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

class TowersOfHanoiThread extends Thread {
    public TowersOfHanoiThread(TowerDisplay td, 
                                              int nDisks) {
        this.td = td;
        this.nDisks = nDisks;
        td.setup(nDisks,1);
    }
    public void run() {
        amRunning = true;
        amStopped = false;
        solveIt(nDisks, 1, 3);
    }
    public void ourSuspend() { amRunning = false;}
    public void ourResume()  { amRunning = true;}
    public void ourStop()    { amStopped = true;}
    private void delay(int n) {
        try {
           Thread.sleep(n);
        } catch(Exception e) {}
    }
    private void solveIt(int nDisks, int source, int target) {
        if (nDisks<=0)
           return;
        int holdingTower = getholdingTower(source,target);
        solveIt(nDisks-1,source,holdingTower);
        if (amStopped)
           return;
        while (!amRunning)
           delay(80);
        td.displayMove(source,target);
        solveIt(nDisks-1,holdingTower,target);
    }
    private int getholdingTower(int source, int target) {
        if (source==2 && target==3 ||
           source==3 && target==2)
               return 1;
        if (source==1 && target==3 ||
           source==3 && target==1)
               return 2;
        return 3;
    }
    private boolean        amRunning, amStopped;
    private int            nDisks;
    private TowerDisplay   td;
}