private void showProgressDialog() {
    final ProgressMonitorDialog dialog = new ProgressMonitorDialog( getShell() ) {

      @Override
      public boolean close() {
        return super.close();
      }
    };
    dialog.setBlockOnOpen( false );
    try {
      dialog.run( true, true, new IRunnableWithProgress() {

        @Override
        public void run( IProgressMonitor monitor )
          throws InvocationTargetException, InterruptedException
        {
          monitor.beginTask( "Counting to 12...", 12 );
          for( int i = 1; !monitor.isCanceled() && i <= 12; i++ ) {
            monitor.worked( 1 );
            Thread.sleep( 300 );
          }
          // open a blocking dialog 
          dialog.getShell().getDisplay().syncExec( new Runnable() {
            @Override
            public void run() {
              MessageDialog.openInformation( getShell(), "Blocking Dialog", "Hallo!" );
            }
          } );
          monitor.done();
        }
      } );
    } catch( Exception e ) {
      MessageDialogUtil.openError( getShell(), "Error", e.getMessage(), null );
    }
  }