/// <summary>PDF 2.0.</summary>
/// <remarks>
/// PDF 2.0. Sets an array of names of Viewer preference settings that
/// shall be enforced by PDF processors and that shall not be overridden by
/// subsequent selections in the application user interface
/// </remarks>
/// <param name="enforce">array of names specifying settings to enforce in the PDF processors</param>
/// <returns>
/// this
/// <see cref="PdfViewerPreferences"/>
/// instance
/// </returns>
public virtual iText.Kernel.Pdf.PdfViewerPreferences SetEnforce(PdfArray enforce)
{
for (int i = 0; i < enforce.Size(); i++)
{
PdfName curEnforce = enforce.GetAsName(i);
if (curEnforce == null)
{
throw new ArgumentException("Enforce array shall contain PdfName entries");
}
else
{
if (PdfName.PrintScaling.Equals(curEnforce))
{
// This name may appear in the Enforce array only if the corresponding entry in
// the viewer preferences dictionary specifies a valid value other than AppDefault
PdfName curPrintScaling = GetPdfObject().GetAsName(PdfName.PrintScaling);
if (curPrintScaling == null || PdfName.AppDefault.Equals(curPrintScaling))
{
throw new PdfException(PdfException.PrintScalingEnforceEntryInvalid);
}
}
}
}
return(Put(PdfName.Enforce, enforce));
}
/// <summary>
/// Performs a check if the
/// <see cref="PdfStream"/>
/// with provided setup of the filters requires
/// memory limits awareness during decompression.
/// </summary>
/// <param name="filters">
/// is an
/// <see cref="PdfArray"/>
/// of names of filters
/// </param>
/// <returns>true if PDF stream is suspicious and false otherwise</returns>
public virtual bool IsMemoryLimitsAwarenessRequiredOnDecompression(PdfArray filters)
{
HashSet <PdfName> filterSet = new HashSet <PdfName>();
for (int index = 0; index < filters.Size(); index++)
{
PdfName filterName = filters.GetAsName(index);
if (!filterSet.Add(filterName))
{
return(true);
}
}
return(false);
}
protected internal virtual byte[] DecodeFlateBytes(PdfStream stream, byte[] bytes)
{
PdfObject filterObject = stream.Get(PdfName.Filter);
if (filterObject == null)
{
return(bytes);
}
// check if flateDecode filter is on top
PdfName filterName;
PdfArray filtersArray = null;
if (filterObject is PdfName)
{
filterName = (PdfName)filterObject;
}
else
{
if (filterObject is PdfArray)
{
filtersArray = (PdfArray)filterObject;
filterName = filtersArray.GetAsName(0);
}
else
{
throw new PdfException(PdfException.FilterIsNotANameOrArray);
}
}
if (!PdfName.FlateDecode.Equals(filterName))
{
return(bytes);
}
// get decode params if present
PdfDictionary decodeParams;
PdfArray decodeParamsArray = null;
PdfObject decodeParamsObject = stream.Get(PdfName.DecodeParms);
if (decodeParamsObject == null)
{
decodeParams = null;
}
else
{
if (decodeParamsObject.GetObjectType() == PdfObject.DICTIONARY)
{
decodeParams = (PdfDictionary)decodeParamsObject;
}
else
{
if (decodeParamsObject.GetObjectType() == PdfObject.ARRAY)
{
decodeParamsArray = (PdfArray)decodeParamsObject;
decodeParams = decodeParamsArray.GetAsDictionary(0);
}
else
{
throw new PdfException(PdfException.DecodeParameterType1IsNotSupported).SetMessageParams(decodeParamsObject
.GetType().ToString());
}
}
}
// decode
byte[] res = FlateDecodeFilter.FlateDecode(bytes, true);
if (res == null)
{
res = FlateDecodeFilter.FlateDecode(bytes, false);
}
bytes = FlateDecodeFilter.DecodePredictor(res, decodeParams);
//remove filter and decode params
filterObject = null;
if (filtersArray != null)
{
filtersArray.Remove(0);
if (filtersArray.Size() == 1)
{
filterObject = filtersArray.Get(0);
}
else
{
if (!filtersArray.IsEmpty())
{
filterObject = filtersArray;
}
}
}
decodeParamsObject = null;
if (decodeParamsArray != null)
{
decodeParamsArray.Remove(0);
if (decodeParamsArray.Size() == 1 && decodeParamsArray.Get(0).GetObjectType() != PdfObject.NULL)
{
decodeParamsObject = decodeParamsArray.Get(0);
}
else
{
if (!decodeParamsArray.IsEmpty())
{
decodeParamsObject = decodeParamsArray;
}
}
}
if (filterObject == null)
{
stream.Remove(PdfName.Filter);
}
else
{
stream.Put(PdfName.Filter, filterObject);
}
if (decodeParamsObject == null)
{
stream.Remove(PdfName.DecodeParms);
}
else
{
stream.Put(PdfName.DecodeParms, decodeParamsObject);
}
return(bytes);
}
