protected internal virtual void UpdateCompressionFilter(PdfStream pdfStream)
{
PdfObject filter = pdfStream.Get(PdfName.Filter);
if (filter == null)
{
pdfStream.Put(PdfName.Filter, PdfName.FlateDecode);
}
else
{
PdfArray filters = new PdfArray();
filters.Add(PdfName.FlateDecode);
if (filter is PdfArray)
{
filters.AddAll((PdfArray)filter);
}
else
{
filters.Add(filter);
}
PdfObject decodeParms = pdfStream.Get(PdfName.DecodeParms);
if (decodeParms != null)
{
if (decodeParms is PdfDictionary)
{
PdfArray array = new PdfArray();
array.Add(new PdfNull());
array.Add(decodeParms);
pdfStream.Put(PdfName.DecodeParms, array);
}
else
{
if (decodeParms is PdfArray)
{
((PdfArray)decodeParms).Add(0, new PdfNull());
}
else
{
throw new PdfException(PdfException.DecodeParameterType1IsNotSupported).SetMessageParams(decodeParms.GetType
().ToString());
}
}
}
pdfStream.Put(PdfName.Filter, filters);
}
}