// Windchill GUI 	
	
import javax.swing.*;	
import java.awt.*;	
import java.awt.event.*;	
	
public class Windchill implements ActionListener {	
	// class constants 	
	private static final int WINDOW_WIDTH = 275;   // pixels	
	private static final int WINDOW_HEIGHT = 250;  // pixels	
	private static final int TEXT_WIDTH = 20;      // characters	
	
	private static final FlowLayout LAYOUT_STYLE =	
		new FlowLayout();	
	
	private static final String LEGEND = "This windchill "	
		+ "calculator is intended for velocities greater than 4 mph.";	
	
	// instance variables 	
	
	// window for GUI 	
	private JFrame window = new JFrame("Windchill Calculator");	
	
	// legend 	
	private JTextArea legendArea = new JTextArea(LEGEND, 2, 	
		TEXT_WIDTH);	
	
	// user entry area for temperature 	
	private JLabel fahrTag = new JLabel("Fahrenheit temperature");	
	private JTextField fahrText = new JTextField(TEXT_WIDTH);	
		 	
	// user entry area for windspeed 	
	private JLabel windTag = new JLabel("Windspeed (mph)");	
	private JTextField windText = new JTextField(TEXT_WIDTH);	
	
	// entry area for windchill result 	
	private JLabel chillTag = new JLabel("Windchill temperature");	
	private JTextField chillText = new JTextField(TEXT_WIDTH);	
	
	// run button 	
	private JButton runButton = new JButton("Run");	
	
	// Windchill(): constructor 	
	public Windchill() {	
		// configure GUI 	
		window.setSize(WINDOW_WIDTH, WINDOW_HEIGHT);	
		window.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);	
			
		legendArea.setEditable(false);	
		legendArea.setLineWrap(true);	
		legendArea.setWrapStyleWord(true);	
		legendArea.setBackground(window.getBackground());	
	
		chillText.setEditable(false);	
		chillText.setBackground(Color.WHITE);	
	
		// register event listener 	
		runButton.addActionListener(this);	
	
		// arrange components in GUI 	
		window.setLayout(LAYOUT_STYLE);	
		window.add(legendArea);	
		window.add(fahrTag);	
		window.add(fahrText);	
		window.add(windTag);	
		window.add(windText);	
		window.add(chillTag);	
		window.add(chillText);	
		window.add(runButton);	
	
		// display GUI 	
		window.setVisible(true);	
	}	
	
	// actionPerformed(): run button action event handler	
	public void actionPerformed(ActionEvent e) {	
		// get user's responses 	
		String response1 = fahrText.getText();	
		double t = Double.parseDouble(response1);	
		String response2 = windText.getText();	
		double v = Double.parseDouble(response2);	
	
		// compute windchill 	
		double windchillTemperature = 0.081 * (t - 91.4)	
					 * (3.71*Math.sqrt(v) + 5.81 - 0.25*v) + 91.4;	
	
		int perceivedTemperature = 	
				(int) Math.round(windchillTemperature);	
			
		// display windchill 	
		String output = String.valueOf(perceivedTemperature);	
		chillText.setText(output);	
	}	
	
	// main(): application entry point	
	public static void main(String[] args) {	
		Windchill gui = new Windchill();	
	}	
}