public virtual void FullCompressionAppendMode()
{
PdfWriter writer = new PdfWriter(destinationFolder + "fullCompressionAppendMode.pdf", new WriterProperties
().SetFullCompressionMode(true).SetCompressionLevel(CompressionConstants.NO_COMPRESSION));
PdfDocument pdfDocument = new PdfDocument(new PdfReader(sourceFolder + "fullCompressionDoc.pdf"), writer,
new StampingProperties().UseAppendMode());
PdfPage page = pdfDocument.GetPage(1);
PdfStream contentStream = new PdfStream();
String contentStr = iText.IO.Util.JavaUtil.GetStringForBytes(pdfDocument.GetPage(1).GetFirstContentStream(
).GetBytes(), Encoding.ASCII);
contentStream.SetData(contentStr.Replace("/F1 16", "/F1 24").GetBytes(Encoding.ASCII));
page.GetPdfObject().Put(PdfName.Contents, contentStream);
page.SetModified();
pdfDocument.Close();
NUnit.Framework.Assert.IsNull(new CompareTool().CompareByContent(destinationFolder + "fullCompressionAppendMode.pdf"
, sourceFolder + "cmp_fullCompressionAppendMode.pdf", destinationFolder, "diff_"));
PdfDocument assertDoc = new PdfDocument(new PdfReader(destinationFolder + "fullCompressionAppendMode.pdf")
);
NUnit.Framework.Assert.IsTrue(assertDoc.GetPdfObject(9).IsStream());
NUnit.Framework.Assert.AreEqual(1, ((PdfDictionary)assertDoc.GetPdfObject(9)).GetAsNumber(PdfName.N).IntValue
());
}
/// <summary>
/// Flushes to the output stream modified objects that can belong only to the given page, which makes this method
/// "safe" compared to the
/// <see cref="UnsafeFlushDeep(int)"/>
/// . Flushed object frees the memory, but it's impossible to
/// modify such objects or read data from them. This method releases all other page structure objects that are not
/// modified.
/// <p>
/// This method is mainly designed for the append mode. It is similar to the
/// <see cref="PdfPage.Flush()"/>
/// , but it
/// additionally releases all page objects that were not flushed. This method is ideal for small amendments of pages,
/// but it makes more sense to use
/// <see cref="PdfPage.Flush()"/>
/// for newly created or heavily modified pages. <br />
/// This method will throw an exception for documents opened in reading mode (see
/// <see cref="PageFlushingHelper"/>
/// for more details on modes). It is also not advised to be used in stamping mode: even though it will indeed
/// release the objects and free the memory, the released objects will definitely be re-read again on document
/// closing, which would affect performance.
/// </p>
/// <p>
/// When using this method in append mode (or in stamping mode), be careful not to try to modify the object instances
/// obtained before this method call! See
/// <see cref="PageFlushingHelper"/>
/// for details on released and flushed objects state.
/// </p>
/// <p>
/// This method shall be used only when it's known that the page and its inner structures processing is finished.
/// This includes reading data from pages, page modification and page handling via addons/utilities.
/// </p>
/// </summary>
/// <param name="pageNum">the page number which low level objects structure is to be flushed or released from memory.
/// </param>
public virtual void AppendModeFlush(int pageNum)
{
if (pdfDoc.GetWriter() == null)
{
throw new ArgumentException(PdfException.FlushingHelperFLushingModeIsNotForDocReadingMode);
}
PdfPage page = pdfDoc.GetPage(pageNum);
if (page.IsFlushed())
{
return;
}
page.GetDocument().DispatchEvent(new PdfDocumentEvent(PdfDocumentEvent.END_PAGE, page));
bool pageWasModified = page.GetPdfObject().IsModified();
page.SetModified();
release = true;
pageWasModified = FlushPage(pageNum) || pageWasModified;
PdfArray annots = page.GetPdfObject().GetAsArray(PdfName.Annots);
if (annots != null && !annots.IsFlushed())
{
ArrayFlushIfModified(annots);
}
PdfObject thumb = page.GetPdfObject().Get(PdfName.Thumb, false);
FlushIfModified(thumb);
PdfObject contents = page.GetPdfObject().Get(PdfName.Contents, false);
if (contents is PdfIndirectReference)
{
if (contents.CheckState(PdfObject.MODIFIED) && !contents.CheckState(PdfObject.FLUSHED))
{
PdfObject contentsDirectObj = ((PdfIndirectReference)contents).GetRefersTo();
if (contentsDirectObj.IsArray())
{
ArrayFlushIfModified((PdfArray)contentsDirectObj);
}
else
{
contentsDirectObj.Flush();
}
}
}
else
{
// already checked that modified
if (contents is PdfArray)
{
ArrayFlushIfModified((PdfArray)contents);
}
else
{
if (contents is PdfStream)
{
FlushIfModified(contents);
}
}
}
// Page tags flushing is supported only in PdfPage#flush and #unsafeFlushDeep: it makes sense to flush tags
// completely for heavily modified or new pages. For the slightly modified pages it should be enough to release
// the tag structure objects via tag structure releasing utility.
if (!pageWasModified)
{
page.GetPdfObject().GetIndirectReference().ClearState(PdfObject.MODIFIED);
pdfDoc.GetCatalog().GetPageTree().ReleasePage(pageNum);
page.UnsetForbidRelease();
page.GetPdfObject().Release();
}
else
{
// inherited and modified resources are handled in #flushPage call in the beginning of method
page.ReleaseInstanceFields();
page.GetPdfObject().Flush();
}
}
