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Re: reflow and PDFs

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From: Duff Johnson
Date: May 11, 2022 12:14PM


Hi Steve,

> In terms of WCAG conformance, there is an exemption for data tables, so it is ok if there are both horizontal and vertical scrollbars. My (possibly incorrect) recollection is that VIP PDF Reader allows users to freeze rows or columns so they are always visible when scrolling the rest of the table.

Indeed; that sort of functionality is an excellent example of AT “doing the right thing” with large / complex tables in PDF.

Duff.



> -----Original Message-----
> From: WebAIM-Forum < <EMAIL REMOVED> > On Behalf Of Duff Johnson
> Sent: 10 May 2022 21:14
> To: WebAIM Discussion List < <EMAIL REMOVED> >
> Subject: Re: [WebAIM] reflow and PDFs
>
> Hi Alan,
>
>> I am working on a PDF with tables that have 10 columns, At zoom above
>> 200% you have to do horizontal scrolling and "lose" the left most row
>> header cell.
>
> Please allow me to rephrase your statement from a file format specification point of view…
>
> “The application fails to account for tables with many (or wide) columns at high zoom levels."
>
>> Apart from the tables, the document is mostly 2 column layout, and
>> this will not stack into 1 column, either, so you have to constantly
>> scroll to read, then scroll back and down, etc.
>
> Sounds like a pain. To support such tables the application needs to be able to represent the TH cells for the currently-displayed TD cells regardless of any given location in the table.
>
>> These documents are legacy, and there is no way to redesign them in
>> any significant way.
>
> Nor should that be necessary, if the application would just do the right thing.
>
>> Question: is the above a serious failure or just a nuisance?
>
> It's no statement about the file per se, as the file may well include a correctly-tagged table. It's a problem with the zooming software, and should be reported to the developer as a necessary enhancement required in order to credibly support larger tables under high magnification.
>
>> I suppose what I am asking relates to the question: what are the
>> PDF/UA reflow requirements, as opposed to best requirements?
>
> There are no PDF/UA requirements for reflow at all. PDF/UA specifies that the content be correctly tagged. It leaves the implementation of the tagging in a viewer (of which reflow is one such) to the viewer software developer.
>
> I hope this helps.
>
> Duff.
> > > > > > >