Re: Media feature based on parent width instead of viewport/device width

|  ...
|

<thinking about a "sticky post" on the ML / on a blog somewhere about the 
general pitfalls of CSS or why your favorite feature may not be doable in 
CSS right now; the property-selector dependency would certainly make the cut 
for that>


|  It's possible in the future that we may be able to add a more
|  restricted form of layout that can have this kind of interdependency
|  (its simplicity might make cycle detection + breaking more tractable),
|  but it won't allow arbitrary constraints.

To be more concrete, I've an (unproposed) proposal that would enable authors 
to create "local viewports" (display: viewport). One of the goals of local 
viewports will be to allow those kinds of usage. However, I agree with Tab 
that what you're going to win at one side, you're going to loose it on the 
other one: to introduce more freedom to the author, we introduce more 
constraints for the layout engine; there doesn't exist a "perfect" solution 
to this problem.

Specifically, the current layout algorithms are made such that the layout of 
the children affect the layout of the parent; if we want the layout of the 
children to depend on the size of the parent, we need the size of the parent 
to be independant of the layout of the children. From a performance point of 
view, the case where the layout of the parent doesn't depend on the layout 
of the children is very interesting (particulary in the case of ininitely 
scrollable lists), which is one of the other motivations for this proposal.


Best regards,
François 

Received on Monday, 17 December 2012 15:44:42 UTC