/// <summary>
/// Reads the next token that must be the specified one.
/// </summary>
Symbol ReadToken(string token)
{
Symbol current = this.lexer.ScanNextToken();
if (token != this.lexer.Token)
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
return current;
}
/// <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));
}
}
}
/// <summary>
/// Reads the next symbol that must be the specified one.
/// </summary>
Symbol ReadSymbol(Symbol symbol)
{
Symbol current = this.lexer.ScanNextToken();
if (symbol != current)
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
return current;
}
/// <summary>
/// Reads a name from the PDF data stream. The preceding slash is part of the result string.
/// </summary>
string ReadName()
{
string name;
Symbol symbol = ScanNextToken(out name);
if (symbol != Symbol.Name)
throw new PdfReaderException(PSSR.UnexpectedToken(name));
return name;
}
/// <summary>
/// Reads the next symbol that must be the specified one.
/// </summary>
CSymbol ReadSymbol(CSymbol symbol)
{
CSymbol current = _lexer.ScanNextToken();
if (symbol != current)
{
ContentReaderDiagnostics.ThrowContentReaderException(PSSR.UnexpectedToken(_lexer.Token));
}
return(current);
}
/// <summary>
/// Reads the next token that must be the specified one.
/// </summary>
Symbol ReadToken(string token)
{
Symbol current = lexer.ScanNextToken();
if (token != lexer.Token)
{
throw new PdfReaderException(PSSR.UnexpectedToken(lexer.Token));
}
return(current);
}
/// <summary>
/// Reads the next symbol that must be the specified one.
/// </summary>
Symbol ReadSymbol(Symbol symbol)
{
Symbol current = lexer.ScanNextToken();
if (symbol != current)
{
throw new PdfReaderException(PSSR.UnexpectedToken(lexer.Token));
}
return(current);
}
/// <summary>
/// Reads the next symbol that must be the specified one.
/// </summary>
CSymbol ReadSymbol(CSymbol symbol)
{
CSymbol current = this.lexer.ScanNextToken();
if (symbol != current)
{
throw new ContentReaderException(PSSR.UnexpectedToken(this.lexer.Token));
}
return(current);
}
/*
/// <summary>
/// Reads a string immediately or (optionally) indirectly from the PDF data stream.
/// </summary>
protected string ReadString(bool canBeIndirect)
{
Symbol symbol = Symbol.None; //this.lexer.ScanNextToken(canBeIndirect);
if (symbol == Symbol.String || symbol == Symbol.HexString)
return this.lexer.Token;
else if (symbol == Symbol.R)
{
int position = this.lexer.Position;
MoveToObject(this.lexer.Token);
ReadObjectID(null);
string s = ReadString();
ReadSymbol(Symbol.EndObj);
this.lexer.Position = position;
return s;
}
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
}
protected string ReadString()
{
return ReadString(false);
}
/// <summary>
/// Reads a string immediately or (optionally) indirectly from the PDF data stream.
/// </summary>
protected bool ReadBoolean(bool canBeIndirect)
{
Symbol symbol = this.lexer.ScanNextToken(canBeIndirect);
if (symbol == Symbol.Boolean)
return this.lexer.TokenToBoolean;
else if (symbol == Symbol.R)
{
int position = this.lexer.Position;
MoveToObject(this.lexer.Token);
ReadObjectID(null);
bool b = ReadBoolean();
ReadSymbol(Symbol.EndObj);
this.lexer.Position = position;
return b;
}
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
}
protected bool ReadBoolean()
{
return ReadBoolean(false);
}
*/
/// <summary>
/// Reads an integer value directly from the PDF data stream.
/// </summary>
int ReadInteger(bool canBeIndirect)
{
Symbol symbol = this.lexer.ScanNextToken();
if (symbol == Symbol.Integer)
return this.lexer.TokenToInteger;
else if (symbol == Symbol.R)
{
int position = this.lexer.Position;
// MoveToObject(this.lexer.Token);
ReadObjectID(null);
int n = ReadInteger();
ReadSymbol(Symbol.EndObj);
this.lexer.Position = position;
return n;
}
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
}
/// <summary>
/// Reads PDF object from input stream.
/// </summary>
/// <param name="pdfObject">Either the instance of a derived type or null. If it is null
/// an appropriate object is created.</param>
/// <param name="objectID">The address of the object.</param>
/// <param name="includeReferences">If true, specifies that all indirect objects
/// are included recursively.</param>
public PdfObject ReadObject(PdfObject pdfObject, PdfObjectID objectID, bool includeReferences)
{
MoveToObject(objectID);
int objectNumber = ReadInteger();
int generationNumber = ReadInteger();
#if DEBUG
// The following assertion sometime failed (see below)
//Debug.Assert(objectID == new PdfObjectID(objectNumber, generationNumber));
if (objectID != new PdfObjectID(objectNumber, generationNumber))
{
// A special kind of bug? Or is this an undocumented PDF feature?
