1975870 - cannot click at end of a line in a scrollable area (e.g. to select text or middle-click-paste) if an overlay scrollbar is in the way

Status: UNCONFIRMED

(Core :: Layout: Scrolling and Overflow, defect, P3)

Description

[Vincent Lefevre]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:140.0) Gecko/20100101 Firefox/140.0

Steps to reproduce:

1. Go to Wikipedia and edit. That was https://fr.wikipedia.org/w/index.php?title=La_Soif_du_mal&action=edit for me.
2. Scroll under the longest physical line gets visible.
3. Click at the end of this line.

Actual results:

As the line fills the width of the textarea, moving the mouse pointer just after the last character makes the scrollbar wider, so that the click has the effect to scroll instead of putting the text cursor at the end of the line.

In particular, it is impossible to paste with the middle button, which is much more problematic.

Expected results:

The scrollbar should not get wider, or it should extend outside of the textarea rather than inside.

Comment 1

[Daniel Holbert [:dholbert]]

Thanks for the bug report. This is a known limitation of "overlay scrollbars" (enabled by default in Firefox on Linux). There's some related discussion in bug 1790747, which was filed for similar interaction issues when we enabled this category of scrollbar on Windows 11.

If you'd like: you can disable this sort of scrollbar in Firefox's settings page (Edit|Settings) and check the box for "Always Show Scrollbars" (at the bottom of the "General" section -- though it's easiest to find by just typing "scroll" into the settings-page's searchbox). This makes scrollbars take up their own layout space on the page, so that they don't overlap page-content and so they don't get wider/skinnier when hovered/unhovered.

Comment 2

[Botond Ballo [:botond]]

I'm not sure what we can do about this as a browser, other than not enabling overlay scrollbars by default (which as a personal preference I would totally get behind, but is not the product/UX direction we have chosen). If anyone does have ideas for another browser solution here, please feel free to share it in a comment.

Comment 3

[Daniel Holbert [:dholbert]]

(In reply to Botond Ballo [:botond] from comment #2)

I'm not sure what we can do about this as a browser, other than not enabling overlay scrollbars by default

Note that WebKit/Chromium allow overlay scrollbars to be selectively disabled via -webkit-scrollbar prefixed styles. If we add support for that as a simplified switch of some sort (as in bug 1973196 [EDIT: typo, I meant to say bug 1977511]), that would be one way that websites and/or users could selectively work around this.

Comment 4

[Daniel Holbert [:dholbert]]

(er sorry, I meant to reference bug 1977511 in comment 3.)

Comment 5

[Botond Ballo [:botond]]

I came across a CSS Working Group issue proposing a new media query that I think would address this: https://github.com/w3c/csswg-drafts/issues/7420