Clock.java Source code

Introduction

Here is the source code for Clock.java

Source

import java.awt.Color;
import java.awt.Dimension;
import java.awt.FontMetrics;
import java.awt.Graphics;
import java.awt.event.WindowAdapter;
import java.awt.event.WindowEvent;
import java.beans.Customizer;
import java.beans.PropertyChangeListener;
import java.beans.PropertyChangeSupport;
import java.io.Externalizable;
import java.io.IOException;
import java.io.ObjectInput;
import java.io.ObjectOutput;
import java.util.Calendar;
import java.util.Date;

import javax.swing.JButton;
import javax.swing.JFrame;

public class Clock extends JButton implements Customizer, Externalizable, Runnable {

    protected PropertyChangeSupport propertyChangeSupport;

    protected boolean isDigital = false;

    protected Calendar calendar = Calendar.getInstance();

    public Clock() {

        propertyChangeSupport = new PropertyChangeSupport(this);

        setBackground(Color.white);
        setForeground(Color.black);

        (new Thread(this)).start();
    }

    public void writeExternal(ObjectOutput out) throws IOException {
        out.writeBoolean(isDigital);
        out.writeObject(getBackground());
        out.writeObject(getForeground());
        out.writeObject(getPreferredSize());
    }

    public void readExternal(ObjectInput in) throws IOException, ClassNotFoundException {
        setDigital(in.readBoolean());
        setBackground((Color) in.readObject());
        setForeground((Color) in.readObject());
        setPreferredSize((Dimension) in.readObject());
    }

    public Dimension getPreferredSize() {
        return new Dimension(50, 50);
    }

    public Dimension getMinimumSize() {
        return getPreferredSize();
    }

    public Dimension getMaximumSize() {
        return getPreferredSize();
    }

    public void setDigital(boolean digital) {
        propertyChangeSupport.firePropertyChange("digital", new Boolean(isDigital), new Boolean(digital));
        isDigital = digital;
        repaint();
    }

    public boolean getDigital() {
        return isDigital;
    }

    public void addPropertyChangeListener(PropertyChangeListener lst) {
        if (propertyChangeSupport != null)
            propertyChangeSupport.addPropertyChangeListener(lst);
    }

    public void removePropertyChangeListener(PropertyChangeListener lst) {
        if (propertyChangeSupport != null)
            propertyChangeSupport.removePropertyChangeListener(lst);
    }

    public void setObject(Object bean) {
    }

    public void paintComponent(Graphics g) {
        super.paintComponent(g);
        Color colorRetainer = g.getColor();

        g.setColor(getBackground());
        g.fillRect(0, 0, getWidth(), getHeight());
        getBorder().paintBorder(this, g, 0, 0, getWidth(), getHeight());

        calendar.setTime(new Date()); // get current time
        int hrs = calendar.get(Calendar.HOUR_OF_DAY);
        int min = calendar.get(Calendar.MINUTE);

        g.setColor(getForeground());
        if (isDigital) {
            String time = "" + hrs + ":" + min;
            g.setFont(getFont());
            FontMetrics fm = g.getFontMetrics();
            int y = (getHeight() + fm.getAscent()) / 2;
            int x = (getWidth() - fm.stringWidth(time)) / 2;
            g.drawString(time, x, y);
        } else {
            int x = getWidth() / 2;
            int y = getHeight() / 2;
            int rh = getHeight() / 4;
            int rm = getHeight() / 3;

            double ah = ((double) hrs + min / 60.0) / 6.0 * Math.PI;
            double am = min / 30.0 * Math.PI;

            g.drawLine(x, y, (int) (x + rh * Math.sin(ah)), (int) (y - rh * Math.cos(ah)));
            g.drawLine(x, y, (int) (x + rm * Math.sin(am)), (int) (y - rm * Math.cos(am)));
        }

        g.setColor(colorRetainer);
    }

    public void run() {
        while (true) {
            repaint();
            try {
                Thread.sleep(30 * 1000);
            } catch (InterruptedException ex) {
                break;
            }
        }
    }

    public static void main(String[] a) {
        JFrame f = new JFrame();
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });
        Clock c = new Clock();
        f.getContentPane().add("Center", c);
        f.pack();
        f.setSize(new Dimension(300, 300));
        f.show();

    }
}