Re: widget woes (input fields)

On 6/6/26 18:51, Jim via ntg-context wrote:
> On Fri, Jun  5, 2026 at 19:58 (+0200), Hans Hagen via ntg-context
> wrote: […]
>> so didn't follow this thread but normally Pablo comments on it
> 
> I believe Pablo has been silent on this particular topic.  Unless JP
> was pinch-hitting for him (JP did offer some insights, but, sadly,
> not a solution).

Hi Hans and Jim,

I avoided commenting this thread since the structure fields + widgets
seems to be a problematic one for “Acrobat”.

This isn’t just my impression, but something I discovered when I
proposed a fix for (unsigned) signature fields in ConTeXt:
https://github.com/pdf-association/pdf-issues/
issues/714#issuecomment-3758866240.

The patch for (unsigned) signature fields is a compromise solution: it
works with “Acrobat” (I have only current “Reader DC” available), but
(almost?) everything else needs fixing. Just as an example, MuPDF needs
that to be fixed (https://bugs.ghostscript.com/show_bug.cgi?id=709076).

>> ... widgets are a bit of a pain (ended up in the pdf spec before 
>> supported, bugs that became features - esp defaults - parent/kid
>> issues and differences between viewers, appearance streams, etc).
>> The same for some annotations that basicaly got dropped. It has
>> always been about adapting to observations.
> 
> As you may have noticed, Ulrike followed up with some analysis of
> the PDF internals, which may help to get ConTeXt's implementation
> onto the straight and narrow.

Sorry, but I didn’t analyze this particular issue (no time for that
now), but when I provided the patch to `lpdf-fld.lmt` (for signature
fields), I tested all other fields.

“Acrobat” is happy with (unsigned) signature fields with a parent
dictionary for only the field and a child dictionary for a pure widget.

“Acrobat” would also allow a single dictionary of field and widget, but
`lpdf-fld.lmt` needs to make a two distinct dictionaries (parent and
child) for fields.

I tested that with other fields (parent field-only dictionary and pure
widget child dictionary). But although this is techically right (it is
conformant to Arlington), “Acrobat” isn’t happy with the output.

“Acrobat” prompted for file saving when closing the documents (with two
distinct dictionaries, one for the field and another for the widget).
The saved document was mixed the two dictionaries and Arlington complained.

At the end of May, (at work) we had to send a document with both text
fields and a signature field (all to be filled-in). Partially thanks to
having not used “Acrobat” for signing (and also avoiding the already-
available signature field), we got a document which “Acrobat” only
displays the signature and its signature annotation, but no text from
the text fields; “Edge” displayed all text from the text fields, but not
the signature.

This is the first time I experience this such level of dissonance by PDF
viewers displaying a document.

I don’t know (well, I have no idea about) what is wrong here. Sorry, but
it will take some time before I can invest some time investigating this.

I’m afraid this is all I can do for now.

Best wishes,

Pablo
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