public string Build()
{
PdfMetadata = ValueOrDefault(PdfMetadata, PdfMetadataDefaultValue);
AddMetadata(PdfMetadata);
StringBuilder sb = new StringBuilder();
sb.Append($"%PDF-{Version}\n");
sb.Append(BinaryComment());
foreach (PdfObject pdfObject in PdfObjects)
{
sb.Append(pdfObject.Build());
}
var pdfFileUpUntilXref = sb.ToString(); // Temp pdf so that we can calculate position to Reference table
var xref = new PdfReferenceTable(pdfFileUpUntilXref, PdfObjects);
var xrefPosition = PdfHelpers.Encoding.GetByteCount(pdfFileUpUntilXref);
sb.Append($"{xref.ToString()}");
var trailer = new PdfTrailer(this.Catalog, PdfObjects.Count + 1, PdfMetadata);
sb.Append(trailer.Build());
// Tells pdf where to find xref table
sb.Append("startxref\n");
sb.Append($"{xrefPosition}\n");
sb.Append("%%EOF");
return(sb.ToString());
}
/// <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: It is very high on the todo list, but still undone
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));
}
}
}