[NTG-context] PDF viewer

[Max Chernoff]

Hi Hraban,

> Unfortunately, Firefox doesn’t register itself as a PDF viewer (at least 
> on MacOS), that means I can’t use it easily to open a PDF from the 
> command line (e.g. in scripts).

That's odd. You can set it as the default PDF viewer on Windows and
Linux at least.

> >> for forms:
> >>   - fill in
> > Yes.
> 
> Just checked again with current Firefox: It doesn’t work with all of my 
> test files.

I tested it with the eforms manual:

   http://mirrors.ctan.org/macros/latex/contrib/acrotex/doc/eformman.pdf
   
and it seems to work fine for me. I've also used it to fill out a few
government forms in the past and it's worked too. Unfortunately, I think
that there are like 12 incompatible ways of making a form in PDF, so
support probably heavily depends on how the document was made.

> >>   - print documents with/without form contents
> > Yes.
> 
> I couldn’t find an option to print without form contents. (But usually
> you would want filled forms, so “with” is ok.)

Well if you refresh the page, you can delete everything that you've
filled in :)

> >>   - custom checkmarks/radiobuttons should work & display correctly
> > 
> > Usually it works, sometimes it doesn't.
> > 
> >>   - JS for calculations
> > 
> > Usually it works, sometimes it doesn't.
> 
> Need to check further...

I checked with the eforms manual linked above. Check marks and radio
buttons seem to work, but calculations don't.

> >> for annotations (correction workflow; generally just nice to have):
> >>   - similar to Adobe/Foxit Reader
> > 
> > Reading annotations works, but you can't modify anything.
> 
> Ok. There’s still no PDF viewer on Linux that can handle annotations 
> well. (But even Acrobat Reader on MacOS frequently crashes on them; I’m 
> using Foxit Reader for annotations, but the one for Linux is too old.)

Microsoft Edge has decent PDF annotation support. I've never tested it
on Linux, but a Linux version does exist. Okular also lets you add some
annotations.


> > I've been using pdf.js almost exclusively for the past few years either
> > via Firefox or VS Code, and I've never really had any problems. The only
> > real issue that I've had is that it gets fairly slow with documents over
> > a few thousand pages long. Otherwise, it seems pretty fast and stable,
> > and it supports nearly every feature that I tend to need.
> 
> Well, documents with thousands of pages are probably unreliable/slow in 
> most viewers.

I've got a 1.1GB document with 16000 pages, and Okular handles it just
as fast as a 10 page document. Firefox at least manages to not crash
when opening the document, which is better than most viewers.

Okular is actually a pretty nice viewer in general. It's really fast,
and it also seems to support most of these features. The tricky thing
with it though is that I think that it would be much harder to modify
compared to pdf.js.

-- Max