Help with creating an animated java applet...

Question

Hello, everyone! I'm working on a homework assignment for my Intro to Java class, and I'm having a problem I've never run into before. My assignment is to create a animated Java applet which displays an image of an alien spaceship which travels in diagonal lines across the applet area. My main problem is that when I try to compile my code, I get three "cannot find symbol" errors about my variable "alien." I can't figure out why declaring it as a class variable hasn't solved my problem. The errors pop up for the repaint() method, as well as the pane.add and the paintIcon. Here's my code:
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.Timer;
class DrawAlien extends JPanel
public class Alien extends JApplet implements ActionListener
  ImageIcon alien;
  public void init()
    Container pane = getContentPane();
    alien = new ImageIcon(getClass().getResource("alien.gif"));
    pane.setBackground(Color.black);
    pane.add(alien);
    Timer timer = new Timer(30, this);
    timer.start();
  public void actionPerformed(ActionEvent e)
    alien.repaint();
}I've only posted the section which I think is relevant to my problem, but I can post the rest if anyone thinks it's necessary.
I'm aware that the code isn't ready yet in several other ways, but I don't think I can move on until I figure out what's up with the "alien" variable. I don't need anyone to write code for me or anything like that, I just lack perspective here. A couple hints in the right direction would be invaluable. Thanks!
Edited by: springer on Nov 25, 2007 10:46 PM

Answer 1

You can?t add ImageIcon into pane, you can do like below.
alien = new ImageIcon(getClass().getResource("alien.gif"));
    pane.setBackground(Color.black);
    JLabel label = new JLabel(alien);
    pane.add(label);