/// ------------------------------------------------------------------------------------
 /// <summary>
 /// Gets the HVO of the current book, or -1 if there is no current book (e.g. no
 /// selection or empty view).
 /// </summary>
 /// <param name="selHelper">The selection helper.</param>
 /// <param name="selLimitType">Which end of the selection</param>
 /// <returns>The book hvo.</returns>
 /// ------------------------------------------------------------------------------------
 public int GetBookHvo(SelectionHelper selHelper,
                       SelectionHelper.SelLimitType selLimitType)
 {
     return(m_locationTracker.GetBookHvo(selHelper, selLimitType));
 }