/*
  <applet code=MoscowTime.class width=400 height=60>
  </applet>

  The applet "Moscow Time" illustrates, how to use the classes Date,
  GregorianCalendar, TimeZone, and DateFormat.
*/

import java.applet.Applet;
import java.awt.*;
import java.util.Date;
import java.util.Calendar;
import java.util.GregorianCalendar;
import java.util.TimeZone;
import java.text.DateFormat;

public class MoscowTime extends Applet implements Runnable {
    Font f = new Font("Helvetica", Font.PLAIN, 14);
    Thread t;
    TimeZone tz;
    DateFormat df;

    // Clock geometry
    final int clock_w  = 50;
    final int clock_h  = 50;
    final int clock_dx = 5;
    final int clock_dy = 5;

    public void init() {
        // Unfortunately, there is no time zone for Moscow supported
        // in JDK. So we have to construct the Moscow time zone ("MSD")
        // from Central Europian Time zone ("ECT"). The Moscow time zone
        // has the offset +2 hours relatively to CET and the same daylight
        // savings time, at least for the current and, I hope, future dates.

        tz = TimeZone.getTimeZone("ECT");
        tz.setID("MSD");
        tz.setRawOffset(3*60*60*1000);  // Offset +3 hours

        df = DateFormat.getDateTimeInstance(
            DateFormat.FULL, DateFormat.MEDIUM
        );
        df.setTimeZone(tz);
    }

    public void start() {
        t = new Thread(this, "Date");
        t.start();
    }

    public void stop() {
        t = null;
    }

    public void paint(Graphics g) {
        g.setFont(f);
        Date d = new Date();
        g.setColor(Color.black);
        g.drawString(
            df.format(d), 
            clock_dx*3 + clock_w , clock_dy*2 + clock_h / 2
        );
        drawClock(g);
    }

    public void run() {
        while (t != null) {
            repaint();
            try {
                Thread.sleep(1000);
            } catch (Exception e) {
                System.out.println(e);
            }
        }
    }

    void drawClock(Graphics g) {
        g.setColor(Color.blue);
        g.drawOval(clock_dx, clock_dy, clock_w, clock_h);

        int cx = clock_dx + clock_w / 2;
        int cy = clock_dy + clock_h / 2;
        int dx = (clock_dx * 3) / 4;
        int dy = (clock_dy * 3) / 4;

        g.drawLine(cx, clock_dy, cx, clock_dy + dy);
        g.drawLine(cx, clock_dy + clock_h, cx, clock_dy + clock_h - dy);
        g.drawLine(clock_dx, cy, clock_dx + dx, cy);
        g.drawLine(clock_dx + clock_w, cy, clock_dx + clock_w - dx, cy);

        GregorianCalendar c = new GregorianCalendar(tz);
        double h = (double) c.get(Calendar.HOUR);    // 0..12
        double m = (double) c.get(Calendar.MINUTE);  // 0..59
        double s = (double) c.get(Calendar.SECOND);  // 0..59

        // Hours
        double len = 0.5 / 2.;
        g.setColor(Color.black);
        double angle = Math.PI / 2. - 
            ((h + m / 60.) * Math.PI / 6);
        int x = (int)(cx + len * clock_w * Math.cos(angle));
        int y = (int)(cy - len * clock_h * Math.sin(angle));
        g.drawLine(cx, cy, x, y);

        // Minutes
        len = 0.75 / 2.;
        g.setColor(Color.black);
        angle = Math.PI / 2. - 
            ((m + s / 60.) * Math.PI / 30);
        x = (int)(cx + len * clock_w * Math.cos(angle));
        y = (int)(cy - len * clock_h * Math.sin(angle));
        g.drawLine(cx, cy, x, y);

        // Seconds
        len = 0.85 / 2.;
        g.setColor(Color.red);
        angle = Math.PI / 2. - (s * Math.PI / 30);
        x = (int)(cx + len * clock_w * Math.cos(angle));
        y = (int)(cy - len * clock_h * Math.sin(angle));
        g.drawLine(cx, cy, x, y);
    }
}