code: protected File getDownloadFile() throws CmsRuntimeException {
  
          if (m_downloadFile == null) {
              // no clone needed: we just read here.
              CmsRfsFileViewer fileView = OpenCms.getWorkplaceManager().getFileViewSettings();
              m_downloadFile = new File(fileView.getFilePath());
              try {
                  // 2nd check: it is impossible to set an invalid path to that class.
                  m_downloadFile = m_downloadFile.getCanonicalFile();
              } catch (IOException ioex) {
                  throw new CmsRuntimeException(Messages.get().container(Messages.ERR_FILE_ACCESS_0), ioex);
              }
          }
          return m_downloadFile;
      }
docs: Returns the file that will be downloaded upon clicking the download button
  generated in this form by <code>{@link #dialogButtonsOkCancel()}</code>.<p>
  
  @return the file that will be downloaded upon clicking the download button
  generated in this form by <code>{@link #dialogButtonsOkCancel()}</code>
  
  @throws CmsRuntimeException if access to the chosen file to download fails