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

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.

• prefers-reduced-transparency
  Allows certain translucent views to switch to an opaque rendering.

• 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.

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

PS. I plan to post new thread topics for high/increased contrast (including the MS proposal) and full keyboard access media features. Those are specific and complex enough that they deserve their own threads.

Received on Thursday, 30 October 2014 23:35:26 UTC