RE: [css-snappoints] 10/24 Snap points draft update

Thanks Rob,

I'll spend some time describing the behavior as an invariant and edge case behavior.

Good point regarding the lack of "none".  It was not originally necessary when "repeat()" and the "elements" value forced mutual exclusivity of interval and element snap points (since scroll-snap-type can be set to "none" to eliminate all snapping), but now there does seem to be a need to explicitly turn off the interval to avoid mixing the interval with element snap points.  I'll add it in as the initial value.

I'll specify repeat(<length>) as requiring a positive value.

I'm ok with "target" as a name, but I think "target" and "destination" sound a bit too synonymous.  Perhaps if "destination" is also renamed to help differentiate the two.


>From: [] On Behalf Of Robert O'Callahan
>Sent: Monday, October 27, 2014 4:01 AM
>To: Matt Rakow
>Subject: Re: [css-snappoints] 10/24 Snap points draft update
>I think it would be helpful for the spec to define in one place what the behavior of scroll snapping is. Right now text says "The visual viewport of this scroll container is guaranteed to rest on a snap point when there are no active scrolling operations." and in another place "scroll-snap-destination" modifies this. We should be able to describe precisely in CSS terms what invariant holds when there are no active scrolling operations, in terms of the CSSOM scroll position.
>This would also be a good place to define edge case behavior. AFAICT right now it's undefined what happens if there no snappoints, or more specifically if there are no snappoints that can be snapped to by scrolling within the normally allowed scroll range.
>The only allowed syntax for scroll-snap-points-x/y is 'repeat(<length>)'. In particular there is no 'none' or equivalent. Is that an oversight? How would zero or negative lengths behave here?
>Can we call 'scroll-snap-coordinate' 'scroll-snap-target'?
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Received on Monday, 27 October 2014 16:40:23 UTC