TwoStateButton.swift

SwiftUI Button with two view states

struct TwoStateButton<Content: View>: View {
    @State private var isPressed = false
    
    let touchDownView: () -> Content
    let touchUpView: () -> Content
    let action: () -> ()
    let touchDownAction: (() -> ())?
    
    var body: some View {
        Button(action: action, label: {
            ZStack {
                if isPressed {
                    touchDownView()
                } else {
                    touchUpView()
                }
            }
        }).buttonStyle(CustomButtonStyle(onPressed: {
            isPressed = true
            touchDownAction?()
        }, onReleased: {
            isPressed = false
        }))
    }

    // https://stackoverflow.com/a/71714195/8047
    private struct CustomButtonStyle: ButtonStyle {
        
        var onPressed: () -> Void
        
        var onReleased: () -> Void
        
        // Wrapper for isPressed where we can run custom logic via didSet (or willSet)
        @State private var isPressedWrapper: Bool = false {
            didSet {
                // new value is pressed, old value is not pressed -> switching to pressed state
                if (isPressedWrapper && !oldValue) {
                    onPressed()
                }
                // new value is not pressed, old value is pressed -> switching to unpressed state
                else if (oldValue && !isPressedWrapper) {
                    onReleased()
                }
            }
        }
        
        // return the label unaltered, but add a hook to watch changes in configuration.isPressed
        func makeBody(configuration: Self.Configuration) -> some View {
            return configuration.label
                .onChange(of: configuration.isPressed, perform: { newValue in isPressedWrapper = newValue })
        }
    }
}

In the end, in most cases the ON state won't show fast enough anyway... sad.