// PDF4NET 2.6 provides a sample called 'Unicode', which produces a file 'unicode.pdf'
// The iref table of this file contains the following entries:
// iref
// 0 148
// 0000000000 65535 f
// 0000000015 00000 n
// 0000000346 00000 n
// ....
// 0000083236 00000 n
// 0000083045 00000 n
// 0000083045 00000 n
// 0000083045 00000 n
// 0000083045 00000 n
// 0000080334 00000 n
// ....
// Object 84, 85, 86, and 87 maps to the same dictionary, but all PDF readers I tested
// ignores this mismatch! The following assertion failed about 50 times with this file.
#if true_
string message = String.Format("xref entry {0} {1} maps to object {2} {3}.",
objectID.ObjectNumber, objectID.GenerationNumber, objectNumber, generationNumber);
Debug.Assert(false, message);
#endif
}
#endif
// Always use object ID from iref table (see above)
objectNumber = objectID.ObjectNumber;
generationNumber = objectID.GenerationNumber;
#if true_
Debug.WriteLine(String.Format("obj: {0} {1}", objectNumber, generationNumber));
#endif
ReadSymbol(Symbol.Obj);
bool checkForStream = false;
Symbol symbol = ScanNextToken();
switch (symbol)
{
case Symbol.BeginArray:
PdfArray array;
if (pdfObject == null)
{
array = new PdfArray(this.document);
}
else
{
array = (PdfArray)pdfObject;
}
//PdfObject.RegisterObject(array, objectID, generation);
pdfObject = ReadArray(array, includeReferences);
pdfObject.SetObjectID(objectNumber, generationNumber);
break;
case Symbol.BeginDictionary:
PdfDictionary dict;
if (pdfObject == null)
{
dict = new PdfDictionary(this.document);
}
else
{
dict = (PdfDictionary)pdfObject;
}
//PdfObject.RegisterObject(dict, objectID, generation);
checkForStream = true;
pdfObject = ReadDictionary(dict, includeReferences);
pdfObject.SetObjectID(objectNumber, generationNumber);
break;
// Acrobat 6 Professional proudly presents: The Null object!
// Even with a one-digit object number an indirect reference �x 0 R� to this object is
// one character larger than the direct use of �null�. Probable this is the reason why
// it is true that Acrobat Web Capture 6.0 creates this object, but obviously never
// creates a reference to it!
case Symbol.Null:
pdfObject = new PdfNullObject(this.document);
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.Boolean:
pdfObject = new PdfBooleanObject(this.document, string.Compare(this.lexer.Token, Boolean.TrueString, true) == 0); //!!!mod THHO 19.11.09
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.Integer:
pdfObject = new PdfIntegerObject(this.document, this.lexer.TokenToInteger);
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.UInteger:
pdfObject = new PdfUIntegerObject(this.document, this.lexer.TokenToUInteger);
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.Real:
pdfObject = new PdfRealObject(this.document, this.lexer.TokenToReal);
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.String:
pdfObject = new PdfStringObject(this.document, this.lexer.Token);
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.Name:
pdfObject = new PdfNameObject(this.document, this.lexer.Token);
pdfObject.SetObjectID(objectNumber, generationNumber);
ReadSymbol(Symbol.EndObj);
return(pdfObject);
case Symbol.Keyword:
// Should not come here anymore
throw new NotImplementedException("Keyword");
default:
// Should not come here anymore
throw new NotImplementedException("unknown token \"" + symbol + "\"");
}
symbol = ScanNextToken();
if (symbol == Symbol.BeginStream)
{
PdfDictionary dict = (PdfDictionary)pdfObject;
Debug.Assert(checkForStream, "Unexpected stream...");
int length = GetStreamLength(dict);
byte[] bytes = this.lexer.ReadStream(length);
#if true_
if (dict.Elements.GetString("/Filter") == "/FlateDecode")
{
if (dict.Elements["/Subtype"] == null)
{
try
{
byte[] decoded = Filtering.FlateDecode.Decode(bytes);
if (decoded.Length == 0)
{
goto End;
}
string pageContent = Filtering.FlateDecode.DecodeToString(bytes);
if (pageContent.Length > 100)
{
pageContent = pageContent.Substring(pageContent.Length - 100);
}
pageContent.GetType();
bytes = decoded;
dict.Elements.Remove("/Filter");
dict.Elements.SetInteger("/Length", bytes.Length);
}
catch
{
}
}
End :;
}
#endif
PdfDictionary.PdfStream stream = new PdfDictionary.PdfStream(bytes, dict);
dict.Stream = stream;
ReadSymbol(Symbol.EndStream);
symbol = ScanNextToken();
}
if (symbol != Symbol.EndObj)
{
throw new PdfReaderException(PSSR.UnexpectedToken(this.lexer.Token));
}
return(pdfObject);
}
