import javax.swing.JFrame;     //imports for the frame
import java.awt.Color;         //imports the colour
import java.awt.Graphics;    //imports the graphics
import java.util.Random;  // imports the random class for random colour
public class SierpinskiSquare
{
  public static void main (String[]args)
  {
    new SFrame();  // call to the frame, program
  }
}
class SFrame extends JFrame
{
  Graphics g;     // graphics
  Color c =Color.WHITE; // set colour to white to creat the blanks
  Random r = new Random();
  public SFrame()
  {
    setTitle("Sierpinski Square"); // name of the window/frame
    setVisible(true); // true to show the window
    setSize(500,500); // creats the frame, starting window visible true
    //  setResizable(false); //cannot resize the frame/window     --  useless, since fratal base is on window size
    setLocationRelativeTo(null); //center the frame/window
    setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); //exit window, omit this line to avoid annoying pop up, useless
    //   setBackground(Color.WHITE); //set background to white
  }
  public void paint(Graphics g)
  {
    this.g = g;
    repaint(); // incase if the window size is change, then "refresh" page, useless since window size never change
    drawSierpinskiSquare( 0, 0, getWidth(), getHeight());     // start recursion
  }
  private void drawSierpinskiSquare ( int x, int y ,int w, int h)
  {
    if (w>2 && h>2) //control when to stop
    {       
      int nw=w/3, nh=h/3;    // the new square's width and height
      g.setColor(c);          //random colour (default is white)
      g.fillRect ( x+nw,y+nh,nw,nh);  //draws and fill the square, bigger one
      for (int k=0;k<9;k++)         // inside the big square, divide it into 9 smaller one equally
        if (k!=4)                  // if is not the middle square
      {                 
        c=new Color( r.nextInt(256), r.nextInt(256), r.nextInt(256));      //makes the new colour
        int i=k/3, j=k%3;                                     // dividing the 8 equal squares into another 9 smaller ones
        drawSierpinskiSquare ( x+i*nw, y+j*nh, nw, nh );                 // draws out the recursion
      }
    }
  }
}

import javax.swing.JFrame
import java.awt.{Color, Graphics}
import java.util.Random

import Color.WHITE
import JFrame.EXIT_ON_CLOSE

object SierpinskiSquare extends Application {
    new SFrame
}

class SFrame extends JFrame("Sierpinski Square") {
    var g: Graphics = null
    var c = WHITE
    val r = new Random

    this setVisible true
    this setSize (500, 500)
    this setLocationRelativeTo null
    this setDefaultCloseOperation EXIT_ON_CLOSE

    override def paint(g: Graphics) {
        this g = g
        this repaint ()
        this drawSierpinskiSquare (0, 0, getWidth, getHeight)
    }

    def drawSierpinskiSquare(x: Int, y: Int, w: Int, h: Int) {
        def rand = r nextInt 256

        if (w > 2 && h > 2) {
            val nw = w / 3
            val nh = h / 3

            g setColor c
            g fillRect (x + nw, y + nh, nw, nh)

            for (val k <- 0 to 9 if k != 4) {
                c = new Color(rand, rand, rand)
               
                val i = k / 3
                val j = k % 3
       
                this drawSierpinskiSquare (x + i * nw, y + j * nh, nw, nh)
            }
        }
    }
}