Re: The :min-width/:max-width pseudo-classes

On Fri, Mar 22, 2013 at 9:26 AM, Boris Zbarsky <bzbarsky@mit.edu> wrote:
> On 3/22/13 12:15 PM, Tab Atkins Jr. wrote:
>> Or one could just say that anything below a viewport
>> element is automatically in the slow path
>
> Even this requires consumers who currently only say "hey, make styles up to
> date" to instead give the list of elements they need styles up to date for.

The "consumers" here are internal API, right?  If so, yeah, you're
right.  That's not great.

>> I assume this is because viewport MQs in the iframe depend on styling
>> in the outer document?
>
> Indeed.  And layout in the subframe depends on layout in the outer document
> too.

Hm, ok.  Well then, we should investigate the <iframe> behavior, and
see if it's okay to duplicate, perhaps with my suggestion of an opt-in
way to get the more expensive "true" value out of getComputedStyle.

If we did this, I wonder what the effect would be on nested viewport elements?

~TJ