Java Clock

[hot_ice]

Hey everyone,

I'm just posting this clock/timer applet I created. It's nothing special, just a timer - I find it very usefull when I listen to the footy on the radio. If any Aussies here follow the AFL, hopefully you'll know what I mean. Well anyways, if you are learning java, I'm hoping this will be a good example for you. I find that example applets/applications are really good to learn from - you can't just read text books...too boring.

Well, I'll post the source code here and hopefully my poor documentation will explain most of the things.

(Note: It's java, even though I put it in PHP quotes - it just looked the best in them - I tried 'code' quotes, but it was all over the place.)

//import the packages that will be used
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

//define the class Clock
public class Clock extends JApplet implements ActionListener
{
    //define all instance variables
    private Container pane;
    private JPanel center, south;
    private JLabel hours, minutes, seconds;
    private JTextField hourValue, minuteValue, secondValue;
    private JButton startButton, stopButton;
    private String theHour, theMinute, theSecond;
    private Timer theTimer;

    //define the init method, which basically outlines what the applet looks like
    public void init()
    {
        //define the pane where everything will be added
        pane = getContentPane();
        //define what layout the pane will use
        pane.setLayout(new BorderLayout());

        center = new JPanel();
        center.setLayout(new FlowLayout());
        pane.add(center, "Center");
        south = new JPanel();
        south.setLayout(new FlowLayout());
        pane.add(south, "South");

        //define the labels
        hours = new JLabel("Hours");
        minutes = new JLabel("Minutes");
        seconds = new JLabel("Seconds");

        //define the text fields - the actual timer
        hourValue = new JTextField("0", 3);
        minuteValue = new JTextField("0", 3);
        secondValue = new JTextField("0", 3);

        //define the buttons to start and stop the timer
        startButton = new JButton("Start Timer");
        stopButton = new JButton("Stop Timer");

        //add the buttons to the action listener - so they fire an event when clicked
        startButton.addActionListener(this);
        stopButton.addActionListener(this);

        //add the buttons to the pane
        south.add(startButton);
        south.add(stopButton);

        //add all other objects to the pane
        center.add(hours);
        center.add(hourValue);
        center.add(minutes);
        center.add(minuteValue);
        center.add(seconds);
        center.add(secondValue);

        //create a timer that fires an event every second (1000 milliseconds)
        theTimer = new Timer(1000, this);
    }

    //defines the method which is called when an event is fired
    public void actionPerformed(ActionEvent e)
    {
        //capture the source which fired the event
        Object event = e.getSource();

        //define what to do when the start button is pushed
        if(event == startButton)
        {
            theTimer.start();
        }
        //define what to do when the stop button is pushed
        else if(event == stopButton)
        {
            theTimer.stop();
        }
        //define what to do when the timer fires the event (every 1000 milliseconds in this case)
        else if(event == theTimer)
        {
            addSecondValue();
        }
    }

    //define the method that increments the 'hours' section
    public void addHourValue()
    {
        theHour = hourValue.getText();
        int theHourValue = (Integer.parseInt(theHour)) + 1;

        hourValue.setText(Integer.toString(theHourValue));
    }

    //define the method that increments the 'minutes' section
    public void addMinuteValue()
    {
        theMinute = minuteValue.getText();
        String incrementedValue = increment(theMinute);

        minuteValue.setText(incrementedValue);

        if(incrementedValue.equals("0"))
            addHourValue();
    }

    //define the method that increments the 'seconds' section
    public void addSecondValue()
    {
        theSecond = secondValue.getText();
        String incrementedValue = increment(theSecond);

        secondValue.setText(incrementedValue);

        if(incrementedValue.equals("0"))
            addMinuteValue();
    }

    //define the method that increments the seconds and minutes, reseting the value to '0' every 60 occurances
    public String increment(String value)
    {
        int theValue = Integer.parseInt(value);

        if(theValue <= 58)
            theValue++;
        else
            theValue = 0;

        return Integer.toString(theValue);
    }
} 

And here is the ZIP file that contains the HTML file and the CLASS file so that you can view it (the JAVA file is there aswell - the source code). Just open it in any java-enabled browser and it should work fine. Any questions just reply and I'll be happy to help.

EDIT: OK, so the ZIP file is attached in my post below (2 posts down).

Cheers,
Greg