1874746 - Swiping on Firefox app menu does not scroll the menu on Steam Deck

Status: NEW

(Core :: Panning and Zooming, defect, P3)

Description

[Kagami Rosylight [:saschanaz] (they/them)]

I think I experienced this on Windows too when I dealt with scroll_by_pen pref and I vaguely remember it was because APZ doesn't cover the app menu. Per my memory this works on Windows solely because Windows emulates mouse wheel event from touch/pen. But someone needs to confirm this.

Comment 1

[Botond Ballo [:botond]]

Can you provide steps to set this up and reproduce this please? Are you referring to touch input on a touchscreen laptop?

Comment 2

[Kagami Rosylight [:saschanaz] (they/them)]

Yes, the steps would be:

1. Get a Linux device with touchscreen capability (That's a Steam Deck for me)
2. Open the app menu and try scrolling on it by a vertical touch swipe (you may need to adjust the screen resolution or Firefox UI scale ratio to make it actually scrollable)

Comment 3

[Botond Ballo [:botond]]

Thanks. While I don't have a touchscreen to test with at the moment, I do see that mousewheel/touchpad scrolling on the app menu is not going through APZ, and so your theory that the app menu's window is not using APZ seems to be correct.

Comment 4

[Botond Ballo [:botond]]

The decision to use APZ for a given window is made here.

For the app menu's window, we have mWindowType == WindowType::Popup and HasRemoteContent() == false, hence the current outcome is "no".

Comment 5

[Botond Ballo [:botond]]

This would be addressed by bug 1682629.

Comment 6

[Botond Ballo [:botond]]

We discussed this in today's APZ meeting to try and decide what severity to assign to it.

The symptoms suggest a potential S2 (user has no way of getting to an item in the application menu), but the device / form factor on which the issue arises seems somewhat niche.

Kagami, a couple of questions:

1. Is there a workaround, e.g. another way for the user to scroll the app menu in such cases?
2. Do you have a sense of how widely used Firefox is on SteamDeck (e.g. maybe we have telemetry that would give us an install count?) so we have a better idea of how many users this affects?

Comment 7

[Kagami Rosylight [:saschanaz] (they/them)]

(In reply to Botond Ballo [:botond] from comment #6)

1. Is there a workaround, e.g. another way for the user to scroll the app menu in such cases?

Yes, Steam Deck also has a touchpad so user can control the mouse cursor to drag the scroll bar. No scroll gesture exists though as laptop touchpads have.

2. Do you have a sense of how widely used Firefox is on SteamDeck (e.g. maybe we have telemetry that would give us an install count?) so we have a better idea of how many users this affects?

I'll have to query some telemetry data to get the exact number. For now I can only say it should be somewhere below 1.726% of Linux-6.x in https://data.firefox.com/dashboard/hardware, as Steam OS is described as Linux 6.1.52-valve9-1-neptune-61 in about:support.

Comment 8

[Botond Ballo [:botond]]

Thanks. Given the workaround of dragging the scrollbar of the application menu, we're going to mark this as S3 for now.

That said, APZ support for all scrollable popups (bug 1682629), which would fix this and a few other bugs, is something I'd like to get onto our team's agenda.