Question

I am creating and updating a BufferedImage on a background thread. The image is then drawn onto a JPanel by overriding the panels paint method as shown.

@Override
public void paint(Graphics g) {
    g.drawImage(image, 0, 0, null);
}

The background thread periodically updates the image then calls the panels invalidate method.

Will I run into any issues with this approach? Will the swing thread reading and the background thread updating the image cause any problems?

Thanks

Ben

Answer 1

The two threads must synchronize access to the shared data. SwingWorker is the most reliable approach with which to periodically publish the BufferedImage; there’s an example here using Double. You might also look at the example here, which relies on the (implicit) ordering afforded by he EventQueue and repaint(). In either case, the limiting factor is the timer frequency relative to the repaint time.