Не пойму как через цикл выводится движение и отображение прямоугольника

for (int i = 1; i <= STEPS; i++)

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
 
/**
 * Shows an animated bouncing ball.
 * @version 1.33 2007-05-17
 * @author Cay Horstmann
 */
public class Bounce
{
   public static void main(String[] args)
   {
      EventQueue.invokeLater(new Runnable()
         {
            public void run()
            {
               JFrame frame = new BounceFrame();
               frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
               frame.setVisible(true);
            }
         });
   }
}
 
/**
 * The frame with ball component and buttons.
 */
class BounceFrame extends JFrame
{
   /**
    * Constructs the frame with the component for showing the bouncing ball and Start and Close
    * buttons
    */
   public BounceFrame()
   {
      setSize(DEFAULT_WIDTH, DEFAULT_HEIGHT);
      setTitle("Bounce");
 
      comp = new BallComponent();
      add(comp, BorderLayout.CENTER);
      JPanel buttonPanel = new JPanel();
      addButton(buttonPanel, "Start", new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               addBall();
            }
         });
 
      addButton(buttonPanel, "Close", new ActionListener()
         {
            public void actionPerformed(ActionEvent event)
            {
               System.exit(0);
            }
         });
      add(buttonPanel, BorderLayout.SOUTH);
   }
 
   /**
    * Adds a button to a container.
    * @param c the container
    * @param title the button title
    * @param listener the action listener for the button
    */
   public void addButton(Container c, String title, ActionListener listener)
   {
      JButton button = new JButton(title);
      c.add(button);
      button.addActionListener(listener);
   }
 
   /**
    * Adds a bouncing ball to the panel and makes it bounce 1,000 times.
    */
   public void addBall()
   {
      try
      {
         Ball ball = new Ball();
         comp.add(ball);
 
         for (int i = 1; i <= STEPS; i++)
         {
            ball.move(comp.getBounds());
            comp.paint(comp.getGraphics());
            Thread.sleep(DELAY);
         }
      }
      catch (InterruptedException e)
      {
      }
   }
 
   private BallComponent comp;
   public static final int DEFAULT_WIDTH = 450;
   public static final int DEFAULT_HEIGHT = 350;
   public static final int STEPS = 1000;
   public static final int DELAY = 3;
}

import java.awt.*;
import java.util.*;
import javax.swing.*;
 
/**
 * The component that draws the balls.
 * @version 1.33 2007-05-17
 * @author Cay Horstmann
 */
public class BallComponent extends JPanel
{
   /**
    * Add a ball to the component.
    * @param b the ball to add
    */
   public void add(Ball b)
   {
      balls.add(b);
   }
 
   public void paintComponent(Graphics g)
   {
      super.paintComponent(g); // erase background
      Graphics2D g2 = (Graphics2D) g;
      for (Ball b : balls)
      {
         g2.fill(b.getShape());
      }
   }
 
   private ArrayList<Ball> balls = new ArrayList<Ball>();
}

import java.awt.geom.*;
 
/**
 * A ball that moves and bounces off the edges of a rectangle
 * @version 1.33 2007-05-17
 * @author Cay Horstmann
 */
public class Ball
{
   /**
    * Moves the ball to the next position, reversing direction if it hits one of the edges
    */
   public void move(Rectangle2D bounds)
   {
      x += dx;
      y += dy;
      if (x < bounds.getMinX())
      {
         x = bounds.getMinX();
         dx = -dx;
      }
      if (x + XSIZE >= bounds.getMaxX())
      {
         x = bounds.getMaxX() - XSIZE;
         dx = -dx;
      }
      if (y < bounds.getMinY())
      {
         y = bounds.getMinY();
         dy = -dy;
      }
      if (y + YSIZE >= bounds.getMaxY())
      {
         y = bounds.getMaxY() - YSIZE;
         dy = -dy;
      }
   }
 
   /**
    * Gets the shape of the ball at its current position.
    */
   public Ellipse2D getShape()
   {
      return new Ellipse2D.Double(x, y, XSIZE, YSIZE);
   }
 
   private static final int XSIZE = 15;
   private static final int YSIZE = 15;
   private double x = 0;
   private double y = 0;
   private double dx = 1;
   private double dy = 1;
}

int i = 0;
int max = 100;
int step = 2;
for (;;) {
   if (i > max) {
      break;
   }
   i+= step;
}

public static final int STEPS = 1000;

public static final int DELAY = 3;

x += dx;
y += dy;