[NTG-context] attachments working again (issue with /EmbeddedFiles)

[Hans Hagen]

On 2/7/2020 9:55 PM, Pablo Rodriguez wrote:
> On 2/7/20 9:19 PM, Rik Kabel wrote:
>>
>> On 2/7/2020 14:46, Pablo Rodriguez wrote:
>>> many thanks for having fixed the issues with attachments (in latest beta
>>> from 2020.02.07 18:36). I haven’t tested attachments with PDF/A-3a.
>>>
>> PDF/A-3a attachments still fail validation with the same issues.
> 
> Hi Rik,
> 
> it has way less issues, at least using verapdf-1.5.18 and the following
> sample:
> 
>      \setuptagging[state=start]
> 
>      \setupbodyfont[30pt]
> 
>      \setupbackend
>        [format=PDF/A-3a,
>         intent=sRGB IEC61966-2.1,
>         profile={sRGB.icc,default_gray.icc},
>         level=0]
> 
>      \setupcolors[pagecolormodel=auto]
> 
>      \setupinteraction[state=start]
>      \starttext
>      \startTEXpage[offset=1em]
>      an attachment\attachment[file=xml-mkiv.pdf,
>          type={application/pdf}]
>      \stopTEXpage
>      \stoptext
> 
> With "method=hidden" (no attachment annotation) it has no issue.
> 
> Both issues are related to annotations in general:
> 
> - If the flag annotation is present (/F key), it should be set to print
> and disable everything else.
> - Annotations need an appearance dictionary (unless their /Rect is one
> and the same point, or /Popup or /Link annotations).
> 
> Actual value of the annotation flag key is "/F null". I wonder whether
> this is a bug (for having wanted to avoid the presence of /F at all).
> 
> Otherwise, I don’t think that setting all embedded file annotations to
> printable is a good default.
> 
> Just in case it helps to the discussion,
Peter is stepwise looking into all these issues but we decided to also 
see how that checking and standards evolve in cases where it's a 
confusing mess. And these 'appearance dicts' are an example of a mess. 
On the one hand there's predefined appearances and on the other hand 
enforced renderings which gives some chicken-egg issue. It smells a lot 
like bugs became features (standards) or 'acrobat behaviour' made the 
standard or ... (like the zero rect thing, which, given t e plenty of 
flags there are and verbosity there is in pdfm is pretty weird and 
actually can make viewers bark. Irr the current approach we follow is 
kind of a compromis.

Now, of course we can play safe and *always* have some fake appearance 
(we could basically choose whatever funny shape we like as over time 
people will interpret hard codes symbols for attachments differently) 
and drop support for standardized renderings (that could adapt over 
time).

So ... no changes etc till Peter gives his blessing as he is testing all 
this in the framework we've set up for it.

Hans

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                                           Hans Hagen | PRAGMA ADE
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