public DocumentDisplayWork AddDocumentDisplayWork(DocumentDisplayWork.StarburstColor starburst_color, string starburst_caption, PDFDocument pdf_document)
            {
                DocumentDisplayWork ddw = new DocumentDisplayWork();

                ddw.starburst_color   = starburst_color;
                ddw.starburst_caption = starburst_caption;
                ddw.pdf_document      = pdf_document;
                ddws.Add(ddw);

                return(ddw);
            }
 private void UpdateLibraryStatistics_Stats_Background_GUI_FillPlaceHolder(DocumentDisplayWork ddw)
 {
     ddw.image.Source      = ddw.page_bitmap_source;
     ddw.border.Visibility = Visibility.Visible;
 }