MyAuthorizationAppleIDButton.swift

// cf. https://swiftsenpai.com/xcode/asauthorizationappleidbutton-in-storyboard/

import UIKit
import AuthenticationServices

@IBDesignable
class MyAuthorizationAppleIDButton: UIButton {
    
    private var authorizationButton: ASAuthorizationAppleIDButton!
    
    @IBInspectable
    var cornerRadius:CGFloat = 6.0
    
    @IBInspectable
    var authButtonType: Int = ASAuthorizationAppleIDButton.ButtonType.default.rawValue
        
    @IBInspectable
    var authButtonStyle: Int = ASAuthorizationAppleIDButton.Style.black.rawValue
    
    override public func draw(_ rect: CGRect) {
        super.draw(rect)
        
        let type = ASAuthorizationAppleIDButton.ButtonType.init(rawValue: authButtonType) ?? .signIn
        let style = ASAuthorizationAppleIDButton.Style.init(rawValue: authButtonStyle) ?? .black
        authorizationButton = ASAuthorizationAppleIDButton(authorizationButtonType: type,
                                                           authorizationButtonStyle: style)
        authorizationButton.cornerRadius = cornerRadius
        
        authorizationButton.addTarget(self, action: #selector(authorizationAppleIDButtonTapped(_:)), for: .touchUpInside)
        
        // Show authorizationButton
        addSubview(authorizationButton)

        // Use auto layout to make authorizationButton follow the MyAuthorizationAppleIDButton's dimension
        authorizationButton.translatesAutoresizingMaskIntoConstraints = false
        NSLayoutConstraint.activate([
            authorizationButton.topAnchor.constraint(equalTo: self.topAnchor, constant: 0.0),
            authorizationButton.leadingAnchor.constraint(equalTo: self.leadingAnchor, constant: 0.0),
            authorizationButton.trailingAnchor.constraint(equalTo: self.trailingAnchor, constant: 0.0),
            authorizationButton.bottomAnchor.constraint(equalTo: self.bottomAnchor, constant: 0.0),
        ])
    }
    
    @objc func authorizationAppleIDButtonTapped(_ sender: Any) {
        // Forward the touch up inside event to MyAuthorizationAppleIDButton
        sendActions(for: .touchUpInside)
    }

    override public init(frame: CGRect) {
        super.init(frame: frame)
    }
    
    required public init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
    }
}


extension MyAuthorizationAppleIDButton{
    
    @available(iOS 13.0, *)
    enum ButtonType: Int{
        case signIn
        case continues
        @available(iOS 13.2, *)
        case signUp
    }
    
    @available(iOS 13.0, *)
    enum Style: Int {
        case white
        case whiteOutline
        case black
    }
}