1955947 - Implement #restore-scroll-position-data

Status: RESOLVED FIXED

(Core :: DOM: Navigation, task)

Description

[Andreas Farre [:farre]]

Bug 1948249 implements #process-scroll-behavior, which uses #restore-scroll-position-data.

Comment 1

[Keith Cirkel [:keithamus]]

Attachment: Bug 1955947 - Part 1: Implement Document::HasBeenScrolledSince, replacing Document::HasBeenScrolled r?#dom-core,farre

This change replaces the Document::HasBeenScrolled method, introducing
Document::HasBeenScrolledByUser. This method delegates to
ScrollContainerFrame::HasBeenScrolledByUser which is a new boolean in
ScrollContainerFrame that marks when scrolls occur outside of a JS Stack
Frame.

This change is required because Navigations that cause scrolling should
(such as prior .scroll() calls, or navigating to an anchor and
navigating back) should properly restore scroll position, which won't
occur if we simply track whether or not a frame has been scrolled (since
those APIs can scroll).

Comment 2

[Keith Cirkel [:keithamus]]

Attachment: Bug 1955947 - Part 2: Implement RestoreScrollPositionData r?#dom-core,farre

This implements the basics of RestoreScrollPositionData as per spec;
introducing the new method nsDocShell::RestoreScrollPosFromActiveSHE
which will set the scroll position to the position stored by the active
session history entry.

It does not pass all scroll-behavior tests, as some rely on an unspecced
behaviour whereby the scroll restoration is deferred until the active
navigation interception promise has settled. We can resolve this in
another bug because this behaviour is not detailed in the spec.

Comment 3

[Pulsebot]

Pushed by [e-mail]:
https://github.com/mozilla-firefox/firefox/commit/25cebeac46f8
https://hg.mozilla.org/integration/autoland/rev/9d1929e60c1d
Part 1: Implement Document::HasBeenScrolledSince, replacing Document::HasBeenScrolled r=farre,layout-reviewers,emilio,hiro
https://github.com/mozilla-firefox/firefox/commit/451168ca30b2
https://hg.mozilla.org/integration/autoland/rev/7cd71026e377
Part 2: Implement RestoreScrollPositionData r=farre,dom-core
https://github.com/mozilla-firefox/firefox/commit/892291a2d2ed
https://hg.mozilla.org/integration/autoland/rev/d8c4a956de06
apply code formatting via Lando

Comment 4

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/9d1929e60c1d
https://hg.mozilla.org/mozilla-central/rev/7cd71026e377
https://hg.mozilla.org/mozilla-central/rev/d8c4a956de06

Comment 5

[Hiroyuki Ikezoe (:hiro)]

Keith, would you mind filing a follow-up bug to implement HasBeenScrolledByUser? Whether we need it for shipping navigation-api or need it for enabling navigation-api on nightly, we will have to implement it, right?

Comment 6

[Keith Cirkel [:keithamus]]

Yes I still contend it might be the wrong thing to implement (see https://github.com/whatwg/html/issues/11732 for more), but bug 1992713 can follow this.

Comment 7

[Hiroyuki Ikezoe (:hiro)]

Thanks! I didn't realize that you've already filed the spec issue.