Issue on Firefox with trackpad

[jankohlbach]

I realized this because of using locomotive scroll and thought the issue is there, but they use virtual-scroll and for me it looks like the issue lays in following line:

virtual-scroll/src/index.js

Line 83 in 4763533

evt.deltaY = e.wheelDeltaY || e.deltaY * -1

Basically, if I'm in Firefox and using a trackpad, the scrolling is way too fast.

if I only use
evt.deltaY = e.deltaY * -1;
instead of
evt.deltaY = e.wheelDeltaY || e.deltaY * -1;

it looks like it's the same behaviour as in chrome again, so maybe somethin inside Firefox changed regarding wheelDeltaY or something

[ayamflow]

Hi @jankohlbach !
Thanks for looking into it. I had not heard about this issue before but I think it would be great to find a fix for VirtualScroll.
I think the fix will probably use something similar to what's on this stackoverflow answer to toggle between wheelDeltaY and deltaY.

I am not sure when I will be able to incorporate this as a stable fix, so in the meantime, a temporary fix could be something like:

new VirtualScroll({
    mouseMultiplier: isTrackpad && isFirefox ? 1/3 : 1
})

where isTrackpad comes from the above stackoverflow link, and isFirefox is obtained from user-agent sniffing.
1/3 is because I believe the trackpad will fire at 300% the rate of the mouse but I could be wrong - tweak at will.
Let me know if that works for you!

Edit: it looks like wheelDetaX/Y are deprecated so I might just remove them altogether. Just need to test a bit.

[jankohlbach]

Hey @ayamflow,
thanks for the response :)
It's extremely busy for me as well right now, so don't worry.
Thanks for looking into it 💯

[jankohlbach]

Hey @ayamflow ,
do you have any news regarding this? asking because the folks at locomotive are working on the issues and making updates, so maybe it would be nice if this is fixed

[ayamflow]

hey @jankohlbach,
I looked at https://locomotivemtl.github.io/locomotive-scroll/ on Chrome & Firefox and the scroll speed looks the same to me, on a trackpad.
Can you confirm that you see an obvious difference on this site between Firefox and other browsers? What OS are you on?

[jankohlbach]

@ayamflow
hmm ... yeah it's pretty obvious 😅
I'm on windows 10, dell xps13, are you on a mac?
maybe it's even device related ...

[ayamflow]

Yep, I'm on mac.
I just gave it a try on Windows 10 with Parallels desktop and there was no noticeable speed difference either. It's the same trackpad tho so maybe it's a device thing, but it's surprising that it would only affect firefox 🤔
Does this shows isTrackpad: true for you ? https://jsfiddle.net/ayamflow/j09qsrLd/7/ (when scrolling in the white rect)

I'm thinking I could expose another param trackpadMultiplier: 1 (default) and let the user find the best value for their use case, as I don't want to add a breaking behavior.

[jankohlbach]

as much as I'd like to see more people using firefox, in this case it's a good thing only few people (and even less with trackpad) are using it 😂
your fiddle shows nothing for me 🤔
maybe also your idea from above could be enough for the moment then ...

[ayamflow]

@jankohlbach you need to scroll in the white area for the jsfiddle to display something 👀

[jankohlbach]

@ayamflow I promise you I don't see anything 😂 maybe onwheel doesn't capture the trackpad, but only mousewheel ...
or I just throw this specific laptop out of the window ...

[makc]

@jankohlbach

Basically, if I'm in Firefox and using a trackpad, the scrolling is way too fast.

I think it is because this lib assumes the firefox is slow, and it isn't ¯\_(ツ)_/¯

firefoxMultiplier: Firefox on Windows needs a boost, since scrolling is very slow. Defaults to 15.

and here I am, scrolling locomotive demo in firefox on windows to the bottom in a split-second :')

@ayamflow,

where isTrackpad comes from the above stackoverflow link

for me those snippets just do not detect a touchpad at all. they probably work on authors hardware only.

[makc]

ah no, I take it back - not a firefox issue for me, locomotive demo scrolls super-fast in chromium as well