsius);
				degreesFField.setText(String.format("%.2f", fahr));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	} // end class makeCelsius

	private class makeCelsius implements ActionListener {
		public void actionPerformed(ActionEvent evt) {
			try {
				String input = degreesFField.getText();
				double fahr = Double.parseDouble(input);
				double celsius = TempConverter.F2C(fahr);
				degreesCField.setText(String.format("%.2c", celsius));
			} catch (Exception e) {
				e.printStackTrace();
			}
		}
	} // end class makeFahrenheit
}