Thread: How to remove a brick (Java)

Originally Posted by jps

Store your brick object in a variable so you have access to it. Then you can add/relocate/remove it with a method call. Same for the ball.

I have it stored as a method. How do i store it as a variable?

I have finally managed to do it even though it may not be the correct way.

I have done it for a brick i know the location of but now i want to try and improve it by having a randomly displayed brick.

yeah sure. I know have a button that adds the brick instead of the brick being added straight away. Only reason for this is because it states that in the assignment criteria.

 
 
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.util.Random;
 
public class BouncingBall extends JFrame implements ActionListener {
 
	private JPanel paper;
	private JButton btnGo, btnStop, btnFinish, btnBrick, btnLeft, btnRight, btnUp, btnDown;
	private int x, y, xChange, yChange, diameter;
	private int x1, x2, y1, y2, width, height;
	int col1, col2, col3;
	private Timer timer1;
	private JTextField txtScore;
	private JLabel lblScore;
	private int score;
	private Random random;
 
	boolean beenHit = false;
 
	{
	x1= 80;
	x2 =120;
	y1= 100;
	y2 = 110;
	width = 30;
	height = 10;
 
	}
 
	public static void main(String[] args)
	{
 
		BouncingBall ball = new BouncingBall();
		ball.setSize(550, 550);
		ball.setBackground(Color.GREEN);
		ball.setVisible(true);
 
	}
 
	public BouncingBall(){
 
		setLayout(new FlowLayout());	
 
		btnGo = new JButton("Start");
		btnGo.setPreferredSize(new Dimension (70,40));
		btnGo.setBackground(Color.gray);
 
		btnStop = new JButton("Stop");
		btnStop.setPreferredSize(new Dimension (70,40));
		btnStop.setBackground(Color.gray);
 
		btnFinish = new JButton("Finish");
		btnFinish.setPreferredSize(new Dimension (70,40));
		btnFinish.setBackground(Color.gray);
 
		btnBrick = new JButton("Add Brick");
		btnBrick.setPreferredSize(new Dimension (100,40));
		btnBrick.setBackground(Color.gray);
 
		btnLeft = new JButton("Left");
		btnLeft.setPreferredSize(new Dimension (70,40));
		btnLeft.setBackground(Color.gray);
 
		btnRight = new JButton("Right");
		btnRight.setPreferredSize(new Dimension (70,40));
		btnRight.setBackground(Color.gray);
 
		btnUp = new JButton("Up");
		btnUp.setPreferredSize(new Dimension (70,40));
		btnUp.setBackground(Color.gray);
 
		btnDown = new JButton("Down");
		btnDown.setPreferredSize(new Dimension (70,40));
		btnDown.setBackground(Color.gray);
 
		lblScore = new JLabel("Score");
		lblScore.setPreferredSize(new Dimension(50,40));
		lblScore.setBackground(Color.gray);
 
		txtScore = new JTextField(3);
		txtScore.setFont(new Font("TimesRoman", Font.BOLD,16));
		txtScore.setBackground(Color.white);
		txtScore.setForeground(Color.blue);
 
		paper = new JPanel();
		paper.setPreferredSize(new Dimension(500,400));
		paper.setBackground(Color.black);
 
 
 
		add(btnGo);
		add(btnBrick);
		add(lblScore);
		add(txtScore);
		add(btnStop);
		add(btnFinish);
		add(paper);
		add(btnLeft);
		add(btnRight);
		add(btnUp);
		add(btnDown);
 
		btnGo.addActionListener(this);
		btnStop.addActionListener(this);
		btnFinish.addActionListener(this);
		btnBrick.addActionListener(this);
		btnLeft.addActionListener(this);
		btnRight.addActionListener(this);
		btnUp.addActionListener(this);
		btnDown.addActionListener(this);
 
		random = new Random();
 
		x=10; y=10; xChange = 10; yChange = 0; diameter = 10;
 
	}
 
	public void moveBall()
 
	{
 
		Graphics myPen = paper.getGraphics();
		myPen.setColor(Color.black);
		myPen.fillOval(x, y, diameter, diameter);
 
		x = x + xChange;
		y = y + yChange;
 
		if(x <= 0)
			xChange = -xChange;
		if(y <= 0)
			yChange = -yChange;
		if(x >= paper.getWidth())
			xChange = -xChange;
		if(y >= paper.getHeight())
			yChange = -yChange;
 
		myPen.setColor(Color.white);
		myPen.fillOval(x, y, diameter, diameter);
 
 
 
		if((x>=x1 && x<=x2) && (y==y1) && (beenHit == false))
 
			removeRectangle();
 
 
	}
 
 
 
	public void drawRectangle()
	{
 
		Graphics myPen1 = paper.getGraphics();
		myPen1.fillRect(80, 80, paper.getWidth(), paper.getHeight());
 
			col1 = random.nextInt(255);
			col2 = random.nextInt(255);
			col3 = random.nextInt(255);
 
		myPen1.setColor(new Color(col1, col2, col3));
		myPen1.drawRect(x1, y1, width, height);
	}
 
 
	public void removeRectangle()
	{
 
		Graphics myPen2 = paper.getGraphics();
		myPen2.setColor(Color.black);
		myPen2.fillRect(x1, y1, paper.getWidth(),paper.getHeight());
 
		Score();
		beenHit = true;		
	}
 
	public void Score()
 
	{
		score = score+10;
		txtScore.setText(score + "");
 
	}
 
 
 
 
 
	public void actionPerformed(ActionEvent event)
 
	{
		if(event.getSource()==btnGo)
 
		{
			timer1 = new Timer(50,this);
			timer1.start();
 
		}
 
		if(event.getSource()==timer1)
		{
			moveBall();
		}
 
		if(event.getSource()==btnStop)
		{
			timer1.stop();
 
		}
 
		if(event.getSource()==btnBrick)
 
		{
			drawRectangle();
		}
 
 
		if(event.getSource()==btnFinish)
		{
			JOptionPane.showMessageDialog(null, "Thank You for Playing! You scored  " +score++);
			System.exit(0);
 
		}
 
		if(event.getSource()==btnLeft)
		{
			xChange = -10; yChange = 0;
		}
		if(event.getSource()==btnRight)
		{
			xChange = 10; yChange = 0;
		}
		if(event.getSource()==btnUp)
		{
			xChange = 0; yChange = -10;
		}
		if(event.getSource()==btnDown)
		{
			xChange = 0; yChange = 10;
		}
		moveBall();
	}
 
 
	}

i don't know how to link classes together so i just used a method. The methos is called drawRectangle

Originally Posted by usherlad

I have it stored as a method. How do i store it as a variable?

Your method does not really store a brick, it just draws a filled rectangle.

Like Norm said in post #29, you should have a brick class (and a ball class).

The brick class constructor would be used to create an object to store in a variable.
Brick myBrick = new Brick(myBrickSpec1, myBrickSpec2, myBrickSpecN...);

Then later you can say:
myBrick.move(deltaX, deltaY);
or: (iirc you called your canvas 'paper')
paper.remove(myBrick);