class LabeledSwitchView: UIView {

    let theLabel: UILabel = {
        let v = UILabel()
        v.translatesAutoresizingMaskIntoConstraints = false
        v.backgroundColor = .cyan
        v.numberOfLines = 0
        return v
    }()

    let theSwitch: UISwitch = {
        let v = UISwitch()
        v.translatesAutoresizingMaskIntoConstraints = false
        return v
    }()

    override init(frame: CGRect) {
        super.init(frame: frame)
        commonInit()
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        commonInit()
    }

    func commonInit() -> Void {

        addSubview(theLabel)
        addSubview(theSwitch)

        NSLayoutConstraint.activate([

            // at least 8-pts top and bottom spacing for the label
            theLabel.topAnchor.constraint(greaterThanOrEqualTo: topAnchor, constant: 8.0),
            theLabel.bottomAnchor.constraint(lessThanOrEqualTo: bottomAnchor, constant: -8.0),

            // at least 8-pts top and bottom spacing for the switch
            theSwitch.topAnchor.constraint(greaterThanOrEqualTo: topAnchor, constant: 8.0),
            theSwitch.bottomAnchor.constraint(lessThanOrEqualTo: bottomAnchor, constant: -8.0),

            // 8-pts leading padding for the label
            theLabel.leadingAnchor.constraint(equalTo: leadingAnchor, constant: 8.0),

            // 8-pts trailing padding for the switch
            theSwitch.trailingAnchor.constraint(equalTo: trailingAnchor, constant: -8.0),

            // center the switch vertically with the label
            theSwitch.centerYAnchor.constraint(equalTo: theLabel.centerYAnchor, constant: 0.0),

            // 8-pts horizontal between the label and the switch
            theLabel.trailingAnchor.constraint(equalTo: theSwitch.leadingAnchor, constant: -8.0),

            ])

    }

}

class HupkesViewController: UIViewController {

    let theStack: UIStackView = {
        let v = UIStackView()
        v.translatesAutoresizingMaskIntoConstraints = false
        v.axis = .vertical
        v.alignment = .fill
        v.distribution = .fill
        return v
    }()

    let theScrollView: UIScrollView = {
        let v = UIScrollView()
        v.translatesAutoresizingMaskIntoConstraints = false
        v.backgroundColor = .orange
        return v
    }()

    let theData = [
        "WordOne",
        "WordOne WordTwo",
        "WordOne WordTwo WordThree",
        "WordOne WordTwo WordThree WordFour",
        "WordOne WordTwo WordThree WordFour WordFive",
        "WordOne WordTwo WordThree WordFour WordFive WordSix",
    ]

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = UIColor(red: 0.25, green: 0.5, blue: 1.0, alpha: 1.0)

        view.addSubview(theScrollView)
        theScrollView.addSubview(theStack)

        NSLayoutConstraint.activate([

            // constrain the scroll view to top / leading / trailing
            theScrollView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor, constant: 0.0),
            theScrollView.leadingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.leadingAnchor, constant: 0.0),
            theScrollView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor, constant: 0.0),

            // short scroll view, so we can get some scrolling
            theScrollView.heightAnchor.constraint(equalToConstant: 240.0),

            // constrain the stack view 20-pts top / bottom / leading / trailing
            theStack.topAnchor.constraint(equalTo: theScrollView.topAnchor, constant: 20.0),
            theStack.bottomAnchor.constraint(equalTo: theScrollView.bottomAnchor, constant: -20.0),
            theStack.leadingAnchor.constraint(equalTo: theScrollView.leadingAnchor, constant: 20.0),
            theStack.trailingAnchor.constraint(equalTo: theScrollView.trailingAnchor, constant: -20.0),

            // constrain stack view width equal to scroll view width - 40 (20-pts on each side)
            theStack.widthAnchor.constraint(equalTo: theScrollView.widthAnchor, multiplier: 1.0, constant: -40.0),

            ])

        // create and add the custom views to the stack view
        theData.forEach { s in
            let v = LabeledSwitchView()
            v.translatesAutoresizingMaskIntoConstraints = false
            v.backgroundColor = .white
            v.theLabel.text = s
            v.theSwitch.isOn = true
            theStack.addArrangedSubview(v)

            // if it's not the last one, add a "separator line"
            if s != theData.last {
                let v = UIView()
                v.translatesAutoresizingMaskIntoConstraints = false
                v.backgroundColor = .lightGray
                v.heightAnchor.constraint(equalToConstant: 1.0).isActive = true
                theStack.addArrangedSubview(v)
            }
        }

    }

}