How to convert an array of stream in Contents to PRIndirectRefernce? - itext

Question

I am trying to read pdf and get the text present in it. Using Nugget iTextSharp -LGPL v4.1.5 . (I am not allowed to use ITextsharp v5.5.13 and it makes life difficult)
private string GetTextFromPage(PdfReader pdfReader, int page)
{
StringBuilder pageText = new StringBuilder();
var cpage = pdfReader.GetPageN(page);
var content = cpage.Get(PdfName.CONTENTS);
//Error for casting Pdfarray to PRIndirectReference
var indirectReference = (PRIndirectReference)content;
}
Getting Exception
System.InvalidCastException : Unable to cast object of type 'iTextSharp.text.pdf.PdfArray' to type 'iTextSharp.text.pdf.PRIndirectReference'.
Kindly suggest how to handle PdfArray object (multiple streams in contents)

Answer 1

I am not too versed in c# but the java code should be easily transferable to c#
I would do it like this:
private byte[] getTextFromPage(PdfReader pdfReader, int page){
PdfDictionary cpage = pdfReader.GetPageN(page);
PdfObject content = cpage.get(PdfName.CONTENTS);
return getContent(content);
}
private byte[] getContent(PdfObject content) throws IOException {
byte[] result=null;
switch (content.type()){
case PdfObject.INDIRECT:
PRIndirectReference ref = (PRIndirectReference) content;
PdfObject directObject = PdfReader.getPdfObject(ref);
result = getContent(directObject);
break;
case PdfObject.ARRAY:
ByteArrayOutputStream baos = new ByteArrayOutputStream();
PdfArray cArray = (PdfArray) content;
for(Object object : cArray.getArrayList()) {
baos.write(getContent((PdfObject) object));
}
result = baos.toByteArray();
break;
case PdfObject.STREAM:
PRStream stream = (PRStream) PdfReader.getPdfObject(content);
result = PdfReader.getStreamBytes(stream);
break;
default:
throw new IllegalStateException("Unsupported content type");
}
return result;
}
But this is only a small step in retrieving the text. You need the whole operator processing, leading, spacing, scaling, font handling etc. So to completely write it from scratch is a big task...