making image disappeared

[rajendra peddinti]

hi,

i am desiging a dx-ball game in awt/swing where, bricks will placed in rows, a ball will hit the bricks and what ever brick is touched by the ball should be disappeared.

so i've loaded images for bricks and animated ball. i used "clearRect"(java.awt.Graphics)for disappearing image depending on the ball position.

the problem is it is clearing the lower row perfectly and not going to the next row(obviously it wont go ) because it is clearing the same rectangle which it has already cleared.

so can any one suggest me how to remove an image completely(i think you got my sense in using "completley)?

thank you.

[Gregg Bolinger]

Without knowing how you have drawn your bricks, it's difficult to say. If they are components (JPanel, JButton, JLabel, etc) then you can simply remove them from their parent.

However, from your description, I'm assuming you have overridden paintComponent and are drawing them manually that way? Could you give us a bit more info regarding this?

[rajendra peddinti]

Gregg,

your assumption is right. i've overridden paintComponent().following is my piece of code...

Image image =new ImageIcon("small.gif").getImage();
      public void paintComponent(Graphics g)
 {

g.drawImage(image,x,y,this); 
        }   

[Campbell Ritchie]

You didn't include "super.paintComponent(g);"? Does that make any difference?

[Craig Wood]

import java.awt.*;
import java.awt.geom.Ellipse2D;
import javax.swing.*;
 
public class Contact extends JPanel implements Runnable {
    Rectangle[] blocks;
    boolean[] showBlocks;
    Ellipse2D.Double ball;
    double dx = 3;
    double dy = 2;
 
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);
        Graphics2D g2 = (Graphics2D)g;
        g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                            RenderingHints.VALUE_ANTIALIAS_ON);
        if(blocks == null)
            initGeometry();
        g2.setPaint(Color.blue);
        for(int j = 0; j < blocks.length; j++) {
            if(showBlocks[j])
                // drawImage(images[j], blocks[j].x, blocks[j].y
                g2.draw(blocks[j]);
        }
        g2.setPaint(Color.red);
        g2.draw(ball);
    }
 
    public void run() {
        boolean running = true;
        while(running) {
            try {
                Thread.sleep(75);
            } catch(InterruptedException e) {
                System.out.println("interrupted");
                running = false;
            }
            advance();
        }
    }
 
    private void advance() {
        validateBoundries();
        ball.x += dx;
        ball.y += dy;
        checkForContact();
        repaint();
    }
 
    private void validateBoundries() {
        if(ball.x + dx < 0 || ball.x + ball.width + dx > getWidth())
            dx *= -1;
        if(ball.y + dy < 0 || ball.y + ball.height + dy > getHeight())
            dy *= -1;
    }
 
    private void checkForContact() {
        for(int j = 0; j < blocks.length; j++) {
            if(showBlocks[j] && ball.intersects(blocks[j]))
                showBlocks[j] = false;
        }
    }
 
    private void initGeometry() {
        int rows = 2;
        int cols = 3;
        int w = getWidth();
        int h = getHeight();
        int width  = w/(2*cols+1);
        int height = h/(2*rows+1);
        blocks = new Rectangle[rows*cols];
        showBlocks = new boolean[rows*cols];
        for(int j = 0; j < rows; j++) {
            for(int k = 0; k < cols; k++) {
                int index = j*cols + k;
                int x = width + 2*k*width;
                int y = height + 2*j*height;
                blocks[index] = new Rectangle(x, y, width, height);
                showBlocks[index] = true;
            }
        }
        ball = new Ellipse2D.Double(0,0,50,50);
    }
 
    public static void main(String[] args) {
        Contact test = new Contact();
        JFrame f = new JFrame();
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        f.getContentPane().add(test);
        f.setSize(400,400);
        f.setLocation(200,200);
        f.setVisible(true);
        new Thread(test).start();
    }
}