W3C home > Mailing lists > Public > www-style@w3.org > January 2013

Re: [css3-conditional] What does @supports return when the OS prevents the support?

From: James Nurthen <james.nurthen@oracle.com>
Date: Fri, 11 Jan 2013 10:43:21 -0800
Message-ID: <50F05D49.4010302@oracle.com>
To: Sylvain Galineau <sylvaing@microsoft.com>
CC: CSS WG <www-style@w3.org>
Sylvain,
Please see inline.

On 1/10/2013 11:38 AM, Sylvain Galineau wrote:
> [James Nurthen:]
>> When the CSS processor "supports" a value BUT the OS prevents the support
>> from actually occurring what would be the result?
>> For example. Would
>> @supports (background-color: #CCC) return true or false when running in
>> Windows High Contrast mode where background colours are not applied.
>>
>> It would be very useful if this would return false - so this situation
>> could be detected in CSS and appropriate styles applied.
>>
> What would you expect when the document is being printed and the color might
> either end up in a shade of grey or the UA might disable backgrounds entirely
> when printing based on a user setting?
Shades of grey is a tricky one but if the background is disabled 
completely I might actually expect that the rule to return false.
>
> Whether the UA supports a particular property-value pair and what the target
> media does with this same feature are orthogonal in my mind.
>
> Granted, I am somewhat biased since we have already implemented it that way[1].
>
> [1] http://msdn.microsoft.com/en-us/library/windows/apps/hh465764.aspx
I wasn't aware of this implementation. I only care about the problem 
being solved and this seems a good solution (albeit only for Windows 8 
and presumably IE).  However, I don't see this even in the editor's 
draft of CSS4 Media Queries http://dev.w3.org/csswg/mediaqueries4/
Will this be added?

Regards,
James
Received on Friday, 11 January 2013 18:43:54 GMT

This archive was generated by hypermail 2.3.1 : Tuesday, 26 March 2013 17:21:04 GMT