//------------
// Introduction to Programming Using Java: An Object-Oriented Approach
//Arnow/Weiss
//------------
import java.util.*;
import java.awt.*;
import java.awt.event.*;
import java.applet.*;

public class TowerApplet extends Applet
                              implements ActionListener {
    public void init() {
        setBackground(new Color(200,255,255));
        this.setLayout(new BorderLayout(20,2));
        td = new TowerDisplay();
        add("Center",td);
        startButton = new Button("start");
        startButton.addActionListener(this);
        pauseButton = new Button("pause");
        pauseButton.addActionListener(this);
        Panel pb = new Panel();
        pb.setLayout(new BorderLayout(2,2));
        pb.add("North",startButton);
        pb.add("South",pauseButton);
        numDisks = new TextField(" 7");
        numDisks.setFont(new Font("Courier",Font.BOLD,10));
        Label numDisksLabel = new Label(" Number of disks:",Label.RIGHT);
        Label stepDelayLabel = new Label("Delay (millisecs):",Label.RIGHT);
        numDisksLabel.setFont(new 
                             Font("Courier",Font.BOLD,10));
        stepDelayLabel.setFont(new 
                             Font("Courier",Font.BOLD,10));
        Panel pn = new Panel();
        pn.setLayout(new BorderLayout(2,2));
        pn.add("East",numDisks);
        pn.add("West",numDisksLabel);
        stepDelay = new TextField("1000");
        stepDelay.addActionListener(this);
        stepDelay.setFont(new 
                          Font("Courier",Font.BOLD,10));
        Panel ps = new Panel();
        ps.setLayout(new BorderLayout(2,2));
        ps.add("East",stepDelay);
        ps.add("West",stepDelayLabel);
        Panel pp = new Panel();
        pp.setLayout(new BorderLayout(2,2));
        pp.add("North",pn);
        pp.add("South",ps);
        Panel p = new Panel();
        p.setLayout(new 
                    FlowLayout(FlowLayout.CENTER,50,20));
        p.add(pb);
        p.add(pp);
        p.setBackground(new Color(255,200,200));
        add("South",p);
    }
    public void actionPerformed(ActionEvent ae) {
        String whichButton = ae.getActionCommand();
        if (whichButton.equals("start"))
           handleStart();
        else if (whichButton.equals("restart"))
           handleRestart();
        else if (whichButton.equals("pause"))
           handlePause();
        else if (whichButton.equals("resume"))
           handleResume();
        else
           handleKeyboard();
    }
    private void handleStart() {
        int nDisks = 
               Integer.parseInt(numDisks.getText().trim());
        handleKeyboard();
        towersTicker = new TowersOfHanoiThread(td, nDisks);
        towersTicker.start();
        startButton.setLabel("restart");
        pauseButton.setLabel("pause");
    }
    private void handleRestart() {
        towersTicker.ourStop();
        handleStart();
    }
    private void handlePause() {
        towersTicker.ourSuspend();
        pauseButton.setLabel("resume");
    }
    private void handleResume() {
        towersTicker.ourResume();
        pauseButton.setLabel("pause");
    }
    private void handleKeyboard() {
        int sDelay = 
              Integer.parseInt(stepDelay.getText().trim());
        td.setDelay(sDelay);
    }
    private   Button                  startButton, 
                                          pauseButton;
    private   TextField               numDisks, stepDelay;
    private   TowerDisplay            td;
    private   TowersOfHanoiThread     towersTicker = null;
    private   int                     source = 1;
    private   int                     target = 3;
}