[Java-gnome-developer] Problem with Threading (I guess)

[Stefan P. <pr...@tz...>]

Hi all,

I am trying to build a splashscreen that shows the process while the
application is loading data. I found that after a short time, no
progress changes are visible while the loading continues.

I broke my problems down to a simple test program that forks a thread to
change the progress and that waits a specific amount of time between two
changes. 

public class SplashTest {

    static ProgressBar bar;
    static TextView text;
    
    //------------------------------------------------------
    public static void main(String[] args) {
        Gtk.init(args);
        
        // Open a window with a progress bar and a text view.
        Window window = new Window();
        VBox box = new VBox(false,5);
        window.add(box);
        bar = new ProgressBar();
        box.add(bar);
        text = new TextView();
        box.add(text);
        window.showAll();
        
        // Now create progress changing thread
        Thread thread = new Thread(new Runnable(){
           public void run() {
               for (int i=0; i<=100; i+=10) {
                   System.out.println("Now "+i);
                   bar.setFraction(i/100.0);
                   bar.setText(i+"%");
                   text.getBuffer().setText("Loaded "+i+"%");
                   synchronized(this) {
                       try {
                           Thread.sleep(1000);
                       } catch (InterruptedException e) {
                           // TODO Auto-generated catch block
                           e.printStackTrace();
                       }
                   }
               }                
            }});
        
        thread.start();
        Gtk.main();
    }
}

When I do run this program, the progress bar stops at 10 or 20 percent,
the text view stops at 0 or 10 percent. 
If you reduce the waiting time between changes to a lower value - e.g.
500ms - everything is fine.

Any idea what is causing this?

Regards,
  Stefan