SnowmanOfHanoi.java

package SOH;

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

@SuppressWarnings("serial")
public class SnowmanOfHanoi extends JComponent {
    private int n, snowmanHeight, floorLevel;
    private final int snowballSize = 25;
    private int[] x = new int[6], y = new int[6], diameter = new int[6];
    private JFrame frame;

    SnowmanOfHanoi (int n, JFrame frame) {
        this.frame = frame;                 // referenca
        floorLevel = frame.getHeight() - 250;
        setN(n);
    }

    public void repaint() {
        frame.repaint();
        try {
            Thread.sleep(2);
        } catch (Exception e) {
            e.printStackTrace();
        }
    }

    public void setN(int n) {
        this.n = n;
        snowmanHeight = n * (n+1) * snowballSize / 2;
        for(int i = n-1; i >= 0; --i) {                     // 0-ti block je najmanji
            diameter[i] = (i+1) * snowballSize;
            x[i] = calculateX(1, i+1);
            y[i] = (i == n-1) ? floorLevel : y[i+1];
            y[i] += 2*i+1 - diameter[i];                    // malo utonuti u onu vecu kuglu
        }
        repaint();
    }

    void towerOfHanoi(int n, int from_rod, int to_rod, int aux_rod) {
        if (n == 0)   return;
        towerOfHanoi(n-1, from_rod, aux_rod, to_rod);
        moveAndPaint(n-1, to_rod);
        //System.out.println("Move disk " + n + " from rod " +  from_rod + " to rod " + to_rod);
        towerOfHanoi(n-1, aux_rod, to_rod, from_rod);
    }

    void moveAndPaint(int which, int dest) {
        // dizemo pravokutnik
        int top = floorLevel - snowmanHeight - diameter[n-1] - 100;
        while(y[which] != top) {
            --y[which];
            repaint();
        }
        // micemo pravokutnik lijevo ili desno
        int destX = calculateX(dest, which+1);
        while(x[which] != destX) {
            x[which] += (x[which] > destX) ? -1 : 1;
            repaint();
        }
        // spustamo pravokutnik
        int max = floorLevel;
        for(int i = 0; i < n; ++i) {
            if (i == which) continue;
            if (getRodFromPos(i+1) == dest && y[i] < max)
                max = y[i];
        }
        while(y[which] != max - diameter[which] + 2*which + 1) {    // malo utonuti u onu vecu kuglu
            ++y[which];
            repaint();
        }
    }

    protected void paintComponent(Graphics g) {
        int start = floorLevel - snowmanHeight - 50;
        Image img = Toolkit.getDefaultToolkit().getImage(SnowmanOfHanoi.class.getResource("download.jpg"));
        g.drawImage(img, 0, 0, this);
        g.drawLine(getPosFromRod(1), start, getPosFromRod(1), floorLevel);
        g.drawLine(getPosFromRod(2), start, getPosFromRod(2), floorLevel);
        g.drawLine(getPosFromRod(3), start, getPosFromRod(3), floorLevel);
        for (int i = 0; i < n; ++i) {
            g.setColor(new Color(255, 255, 255));
            g.fillOval(x[i], y[i], snowballSize*(i+1), snowballSize*(i+1));
        }
    }

    public int calculateX(int which_rod, int which_block) {
        int offset = which_block * snowballSize / 2;
        return getPosFromRod(which_rod) - offset;
    }

    public int getPosFromRod(int which_rod) {
        return which_rod * frame.getWidth() / 4;
    }

    public int getRodFromPos(int which_block) {
        // iz jednadzbe calculateX = x[i] izvedemo varijablu which_rod
        return (x[which_block-1] * 4 + 2 * which_block * snowballSize) / frame.getWidth();
    }

}