Proposal: MUXC ScrollView should implement IScrollAnchorProvider

[marcelwgn]

Proposal: MUXC ScrollView should implement IScrollAnchorProvider

Summary

The muxc ScrollView should implement the IScrollAnchorProvider interface, just like the wuxc version does.

Rationale

• Consistency with wuxc ScrollViewer
• Makes it easier to switch to muxc ScrollViewer

Scope

Capability	Priority
Be consistent with existing wuxc ScrollViewer	Must

Important Notes

[StephenLPeters]

@RBrid I'm surprised this isn't already the case.. I this a bug or a feature proposal?

[marcelwgn]

The interesting thing is that ScrollPresenter does implement that interface, but the ScrollView which contains a ScrollPresenter does not.

[RBrid]

Yes this is intentional - By Design. The ScrollView publicly exposes the three IScrollAnchorProvider APIs and delegates the calls to its inner ScrollPresenter which actually implements the interface.

[marcelwgn]

@RBrid ScrollView does implement RegisterAnchorCandidate and UnregisterAnchorCandidate, but I can't seem to find the CurrentAnchor property that IScrollAnchorProvider has. Is it missing in the docs or is this intentional too?

[RBrid]

I added it recently - it should be in the code at least: see #2936 "Adding public ScrollView.CurrentAnchor read-only property"

I mentioned "I updated the ScrollView spec reviewed here microsoft/microsoft-ui-xaml-specs#56 accordingly."

[marcelwgn]

Oh must have missed that PR, sorry about that. In that case, there isn't anything to track with this issue then, given that it is by design to not implement the interface on ScrollView but instead on ScrollPresenter.

[RBrid]

Thank you Marcel!