UIHostingCell

FixedSafeAreaInsetsHostingViewController.swift

@available(iOS 13.0, *)
final class FixedSafeAreaInsetsHostingViewController<Content: SwiftUI.View>: UIHostingController<Content> {

    override var prefersStatusBarHidden: Bool {
        return false
    }

    override init(rootView: Content) {
        super.init(rootView: rootView)
        UIView.classInit
    }

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

extension UIView {

    fileprivate static let classInit: Void = {
        guard let originalSafeAreaInsets = class_getInstanceMethod(UIView.self, #selector(getter: UIView.safeAreaInsets)),
              let fixedSafeAreaInsets = class_getInstanceMethod(UIView.self, #selector(fix_safeAreaInsets)) else {
            return
        }

        guard let originalSafeAreaLayoutGuide = class_getInstanceMethod(UIView.self, #selector(getter: UIView.safeAreaLayoutGuide)),
              let fixedSafeAreaLayoutGuide = class_getInstanceMethod(UIView.self, #selector(fix_safeAreaLayoutGuide)) else {
            return
        }

        method_exchangeImplementations(originalSafeAreaInsets, fixedSafeAreaInsets)
        method_exchangeImplementations(originalSafeAreaLayoutGuide, fixedSafeAreaLayoutGuide)
    }()

    private var isHostingView: Bool {
        // _TtGC7SwiftUI14_UIHostingViewGSqV3Edu15PageWordRowItem__
        let className = NSStringFromClass(classForCoder)
        return className.contains("SwiftUI") && className.contains("_UIHostingView")
    }

    private var isNeedFixSafeArea: Bool {
        guard let next = next, NSStringFromClass(next.classForCoder).contains("FixedSafeAreaInsetsHostingViewController") else {
            return false
        }

        return isHostingView
    }

    @objc private func fix_safeAreaInsets() -> UIEdgeInsets {
        isNeedFixSafeArea ? .zero : fix_safeAreaInsets()
    }

    @objc private func fix_safeAreaLayoutGuide() -> UILayoutGuide? {
        isNeedFixSafeArea ? nil : fix_safeAreaLayoutGuide()
    }
}

UIHostingCell1.swift

import UIKit
import SwiftUI

@available(iOS 14.0, *)
public final class UIHostingCell<Content>: UITableViewCell where Content: View {

    private let hostingController = UIHostingController<Content?>(rootView: nil)

    override init(style: UITableViewCell.CellStyle, reuseIdentifier: String?) {
        super.init(style: style, reuseIdentifier: reuseIdentifier)

        hostingController.view.translatesAutoresizingMaskIntoConstraints = false
        contentView.addSubview(hostingController.view)
        hostingController.view.topAnchor.constraint(equalTo: contentView.topAnchor).isActive = true
        hostingController.view.bottomAnchor.constraint(equalTo: contentView.bottomAnchor).isActive = true
        hostingController.view.leadingAnchor.constraint(equalTo: contentView.leadingAnchor).isActive = true
        hostingController.view.trailingAnchor.constraint(equalTo: contentView.trailingAnchor).isActive = true
    }

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

    public override func prepareForReuse() {
        super.prepareForReuse()
        
        hostingController.rootView = nil
    }

    public func configure(with view: Content) {
        hostingController.rootView = view
        setNeedsLayout()
    }
}

UIHostingCell2.swift

import UIKit
import SwiftUI

@available(iOS 14.0, *)
public final class UIHostingCell<Content>: UITableViewCell where Content: View {
    
    // ...생략...
    
    public override func prepareForReuse() {
        super.prepareForReuse()
        
        hostingController.willMove(toParent: nil)
        hostingController.rootView = nil
        hostingController.removeFromParent()
    }
    
    public func configure(view: Content, parent: UIViewController?) {
        parent?.addChild(hostingController)
        hostingController.rootView = view
        hostingController.view.invalidateIntrinsicContentSize()
        hostingController.didMove(toParent: parent)
    }
}