Hello there,
We are working on a product that supports highlighting a PDF as one of its
features. The way we are currently highlighting a document is as follows:
1) Create an empty PDF which has the same number of pages as the 'document
to be highlighted'.
2) Draw a free form highlight on the empty document
3) Put the document to be highlighted on top of the empty document to
highlight the text we want to highlight using library's Overlay.overlay method
as
a. PDDocument finalDoc = new
Overlay().overlay(overlayingPdf.getDocument(), bottomDocument);
This all works perfectly until the document version changes i.e. it won't work
with a document that was created with Adobe version 1.3. Following is the code
from PDDocument.java in PDFBox that hard codes version to be 1.4.
public PDDocument() throws IOException
{
document = new COSDocument();
//First we need a trailer
COSDictionary trailer = new COSDictionary();
document.setTrailer( trailer );
//Next we need the root dictionary.
COSDictionary rootDictionary = new COSDictionary();
trailer.setItem( COSName.ROOT, rootDictionary );
rootDictionary.setItem( COSName.TYPE, COSName.CATALOG );
rootDictionary.setItem( COSName.VERSION, COSName.getPDFName( "1.4" ) );
//next we need the pages tree structure
COSDictionary pages = new COSDictionary();
rootDictionary.setItem( COSName.PAGES, pages );
pages.setItem( COSName.TYPE, COSName.PAGES );
COSArray kidsArray = new COSArray();
pages.setItem( COSName.KIDS, kidsArray );
pages.setItem( COSName.COUNT, COSInteger.ZERO );
}
As you can see that the library sets up the PDF document version to be 1.4
(highlighted above). So if the version is 1.3, the library will only put
highlighting and the original contents of the 'document to be highlighted' will
be gone.
Is it a limitation of the library? Is there a workaround this problem?
We are trying to meet a deadline and were very happy with our approach until we
hit this issue. I would really be thankful for your help into this matter.
Attached is the original pdf and the resulted pdf.
Cheers,
Haris
