SamStone92

class GoodGuy{
    
    private var characterState : CharacterState?
    
    func setState(cs : CharacterState){
        self.characterState = cs
        characterState!.enterState()
    }
}

SamStone92

protocol CharacterState{
    func enterState()
}

SamStone92

class RunningState : CharacterState{
    
    func enterState() {
        print("Entering running state")
    }
}

SamStone92

let goodGuy = GoodGuy()

goodGuy.setState(cs: WalkingState())
goodGuy.setState(cs: StandingState())
goodGuy.setState(cs: RunningState())

SamStone92

class BadGuy{
    
    private var characterState : CharacterState?
    
    func setState(cs : CharacterState){
        self.characterState = cs
        characterState!.enterState()
    }
}

SamStone92

let goodGuy = GoodGuy()
let badGuy = BadGuy()

goodGuy.setState(cs: WalkingState())
goodGuy.setState(cs: StandingState())
goodGuy.setState(cs: RunningState())

badGuy.setState(cs: WalkingState())
badGuy.setState(cs: StandingState())
badGuy.setState(cs: RunningState())

SamStone92

protocol Observer{
    var id : Int{ get }
    func update()
}

SamStone92

class Subject{
    
    private var observerArray = [Observer]()
    private var _number = Int()
    var number : Int {
        set {
            _number = newValue
            notify()
        }
        get {

SamStone92

class BinaryObserver : Observer{
    
    private var subject = Subject()
    var id = Int()

    init(subject : Subject, id : Int) {
        self.subject = subject
        self.subject.attachObserver(observer: self)
        self.id = id
    }

SamStone92

let subject = Subject()

let binary = BinaryObserver(subject: subject, id: 1)
let octal = OctalObserver(subject: subject, id: 2)
let hex = HexaObserver(subject: subject, id: 3)

subject.number = 15
subject.number = 2