/// <summary>
/// Reads cross reference table(s) and trailer(s).
/// </summary>
private PdfTrailer ReadXRefTableAndTrailer(PdfCrossReferenceTable xrefTable)
{
Debug.Assert(xrefTable != null);
Symbol symbol = ScanNextToken();
if (symbol == Symbol.XRef) // Is it a cross-reference table?
{
// Reference: 3.4.3 Cross-Reference Table / Page 93
while (true)
{
symbol = ScanNextToken();
if (symbol == Symbol.Integer)
{
int start = _lexer.TokenToInteger;
int length = ReadInteger();
for (int id = start; id < start + length; id++)
{
int position = ReadInteger();
int generation = ReadInteger();
ReadSymbol(Symbol.Keyword);
string token = _lexer.Token;
// Skip start entry
if (id == 0)
continue;
// Skip unused entries.
if (token != "n")
continue;
// Even it is restricted, an object can exists in more than one subsection.
// (PDF Reference Implementation Notes 15).
PdfObjectID objectID = new PdfObjectID(id, generation);
// Ignore the latter one.
if (xrefTable.Contains(objectID))
continue;
xrefTable.Add(new PdfReference(objectID, position));
}
}
else if (symbol == Symbol.Trailer)
{
ReadSymbol(Symbol.BeginDictionary);
PdfTrailer trailer = new PdfTrailer(_document);
ReadDictionary(trailer, false);
return trailer;
}
else
ParserDiagnostics.HandleUnexpectedToken(_lexer.Token);
}
}
// ReSharper disable once RedundantIfElseBlock because of code readability.
else if (symbol == Symbol.Integer) // Is it an cross-reference stream?
{
// Reference: 3.4.7 Cross-Reference Streams / Page 93
// TODO: Handle PDF files larger than 2 GiB, see implementation note 21 in Appendix H.
// The parsed integer is the object id of the cross-refernece stream.
return ReadXRefStream(xrefTable);
}
return null;
}
/// <summary>
///
/// </summary>
PdfTrailer ReadXRefTableAndTrailer(PdfReferenceTable xrefTable)
{
Debug.Assert(xrefTable != null);
Symbol symbol = ScanNextToken();
// Is it an xref stream?
if (symbol == Symbol.Integer)
throw new PdfReaderException(PSSR.CannotHandleXRefStreams);
// TODO: We have all code to handle them -> just do it
Debug.Assert(symbol == Symbol.XRef);
while (true)
{
symbol = ScanNextToken();
if (symbol == Symbol.Integer)
{
int start = this.lexer.TokenToInteger;
int length = ReadInteger();
for (int id = start; id < start + length; id++)
{
int position = ReadInteger();
int generation = ReadInteger();
ReadSymbol(Symbol.Keyword);
string token = lexer.Token;
// Skip start entry
if (id == 0)
continue;
// Skip unused entries.
if (token != "n")
continue;
// Even it is restricted, an object can exists in more than one subsection.
// (PDF Reference Implementation Notes 15).
PdfObjectID objectID = new PdfObjectID(id, generation);
// Ignore the latter one
if (xrefTable.Contains(objectID))
continue;
xrefTable.Add(new PdfReference(objectID, position));
}
}
else if (symbol == Symbol.Trailer)
{
ReadSymbol(Symbol.BeginDictionary);
PdfTrailer trailer = new PdfTrailer(this.document);
this.ReadDictionary(trailer, false);
return trailer;
}
else
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
}
}
void Initialize()
{
//_info = new PdfInfo(this);
_fontTable = new PdfFontTable(this);
_imageTable = new PdfImageTable(this);
_trailer = new PdfTrailer(this);
_irefTable = new PdfCrossReferenceTable(this);
_trailer.CreateNewDocumentIDs();
}
