Re: [NTG-context] PDF viewer poll

Thank you all for you valuable insights so far! I’ll compile them to a wiki page and also complete the list in my upcoming book.

Am 2019-10-14 um 11:17 schrieb Hans Hagen :

When developing pdf specific code (like last months) I do use acrobat reader and an older acrobat x (which keeps telling me that it wants to be updated but the update fails) ... both have their different issues. Acrobat X has some validation on board and one can introspect the file (and fonts) to some extend but in the end it's often still trial and error.

Do you know any other tools for PDF debugging? Those few I know of cost four to five figures or were plugins to very old versions of Acrobat.

On the commandline, when I need to check a pdf I sometimes use qpf (quite ok but I always need to stepwise build the commandline using help as it's somewhat complex). The other command line tool I use is mutool (mudraw) which is different but also ok.

Need to look into those.

Acrobat used to be ok upto version 6 (I even remember the msdos version to be ok) but each version the user interface changed fo rthe worse (very bad imo and an indication that it's not meant for power usage as there one wants at least an upward compatible interface) and it's slower compared to other viewers (probably due to color management).

I agree. Adobe needlessly changed the interface with every release, and it didn’t get better. There were different translation errors (at least in the German interface) in every version, and they never got fixed with the updates. Updates were announced by the Updater, but never installed. Don’t know about the speed – some functions like certificate lookup were always dead slow, and the display speed was mostly ok. (I should benchmark different viewers with my OpenStreetMap vector maps…) I found Qoppa’s PDF Studio Pro a viable alternative to Acrobat Pro with a usable interface (default has ribbons, but you can switch it). Their customer support is friendly, I hope they will also fix the problems I reported.

=== javascript === Only acrobat offers that.

Not completely true. But there aren’t a lot of apps that support JS in PDF - for a reason: if you allow scripting, you create a lot of vulnerabilities that you can easily avoid leaving out this feature that "nobody" needs. It would have made sense to define a small and safe JS (or whatever scripting language) _subset_ from the start, but the early versions of Acrobat were completely "hackable", and they only much later thought about security (like in lots of other programs). PDF viruses existed.

Basically javascript can be limited to (1) setting annotation properties, like toggling layers or button renditions, and (2) some simple calculations (for forms). Constructing pdf runtime using javascript is pretty braindead (use html instead then).

D’accord.

It is one of the puzzling areas to me: no problem in browsers and elsewhere but not in open source pdf viewers. It's not the most complex stuff so it probably indicates that no one cares much about these features.

I wouldn’t say "no problem", because JS causes security problems everywhere.

=== annotations ===

Some useful stuff was dropped: like native sound and movies (was very simple: show a movie, play a sound, simple annotations). What seems to be natural to html became complex and unuseable in pdf ... the media subsystem is (obsolete) flash based, imo mostly driven by third party commercial pressure / demand / whatever. Not future safe, if working at all: from simple to complex to useless.

If I remember correctly, Adobe first based the media subsystem on Apple’s Quicktime until Apple discontinued that on Windows and Adobe bought Macromedia, including Flash. 3D media was a short hype, nobody used it. Anyway, doesn’t matter. Nowadays PDF doesn’t have any working media subsystem.

In a similar fashion forms (for some widgets bugs because features esp default rendering, inheritance, etc and also some strange relation with viewer settings, that change per version). It made me loose interest it those things that once were promising.

I can understand that, but at least ConTeXt’s radiobuttons *have* bugs; the few viewers that support forms stumble over some parsing/nesting error. Adobe catches it apparently.

(Some of the bad in pdf is a result from it being a container format for a lot of things: documents, editing tools, printing, application stuff turned annotation, etc.).

D’accord. Herzliche Grüße, Hraban