ListBox virtualization with smooth scrolling.

[x2bool]

Right now Avalonia provides only two virtualization methods: None and Simple. The first one provides ablility to scroll smoothly but does not virtualize items. It would be nice to have third option with smooth scrolling and virtualization.

Theoretically views like this exist in other GUI frameworks: an example would be Android's RecyclerView.

[jmacato]

@x2bool You're welcome to file an PR for that smooth-scroll virt 😄 I think either SmoothItemVirtualizer or SeamlessItemVirtualizer would be a good name for that but that's subject to change anyway

[ashelleyPurdue]

I've made a sloppy, hacky, proof-of-concept implementation. It works by shifting the virtual items panel up/down to simulate scrolling "in between" items.

I wouldn't put this code directly into Avalonia, since it probably follows none of Avalonia's recommended patterns. It's just to throw an idea out there for how an implementation would work.

https://gist.github.com/ashelleyPurdue/c81fcb706079d4736c20380c067c5156

[jmacato]

@ashelleyPurdue I think this is already solved by @grokys 's ItemsRepeater control (based on its UWP counterpart).

[ashelleyPurdue]

Even better!

[grokys]

I'm going to close this issue and track the transition to ItemsRepeater for ListBox etc over at #2594.

[Whiletru3]

Hello,

@grokys : As the #2594 is a dead end and won't be fixed, this issue need to be reopened.
The issue #8495 expose in a sample project the issues with the Listbox simple virtualization.

Thanks :)