Observing Appearance Changes
I needed to get notified when the system appearance changed. On iOS, this is very straight-forward and a first-class API. On iOS 13, the interface style is part of
UITraitCollection.[…]
[On macOS,] you can KVO on
NSApp.effectiveappearance. […] Using KVO still does not feel great, but this is the best solution I could find without having an explicit API like iOS.
Previously:
