ReadViewSDK/Sources/RDEpubReaderView/ReaderView/RDEpubReaderPageChildViewController.swift

import UIKit

class RDEpubReaderPageChildViewController: UIViewController {

    private let contentContainerView = UIView()

    var contentView: UIView? {
        didSet {
            guard isViewLoaded else { return }
            installContentView()
        }
    }

    var pageNum: Int = 0

    init(contentView: UIView?, pageNum: Int = 0) {
        self.contentView = contentView
        self.pageNum = pageNum
        super.init(nibName: nil, bundle: nil)
    }

    override func loadView() {
        view = UIView()
        view.backgroundColor = .clear
        contentContainerView.frame = view.bounds
        contentContainerView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        contentContainerView.backgroundColor = .clear
        view.addSubview(contentContainerView)
        installContentView()
    }

    required init?(coder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    override func viewDidLoad() {
        super.viewDidLoad()

    }

    private func installContentView() {
        contentContainerView.subviews.forEach { $0.removeFromSuperview() }
        guard let contentView else { return }
        contentView.removeFromSuperview()
        contentView.frame = contentContainerView.bounds
        contentView.autoresizingMask = [.flexibleWidth, .flexibleHeight]
        contentContainerView.addSubview(contentView)
    }

}