import java.applet.Applet;
import java.applet.*;
import java.awt.*;

public class bball extends Applet implements Runnable {
    private Color background;
    private Color foreground;
    private boolean running;
    public Image image;
    public Graphics offscreen;
    public Thread runner;
    //border sizes
    static final int startX=10;
    static final int startY=10;
    private int maxX;
    private int maxY;
    //sounds
    AudioClip beep;
    AudioClip hurt;
    
    
    //create ball objects
    ball ballOne = new ball(20,50,Color.red);
    ball ballTwo = new ball(32,78,Color.blue);
    
	public void init() {
        	background = Color.black;
        	foreground = Color.black;
        	//find screen size
        	maxX=size().width;
        	maxY=size().height;
        	//create offscreen image
        	image=createImage(maxX,maxY);
        	offscreen=image.getGraphics();
        	Font f=new Font("Dialog",Font.BOLD,10);
        	offscreen.setFont(f);
        	offscreen.drawString("Bouncing Balls 2.0",9,10);
        	//make ball2 different direction, speed & size
        	ballTwo.moveY=-3;
        	ballTwo.moveX=3;
        	ballTwo.diameter=10;
        	//sounds
        	beep=getAudioClip(getDocumentBase(),"beep.au");
        	hurt=getAudioClip(getDocumentBase(),"hurts.au");
    	}
  
        public void update(Graphics g) {
    		paint(g);
   	}
  
   	public void paint(Graphics g) {
    		offscreen.setColor(background);
    		offscreen.fillRect(startX,startY,maxX-startX,maxY-startY);
    		ballOne.drawBall();
    		ballTwo.drawBall();
    		g.drawImage(image,0,0,this);
      	}
    
    	public void destroy() {
    		offscreen.dispose();
        }
        
        public void start() {
        	if (runner==null) {
        		runner=new Thread(this);
        		runner.start();
        		running=true;
        	}
        }
        
        public void stop() {
        	runner=null;
        }
        
        public void run() {
        	try {
            		while (running) {
            			runner.sleep(40);
                		repaint();
            		}
        	} 
        	catch(InterruptedException e) {
            	running = false;
            	}
        }
        
        class ball {
        	//instance variables
        	int xPos;
        	int yPos;
        	Color ballColor;
        	int moveX=2;
        	int moveY=2;
        	int diameter=20;
    
        	
        	//constructor
        	public ball (int xPos, int yPos, Color ballColor) {
        		this.xPos=xPos;
        		this.yPos=yPos;
        		this.ballColor=ballColor;
        	}
        	
        	//calculate positions and draw ball to offscreen image
        	public void drawBall() {
        		if (xPos+moveX<startX || xPos+diameter>maxX) {
        			moveX*=-1;
        			if (beep!=null) {
        				beep.play();
        			}
        		}
        		else if (yPos+moveY<startY || yPos+diameter>maxY) {
        			moveY*=-1;
        			if (hurt!=null) {
        				hurt.play();
        				}
        		}
        		xPos+=moveX;
        		yPos+=moveY;
        		offscreen.setColor(ballColor);
	        	offscreen.fillOval(xPos,yPos,diameter,diameter);
	       	}
	}
}