code: public void setDisplayOnly(boolean displayOnly) {
  
          m_isDiplayOny = displayOnly;
          if (displayOnly) {
              setVisibleColumns(TITLE, PATH);
          } else {
              setVisibleColumns(CHECKBOX, TITLE, PATH);
          }
      }
docs: Sets the display mode.<p>
  
  @param displayOnly <code>true</code> to display categories only, not selectable with a hidden check box