* Extracted IInputRoot out of TopLevel
* Move some input handling out of TopLevel
* Remove old class, make layout manager private
* Removed IRenderRoot
* Make VisualTreeAttachmentEventArgs a bit more sensible
* Move ILayoutRoot to PresentationSource
# Conflicts:
# tests/Avalonia.Controls.UnitTests/TabControlTests.cs
* Updated some VisualRoot / GetVisualRoot usages
* Updated more XxxRoot usages
* More Root usages
* Addressed review
* Hurr-durr xml
* More fixes
* Maybe fix android compilation
* API diff
* Yet another cast
* I had to use MSIL analysis to detect those casts
* Fixed automation
* Fix PointerOverPreProcessor
* Fix?
* Removed yet another cast to Visual
* The amount of random downcasts is astonishing
* Maybe fix mac
* Addressed review
A lot still broken, in particular virtualization is completely removed.`ItemsPresenter` now no longer has an `Items` or `ItemTemplate` property; it detects when it's hosted in an `ItemsControl`. `IItemsPresenter` interface removed.
`SelectionModel` needs to subscribe to `CollectionChanged` on the items before `ItemsControl` in order for the selection to be correct when we come to setting the selected state.
Because `SelectionModel.Source` isn't subscribed during initialization in `ItemsChanged`, we also need to make sure we don't subscribe `ItemsControl` to the collection changes during initialization. Instead subscribe in `OnInitialized` (this requires a few tests to be rooted in order to be called).
Fixes#4293
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
Make the untyped ItemContainerGenerator create `ContentPresenter`
containers when the data isn't a control. This is required for correct
binding to `DataContext` in a data template.
...during ApplyTemplate. This was so that ItemsControls could their find
ItemsPresenters nested in other templated controls. Instead use
IItemsPresenterHost to make the presenter register itself with its
TemplatedParent.