[csswg-drafts] [cssom-view] Clarify about scroll completion (#11973)

hiikezoe has just created a new issue for https://github.com/w3c/csswg-drafts:

== [cssom-view] Clarify about scroll completion ==
Scroll completion is defined in the CSSOM View spec;

> Scroll is completed when the scroll position has no more pending updates or translations and the user has completed their gesture.

But touchpads on MacOS basically send "momentum" events, thus even after the user has lifted their fingers from the touchpad, momentum events are sent to applications. 

There's an interesting case we got recently related to this definition, [here](https://bug1954609.bmoattachments.org/attachment.cgi?id=9473512) is the case.

On Chrome, if you try to scroll on the "iframe Scroll Reporter" strongly, you will see a bunch of "type=wheel, button=0, buttons=0 ..." messages even after the scroll position has reached to the bottom edge, then finally you will see a "type=scrollend, target=html" message.

So apparently Chrome considers "momentum events" are parts of a user gesture, but in my naive understanding, "when the user lifted their finger" is corresponding to the "the user has completed their gesture".

Please view or discuss this issue at https://github.com/w3c/csswg-drafts/issues/11973 using your GitHub account


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Received on Friday, 21 March 2025 03:45:01 UTC