[swift] How to display an activity indicator with text on iOS 8 with Swift?

Xcode 10.1 • Swift 4.2

import UIKit

class ProgressHUD: UIVisualEffectView {

    var title: String?
    var theme: UIBlurEffect.Style = .light

    let strLabel = UILabel(frame: CGRect(x: 50, y: 0, width: 160, height: 46))
    let activityIndicator = UIActivityIndicatorView()

    init(title: String, theme: UIBlurEffect.Style = .light) {
        super.init(effect: UIBlurEffect(style: theme))

        self.title = title
        self.theme = theme

        [activityIndicator, strLabel].forEach(contentView.addSubview(_:))
    }

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

    override func didMoveToSuperview() {
        super.didMoveToSuperview()

        if let superview = self.superview {
            frame = CGRect(x: superview.frame.midX - strLabel.frame.width / 2,
                           y: superview.frame.midY - strLabel.frame.height / 2, width: 160, height: 46)

            layer.cornerRadius = 15.0
            layer.masksToBounds = true

            activityIndicator.frame = CGRect(x: 0, y: 0, width: 46, height: 46)
            activityIndicator.startAnimating()

            strLabel.text = title
            strLabel.font = .systemFont(ofSize: 14, weight: UIFont.Weight.medium)

            switch theme {
            case .dark:
                strLabel.textColor = .white
                activityIndicator.style = .white
            default:
                strLabel.textColor = .gray
                activityIndicator.style = .gray
            }
        }

    }

    func show() {
        self.isHidden = false
    }

    func hide() {
        self.isHidden = true
    }
}

Use:

let progress = ProgressHUD(title: "Authorization", theme: .dark)
[progress].forEach(view.addSubview(_:))