headfirst设计模式swift版01

protocol FlyBehavior {
    func fly()  ->Void
}

protocol QuackBehavior {
    func quack() ->Void
}

class CannotFly:FlyBehavior {
    init() {
        
    }
    func fly()  {
        println("不会飞")
    }
}

class Quack:QuackBehavior {
    init() {
        
    }
    func quack()  {
        println("嘎嘎")
    }
}

class Duck {
    var flyBehavior:FlyBehavior?
    var quackBehavior:QuackBehavior?
    
    init() {
        
    }
    func swim(){
        
    }
    func display(){
        
    }
    
    func fly() {
        flyBehavior?.fly()
    }
    func quack()  {
        quackBehavior?.quack()
    }
}


class MiniDuckSimulator:Duck {
    override init() {
        super.init()
    }
    
}

let miniDuck = MiniDuckSimulator()
println("................")
miniDuck.fly()
miniDuck.flyBehavior = CannotFly()
println("................")
miniDuck.fly()