Stop Carousel from resetting when ItemsSource is updated

[gavinwilliams]

I'm submitting a...

Documentation issue or request

Current behavior

Updating a value in ItemsSource resets the carousel.

Expected behavior

The carousel doesn't reset to the beginning or has an option not to when a new item is added or a property in the underlying collection changes, i.e. ItemsUpdatingScrollMode="KeepItemsInView"

Minimal reproduction of the problem with instructions

1. Create a project
2. Add a carousel
3. Set the carousel's ItemsSource using MVVM and an ObservableCollection
4. Add an item to the collection

Environment

Nuget Package(s): 

Package Version(s): 

Windows 10 Build Number:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [ ] October 2018 Update (17763)
- [X] Insider Build (build number: 18362.145)

App min and target version:
- [ ] Fall Creators Update (16299)
- [ ] April 2018 Update (17134)
- [X] October 2018 Update (17763)
- [ ] Insider Build (xxxxx)

Device form factor:
- [X] Desktop
- [ ] Mobile
- [ ] Xbox
- [ ] Surface Hub
- [ ] IoT

Visual Studio 
- [ ] 2017 (version: )
- [ ] 2017 Preview (version: )
- [X] 2019 (version: 4.8.03752)

[michael-hawker]

Thanks @gavinwilliams for the report. Based on some recent investigations by @JustinXinLiu, I think we want to rewrite the Carousel soon.

[gavinwilliams]

No worries! We ended up simplifying what we made anyway.

[michael-hawker]

Good to know @gavinwilliams, I'm going to leave this open for our tracking still.

[Kyaa-dost]

@jamesmcroft is this something we can update with the changes we are making in #3507? is this an easy fix?

CC: @Sergio0694

[jamesmcroft]

I can take a look and if so, fix it 👍

[Kyaa-dost]

Thanks @jamesmcroft ❤️