SwiftUI Repaint View Components on Device Rotation

Here‘s an idiomatic SwiftUI implementation based on a notification publisher:

struct ContentView: View {
    
    @State var orientation = UIDevice.current.orientation

    let orientationChanged = NotificationCenter.default.publisher(for: UIDevice.orientationDidChangeNotification)
        .makeConnectable()
        .autoconnect()

    var body: some View {
        Group {
            if orientation.isLandscape {
                Text("LANDSCAPE")
            } else {
                Text("PORTRAIT")
            }
        }.onReceive(orientationChanged) { _ in
            self.orientation = UIDevice.current.orientation
        }
    }
}

The output of the publisher (not used above, therefor _ as the block parameter) also contains the key "UIDeviceOrientationRotateAnimatedUserInfoKey" in its userInfo property if you need to know if the rotation should be animated.