import java.awt.*;
import java.awt.event.*;
public class Lab0902 {

		public static void main(String args[])
		{
	    	GfxApp gfx = new GfxApp();
	    	gfx.setSize(900,700);
	    	gfx.addWindowListener(new WindowAdapter() {public void
	    	windowClosing(WindowEvent e) {System.exit(0);}});
	    	gfx.show();
		}
	}
	class GfxApp extends Frame
	{
		public void paint(Graphics g)
		{
	    	Circle circle = new Circle(30, 10, 10, 1);

	    	for(int K = 0; K < 1000; K++)
	    	{
	        	circle.drawCircle(g);

	    	}
		}
	}

	class Circle
	{
		private int topleftX;
		private int topleftY;

		private int incX;
		private int incY;

		private boolean addX;
		private boolean addY;

		private int size;

		private double timeDelay;


		public Circle(int size, int incX, int incY, double timeDelay)
		{
	    	this.size = size;
	    	this.incX = incX;
	    	this.incY = incY;
	    	this.timeDelay = timeDelay;
		}

		private void delay(double d)
		{
	        	long beginDelay = System.currentTimeMillis();
	        	long stopDelay = 0;
	        	while (stopDelay - beginDelay < d)
	        	{
	        	stopDelay = System.currentTimeMillis();
	        	}
				//for (double k = 1; k < d; k+=0.001);
		}

		public void drawCircle(Graphics g)
		{
	    	g.setColor(Color.blue);
	    	settlX();
	    	settlY();
	    	g.drawOval(topleftX, topleftY, size, size);
	    	delay(100);
		}

		public void settlX()
		{
	    	hitEdge();
	    	topleftX += incX;
		}

		public void settlY()
		{
	    	hitEdge();
	    	topleftY += incY;
		}

		public void newData()
		{
	    	if(topleftX <= 0 || topleftX >= 870)
	    	{
	        	incX = (int)(Math.random() * 8) + 5;
	    	}

	    	if(topleftY <= 0 || topleftY >= 670)
	    	{
	        	incY = (int)(Math.random() * 8) + 5;
	    	}

	    	if(topleftY >= 670) { incY *= -1;}

	    	if(topleftX >= 870) { incX *= -1;}
		}

		public void hitEdge()
		{
	    	addX = false;
	    	addY = false;

	    	if(topleftX <= 0 || topleftX >= 870) { addX = true;}

	    	if(topleftY <= 0 || topleftY >= 670) { addY = true;}

	    	if(addX == true || addY ==  true) {newData();}

		}
	}