MBProgressHUD Swift extension with dimmed background

HUDLoadingIndicator.swift

import UIKit

public extension MBProgressHUD {
    @objc func dimBackgroundView() {
        backgroundView.style = .solidColor
        backgroundView.color = UIColor(white: 0.0, alpha: 0.4)
        bezelView.style = .solidColor
        bezelView.backgroundColor = UIColor(white: 0.0, alpha: 0.9)
        contentColor = .white
    }
}

public protocol HUDLoadingIndicator: class {
    var hudLoadingIndicator: MBProgressHUD? { get set }
}

public extension HUDLoadingIndicator where Self: UIViewController {
    
    func showHUDLoadingIndicator(_ message: String = "", details: String? = nil) {
        OperationQueue.main.addOperation({ [weak self] in
            guard let `self` = self else { return }
            guard self.navigationController != nil
                else { self.hudLoadingIndicator = nil; return }
            let hud = MBProgressHUD.showAdded(to: self.navigationController!.view, animated: true)
            hud.label.text = message
            hud.detailsLabel.text = details
            hud.dimBackgroundView()
            hud.show(animated: true)
            
            self.hudLoadingIndicator = hud
            self.navigationController?.interactivePopGestureRecognizer?.isEnabled = false
        })
    }
    
    func hideHUDLoadingIndicator() {
        OperationQueue.main.addOperation({ [weak self] in
            guard let `self` = self, let loadingIndicator = self.hudLoadingIndicator else { return }
            
            loadingIndicator.hide(animated: true)
            self.navigationController?.interactivePopGestureRecognizer?.isEnabled = true
        })
    }
}