GUI freezes when new Thread object start()ed. Neat, brief code included :)

Question

The title says it all really.. I have the code below in a method startScan() that is called when a button is pressed. The thread executes fine, but the GUI locks up while the thread is executing. I don't really understand why, since a new thread is implicitly separate from the event dispatch thread.
Must I use a SwingWorker to get things working? Would someone be kind enough to explain why, if this is the case?
private void startScan() throws InterruptedException {
          final Runnable breadthFirstComparer = new Runnable() {
               /** Sleep interval used when scan paused */
               private int interval = 1000;
                * Kills the current thread
               public void stop() {
                    scanProgressLabel.setText("Scanning complete");
                    scanComplete = true;
                * Sleeps the currently running thread if user has paused the scan,
                * otherwise initiates comparison of the trees' next depth node sets
               public void run() {
                    while (!scanComplete) {
                         while (scanPaused) {
                              try {
                                   Thread.sleep(interval);
                              } catch (Throwable exc) {
                                   Gecko.logException("Scanner thread could not be paused", exc);
                         compareTrees();
                    // Stop thread execution once scan is complete, and disable
                    // scanner-related buttons
                    toggleScanButton.setEnabled(false);
                    stop();
          scanner = new Thread(breadthFirstComparer)
               public void start() {
                    scanProgressLabel.setText("Scanning in progress...");
                    breadthFirstComparer.run();
          scanButton.setEnabled(false);
          scanner.start();
     }Many thanks.

Answer 1

it's getting really irritating that pretty much every thread out of the last
20 I've made, you've criticised me for not posting an SSCCE. How do you think I feel. I'm donating my time to help you solve a problem, but you are not willing to spend 5-10 minutes to post a SSCCE so that we can fully understand what you have done and what the problem is.
You don't have to post a SSCCE if you don't want to. Thats fine, I just won't answer your questions.
what's the point me spending 30 minutes or more my end creating an
SSCE, and you spending 10 minutes or more compiling, running and analyzing it your end?It should not take 30 minutes. If it does it just goes to prove that you don't really understand what you are attempting to do. And if you don't know what you are doing how do you expect us to guess what you are doing? One of the benefits of a SSCCE it to help you learn to develop problem solving skills by learning to simplfy the problem.
Also, what if we can't figure out the problem based on your verbal description of the problem? If you post code it gives us the option of compiling and testing the code if we so desire. Without the code we give up and move on to the next question.
but since the simple information that you've provided, and the chunk of code that Michal so kindly donated, are likely more than enough of an explanationThis time we were able to guess what the problem was, but that is not true in all cases. You seem to think that we are all miracle workers, that you can place a couple of lines of code in front of us and we can automatically tell whats wrong. Well, thats not true (at least for me). Many times I use my problem solving skills to solve the problem.
I really should learn to scroll down and read all the posting before replying. es5f2000 pretty much said it all for me.
Message was edited by:
camickr