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Re: Zoom content updates Pt3

From: Alastair Campbell <acampbell@nomensa.com>
Date: Tue, 6 Jun 2017 10:09:00 +0000
To: Andrew Kirkpatrick <akirkpat@adobe.com>, Joshue O Connor <josh@interaccess.ie>
CC: WCAG <w3c-wai-gl@w3.org>
Message-ID: <F7C27B23-3ED8-49B7-A8CE-2C9B21A40AFF@nomensa.com>
Hi Andrew, Josh,

There is a feeling on the github thread we’ve got as far as we can without wider public comment, so I’d like to put this out for CFC for inclusion in the draft please?

After a 3rd round of updates & discussion (since the call in late May), this seems to be the text people can live with:
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Content can be zoomed to an equivalent width of 320 CSS pixels without loss of content or functionality, and without requiring scrolling on more than one axis except for parts of the content which require two-dimensional layout for usage or meaning.

Note: 320 CSS pixels is equivalent to a starting viewport width of 1280 CSS pixels wide at 400% zoom. For web pages which are designed to scroll horizontally, the 320px should be taken as the height rather than width.

Note: Examples of content which require two-dimensional layout are images, maps, diagrams, video, games, presentations, data tables, and interfaces where it is necessary to keep toolbars in view while manipulating content.
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The only change was:
 “without requiring scrolling on more than one axis”.

There are two somewhat vague but unresolved questions:

1. The PDF implementations of reflow are buggy, and the authoring guidance for making it work is non-existent, see the comments from here onwards:
https://github.com/w3c/wcag21/issues/77#issuecomment-306240083 

I’m inclined to say this is a tricky issue in practice, but at the content/format level it is feasible to do. It could be longer before organisations use WCAG 2.1 for PDFs, but having this SC could help shine a light on those issues. Any pointers to documentation on how PDF reflow is supposed to work (and be authored for) would be gratefully received.

2. Websites in China, Japan and other non-western language regions do not seem to use responsive (or adaptive) design techniques at all, why not? There are a multitude of possible explanations, perhaps they are more app centric, or it just hasn’t taken off there, or the writing-mode CSS hasn’t been well enough supported until very recently? 

I’d like to hear from people with experience about that, putting the SC out would be a good way to get more coverage.

Oh, and for anyone still wanting to define 2D scrolling as a measure of which direction text goes, please see this comment:
https://github.com/w3c/wcag21/issues/77#issuecomment-306433647


I’ve posted answers to all the comments:
https://github.com/w3c/wcag21/issues?utf8=%E2%9C%93&q=is%3Aopen%20assignee%3Aalastc%20resize 

Jared from Webaim is even coming around…

Cheers,

-Alastair

Received on Tuesday, 6 June 2017 10:09:43 UTC

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