【SwiftUI】よくある感じのくるくるインジケーター

struct SpinnerView: View {
    @State private var showSpinner = false
    @State private var degree: Int = 270
    @State private var spinnerLength = 0.6
    
    var body: some View {
        ZStack {
            VStack {
                Button {
                    showSpinner.toggle()
                } label: {
                    Text("show spinner")
                }
            }
            if showSpinner {
                Circle()
                    .trim(from: 0.0, to: spinnerLength)
                    .stroke(.green, style: StrokeStyle(lineWidth: 8.0, lineCap: .square, lineJoin: .round))
                    .animation(Animation.easeIn(duration: 1.5).repeatForever(autoreverses: true), value: spinnerLength)
                    .frame(width: 60, height: 60)
                    .rotationEffect(Angle(degrees: Double(degree)))
                    .animation(Animation.linear(duration: 1).repeatForever(autoreverses: false), value: degree)
                    .onAppear {
                        degree = 270 + 360
                        spinnerLength = 0
                    }
            }
        }
    }
}