Bug 211374 – REGRESSION(r260571): RequestedScrollPosition doesn't have its scroll change applied to layers anymore

• Component: Scrolling
• Status: RESOLVED FIXED

[Zan Dobersek]

After r260571, in the Nicosia scrolling mechanisms, scrolling changes applied onto the main-frame scrolling nodes through the RequestedScrollPosition state property change don't have any effect anymore. I assume this problem isn't exhibited on Mac/iOS.
https://trac.webkit.org/changeset/260571/webkit

This leaves the RequestedScrollPosition state changes to have no effect on the positioning of the layers, ergo scrolling via scrollbars or keyboard does not behave correctly.

A call to applyLayerPositionsInternal() at the end of the ScrollingTree::commitTreeState() would for instance restore the correct behavior.

[Simon Fraser (smfr)]

This is because of me juggling which when layer positions are applied.

Layer positions should be getting applied at the end of the rendering updates; on macOS this happens in Page::finalizeRenderingUpdate().

[Zan Dobersek]

(In reply to Simon Fraser (smfr) from comment #1)
> This is because of me juggling which when layer positions are applied.
> 
> Layer positions should be getting applied at the end of the rendering
> updates; on macOS this happens in Page::finalizeRenderingUpdate().

That's what's needed, thanks for the tip.

[Zan Dobersek]

Created attachment 399254 [details]
Patch

[Carlos Garcia Campos]

Comment on attachment 399254 [details]
Patch

Thanks!

[Zan Dobersek]

Comment on attachment 399254 [details]
Patch

Clearing flags on attachment: 399254

Committed r261616: <https://trac.webkit.org/changeset/261616>

[Zan Dobersek]

All reviewed patches have been landed.  Closing bug.

[Radar WebKit Bug Importer]

<rdar://problem/63183761>