Singleton Code

IHProgressHUD.swift

private static let sharedView : IHProgressHUD = {
        var localInstance : IHProgressHUD?
        if Thread.current.isMainThread {
            if IHProgressHUD.isNotAppExtension {
            if let window = UIApplication.shared.delegate?.window {
                localInstance = IHProgressHUD.init(frame: window?.bounds ?? CGRect.zero)
            } else {
                localInstance = IHProgressHUD()
                }
            }
            else {
            localInstance = IHProgressHUD.init(frame: UIScreen.main.bounds)
            }
        } else {
            DispatchQueue.main.sync {
                if IHProgressHUD.isNotAppExtension {
                if let window = UIApplication.shared.delegate?.window {
                    localInstance = IHProgressHUD.init(frame: window?.bounds ?? CGRect.zero)
                } else {
                    localInstance = IHProgressHUD()
                    }
                } else {
                localInstance = IHProgressHUD.init(frame: UIScreen.main.bounds)
                }
            }
        }
        return localInstance!
    }