1233413 - scroll snapping with touchpad gets stuck sometimes

Status: RESOLVED DUPLICATE of bug 1235994

(Core :: Layout, defect)

Description

[Arpad Borsos [:Swatinem]]

* With a recent nightly (https://hg.mozilla.org/mozilla-central/rev/99137d6d4061f408ae0869122649d8bdf489cc30)
* On a recent archlinux
* When I use my touchpad to do scrolling, scroll snapping will often get stuck.

See the provided URL, you should be able to scroll left/right with your touchpad and the pages should snap using scroll snapping (falling back to js)

I often have the problem that scroll snapping will just get stuck and I’m unable to navigate via the touchpad. When I remove the scroll snapping properties using devtools, the scrolling falls backs to our internal js which then snaps to pages after a short timeout.

Sorry for the very vague report, I wasn’t really able to produce a reduces testcase.

Comment 1

[Kartikaya Gupta (email:[e-mail])]

What I'm seeing using the Mac trackpad is when I do a "fling" it doesn't use the fling velocity at all, it just snaps based on where I lift my fingers. I don't see it get "stuck" the way you seem to be describing, where it doesn't scroll at all. It might be different on Linux though, I don't have a Linux device with a trackpad.

Comment 2

[Kartikaya Gupta (email:[e-mail])]

It looks like the page is doing preventDefault on wheel events, and maybe handling those events directly? The behaviour that I'm seeing (using Mac trackpad) occurs on Aurora as well, and may not be a Gecko bug - it might be a result of the page handling the wheel events and not properly snapping to the velocity-based destination.

It would be helpful if you can create a reduced testcase for the issue you're seeing, as it might turn out to be an issue with the script on the page.

Comment 3

[Botond Ballo [:botond]]

I have a Linux device with a trackpad, but I'm not able to reproduce the problem on the provided test page. I tested with today's nightly.