Re: [csswg-drafts] [cssom-view] New feature - scroll-boundary-behavior (an extension of -ms-scroll-chaining)

There's a related proposal with a confusingly similar name 'overscroll-action':
https://groups.google.com/a/chromium.org/forum/#!msg/blink-dev/Uzit4zDQ1ps/pD_3k2rqBAAJ

overscroll-action applies to the gesture on the viewport for history navigation (2 finger swipe back on Mac) and pull-to-refresh.

I find the nomenclature a bit confusing because 'overscroll-action: auto' would suggest that the element would behave as if it had 'scroll-boundary-behavior: propagate' which is orthogonal.  

1. Should the two proposal be considered orthogonal? If so it allows over-scroll animations (glow/bounce) to be toggled independently from navigation gestures.
2. If we consider the specifications to be orthogonal can we come up with better nomenclature? I would suggest that 'navigation-action' would be better name 'overscroll-action'.
3. Right now it's not possible to propagate scrolling while disabling the overscroll animation. If this is something that's important perhaps a better proposal to cover the 4 logical states could be:
`overscroll-action: [auto || [ [propagate || contain] | [overscroll || no-overscroll] ]`
4. Does 'overscroll-action-x: contain' behave as if 'overscroll-action: no-navigation-x' was set? From an implementation point of view I believe 'overscroll-action-x: contain' should behave as if the script was performing preventDefault on any overscroll and thus disallow events from reaching the viewport and thus would implicitly disallow overscroll (navigation) actions.

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Received on Friday, 24 March 2017 00:08:00 UTC