iTextSharp.text.pdf.PdfStamperImp.ReadOCProperties C# (CSharp) Метод

        protected void ReadOCProperties()
        {
            if (documentOCG.Count != 0) {
                return;
            }
            PdfDictionary dict = reader.Catalog.GetAsDict(PdfName.OCPROPERTIES);
            if (dict == null) {
                return;
            }
            PdfArray ocgs = dict.GetAsArray(PdfName.OCGS);
            PdfIndirectReference refi;
            PdfLayer layer;
            Dictionary<string,PdfLayer> ocgmap = new Dictionary<string,PdfLayer>();
            for (ListIterator<PdfObject> i = ocgs.GetListIterator(); i.HasNext();) {
                refi = (PdfIndirectReference)i.Next();
                layer = new PdfLayer(null);
                layer.Ref = refi;
                layer.OnPanel = false;
                layer.Merge((PdfDictionary)PdfReader.GetPdfObject(refi));
                ocgmap[refi.ToString()] = layer;
            }
            PdfDictionary d = dict.GetAsDict(PdfName.D);
            PdfArray off = d.GetAsArray(PdfName.OFF);
            if (off != null) {
                for (ListIterator<PdfObject> i = off.GetListIterator(); i.HasNext(); ) {
                    refi = (PdfIndirectReference)i.Next();
                    layer = ocgmap[refi.ToString()];
                    layer.On = false;
                }
            }
            PdfArray order = d.GetAsArray(PdfName.ORDER);
            if (order != null) {
                AddOrder(null, order, ocgmap);
            }
            foreach (PdfLayer o in ocgmap.Values)
                documentOCG[o] = null;
            OCGRadioGroup = d.GetAsArray(PdfName.RBGROUPS);
            if (OCGRadioGroup == null)
                OCGRadioGroup = new PdfArray();
            OCGLocked = d.GetAsArray(PdfName.LOCKED);
            if (OCGLocked == null)
                OCGLocked = new PdfArray();
        }