//

class StackTestVC: UIViewController {

    let v1 = UILabel()
    let v2 = UILabel()
    let v3 = UILabel()

    override func viewDidLoad() {
        super.viewDidLoad()

        view.backgroundColor = .systemYellow

        let containerView = UIView()

        let stackView = UIStackView()
        stackView.axis = .horizontal
        stackView.spacing = 0
        stackView.distribution = .fillEqually

        containerView.translatesAutoresizingMaskIntoConstraints = false
        stackView.translatesAutoresizingMaskIntoConstraints = false

        view.addSubview(containerView)
        containerView.addSubview(stackView)

        let g = view.safeAreaLayoutGuide
        NSLayoutConstraint.activate([

            containerView.topAnchor.constraint(equalTo: g.topAnchor, constant: 20.0),
            containerView.leadingAnchor.constraint(equalTo: g.leadingAnchor, constant: 20.0),
            containerView.trailingAnchor.constraint(equalTo: g.trailingAnchor, constant: -20.0),
            containerView.bottomAnchor.constraint(equalTo: g.bottomAnchor, constant: -20.0),

            stackView.topAnchor.constraint(equalTo: containerView.topAnchor, constant: 0.0),
            stackView.leadingAnchor.constraint(equalTo: containerView.leadingAnchor, constant: 0.0),
            stackView.trailingAnchor.constraint(equalTo: containerView.trailingAnchor, constant: 0.0),

        ])

        let colors: [UIColor] = [
            .systemGreen, .systemBlue, .systemOrange
        ]
        let labels: [UILabel] = [
            v1, v2, v3
        ]
        var i: Int = 0
        for (v, c) in zip(labels, colors) {
            i += 1
            v.text = "\(i)"
            v.textAlignment = .center
            v.textColor = .white
            v.font = .systemFont(ofSize: 40.0, weight: .regular)
            v.backgroundColor = c
            v.heightAnchor.constraint(equalToConstant: 150.0).isActive = true
            stackView.addArrangedSubview(v)
        }

        containerView.backgroundColor = .white
        containerView.layer.cornerRadius = 16
        containerView.layer.borderColor = UIColor.white.cgColor
        containerView.layer.borderWidth = 4

        containerView.layer.masksToBounds = true
    }

    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        v2.isHidden.toggle()
    }
}