/*
 * StopWatch.java
 * This file contains a java program to emulate a two button stopwatch
 * Author  Stuart Hansen
 * Last Modified January 31, 2002 
 */

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class StopWatch extends JFrame {
    long currentTime;    // the current time
    long displayTime;    // the display time
    Timer timer;         // the timer goes off every 1/10 seconds
    State state;         // the state keeps track of whether the stopwatch
                         // is running
    JButton startStop;   // starts and stops the watch
    JButton lap;         // freezes/unfreezes and resets the display
    JTextField display;  // this is where the time is displayed
    
    // Creates new StopWatch
    public StopWatch() {
        super ("StopWatch");
        
	// instantiate and initialize the startStop button
        startStop = new JButton("Start/Stop");
        startStop.addActionListener(new startStopController());
        
	// instantiate and initialize the lap button
        lap = new JButton("Lap");
        lap.addActionListener(new lapController());
        
	// instantiate and intialize the display
        display = new JTextField("00:00:0");
	display.setEditable(false);

	// add the GUI components to the window
        Container c = getContentPane();
        c.setLayout (new FlowLayout () );
        c.add(startStop);
        c.add(lap);
        c.add(display);

        // set the window's properties
       	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);     
        setSize( 120, 150);

	// setup all the timer variables and objects
        currentTime = 0;
        displayTime = 0;
        timer = new Timer(100, new TimerHandler ());
        state = new Stopped();
        timer.setRepeats(true);
        timer.start();
        
	// open the window
        show();
    }

    // Get the current time
    public long getCurrentTime () {return currentTime;}

    // Set the current time
    public void setCurrentTime (long timeArg) {currentTime = timeArg;}
    
    // Get the displayed time (not necessarily the same as the current time)
    public long getDisplayTime () {return displayTime;}

    // setDisplayTime updates the displays text, which is a string
    public void setDisplayTime (long timeArg) {
        displayTime = timeArg;

	// Translate the minutes to a string
        String minutes = Long.toString((displayTime/600)%60);
        if ((displayTime/600)%60 < 10) minutes = "0"+ minutes;
        
	// Translate the seconds to a string
        String seconds = Long.toString((displayTime/10%60));
        if ((displayTime/10%60) < 10) seconds = "0" + seconds;
        
        // Translate the tenths of seconds to a string
        String tenths = Long.toString(displayTime%10);
        
        // Display the updated time
        display.setText( minutes + ":" + seconds + ":" + tenths);
    }

    // The state classes represent the different control states the
    // stopwatch can be in.  Button and timer events are ultimately
    // processed by the state.

    // State is the interface that all concrete states must implement
    public interface State {
        public void updateTime();      // run at a timer event
        public void startStopPushed(); // run when startStop is clicked
        public void lapPushed();       // run when lap is clicked
    }
    
    // The state for a stopped stopwatch
    public class Stopped implements State {
        public void updateTime () { }
        public void startStopPushed() {
            state = new Started();
        }
        public void lapPushed() {
            setCurrentTime(0);
            setDisplayTime(0);
        }        
    }

    // The state when the stopwatch is stopped while in lap mode
    public class LapAndStopped implements State {
        public void updateTime () { }
        public void startStopPushed() {
            state = new LapAndStarted();
        }
        public void lapPushed() {
            setDisplayTime(getCurrentTime());
            state = new Stopped();
        }        
    }

    // The state when the stopwatch is running
    public class Started implements State {
        public void updateTime () {
            setCurrentTime(getCurrentTime()+1);
            setDisplayTime(getCurrentTime());
        }
        public void startStopPushed() {
            state = new Stopped();
        }
        public void lapPushed() {
            state = new LapAndStarted();
        }        
    }

    // The state when the stopwatch is running but the display is frozen
    public class LapAndStarted implements State {
        public void updateTime () { 
           setCurrentTime(getCurrentTime()+1);
        }
        public void startStopPushed() {
            state = new LapAndStopped();
        }
        public void lapPushed() {
           setDisplayTime(getCurrentTime());
           state = new Started();
        }        
    }

    // The startStopController simply dispatches the event to the state
    public class startStopController extends AbstractAction {
        public void actionPerformed (ActionEvent e) {
            state.startStopPushed();
        }
    }
    
    // The lapController simply dispatches the event to the state
    public class lapController extends AbstractAction {
        public void actionPerformed (ActionEvent e) {
            state.lapPushed();
        }
    }

    // This class updates the time whenever the timer goes off
    class TimerHandler implements ActionListener {
        public void actionPerformed (ActionEvent e) {
            state.updateTime();
        }        
    }
    
    // A nice simple main program
    public static void main (String args []) {
        new StopWatch();
    }        
}