Tumble feedback

[Eric Smith]

> I've since realised that I fooled the parser, but that the output wasn't
> correct.

I'll take a look when I get a chance, but it may not be too soon.

>  From a cursory look at the code, it appears that the data for the
> missing bookmarks is forgotten about when the closing brace for bookmark
> "2.2" is reached. The bookmark information should have been written out
> to the file when a page was generated, but I haven't output a page at
> that point because I put the label in instead.

Could well be.

> I wonder if the simplest way of solving this problem is to completely
> separate the generation of pages from the making of the bookmark tree.

That's probably a good idea.

> I think that building the outline in this fashion might also solve the
> second problem of misplaced highlighting. In the section of the PDF
> Specification on linearized PDFs, there is a hint that the best order
> for the objects of an outline tree is to skip any subtree that is closed
> (as tumble's subtrees always are), and then go back and fill in the
> subtrees after the top level objects have been made. I wonder whether
> Acrobat relies on this ordering to get highlighting right.

Interesting theory.  In the process of developing Tumble I've definitely
found things that were theoretically legal PDF but that made Acrobat
Reader unhappy.  I've reported some of these to a contact at Adobe, but
I don't know whether any of them have been fixed.  This could well be
another one.

> I was going to test the theory by running pdfopt (part of GhostScript)
> on miniman.pdf, but it crashes!

Curiouser and curiouser.  I wasn't even aware of pdfopt, and had halfway
considered trying to write my own optimizer.  Maybe it's worth sending
a small PDF that crashed pdfopt to the Ghostscript maintainers.  It
could be a Ghostscript bug, but more likely I'm doing something bad in
my PDF output that you and I haven't identified.

It sure would be nice if Adobe offered a PDF file validator.

> Sorry for the length of message again! If my explanation is unclear, I'd
> be happy to have another go at it, because I really would like outlines
> to work in tumble.

So would I.  I really appreciate the feedback, and appologize for not
being able to take action on it quickly.

Best regards,
Eric