import java.applet.Applet;
import java.awt.*;
import java.util.Calendar;

public class DigitalClock extends Applet implements Runnable{
    private Calendar currentTime;
    private Thread thread;
    private Image digits[] = new Image[13];
    private boolean isAMPM;
    private MediaTracker tracker;
    private Image offScreenImage;
    private Graphics offScreenGraphics;

    public void init() {
        currentTime = Calendar.getInstance();

        tracker = new MediaTracker(this);

        String imageDir = getParameter("imagedir");
        for (int i = 0; i < 10; i++) {
            digits[i] = getImage(getDocumentBase(), imageDir + i + ".gif");
            tracker.addImage(digits[i], 0);
        }
        digits[10] = getImage(getDocumentBase(), imageDir + "C.gif");
        tracker.addImage(digits[10], 0);

        try {
            setBackground(new Color(Integer.parseInt(getParameter("bgcolor"), 16)));
        } catch (NumberFormatException e) {
        }

        isAMPM = (getParameter("am_pm") != null) ? true : false;
        if (isAMPM) {
            digits[11] = getImage(getDocumentBase(), imageDir + "A.gif");
            digits[12] = getImage(getDocumentBase(), imageDir + "P.gif");
            tracker.addImage(digits[11], 1);
            tracker.addImage(digits[12], 1);
        }

        offScreenImage = createImage(getSize().width, getSize().height);
        offScreenGraphics = offScreenImage.getGraphics();
    }

    public void paint(Graphics g) {
        if (tracker.isErrorID(0)) {
            offScreenGraphics.setColor(Color.white);
            offScreenGraphics.fillRect(0, 0, getSize().width, getSize().height);

            String timeString = currentTime.get(Calendar.HOUR) + " : " +
                                currentTime.get(Calendar.MINUTE) + " : " +
                                currentTime.get(Calendar.SECOND);
            offScreenGraphics.setColor(Color.black);
            offScreenGraphics.drawString(timeString, 0, 15);

            g.drawImage(offScreenImage, 0, 0, this);

            showStatus("Applet DigitaClock can't find image files.");
            return;
        }

        if (tracker.checkAll()) {
            int imageWidth = 0;

            int hour24 = currentTime.get(Calendar.HOUR);
            if (!isAMPM && currentTime.get(Calendar.AM_PM) == 1) {
                hour24 += 12;
            }

            if (isAMPM && !tracker.isErrorID(1)) {
                offScreenGraphics.drawImage(digits[(currentTime.get(Calendar.AM_PM) == 0) ? 11 : 12], imageWidth, 0, this);
                imageWidth += digits[(currentTime.get(Calendar.AM_PM) == 0) ? 11 : 12].getWidth(this);
            }

            offScreenGraphics.drawImage(digits[hour24 / 10], imageWidth, 0, this);
            imageWidth += digits[hour24 / 10].getWidth(this);

            offScreenGraphics.drawImage(digits[hour24 % 10], imageWidth, 0, this);
            imageWidth += digits[hour24 % 10].getWidth(this);

            offScreenGraphics.drawImage(digits[10], imageWidth, 0, this);
            imageWidth += digits[10].getWidth(this);

            offScreenGraphics.drawImage(digits[currentTime.get(Calendar.MINUTE) / 10], imageWidth, 0, this);
            imageWidth += digits[currentTime.get(Calendar.MINUTE) / 10].getWidth(this);

            offScreenGraphics.drawImage(digits[currentTime.get(Calendar.MINUTE) % 10], imageWidth, 0, this);
            imageWidth += digits[currentTime.get(Calendar.MINUTE) % 10].getWidth(this);

            offScreenGraphics.drawImage(digits[10], imageWidth, 0, this);
            imageWidth += digits[10].getWidth(this);

            offScreenGraphics.drawImage(digits[currentTime.get(Calendar.SECOND) / 10], imageWidth, 0, this);
            imageWidth += digits[currentTime.get(Calendar.SECOND) / 10].getWidth(this);

            offScreenGraphics.drawImage(digits[currentTime.get(Calendar.SECOND) % 10], imageWidth, 0, this);

            g.drawImage(offScreenImage, 0, 0, this);
        } else {
            g.setColor(Color.white);
            g.fillRect(0, 0, getSize().width, getSize().height);

            g.setColor(Color.black);
            g.drawString("Loading...", 0, 15);

            return;
        }
    }

    public void update(Graphics g) {
        paint(g);
    }

    public void run() {
        try {
            tracker.waitForAll();
        } catch (InterruptedException e) {
            return;
        }

        while (true) {
            try {
                Thread.sleep(500);
            } catch (InterruptedException e) {
                break;
            }

            currentTime = Calendar.getInstance();

            repaint();
        }
    }

    public void start() {
        if (thread == null) {
            thread = new Thread(this);
            thread.start();
        }
    }

    public void stop() {
        if (thread != null) {
            thread = null;
        }
    }
}