ViewController.swift

import UIKit
import WebKit

class ViewController: UIViewController {
    var gutenbergView: GutenbergView!

    override func viewDidLoad() {
        super.viewDidLoad()

        gutenbergView = GutenbergView()
        let padding: CGFloat = 30
        let viewWidth = view.frame.width
        let viewHeight = view.frame.height

        let maxHeight: CGFloat = 300
        let height = min(viewHeight / 2 - 2 * padding, maxHeight)
        let centeredFrame = CGRect(x: padding, y: (viewHeight - height + 300) / 2, width: viewWidth - 2 * padding, height: height)
        gutenbergView.view.frame = centeredFrame
        gutenbergView.view.layer.borderWidth = 1
        gutenbergView.view.layer.borderColor = UIColor.black.cgColor
        gutenbergView.view.clipsToBounds = true

        view.addSubview(gutenbergView.view)
        gutenbergView.didMove(toParent: self)
    }
    
    @objc func callRequestHTML() {
        if (gutenbergView != nil) {
            gutenbergView.requestHTML()
        }
    }
}