Pong Rendering and KeyListeners
Hello Everyone,
I have this project due tomorrow so any help on this would be greatly appreciated. I have a render method that shows the paddle and ball in a JPanel. The paddle and ball are JLabels that move around. I get an error the second time the render method is called. How can I prevent this hang up? I also am having trouble using a KeyListener for the paddle movement.
Thanks in Advance
Heres the Code
import java.util.*;
import java.text.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
publicclass workextends JFrame{
int [][] paddle1position ={{200},{10}};
int [][] paddle2position ={{200},{490}};
int ballx;
int bally;
finalint ballwidth=10;
finalint ballheight=10;
finalint tablexmax = 500;
finalint tableymax = 400;
int xvect = 1;
int yvect = 1;
finalint lpaddlex= 0;
finalint rpaddlex= 480;
int lpaddley= 170;
int rpaddley=170;
finalint paddlelength = 60;
finalint paddlewidth = 20;
//paddle maneuvers
int delta1;
int delta2;
JPanel viewer=new JPanel();
// array of jbuttons
public JButton[] keyJButtons =new JButton[KeyEvent.KEY_LAST+1];
public JButton player1upJButton=new JButton();
public JButton player1downJButton =new JButton();
public JButton player2upJButton=new JButton();
public JButton player2downJButton =new JButton();
public JLabel leftpaddle=new JLabel();
public JLabel rightpaddle =new JLabel();
public JLabel balllabel =new JLabel();
//new
public work()
{
createUserInterface();
}
privatevoid createUserInterface()
{
Container contentPane = getContentPane();
contentPane.setBackground(Color.GREEN);
contentPane.setLayout(null );
viewer=new JPanel();
viewer.setLayout(null);
viewer.setBounds (25, 25, 500, 400);
viewer.setBackground(Color.BLACK);
viewer.setVisible(true);
contentPane.add(viewer);
player1upJButton=new JButton();
contentPane.add(player1upJButton);
keyJButtons[KeyEvent.VK_UP]= player1upJButton;
player1upJButton.addActionListener(
new ActionListener()
{
publicvoid actionPerformed(ActionEvent event)
{
}
});
player1downJButton=new JButton();
contentPane.add(player1downJButton);
keyJButtons[KeyEvent.VK_DOWN]= player1downJButton;
player2upJButton=new JButton();
contentPane.add(player2upJButton);
keyJButtons[KeyEvent.VK_Q]= player2upJButton;
player2downJButton=new JButton();
contentPane.add(player2downJButton);
keyJButtons[KeyEvent.VK_A]= player2downJButton;
//objects
setSize(800,600);
setVisible(true);
center();
render();
}
publicvoid poop(ActionEvent event)
{
System.out.print("hello");
}
publicvoid render()
{
leftpaddle=new JLabel();
leftpaddle.setIcon(new ImageIcon("paddle.jpg"));
leftpaddle.setBounds(lpaddlex, lpaddley, paddlewidth, paddlelength);
leftpaddle.setHorizontalAlignment(JLabel.CENTER);
viewer.add(leftpaddle);
leftpaddle.setVisible(true);
rightpaddle =new JLabel();
rightpaddle.setIcon(new ImageIcon("paddle.jpg"));
rightpaddle.setBounds(rpaddlex, rpaddley, paddlewidth, paddlelength);
rightpaddle.setHorizontalAlignment(JLabel.CENTER);
viewer.add(rightpaddle);
rightpaddle.setVisible(true);
balllabel=new JLabel();
balllabel.setIcon(new ImageIcon("ball.jpg"));
balllabel.setBounds(ballx, bally, ballwidth, ballheight);
balllabel.setHorizontalAlignment(JLabel.CENTER);
viewer.add(balllabel);
balllabel.setVisible(true);
frame();
}
publicvoid center()
{
ballx=250;
bally= 200;
}
publicvoid wallcollission()
{
yvect *= -1;
render();
}
publicvoid paddlecollission()
{
xvect *= -1;
}
publicvoid checkside()
{
if ((ballx)==paddlewidth||(ballx+ballwidth==tablexmax-paddlewidth))
{
checkpaddlepos();
}
if(bally==0||bally==tableymax)
{
wallcollission();
}
}
publicvoid checkpaddlepos()
{
if((bally)<=lpaddley+paddlelength&&(bally)>=lpaddley)
{
paddlecollission();
}
if ((bally)<=rpaddley+paddlelength&&(bally)>=rpaddley)
{
paddlecollission();
}
else
render();
}
publicvoid frame()
{
ballx+=xvect;
bally+=yvect;
checkside();
}
publicstaticvoid main( String[] args )
{
work application =new work();
application.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE );
}// end method main
}
