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Re: [mediaqueries] CSS "prefers-" media features (from TPAC discussion)

From: Tab Atkins Jr. <jackalmage@gmail.com>
Date: Fri, 9 Oct 2015 17:26:16 -0700
Message-ID: <CAAWBYDAQir0P5tOw401Mx2VqFpuoSF2eq9JdCkx-3agW=DP8=g@mail.gmail.com>
To: James Craig <jcraig@apple.com>
Cc: www-style list <www-style@w3.org>, Dean Jackson <dino@apple.com>, "Ted O'Connor" <eoconnor@apple.com>
I'm a jerk who sometimes doesn't do the work he promised to do.  I'll
get this stuff together and into a spec soonish.

On Thu, Oct 8, 2015 at 7:31 PM, James Craig <jcraig@apple.com> wrote:
> It's almost a year since our initial discussion at TPAC 2014, but since TPAC
> 2015 is coming up, I'm re-raising several visual design
> accessibility-related media features we discussed last year.
> Please don't let this thread derail into what designers "should" and "should
> not" do. Visual design is subjective, and we take a realist approach to
> accessibility: allow designers to design the primary user interface, while
> allowing end users to adjust the interface to fit their needs.
> On Oct 30, 2014, at 4:34 PM, James Craig wrote:
> Thanks for discussing this topic during the CSS WG meeting at TPAC. I think
> it's important to raise the new distinction of a "prefers-" media feature as
> opposed to an applied one. For example, some of the iOS 7+ and OS X Yosemite
> (10.10) settings might be exposed as:
> • prefers-reduced-motion
>  Allows certain views to remove or tone down animations. For example,
> launching an app
>  on iOS 7 and iOS 8 changes to a subtle dissolve animation rather than a
> full-screen zoom.
> Platform preference is shipping on iOS, watchOS, and tvOS.
> Customers regularly mention to us that common web site patterns (e.g.
> horizontal carousels) cause vestibular issues such as dizziness or vertigo.
> Web developers ought to be able to achieve a similar solution that app
> developers can achieve natively.
> Some background.
> http://simplyaccessible.com/article/balance-awareness/
> • prefers-reduced-transparency
>  Allows certain translucent views to switch to an opaque rendering.
> Platform preference is shipping on iOS, OS X, watchOS, and tvOS. This
> increases readability for certain individuals with vision impairments.
> • prefers-differentiation-without-color (this media feature name needs work)
>  Allows certain views to change from color-dependent renderings. Messages
> app on OS X changes
>  status icons from red/green/orange circles to red squares, green circles,
> and orange triangles.
> Platform preference is shipping on OS X, with some similar app-specific
> settings on iOS. For example, change this setting on OS X, and the Messages
> status icons change from colored circles to colored shapes. Mail on iOS has
> a preference for flag shapes.
> This can increase general usability and is obviously useful for people with
> color-blindness, estimated at about 4% of the world's population.
> Changing these user settings don't change the rendering of anything. It just
> conveys a user preference that allows the frameworks, native apps, or web
> apps to adjust for this user preference/desire/need.
> I should also note these proposed names don't fit well within the "none or
> truthy" pattern of some existing media features. It'd be awkward to specify
> that "prefers-reduced-motion: none" means "user is okay with animation." The
> none value here may be open to misinterpretation, so please consider a
> "default" or "no-preference" value that behaves like "none" for boolean
> comparisons.
>  prefers-reduced-motion: [ default | reduce ];
>  prefers-reduced-motion: [ no-preference | reduce ];
> Thanks for considering,
> James
Received on Saturday, 10 October 2015 00:27:03 UTC

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