Factory method implementation in Swift

factory.swift

//: A UIKit based Playground for presenting user interface
  
import UIKit
import PlaygroundSupport

enum Maps : Int {
    case google = 1
    case apple
}

protocol Display {
    func showMap()
}

class Map {
    let type : Int = 0
    func showMap(type : Maps) -> Display {
        switch type {
        case Maps.apple :
            return AppleMap()
        case Maps.google :
            fallthrough
        default:
            return GoogleMap()
        }
    }
}

class AppleMap : Display {
    func showMap() {
        print("showing apple map")
    }
}

class GoogleMap : Display {
    func showMap() {
        print("showing google map")
    }
}

class MyViewController : UIViewController {
    override func loadView() {
        let view = UIView()
        view.backgroundColor = .white

        let label = UILabel()
        label.frame = CGRect(x: 150, y: 200, width: 200, height: 20)
        label.text = "Hello World!"
        label.textColor = .black
        
        view.addSubview(label)
        self.view = view
        
        let map = Map()
        map.showMap(type: Maps.google)
        map.showMap(type: Maps.apple)
    }
}

// Present the view controller in the Live View window
PlaygroundPage.current.liveView = MyViewController()