CODEWITHSUNDEEP
javaswingtimerjframeimageicon
Zenzu
Zenzu

Reputation: 7

Replacing an image once through timer

I am working on this reaction time game that tells you to click an arrow key once the ball has turned into a different colored ball. However, I can't seem to get the image of the ball to be replaced by the other ball.

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import java.util.Random;
import javax.swing.Timer;

public class Game extends JPanel
{
  private JLabel watch, main;
  private ImageIcon constant, react;
  final int width = 600;
  final int height = 600;
  private Timer replace;
  private ActionListener timerListener;
  
  
  public Game()
  {
    setPreferredSize(new Dimension(width, height));
    setBackground(Color.black);
    
    watch = new JLabel("Click Up Arrow when you see a blue ball");
    watch.setForeground(Color.white);
    add(watch);
   
    constant = new ImageIcon("constantCircle.png");
    main = new JLabel(constant);
    
    replace = new Timer(3000, timerListener);
    replace.setRepeats(false);
    replace.start();
 
    add(main);
    
  }
  
  
  public void actionPerformed (ActionEvent e)
  {
    react = new ImageIcon("reactCircle.png");
    main.setIcon(react);
    
  }
}

This is the code for my display and I wanted to use a swing timer to replace the image after 3 seconds

This is what I want it to look like before

This is what I want it to look like before

and this is what I want it to look like after 3 seconds

and this is what I want it to look like after 3 seconds

Upvotes: 0

Views: 90

Answers (1)

Frakcool
Frakcool

Reputation: 11153

You're never initializing timerListener

private ActionListener timerListener;

Inside your constructor you have to call (With Java 8 lambdas):

timerListener = e -> {
    react = new ImageIcon("reactCircle.png");
    main.setIcon(react);
}

Or (Java 7 and lower):

timerListener = new ActionListener() {
    @Override
    public void actionPerformed(ActionEvent e) {
        react = new ImageIcon("reactCircle.png");
        main.setIcon(react);
    }
}

And don't forget to call timerListener.stop() once the timer has fired, so that you don't keep computing more times

From Andrew Thompson's comment below:

As you only want to replace the image once, call timerListener.setRepeats(false) on your constructor. Check the docs for more information about it.

Upvotes: 1

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