1706048 - [macOS] Scrollbar in panels is offset

Status: VERIFIED FIXED

(Firefox :: Menus, defect, P2)

Description

[Catalin Sasca, Desktop Test Engineering [:csasca]]

Attachment: scrollbar.png

Affected versions

• Firefox 89.0a1

Affected platforms

• macOS 10.15.7

Steps to reproduce

1. Launch Firefox
2. Open a panel which has a scrollbar (ex. library)

Expected result

• The scrollbar is centered in its place

Actual result

• The scrollbar is a bit offset to the right

Regression range

• Will see for a regression

Additional notes

• The issue can be seen in the attachment

Comment 1

[Jared Wein [:jaws] (please needinfo? me)]

I think the offset here wouldn't be noticeable if the background of the scrollbar was the same as the surrounding content. Markus, do you know if there is anything we can do about the scrollbar background color here? Hopefully this is as simple as setting scrollbar-color, but I don't have an environment ready at hand to test.

Comment 2

[Markus Stange [:mstange]]

Attachment: with scrollbar-color: rgba(255,255,255,0.3) transparent

Yes, scrollbar-color accepts two colors, a thumb color and a track color. Setting the track color to transparent fixes this.
For example, scrollbar-color: rgba(255,255,255,0.3) transparent on .panel-subview-body seems to work well.

Comment 3

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: Screen Recording 2021-04-22 at 10.43.34.mov

Hello! I observed that this issue no longer can be seen if Firefox 90.0a1 (20210421212740) is restarted. However, if the scrollbar is hovered or dragged the background is again displayed but with a lighter color. I don't know if this is expected. Please see attached screen recording.

Comment 4

[Markus Stange [:mstange]]

(In reply to Alexandru Trif, QA [:atrif] from comment #3)

Hello! I observed that this issue no longer can be seen if Firefox 90.0a1 (20210421212740) is restarted. However, if the scrollbar is hovered or dragged the background is again displayed but with a lighter color. I don't know if this is expected. Please see attached screen recording.

I'm confused - what is your system "Show Scrollbars" pref set to? During the first part of the screen recording, it looks like it's set to "Always", because you can see the scrollbar track in the profile manager list. And then after the browser restart, it looks like it's set to "When scrolling", because the scrollbar in the panel now fades out. Did you maybe have it set to "Automatic" and used a different input device?

This bug only applies to "Always" visible scrollbars (also called "non-overlay" scrollbars or "classic" scrollbars).

Comment 5

[Alexandru Trif, Desktop Test Engineering [:atrif]]

(In reply to Markus Stange [:mstange] from comment #4)

(In reply to Alexandru Trif, QA [:atrif] from comment #3)

Hello! I observed that this issue no longer can be seen if Firefox 90.0a1 (20210421212740) is restarted. However, if the scrollbar is hovered or dragged the background is again displayed but with a lighter color. I don't know if this is expected. Please see attached screen recording.

I'm confused - what is your system "Show Scrollbars" pref set to? During the first part of the screen recording, it looks like it's set to "Always", because you can see the scrollbar track in the profile manager list. And then after the browser restart, it looks like it's set to "When scrolling", because the scrollbar in the panel now fades out. Did you maybe have it set to "Automatic" and used a different input device?

This bug only applies to "Always" visible scrollbars (also called "non-overlay" scrollbars or "classic" scrollbars).

I was using the Automatically based on mouse or trackpad option but I didn't change the input device. I was using the same mouse USB connected since it's a mac M1 mini arm based. I don't know the expected behavior for this. Also if "Always" is used the bug is reproducible every time and no longer "fixes" the issue after restart. If more information is needed please let me know. Thank you!

Comment 6

[Markus Stange [:mstange]]

Thanks. I'm not sure why "Automatically" gives inconsistent behavior. Anyway, the fix for this bug will work independently of that - it'll work whenever non-overlay scrollbars are used.

Comment 7

[Mike Conley (:mconley) (:⚙️)]

I can reproduce this if using the OS's dark mode on macOS.

Comment 8

[Mike Conley (:mconley) (:⚙️)]

Attachment: Bug 1706048 - Make mini scrollbar track transparent in panel-subview-body on macOS. r?harry!

Using color-mix, I'm able to make this look pretty close for dark, light and custom themes.

Note that the custom colouring goes away if the user hovers the scrollbar track with their
cursor. I don't think there's anything I can currently do about that.

Comment 9

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/db539e6810fc
Make mini scrollbar track transparent in panel-subview-body on macOS. r=harry,desktop-theme-reviewers

Comment 10

[Iulian Moraru]

https://hg.mozilla.org/mozilla-central/rev/db539e6810fc

Comment 11

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:mconley, is this bug important enough to require an uplift?
If not please set status_beta to wontfix.

For more information, please visit auto_nag documentation.

Comment 12

[Mike Conley (:mconley) (:⚙️)]

ni'ing Shilpa to see if this is a bug we want to consider uplifting to 89.

Comment 13

[Catalin Sasca, Desktop Test Engineering [:csasca]]

This issue is fixed on Firefox 90.0b4 and Firefox 91.0a1 (2021-06-06) under macOS 10.15.7.