//------------
// Introduction to Programming Using Java: An Object-Oriented Approach
//	Arnow/Weiss
//------------
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class ClockApplet extends Applet implements ActionListener {
	public void init() {
		Color backgroundColor = new Color(200,255,255);
		this.setLayout(new FlowLayout(FlowLayout.CENTER,4,1));
		clock1 = new Label("EST: 00:00:00.00", Label.CENTER);
		clock2 = new Label("GMT: 00:00:00.00", Label.CENTER);
		clock1Button = new Button(start1ButtonCommand);
		clock1Button.addActionListener(this);
		clock2Button = new Button(start2ButtonCommand);
		clock2Button.addActionListener(this);
		clock1Panel = new Panel();
		clock1Panel.setLayout(new BorderLayout(2,2));
		clock2Panel = new Panel();
		clock2Panel.setLayout(new BorderLayout(2,2));
		clock1Panel.add("West",clock1Button);
		clock1Panel.add("East",clock1);
		clock2Panel.add("West",clock2Button);
		clock2Panel.add("East",clock2);
		mainPanel = new Panel();
		mainPanel.setLayout(new BorderLayout(2,2));
		mainPanel.add("North",clock1Panel);
		mainPanel.add("South",clock2Panel);
		add(mainPanel);
		setBackground(backgroundColor);
	}

	public void actionPerformed(ActionEvent ae) {
		String whichButton = ae.getActionCommand();
		if (whichButton.equals(start1ButtonCommand))
			handleStart(1);
		else if (whichButton.equals(resume1ButtonCommand))
			handleResume(1);
		else if (whichButton.equals(stop1ButtonCommand))
			handleStop(1);
		else if (whichButton.equals(start2ButtonCommand))
			handleStart(2);
		else if (whichButton.equals(resume2ButtonCommand))
			handleResume(2);
		else if (whichButton.equals(stop2ButtonCommand))
			handleStop(2);
	}

	private void handleStart(int n) {
		if (n==1) {
			clock1Button.setLabel(stop1ButtonCommand);
			clockTicker1 = new 
			ClockThread(clock1,"EST");
			clockTicker1.start();
		} else if (n==2) {
			clock2Button.setLabel(stop2ButtonCommand);
			clockTicker2 = new 
			ClockThread(clock2,"GMT");
			clockTicker2.start();
		}
	}

	private void handleResume(int n) {
		if (n==1) {
			clock1Button.setLabel(stop1ButtonCommand);
			clockTicker1.myResume();
		} else if (n==2) {
			clock2Button.setLabel(stop2ButtonCommand);
			clockTicker2.myResume();
		}
	}
	private void handleStop(int n) {
		if (n==1) {
			clock1Button.setLabel(resume1ButtonCommand);
			clockTicker1.mySuspend();
		} else if (n==2) {
			clock2Button.setLabel(resume2ButtonCommand);
			clockTicker2.mySuspend();
		}
	}
	private    Panel     clock1Panel, clock2Panel, mainPanel;
	private    Button    clock1Button, clock2Button;
	private    String    start1ButtonCommand= "Start EST",
		resume1ButtonCommand= "Resume EST",
		stop1ButtonCommand= "Stop EST",
		start2ButtonCommand= "Start GMT",
		resume2ButtonCommand= "Resume GMT",
		stop2ButtonCommand= "Stop GMT";
	private    Label     clock1, clock2;
	private    ClockThread   clockTicker1,clockTicker2;
}

class ClockThread extends Thread {
	ClockThread(Label theLabel, String timeZone) {
		this.clock = theLabel;
		this.timeZone = timeZone;
	}

	public void run() {
		amRunning = true;
		while (true)
			if (amRunning) {
				oneTick();
				try {
					this.sleep(20);
				} catch (Exception e) {;}
			}
	}

	public void mySuspend() {
		amRunning = false;
	}

	public void myResume() {
		amRunning = true;
	}

	private void oneTick() {
		GregorianCalendar gc = 
		new GregorianCalendar(TimeZone.
		getTimeZone(timeZone));
		int      h = gc.get(Calendar.HOUR);
		int      m = gc.get(Calendar.MINUTE);
		int      s = gc.get(Calendar.SECOND);
		int      ms= gc.get(Calendar.MILLISECOND);
		String  hms = leadingDigit(h," ")+":" +
		leadingDigit(m,"0")+":" +
		leadingDigit(s,"0")+"." +
		leadingDigit(ms/10,"0");
		clock.setText(hms);
	}

	private String leadingDigit(int n, String leader) {
		if (n<10)
			return leader+n;
		return ""+n;
	}

	private Label   clock;
	private boolean amRunning;
	private String timeZone;
}