code: public final void setTransferText(final String transferText) {
          if (SwingUtilities.isEventDispatchThread()) {
              setTransferTextIntern(transferText);
          } else {
              try {
                  SwingUtilities.invokeLater(new Runnable() {
                      public void run() {
                          setTransferTextIntern(transferText);
                      }
                  });
              } catch (final Exception ex) {
                  ignore();
              }
          }
      }
docs: Set the transfer text. Can contain two possible variables: $N = Current
  file number, $M = Max file count. If called outside the EDT this method
  will switch to the UI thread using
  <code>SwingUtilities.invokeLater(Runnable)</code>.
  
  @param transferText
  Text to display for file number "N of M".