Thread: JtextArea update issue.

Hi,

I'm currently writing a application, which on a mouse click runs several methods which updates a JtextArea. The problem is even though I'm updating the text area with each method call, it doesn't actually update until everything in the mouseclick has run..

This can take quite a while to run through everything and I would like to see the text area update with each call instead of waiting until everything is done

		btnBeginTest.addMouseListener(new MouseAdapter() {
			@Override
			public void mouseClicked(MouseEvent e) {
				DataCollector dc = new DataCollector();
 
				dataCollected.append("Begining Test...\n\n");
				dataCollected.append("Collecting System Information... \n\n");
				dataCollected.append(dc.getSystem());
                                ... lots more like this...

any ideas how I can make the text area update the way I intended?

Thanks.

Swing uses one particular thread to call things like your mouseClicked() - the so called event dispatch thread (EDT). Painting is also done on this thread which explains why mouseClicked() must complete before anything "shows up". What you are seeing is the reason why code you write that will be invoked on the EDT (handlers and painting code, eg) *must* complete quickly.

If something is going to take a while (>100ms?) then it should happen on another thread. Your mouseClicked() should use another thread to do it's work, updating the gui when it's done.

Google or browse through Oracle's Tutorial where the EDT and using multiple threads is discussed and illustrated.

Thanks, that's what I thought. I was hoping to avoid having to write another method thread, but I guess there is no way around it.