private static ICollection<PdfIndirectReference> GetAllUsedNonFlushedOCGs(IDictionary<PdfPage, PdfPage> page2page
, PdfDictionary toOcProperties) {
// NOTE: the PDF is considered to be valid and therefore the presence of OСG in OCProperties.OCGs is not checked
ICollection<PdfIndirectReference> fromUsedOcgs = new LinkedHashSet<PdfIndirectReference>();
// Visit the pages in parallel to find non-flush OSGs
PdfPage[] fromPages = page2page.Keys.ToArray(new PdfPage[0]);
PdfPage[] toPages = page2page.Values.ToArray(new PdfPage[0]);
for (int i = 0; i < toPages.Length; i++) {
PdfPage fromPage = fromPages[i];
PdfPage toPage = toPages[i];
// Copy OCGs from annotations
IList<PdfAnnotation> toAnnotations = toPage.GetAnnotations();
IList<PdfAnnotation> fromAnnotations = fromPage.GetAnnotations();
for (int j = 0; j < toAnnotations.Count; j++) {
if (!toAnnotations[j].IsFlushed()) {
PdfDictionary toAnnotDict = toAnnotations[j].GetPdfObject();
PdfDictionary fromAnnotDict = fromAnnotations[j].GetPdfObject();
PdfAnnotation toAnnot = toAnnotations[j];
PdfAnnotation fromAnnot = fromAnnotations[j];
if (!toAnnotDict.IsFlushed()) {
iText.Kernel.Pdf.OcgPropertiesCopier.GetUsedNonFlushedOCGsFromOcDict(toAnnotDict.GetAsDictionary(PdfName.OC
), fromAnnotDict.GetAsDictionary(PdfName.OC), fromUsedOcgs, toOcProperties);
iText.Kernel.Pdf.OcgPropertiesCopier.GetUsedNonFlushedOCGsFromXObject(toAnnot.GetNormalAppearanceObject(),
fromAnnot.GetNormalAppearanceObject(), fromUsedOcgs, toOcProperties);
iText.Kernel.Pdf.OcgPropertiesCopier.GetUsedNonFlushedOCGsFromXObject(toAnnot.GetRolloverAppearanceObject(
), fromAnnot.GetRolloverAppearanceObject(), fromUsedOcgs, toOcProperties);
iText.Kernel.Pdf.OcgPropertiesCopier.GetUsedNonFlushedOCGsFromXObject(toAnnot.GetDownAppearanceObject(), fromAnnot
.GetDownAppearanceObject(), fromUsedOcgs, toOcProperties);
}
}
}
PdfDictionary toResources = toPage.GetPdfObject().GetAsDictionary(PdfName.Resources);
PdfDictionary fromResources = fromPage.GetPdfObject().GetAsDictionary(PdfName.Resources);
iText.Kernel.Pdf.OcgPropertiesCopier.GetUsedNonFlushedOCGsFromResources(toResources, fromResources, fromUsedOcgs
, toOcProperties);
}
return fromUsedOcgs;
}