Changed `MenuItem`'s `string InputGestureText` property to `KeyGesture InputGesture` and gave it a value converter in the default template, because the string representation of a key gesture depends on platform, and putting platform-specific behavior into `ToString` isn't a good idea.
To do this we needed to change the `KeyGesture.ToString()` method to produce input gesture text suitable for menus. Also demonstrated in `MainWindow` how to produce different gestures/headers depending on platform.
Match selectors from left-to-right, as before we were checking things like property equality (and creating a `PropertyEqualsActivator`) before checking that the control is of the correct type. Also hopefully makes the selector matching logic more readable.
- 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
We already have some specific internal methods for routing certain methods via an untyped property to a typed property, but adding support for the visitor pattern allows us to support arbitrary use-cases.
`PropertyChanged` is not being fired when binding is disposed. Also change some other unit tests to ensure that priority passed in event args is correct.
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
Steven Kirk
Benedikt Schroeder
Dariusz Komosinski
Deadpikle
Joe Clapis
Chris
Andrey Kunchev