import java.awt.BasicStroke;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.geom.Line2D;
import java.util.ArrayList;

import javax.swing.JFrame;

/**
 * A fractal like printing of the letter H
 **/
public class FH extends JFrame
{
    /** 
     * Private class holding the location and size of the H
     **/
    private class H 
    {
	final int cx;
	final int cy;
	final int siz;
	public H(int ccx, int ccy, int siz)
	{
	    this.cx=ccx;
	    this.cy=ccy;
	    this.siz=siz;
	}
    }
    /**
     * ArrayList holding the Hs to be printed
     **/
    private ArrayList<H> hs;
    
    public FH(){
	hs = new ArrayList<>();
        setSize(820, 820);
        setTitle("JFrame");
        setBackground(Color.WHITE);
        setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        setVisible(true);
    }

    /**
     * Recursive method adding Hs
     **/
    public void addH(int cx, int cy, int siz)
    {
	if (siz<1) {
	    return;
	}
	try { Thread.sleep(10); } catch (Exception e) {}
	hs.add(new H(cx, cy, siz));
	repaint();
	
	addH(cx-siz,cy+siz, siz/2);
	addH(cx-siz,cy-siz, siz/2);
	addH(cx+siz,cy+siz, siz/2);
	addH(cx+siz,cy-siz, siz/2);

	//With this line in the func shows printing H as a depth-first line traversal
	// rather than screen filliing
	//hs.remove(hs.size()-1);
    }
    
    public String toString()
    {
	return "";
    }

    public static void main(String[] args) {
         // TODO Auto-generated method stub
         FH m = new FH();
         m.addH(410,400, 200);
         System.out.println(m);
    }

    /**
     * Does the actual rendering
     **/
    public void paint(Graphics g) 
    {
        Graphics2D g2 = (Graphics2D) g;
        g2.clearRect(0, 0, 800, 800);
        g2.setStroke(new BasicStroke(1));
        for (H h:hs)
        {
            g2.draw(new Line2D.Float(h.cx-h.siz, h.cy, h.cx+h.siz, h.cy));
            g2.draw(new Line2D.Float(h.cx-h.siz, h.cy-h.siz, h.cx-h.siz, h.cy+h.siz));            
            g2.draw(new Line2D.Float(h.cx+h.siz, h.cy-h.siz, h.cx+h.siz, h.cy+h.siz));
        }
    }

}