Java Code

/* Breakout - Final version Part 4
 * remove flicker and update problems
 */
import java.awt.*;
import javax.swing.*;
import java.util.*;
import java.awt.event.*;
import java.awt.image.*;
public class Breakout extends JApplet  implements Runnable, KeyListener
{
    ArrayList blocks;
    int width, height;      // dimensions of applet
    int numBlocks;          // number of blocks horizontally
    int numRows;            // number of rows - 1 least difficult, 5 more difficult
    
    // Part III
    Rectangle paddle;
    int speed;
    // Part II 
    Thread thread;
    Ball ball;
    // Part IV
    BufferedImage buffer;
    
    public void init( )
    {
        resize(600, 400 );
        numBlocks = 10;
        numRows = 3;
        blocks = new ArrayList( );
        width = getWidth( );
        height = getHeight( );
        buildBlocks( );
        // Part II
        paddle = new Rectangle( 50, height-30, 50, 10 );
        addKeyListener( this );
        speed = 10;
        setFocusable(true);
        // PART IV
        buffer = new BufferedImage(width,height,BufferedImage.TYPE_INT_RGB);
        // PART III
        ball = new Ball( 50, 120, 15, 5, width, height );
        thread = new Thread(this);
        thread.start( );
        
    }
    public void buildBlocks( )
    {
        int sizeOfBlock = width / numBlocks;
        int heightOfBlock = 15;
        for( int rows=0; rows<width; rows += sizeOfBlock )
            for( int cols=0; cols<numRows*heightOfBlock; cols += heightOfBlock )
            {
                Rectangle r = new Rectangle( rows,80+cols, sizeOfBlock-2, heightOfBlock-2 );
                blocks.add(r);
            }
    }
/**/  public void update( Graphics g )
    {
        paint(g);
    }
  public void paint( Graphics g )
    {
//        g.clearRect(ball.x-20, ball.y-20, ball.size+40, ball.size+40 );
        Graphics bg = buffer.getGraphics( );
        bg.setColor(Color.WHITE);
        bg.fillRect(0,0,width,height);
        //ball.paint( getGraphics( ) );
        ball.paint( bg );
        //        g.setColor( Color.WHITE );
//        g.fillRect(0,0,width,height);
        bg.setColor( Color.RED );
        for (int i=0; i<blocks.size( ); i++ )
        {
            Rectangle r = (Rectangle )blocks.get(i);
            bg.fillRect( r.x, r.y, r.width, r.height );
        }
        bg.setColor( Color.BLACK );
        bg.fillRect( paddle.x, paddle.y, paddle.width, paddle.height );
        g.drawImage(buffer,0,0,this);
    }
    public void run( )
    {
        while( true )
        {
//            repaint( );
            ball.move( );
            checkForCollision( );
    //        ball.paint( buffer.getGraphics( ) );       
            repaint( );
            try {
                Thread.sleep(15);
            }catch( Exception ex ) { }
        }
    }
    public void checkForCollision( )
    {
        Rectangle ballR = new Rectangle( ball.x, ball.y, ball.size, ball.size);
        for( int i=0; i<blocks.size( ); i++ )
        {
            Rectangle r = (Rectangle )blocks.get(i);
            if ( r.intersects( ballR ) )
            {
                blocks.remove(r);
                getGraphics( ).clearRect(r.x, r.y, r.width, r.height);
                ball.dirX = -1 * ball.dirX;
                ball.dirY = -1 * ball.dirY;
//repaint( );
                return;
            }
        }
        // check for paddle collision
        if ( ballR.intersects( paddle ) )
        {
            ball.dirX = -1 * ball.dirX;
            ball.dirY = -1 * ball.dirY;
  //          repaint( );
        }
//        repaint( );
    }
    public void keyTyped( KeyEvent ke ) {   }
    public void keyReleased( KeyEvent ke ) {    }
    public void keyPressed( KeyEvent ke ) 
    {
        int code = ke.getKeyCode( );
        getGraphics( ).clearRect( paddle.x, paddle.y, paddle.width, paddle.height);
        if( code == KeyEvent.VK_LEFT )
        {
            int x = paddle.x;
            x -= speed;
            paddle.x = x;
        }
        else if( code == KeyEvent.VK_RIGHT )
        {
            int x = paddle.x;
            x += speed;
            paddle.x = x;
        }
        repaint( );
    }
}