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Re: Does 1.4.10 essentially replace 1.4.4?

for

From: Mitchell Evan
Date: Sep 14, 2021 2:09AM

> As the idea behind 1.4.10 was a desktop user on a 1280x768 display
zooming to 400%, it makes sense to test at that exact dimension.

I agree we should test 1.4.10 in a common desktop display size at 400% (or
in a dev tools emulator equivalent). The most common aspect ratio of
desktop screens
<https://gs.statcounter.com/screen-resolution-stats/desktop/worldwide> is
1.78:1 with total usage over 60%, in screens such as 1280x720. Allowing for
browser and OS toolbars as shown in the Understanding 1.4.10 example video
<https://www.w3.org/WAI/WCAG21/Understanding/reflow.html#example-1-responsive-design>,
the
aspect ratio of the browser viewport (not the screen) is around 2:1.

>> 1.4.10 doesn't really say that *both* the width and height must be set.

True — it's a common misunderstanding
<https://github.com/act-rules/act-rules.github.io/issues/1318> that 1.4.10
Reflow specifies a 1280x1024 viewport — at most 3% usage, with a very
different aspect ratio of 1.25:1. The aspect ratio often makes a
pass-or-fail difference with real-world consequences, when sticky content
such as a fixed-position footer ends up covering the entire viewport.

Mitchell Evan, CPWA
linkedin.com/in/mitchellrevan <https://www.linkedin.com/in/mitchellrevan>
Twitter @mitchellrevan <https://twitter.com/mitchellrevan>
+49 1525 8950540
+1 510 375 6104

On Sun, 5 Sept 2021 at 20:00, < <EMAIL REMOVED> > wrote:

>
> ---------- Forwarded message ----------
> From: "Patrick H. Lauke" < <EMAIL REMOVED> >
> To: <EMAIL REMOVED>
> Cc:
> Bcc:
> Date: Sun, 5 Sep 2021 18:30:36 +0100
> Subject: Re: [WebAIM] Does 1.4.10 essentially replace 1.4.4?
> On 05/09/2021 18:22, glen walker wrote:
> > Thanks Birkir and Patrick. I understand the fundamentals of both success
> > criteria. My question was more academic in nature. If you want to
> conform
> > to WCAG 2.1 AA then you must pass 1.4.10. If you pass 1.4.10, doesn't
> that
> > (mostly) imply you also pass 1.4.4 so there's no need to test for 1.4.4?
>
> They're independent, but yes if you start off testing 1.4.10 and it's
> fine, it's likely that 1.4.4 passes as well (barring oddity of
> intermediate viewport sizes if the developers have only set specific
> ones and zooming to 200% would fall between the gaps and leave you in
> unforeseen broken dimensions.
>
> > That's another aspect that isn't completely clear (to me). 1.4.10
> doesn't
> > really say that *both* the width and height must be set. It just says
> that
> > vertical scrolling content (such as English, German, Spanish, etc)
> doesn't
> > require scrolling in two dimensions when at (exactly) 320 CSS px width.
> It
> > doesn't say I must set the height too.
> >
> > Same with horizontal scrolling content (such as Mandarin, Korean,
> Arabic).
> > The requirement refers to setting the height to 256 CSS px but doesn't
> say
> > I must set the width too.
> >
> > Conceptually, if you think of the vertical scrolling case, if you don't
> > have a horizontal scrollbar then you're good for 1.4.10 and since you're
> > scrolling vertically, it doesn't really matter what the height of the
> > browser is.
>
> As the idea behind 1.4.10 was a desktop user on a 1280x768 display
> zooming to 400%, it makes sense to test at that exact dimension. And
> regardless of language, there might be situations (e.g. with fixed
> headers/footer/etc) where there's no bi-directional scrollbars, but
> where content is completely covered by other fixed/absolutely positioned
> content. Or situations like a modal dialog that is centered and gets cut
> off at the top and bottom, with no way for the user to scroll that modal
> properly into view. Those are more general "without loss of information
> or functionality" failures. (But yes this aspect is still quite vague in
> 1.4.10 and the understanding doc, and I'm sure some will argue that
> those aren't failures of 1.4.10 at all)
>
> P
> --
> Patrick H. Lauke
>
> https://www.splintered.co.uk/ | https://github.com/patrickhlauke
> https://flickr.com/photos/redux/ | https://www.deviantart.com/redux
> twitter: @patrick_h_lauke | skype: patrick_h_lauke
>
>