1743045 - Smooth scroll preference is ignored for element.scrollIntoView

Status: RESOLVED FIXED

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

Description

[Matthias]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:95.0) Gecko/20100101 Firefox/95.0

Steps to reproduce:

I have configured my browser with 'smooth scrolling: disabled', then clicked on an element which triggered an element.scrollIntoView({behaviour: 'smooth'}) action.

Example: clicking 'next' on a comment in an HN thread: https://news.ycombinator.com/item?id=29341390

Actual results:

The window, during some 150ms, smoothly scrolled to the element, whilst adding unwanted extra strain onto my eyes.

Expected results:

The window immediately jumps to the element. The user preferences are used instead of the JS value.

Comment 1

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

The Bugbug bot thinks this bug should belong to the 'Core::JavaScript Engine' component, and is moving the bug to that component. Please revert this change in case you think the bot is wrong.

Comment 2

[Estanislao Larriera]

Hi Matthias,

I tested your issue on the latest Nightly 96.0a1, on Beta 94.0 and currente release 94.0 and I did reproduce it, so I´ll tag this as "New" for visibility.

Let´s wait a for a developer to look into this.

Thanks,

Estanislao

Comment 3

[Peter Van der Beken [:peterv]]

I moved this to layout, because I think it would make more sense to check the pref there (in PresShell::ScrollContentIntoView?) instead of in every place that we trigger a scroll. If we need to fix it in the DOM API this would be the location instead: https://searchfox.org/mozilla-central/source/dom/base/Element.cpp#761

Comment 4

[Dan Robertson (:dlrobertson)]

Attachment: Bug 1743045 - Respect general.smoothScroll for programmatic scrolls. r=hiro

For programmatic scrolls, we should respect a users general.smoothScroll
preference. If smooth scrolls are disabled, programmatic scrolls with
behavior: "smooth" should be treated as instant programmatic scrolls.

Comment 5

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/c33204e69e49
Respect general.smoothScroll for programmatic scrolls. r=hiro

Comment 6

[Atila Butkovits]

Backed out for causing failures at scroll-behavior-3.html.

Backout link: https://hg.mozilla.org/integration/autoland/rev/554741893ce270e952a543e1a929d1451db6d6ad

Push with failures: https://treeherder.mozilla.org/jobs?repo=autoland&selectedTaskRun=WPsUq0GFTwyD3WxWBrnOHw.0&resultStatus=testfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel&revision=c33204e69e493b0a77e59e9b3f8c13d69e0c0d8e

Failure log: https://treeherder.mozilla.org/logviewer?job_id=406448640&repo=autoland&lineNumber=10996

Comment 7

[Dan Robertson (:dlrobertson)]

Added fix to the patch last night.

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/05981db2f726
Respect general.smoothScroll for programmatic scrolls. r=hiro

Comment 9

[Natalia Csoregi [:nataliaCs]]

Backed out for causing failures on test_group_scrollend.html

• backout: https://hg.mozilla.org/integration/autoland/rev/65df09c42043b91a0ea56b63960e006fdc3e2bb9
• push: https://treeherder.mozilla.org/jobs?repo=autoland&group_state=expanded&selectedTaskRun=PHfVc-XtQMOBi99rI00Atw.0&revision=05981db2f726213a0653b0e83e661c2bb66202c4
• failure log: https://treeherder.mozilla.org/logviewer?job_id=406609241&repo=autoland&lineNumber=8083

[task 2023-02-23T01:49:34.312Z] 01:49:34     INFO - TEST-PASS | gfx/layers/apz/test/mochitest/test_group_scrollend.html | helper_basic_scrollend.html?chrome-only=true | A scrollend event should be triggered after instant scroll 
[task 2023-02-23T01:49:34.313Z] 01:49:34     INFO - Buffered messages finished
[task 2023-02-23T01:49:34.314Z] 01:49:34     INFO - TEST-UNEXPECTED-FAIL | gfx/layers/apz/test/mochitest/test_group_scrollend.html | Test timed out. - 
[task 2023-02-23T01:49:35.181Z] 01:49:35     INFO - GECKO(2783) | MEMORY STAT | vsize 2590MB | residentFast 172MB | heapAllocated 10MB
[task 2023-02-23T01:49:36.205Z] 01:49:36     INFO - TEST-OK | gfx/layers/apz/test/mochitest/test_group_scrollend.html | took 329740ms
[task 2023-02-23T01:49:39.215Z] 01:49:39     INFO - Error: Unable to restore focus, expect failures and timeouts.

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/fba053844000
Respect general.smoothScroll for programmatic scrolls. r=hiro

Comment 11

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/fba053844000