Check/Radio button, extend class of UIButton.

MyCheckButton.swift

class MyCheckButton: UIButton {
    var baseColor:UIColor = UIColor.lightGray
    private var isMulti:Bool = false
    private let frameShapeLayer:CAShapeLayer = CAShapeLayer()
    private let checkShapeLayer:CAShapeLayer = CAShapeLayer()
    private let framePath:UIBezierPath = UIBezierPath()
    private let checkPath:UIBezierPath = UIBezierPath()
    private let margin:CGFloat = 16
    private let lineWidth:CGFloat = 2
    
    convenience init(isMulti m: Bool, color c:UIColor) {
        self.init()
        isMulti = m
        tintColor = c
        isSelected = false
        layer.addSublayer(frameShapeLayer)
        layer.addSublayer(checkShapeLayer)
    }
    
    override func draw(_ rect: CGRect) {
        super.draw(rect)
        if isMulti {
            // frame is rectangle
            framePath.move(to: CGPoint(x:margin, y:margin))
            framePath.addLine(to: CGPoint(x:margin, y:self.frame.height - margin))
            framePath.addLine(to: CGPoint(x:self.frame.height - margin, y:self.frame.height - margin))
            framePath.addLine(to: CGPoint(x:self.frame.height - margin, y:margin))
            framePath.addLine(to: CGPoint(x:margin - lineWidth/2, y:margin))
            framePath.stroke()
            // selected mark is v
            checkPath.move(to: CGPoint(x:margin + 2, y:self.frame.height/2 - 2))
            checkPath.addLine(to: CGPoint(x:self.frame.height/2, y:self.frame.height/2 + 2))
            checkPath.addLine(to: CGPoint(x:self.frame.height - margin + 2, y:margin - 2))
            checkPath.stroke(with: CGBlendMode.clear, alpha: 0)
            checkShapeLayer.strokeColor = tintColor.cgColor
            checkShapeLayer.fillColor = UIColor.clear.cgColor
        } else {
            // frame is circle
            framePath.addArc(withCenter: CGPoint(x:self.frame.height/2, y:self.frame.height/2),
                             radius: self.frame.height - margin*2 - 6,
                             startAngle: 0,
                             endAngle: CGFloat.pi * 2,
                             clockwise: true)
            framePath.stroke()
            // selected mark is filled circle
            checkPath.addArc(withCenter: CGPoint(x:self.frame.height/2, y:self.frame.height/2),
                             radius: self.frame.height - margin*2 - 9,
                             startAngle: 0,
                             endAngle: CGFloat.pi * 2,
                             clockwise: true)
            checkPath.fill(with: CGBlendMode.clear, alpha: 0)
            checkShapeLayer.strokeColor = UIColor.clear.cgColor
            checkShapeLayer.fillColor = tintColor.cgColor
        }
        frameShapeLayer.path = framePath.cgPath
        frameShapeLayer.strokeColor = baseColor.cgColor
        frameShapeLayer.fillColor = UIColor.clear.cgColor
        frameShapeLayer.lineWidth = lineWidth
        checkShapeLayer.path = checkPath.cgPath
        checkShapeLayer.lineWidth = lineWidth
        checkShapeLayer.isHidden = true
    }
    
    func on(){
        setTitleColor(tintColor, for: .normal)
        frameShapeLayer.strokeColor = tintColor.cgColor
        checkShapeLayer.isHidden = false
        isSelected = true
    }
    
    func off(){
        setTitleColor(baseColor, for: .normal)
        frameShapeLayer.strokeColor = baseColor.cgColor
        checkShapeLayer.isHidden = true
        isSelected = false
    }
    
    func toggle(){
        if isSelected { off() }
        else { on() }
    }
    
}

see: http://www.hakopako.net/entry/2016/10/13/120000