The API for `ScrollChangedEventArgs` is different to WPF's here, because:
- Avalonia's `ScrollViewer` exposes `Extent`, `Offset` and `Viewport` as `Size`/`Vector` structs whereas WPF exposes separate `double` values for the X and Y components for each of these
- The current values are not included in the event args: then can easily be read from the `sender`
- UWP doesn't expose these values at all
For non-logical scrolling:
- Use 16 for small scroll size (value taken from WPF)
- Use viewport size for large scroll
For logical scrolling, use the `ScrollSize`/`PageScrollSize` defined on `ILogicalScrollable`. Note that this required a small breaking change to `ILogicalScrollable`.
Fixed#3245
- Don't use Rx in the styling system. Instead introduces `IStyleActivator` which is like an `IObservable<bool>`-lite in order to cut down on allocations.
- #nullable enable on touched files
Exposing the `ContentPresenter.Child` in `ItemsControl.LogicalChildren` was causing problems when detaching and reattaching an `ItemsControl` to the logical tree. Instead, expose the `ContentPresenter` itself in effect meaning that `ItemsControl` has a "container" type just like the controls derived from it.
Fixes#3487
`SelectionModel` as ported from WinUI has no information about what changed in a `SelectionChanged` event. This adds that information along with unit tests.
`SelectionModel` as ported from WinUI has no information about what changed in a `SelectionChanged` event. This adds that information along with unit tests.
- #nullable enable
- Make it a `readonly struct`
- Most of the time it will only hold a single `int`, so optimize for the common case by having an `int _index` field
- Make `_path` an array rather than a list as it will be fixed-size
- Implement equality
- Implement operators
Steven Kirk
Deadpikle
Benedikt Schroeder
Joe Clapis
Dariusz Komosinski