title: JavaFx ProgressBar doesn't update
body: <p>I try to understand how to update a ProgressBar in a multithreaded environment. I'm doing something wrong here but I don't see what it is. This should simply fill up the bar every 3sec but it doesn't:</p>
  
  <pre><code>    Task&lt;Void&gt; task = new Task&lt;Void&gt;(){
          @Override
          public Void call(){
              for (int i = 1; i &lt; 10; i++)    {
                  try {
                      Thread.sleep(3000);
                  } catch (InterruptedException e) {
                      e.printStackTrace();
                  }
                  System.out.println(i);
                  updateProgress(i , 10);
              }
          return null;                
          }
      };
  
      updProg = new ProgressBar();
      updProg.progressProperty().bind(task.progressProperty());
  
      Thread th = new Thread(task);
      th.setDaemon(true);
      th.start();
  </code></pre>
  
  <p>What am I missing?</p>