ReusableViewController.swift

import UIKit

protocol ReusableViewControllerDelegate {
    func loadView()
    func viewDidLoad()
    func viewWillAppear(_ animated: Bool)
    func viewWillLayoutSubviews()
    func viewDidLayoutSubviews()
    func viewDidAppear(_ animated: Bool)
    func viewWillDisappear(_ animated: Bool)
    func viewDidDisappear(_ animated: Bool)
    func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator)
    func traitCollectionDidChange(from previousTraitCollection: UITraitCollection?, to currentTraitCollection: UITraitCollection?)
    func didReceiveMemoryWarning()
}

extension ReusableViewControllerDelegate {
    func loadView() {}
    func viewDidLoad() {}
    func viewWillAppear(_ animated: Bool) {}
    func viewWillLayoutSubviews() {}
    func viewDidLayoutSubviews() {}
    func viewDidAppear(_ animated: Bool) {}
    func viewWillDisappear(_ animated: Bool) {}
    func viewDidDisappear(_ animated: Bool) {}
    func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {}
    func traitCollectionDidChange(from previousTraitCollection: UITraitCollection?, to currentTraitCollection: UITraitCollection?) {}
    func didReceiveMemoryWarning() {}
}

final class ReusableViewController: UIViewController {
    var delegate: ReusableViewControllerDelegate?
    private let contentView: UIView

    init(with view: UIView) {
        self.contentView = view
        super.init(nibName: nil, bundle: nil)
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }

    override func loadView() {
        super.loadView()
        self.view = contentView
        delegate?.loadView()
    }

    override func viewDidLoad() {
        super.viewDidLoad()
        delegate?.viewDidLoad()
    }

    override func viewWillAppear(_ animated: Bool) {
        super.viewWillAppear(animated)
        delegate?.viewWillAppear(animated)
    }

    override func viewWillLayoutSubviews() {
        super.viewWillLayoutSubviews()
        delegate?.viewWillLayoutSubviews()
    }

    override func viewDidLayoutSubviews() {
        super.viewDidLayoutSubviews()
        delegate?.viewDidLayoutSubviews()
    }

    override func viewDidAppear(_ animated: Bool) {
        super.viewDidAppear(animated)
        delegate?.viewDidAppear(animated)
    }

    override func viewWillDisappear(_ animated: Bool) {
        super.viewWillDisappear(animated)
        delegate?.viewWillDisappear(animated)
    }

    override func viewDidDisappear(_ animated: Bool) {
        super.viewDidDisappear(animated)
        delegate?.viewDidDisappear(animated)
    }

    override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
        super.viewWillTransition(to: size, with: coordinator)
        delegate?.viewWillTransition(to: size, with: coordinator)
    }

    override func traitCollectionDidChange(_ previousTraitCollection: UITraitCollection?) {
        super.traitCollectionDidChange(previousTraitCollection)
        delegate?.traitCollectionDidChange(from: previousTraitCollection, to: traitCollection)
    }

    override func didReceiveMemoryWarning() {
        delegate?.didReceiveMemoryWarning()
    }
}