I'm finding it extremely difficult to find accurate and up-to-date information about support for accessibility with PDF on Apple's platforms, in particular Safari and Preview on iOS and Mac. For a long time it seemed that nothing worked (e.g. browsing a PDF with VoiceOver in Preview), but I've started to get some acceptable, but patchy results.
Apparently things have changed under the hood since the extensive outcry at High Sierra's implementation of PDFKit but what exactly has changed? Is there a change log anywhere? Did any of the notorious PDFKit bugs from 2017 get fixed?
I will mention some important jargon used in the accessibility community: "Accessibility supported". This term has a formal definition in the WCAG spec. Basically it's not enough that a file format (such as PDF) or an app (such as Safari) is hypothetically accessible, if I can't actually browse my PDF in Safari using Voiceover. Legally speaking, this information should be absolutely clear in the VPAT for Mac OS. It isn't. Lawyers with an interest in accessibility suits should take note.
My questions:
I've studied the latest documentation for PDFKit and can find no mention of semantic tagging, read order or the PDF/UA format in general. How does this work? Did Apple invent new names for these features, or is it simply unsupported?
Can I use VoiceOver to browse a well-formed tagged PDF/UA file 'semantically' in Safari? (E.g. 'next heading' keyboard shortcut, or using the rotor).
If I save a PDF from Safari or Preview, do I get a well-formed 'accessible PDF' (i.e. a "tagged PDF" file with the PDF/UA flag)?
How might HTML semantics be mapped onto PDF/UA output, when saving a web page as PDF from Safari, given that there is not 100% parity between the two semantic systems?
Can I browse PDF/UA files in Acrobat Reader with VoiceOver? If not, why aren't Apple and Adobe taking steps to fix this situation?
I understand that Pages, Numbers and Keynote all produce tagged PDF. I assume this means some conformance with the PDF/UA 1.7 spec? Are there any omissions in support for the PDF/UA standard by this route? What are those omissions?
Regarding the accessibility of the output, is there any difference between "Save as PDF", "Export PDF" and "Print to PDF" in Apple's software?
Please advise on any of these points.
Topic:
App & System Services
SubTopic:
Networking
Tags:
PDFKit
Accessibility
Safari and Web
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