Is there a better way to implement a shake animation in swiftui?

Question

I'm trying to get a button to shake when the user tries to log in without filling all the textfields in, and this is what I've come across so far:

struct Shake: GeometryEffect {
    var amount: CGFloat = 10
    var shakesPerUnit = 3
    var animatableData: CGFloat

    func effectValue(size: CGSize) -> ProjectionTransform {
        ProjectionTransform(CGAffineTransform(translationX:
            amount * sin(animatableData * .pi * CGFloat(shakesPerUnit)),
            y: 0))
    }
}

struct Correct: View {
    @State var attempts: Int = 0

    var body: some View {
        VStack {
            Rectangle()
                .fill(Color.pink)
                .frame(width: 200, height: 100)
                .modifier(Shake(animatableData: CGFloat(attempts)))
            Spacer()
            Button(action: {
                withAnimation(.default) {
                    self.attempts += 1
                }

            }, label: { Text("Login") })
        }
    }
}

However, this is particularly useless for a button, and even then the animation seems very off in that its pretty robotic. Can someone suggest an improvement so that I can get my button to shake?

Answer 1

try this

struct ContentView: View {
    @State var selected = false

    var body: some View {
        VStack {
            Button(action: {
                self.selected.toggle()
            }) { selected ? Text("Deselect") : Text("Select") }
            Rectangle()
                .fill(Color.purple)
                .frame(width: 200, height: 200)
                .offset(x: selected ? -30 : 0)
                .animation(Animation.default.repeatCount(5).speed(6))
        }
    }
}

Answer 2

I do this to make the field shake and then gets back to it's original position:

private func signUp() {
        if email.isEmpty {
            withAnimation {
                emailIsWrong = true
            }
            DispatchQueue.main.asyncAfter(deadline: .now() + 0.2) {
                withAnimation {
                    emailIsWrong = false
                }
            }
            return
        }
}

Where emailIsWrong is a @State variable:

@State private var emailIsWrong = false

Basically after 0.2 sec, I change the emailIsWrong back to false so the view goes back to its position. My text field looks like this:

 TextField("Email", text: $email)
    .padding()
    .frame(height: 45)
    .background(Color.white)   
    .colorScheme(.light)
    .offset(x: emailIsWrong ? -8 : 0)
    .animation(Animation.default.repeatCount(3, autoreverses: true).speed(6))