ScrollableStackView.swift

import UIKit

public class ScrollableStackView: UIView {

    // MARK: Private Properties

    private lazy var scrollView: UIScrollView = {
        let scrollView = UIScrollView(frame: .zero)
        scrollView.backgroundColor = .clear
        scrollView.translatesAutoresizingMaskIntoConstraints = false
        scrollView.layoutMargins = .zero
        return scrollView
    }()

    private lazy var stackView: UIStackView = {
        let stackView = UIStackView(frame: .zero)
        stackView.translatesAutoresizingMaskIntoConstraints = false
        stackView.axis = .vertical
        stackView.alignment = .fill
        stackView.distribution = .fill
        return stackView
    }()

    // MARK: Public Properties

    var showsVerticalScrollIndicator: Bool {
        get {
            scrollView.showsVerticalScrollIndicator
        }
        set {
            scrollView.showsVerticalScrollIndicator = newValue
        }
    }

    var refreshControl: UIRefreshControl? {
        get {
            scrollView.refreshControl
        }
        set {
            scrollView.refreshControl = newValue
        }
    }

    // MARK: Life Cycle

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

    @available(*, unavailable)
    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    // MARK: Public

    func addView(_ view: UIView) {
        stackView.addArrangedSubview(view)
    }

    func insertView(_ view: UIView, at index: Int) {
        stackView.insertArrangedSubview(view, at: index)
    }

    func removeView(_ view: UIView) {
        stackView.removeArrangedSubview(view)
    }

    // MARK: Private

    private func setupView() {
        translatesAutoresizingMaskIntoConstraints = false
        clipsToBounds = true
        addSubview(scrollView)
        scrollView.addSubview(stackView)
        NSLayoutConstraint.activate([
            scrollView.topAnchor.constraint(equalTo: topAnchor),
            scrollView.leadingAnchor.constraint(equalTo: leadingAnchor),
            scrollView.trailingAnchor.constraint(equalTo: trailingAnchor),
            scrollView.bottomAnchor.constraint(equalTo: bottomAnchor),
            stackView.topAnchor.constraint(equalTo: scrollView.topAnchor),
            stackView.leadingAnchor.constraint(equalTo: scrollView.leadingAnchor),
            stackView.trailingAnchor.constraint(equalTo: scrollView.trailingAnchor),
            stackView.bottomAnchor.constraint(equalTo: scrollView.bottomAnchor),
            stackView.widthAnchor.constraint(equalTo: scrollView.widthAnchor)
        ])
    }
}