1730503 - Floating scrollbar stylesheet is not added to remote frame documents

Status: RESOLVED FIXED

(DevTools :: Responsive Design Mode, defect, P2)

Description

[Nicolas Chevobbe [:nchevobbe]]

At the moment, we're implementing "floating scrollbars" by injecting a specific stylesheet in all the document of the docShell tree (see https://searchfox.org/mozilla-central/rev/5f81c5091d442d829120e19477ba869ae5219709/devtools/server/actors/emulation/responsive.js#197-199,201-204,211)

As this is only called for the top-level document target, when Fission is enabled, the stylesheet isn't inserted in remote document.

Comment 1

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

The severity field is not set for this bug.
:nchevobbe, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 2

[Nicolas Chevobbe [:nchevobbe]]

only impacting RDM + remote iframes

Comment 3

[Nicolas Chevobbe [:nchevobbe]]

Emilio, with Bug 1730867 being complete, what would be the next steps to cleanup the situation for RDM?

Comment 4

[Emilio Cobos Álvarez (:emilio)]

We basically need to teach RDM-using documents to use the android theme rather than the platform theme. I'm a bit busy with other stuff right now, but I can try to look into it in the coming weeks, or alternatively if it's urgent I'm happy to mentor?

Comment 5

[Nicolas Chevobbe [:nchevobbe]]

It's not really urgent, but I can take a crack at it :)
Would you have some pointers?

Comment 6

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1730503 - Make RDM force Android-style scrollbars better. r=mstange

There are a few bits that still don't work with this patch but will with the
following patches.

Comment 7

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1730503 - Unify macOS and Windows/Linux scrollbars.css. r=mstange

They're basically the same (just setting the right appearance values for all
the scrollbar parts).

The Android ones can be unified as well with a few tweaks to our CSS /
scrollbar caching code (incoming).

Depends on D128083

Comment 8

[Emilio Cobos Álvarez (:emilio)]

I was going to write up what this entailed and realized that it needed a bit more cleanup. So I just did today since it was going to get more complicated than I thought :)

Comment 9

[Emilio Cobos Álvarez (:emilio)]

Attachment: Bug 1730503 - Make anonymous scrollbar caching work on mac by default, and unify scrollbars.css across platforms. r=mstange

We make it work on macOS by setting pointer-events: none + opacity: 0 rather
than visibility: hidden, and tweaking the caching setup to be Android-like.

Now that the scrollbars sheet is the same across platforms, move it to where
the rest of the UA sheets are. This way we guarantee that the RDM vs. Android
difference is less (just the ifdef at the top of the sheet).

Depends on D128084

Comment 11

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/0209c03dc06c
Make RDM force Android-style scrollbars better. r=mstange,devtools-backward-compat-reviewers,nchevobbe
https://hg.mozilla.org/integration/autoland/rev/a342878a1d5f
Unify macOS and Windows/Linux scrollbars.css. r=mstange,desktop-theme-reviewers,dao
https://hg.mozilla.org/integration/autoland/rev/b282eb58ce4e
Make anonymous scrollbar caching work on mac by default, and unify scrollbars.css across platforms. r=mstange,desktop-theme-reviewers,dao

Comment 12

[Noemi Erli[:noemi_erli]]

https://hg.mozilla.org/mozilla-central/rev/0209c03dc06c
https://hg.mozilla.org/mozilla-central/rev/a342878a1d5f
https://hg.mozilla.org/mozilla-central/rev/b282eb58ce4e

Comment 13

[Andra Esanu (needinfo me)]

== Change summary for alert #31889 (as of Fri, 15 Oct 2021 08:28:02 GMT) ==

Improvements:

Ratio	Test	Platform	Options	Absolute values (old vs new)
6%	tscrollx	linux1804-64-shippable-qr	e10s stylo webrender-sw	1.16 -> 1.09
6%	tscrollx	linux1804-64-shippable-qr	e10s stylo webrender-sw	1.16 -> 1.10

For up to date results, see: https://treeherder.mozilla.org/perfherder/alerts?id=31889