private void updatePreviewPanel(JComponent preview)
void updatePreviewPanel(JComponent preview)
  private void updatePreviewPanel(JComponent preview)  {    if (prevContainer == null)      {	prevContainer = new JPanel();	prevContainer.setLayout(new BorderLayout());	chooser.add(prevContainer, BorderLayout.CENTER);      }    prevContainer.removeAll();    prevContainer.add(preview, BorderLayout.CENTER);  }