React-window: Jumps to top of list when scrollbar dragged past bottom

[rssfrncs]

It's a bit tricky to explain i'll do my best!

Browser - Tested only in Chrome (70.0.3538.110).

Example - https://codesandbox.io/s/k2lpl9m0l3

Method - Ensure the scrollbar is not fully scrolled to the bottom of the list (variable or fixed). Next start to drag the scrollbar down, once your mouse cursor gets past the end of the list (at around +30px see below screenshot for rough estimate of where it triggers) the list jumps to the top.

[rssfrncs]

I've also noticed that if you are scrolled somewhere in the list (not top or bottom) and you scroll up and go past the top it will jump back to the start point of the drag.

[rssfrncs]

Might be of interest, I can't reproduce the issue on Firefox or Edge.

[bvaughn]

I can't reproduce this issue using Chrome 70.0.3538.77 on macOS 10.13.6 (with "Show scroll bars: Always")

Any chance I can get a recording from you?

Any chance you could add logging to your version of react-window (inside of node_modules) to print what the scrollTop values are here?

I could add a min/max gate if needed, although it seems like it shouldn't be required.

[JeffBaumgardt]

On Windows 10 I've confirmed the above behavior. I don't have an clues as to the cause as of yet
System: Windows 10
Chrome: 70.0.3538.110

[ghurlman]

Repros in Chrome 70.0.3538.110 on Windows 10
Does not repro in Firefox Dev Edition, 64.0b13 on Windows 10.

[bvaughn]

Probably unsurprisingly, this seems to be Windows behavior (rather than specific to react-window):
http://www.tomshardware.com/answers/id-3663415/stop-scrollbar-jumps-top-behaviour.html

That doesn't mean I shouldn't work around it, just that it seems to be common-ish?

[mattlacey]

Confirmed in Opera Version:56.0.3051.104

But as @bvaughn says, it seems to happen in Explorer too.

[BottomleyIan]

Chrome 70.0.3538.110 Jumps back to where you started dragging from, not just the top. Also happens eventually if you move the mouse to the right.

Firefox 63.0.3 (32-bit) If you start dragging directly down its fine, but drag off to the right and it will jump back

[JeffBaumgardt]

It is a common windows behavior as I've replicated this in non-browser applications as well as browsers.

[Agedjus]

I was playing a bit, looks like the shared behavior between browsers is jumping back to the initial position if you drag the mouse far enough through the other axis direction. Firefox, Edge, IE, Chrome and w10 system. Is it a default behavior in general or it is a windows "feature"?

Dragging in the same axis... it happens to Chrome and w10 explorer, other browsers works fine, even IE

[bvaughn]

Thanks so much for the added context folks. I'm not sure this is something I can reasonably fix– if the browser is sending _valid_ (e.g. between 0 and max offset) but "incorrect" offsets.

[Julienng]

I can reproduce it on the window scroll of the browser, on the windows file explorer.
I don't think you need to fix it since it's consistent for windows users.

[bvaughn]

Thanks again for all of the input everyone!

After looking at this a bit closer, I think I'm going to close this issue as "won't fix" because (1) it seems to be widespread on Windows and (2) I don't think there's a reasonable way for me to detect and work around it.

Cheers!