SkyExtensionResponderChainPlayground.swift

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

enum SkyBehavior: String {
    case clickSky = "clickSky"
    case clickSun = "clickSun"
    case clickSunspot = "clickSunspot"
}

extension UIResponder {
    @objc func routerEvent(name: String, userInfo: [AnyHashable: Any]?) {
        next?.routerEvent(name: name, userInfo: userInfo)
    }
}

class SkyView: UIView {
    let sunView = SunView(frame: .sun)
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .blue
        
        addSubview(sunView)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        routerEvent(name: SkyBehavior.clickSky.rawValue, userInfo: nil)
    }
}

class SunView: UIView {
    let spotView = SunspotView(frame: .sunspot)
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .red
        addSunlight()
        addSubview(spotView)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        routerEvent(name: SkyBehavior.clickSun.rawValue, userInfo: nil)
    }

    override func routerEvent(name: String, userInfo: [AnyHashable : Any]?) {
        super.routerEvent(name: name, userInfo: userInfo)
        if name == SkyBehavior.clickSunspot.rawValue {
            routerEvent(name: SkyBehavior.clickSun.rawValue, userInfo: nil)
        }
    }
}

class SunspotView: UIView {
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .black
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        routerEvent(name: SkyBehavior.clickSunspot.rawValue, userInfo: ["sunspotId": 10])
    }
}

class SkyViewController: UIViewController {
    override func loadView() {
        self.view = SkyView()
    }
    
    override func routerEvent(name: String, userInfo: [AnyHashable : Any]?) {
        guard let event = SkyBehavior(rawValue: name) else { return }
        switch event {
        case .clickSky: print("[Sky] click sky")
        case .clickSun: print("[Sky] click sun")
        case .clickSunspot:
            print("[Sky] click sun spot")
            
        }
    }
}

fileprivate extension SunView {
    func addSunlight() {
        layer.shadowColor = UIColor.red.cgColor
        layer.shadowRadius = 10
        layer.shadowOpacity = 0.8
        layer.shadowPath = UIBezierPath(rect: .sunlight).cgPath
        layer.shouldRasterize = true
        layer.rasterizationScale = UIScreen.main.scale
    }
}

// Colors
fileprivate extension UIColor {
    convenience init(r: UInt32, g: UInt32, b: UInt32) {
        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: 1.0)
    }
    
    static var red: UIColor { return .init(r: 236, g: 67, b: 84) }
    static var blue: UIColor { return .init(r: 44, g: 110, b: 179) }
    static var green: UIColor { return .init(r: 71, g: 180, b: 90) }
    static var black: UIColor { return .init(r: 46, g: 36, b: 35) }
    
    static var random: UIColor {
        return .init(r: arc4random() % 255, g: arc4random() % 255, b: arc4random() % 255)
    }
}

// LayoutConstants
fileprivate extension CGRect {
    static var sun: CGRect {
        return CGRect(x: 50, y: 50, width: 100, height: 100)
    }
    static var sunlight: CGRect {
        return CGRect(x: -10, y: -10, width: 120, height: 120)
    }
    static var sunspot: CGRect {
        return CGRect(x: 20, y: 20, width: 10, height: 10)
    }
}


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

SkyProtocolResponderChainPlayground.swift

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

public protocol ResponderChainEventType {}

public protocol ResponderChainType {
    func router<Event>(event: Event) where Event : ResponderChainEventType
}

extension ResponderChainType where Self: UIResponder {
    public func router<Event>(event: Event) where Event : ResponderChainEventType {
        // Responder handler
        if let n = next as? SkyViewController { 
            n.router(event: event)
        } else {
            next?.router(event: event)
        }
    }
}

extension UIResponder: ResponderChainType {}

//: Custom Events

enum SkyBehavior: ResponderChainEventType {
    case clickSky
    case clickSun
    case clickSunspot(id: Int)
}


//: Custom view

class SkyView: UIView {
    let sunView = SunView(frame: .sun)
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .blue
        
        addSubview(sunView)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        router(event: SkyBehavior.clickSky)
    }
}

class SunView: UIView {
    let spotView = SunspotView(frame: .sunspot, id: 1)
    
    override init(frame: CGRect) {
        super.init(frame: frame)
        backgroundColor = .red
        addSunlight()
        addSubview(spotView)
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        router(event: SkyBehavior.clickSun)
    }
}

class SunspotView: UIView {
    let id: Int
    init(frame: CGRect, id: Int) {
        self.id = id
        super.init(frame: frame)
        backgroundColor = .black
    }
    
    required init?(coder aDecoder: NSCoder) {
        fatalError("init(coder:) has not been implemented")
    }
    
    override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
        router(event: SkyBehavior.clickSunspot(id: id))
    }
}

class SkyViewController: UIViewController {
    override func loadView() {
        self.view = SkyView()
    }
    
    func router<Event>(event: Event) where Event : ResponderChainEventType {
        guard let e = event as? SkyBehavior else { return }
        switch e {
        case .clickSky: print("[Sky] click sky")
        case .clickSun: print("[Sky] click sun")
        case .clickSunspot(let sunspotId): print("[Sky] click sunspot - id: \(sunspotId)")
        }
    }
}

fileprivate extension SunView {
    func addSunlight() {
        layer.shadowColor = UIColor.red.cgColor
        layer.shadowRadius = 10
        layer.shadowOpacity = 0.8
        layer.shadowPath = UIBezierPath(rect: .sunlight).cgPath
        layer.shouldRasterize = true
        layer.rasterizationScale = UIScreen.main.scale
    }
}

// Colors
fileprivate extension UIColor {
    convenience init(r: UInt32, g: UInt32, b: UInt32) {
        self.init(red: CGFloat(r) / 255, green: CGFloat(g) / 255, blue: CGFloat(b) / 255, alpha: 1.0)
    }
    
    static var red: UIColor { return .init(r: 236, g: 67, b: 84) }
    static var blue: UIColor { return .init(r: 44, g: 110, b: 179) }
    static var green: UIColor { return .init(r: 71, g: 180, b: 90) }
    static var black: UIColor { return .init(r: 46, g: 36, b: 35) }
    
    static var random: UIColor {
        return .init(r: arc4random() % 255, g: arc4random() % 255, b: arc4random() % 255)
    }
}

// LayoutConstants
fileprivate extension CGRect {
    static var sun: CGRect {
        return CGRect(x: 50, y: 50, width: 100, height: 100)
    }
    static var sunlight: CGRect {
        return CGRect(x: -10, y: -10, width: 120, height: 120)
    }
    static var sunspot: CGRect {
        return CGRect(x: 20, y: 20, width: 10, height: 10)
    }
}


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