/// <summary>
/// Trim a string of any PDF comment, returning the trimmed string and the extracted comment text
/// </summary>
/// <param name="OriginalLine">Data line as read from PDF file</param>
/// <param name="Comment">Complete text of the comment in the line, null if line contains no comment</param>
/// <param name="CommentStart">Index into OriginalLine of comment character, -1 if line contains no comment</param>
/// <param name="CommentEnd">Index into OriginalLine of last character in comment (after EOL). Will be -1 if line contains no comment</param>
public static void ExtractPDFComment(byte[] OriginalLine, out byte[] Comment, out int CommentStart, out int CommentEnd)
{
CommentStart = PDF.CommentStart(OriginalLine);
Comment = PDF.ExtractPDFLine(OriginalLine, CommentStart, out CommentEnd);
}
/// <summary>
/// Read a number of tokens (seperated by whitespace) from a PDF data stream as UTF8 characters
/// </summary>
/// <param name="Data">Data stream to read</param>
/// <param name="StartingIndex">Starting offset</param>
/// <param name="TokenStartIndex">Offset in the data array where the token appears</param>
/// <param name="EndingIndex">Offset in the data array where reading stopped</param>
/// <param name="WordCount">Number of tokens sepreated by whitespace to read. If multiple words are read, all whitespace will be replaced by a single space character (0x20)</param>
/// <returns>Read tokens as a UTF8 string, or NULL if unable to read the specified number of words before running out of data</returns>
internal static string GetTokenString(byte[] Data, int StartingIndex, out int TokenStartIndex, out int EndingIndex, int WordCount = 1)
{
List <Byte> TokenString = new List <Byte>(20);
bool InComment = false;
bool InWhitespace = false;
TokenStartIndex = 0;
EndingIndex = StartingIndex;
while ((WordCount > 0) && (EndingIndex < Data.Length))
{
byte DataByte = Data[EndingIndex];
InComment = InComment || (DataByte == PDF.CommentDelimiter);
if (InComment)
{
InComment = !PDF.IsEOL(DataByte);
}
else
{
if (InWhitespace && !PDF.IsWhitespace(DataByte))
{
InWhitespace = false;
}
if (!InWhitespace)
{
if (PDF.IsWhitespace(DataByte))
{
InWhitespace = true;
if (TokenString.Count > 0)
{
// Don't add leading/trailing whitespace
WordCount--;
if (WordCount > 0)
{
TokenString.Add(0x20);
}
}
}
else
{
if (TokenString.Count == 0)
{
TokenStartIndex = EndingIndex;
}
TokenString.Add(DataByte);
}
}
}
EndingIndex++;
}
if (WordCount > 0)
{
return(null);
}
return(Encoding.UTF8.GetString(TokenString.ToArray()));
}