Swift-代理-delegate

//*****************************************************************

//

//代理：delegate

//代理是一种设计模式，它允许类或结构体将一些需要他们负责的功能交给其他的类型

//代理的实现：定义协议来封装那些需要被代理的函数和方法，使其遵循者拥有这些被

//代理的函数和方法

//

//*****************************************************************

//

//下面的协议和类是前期准备

//

//**************************

protocol ProtocolRandom {

    func random() -> Double

}

 

class Dice {

    let sides: Int

    let generator: ProtocolRandom

    init(sides: Int,generator: ProtocolRandom) {

       self.sides= sides

       self.generator= generator

    }

    func roll() -> Int{

       return Int(generator.random()*Double(sides)+1 )

    }

}

 

class Gener:ProtocolRandom {

    var lastRandom = 42.0

    let m = 1234.56,a = 2233.11, c = 451.23

    func random() -> Double{

       lastRandom = (lastRandom *a + c) %m

       return lastRandom/ m

    }

}

 

//**************************

//

//下面是两个基于色子游戏的协议

// 1.DiceGame协议可以在任意含有色子的游戏中实现

// 2.DiceGameDelegate协议用来追踪DiceGame的游戏过程

//

//**************************

 

protocol DiceGame {

    var dice: Dice{ get }

    func play()

}

 

//**************************************************************

//

// DiceGameDelegate提供了3个方法跟踪游戏过程，分别是开始，每轮摇色及结束

//

//**************************************************************

protocol DiceGameDelegate {

    func gameDidStart (game: DiceGame)

    func game(game: DiceGame,didStartNewTurnWithDiceRoll diceRoll:Int)

    func gameDidEnd(game: DiceGame)

}

 

 

//**************************************************************

//

// delegate是一个遵循DiceGameDelegate协议的可选属性

//在func()方法中调用代理方法gameDidStart、game和gameDidEnd进行游戏跟踪

//

//**************************************************************

class SnakesAndLadders:DiceGame{

    let finalSquare = 25

    let dice = Dice(sides:7, generator:Gener())

    var square = 0

    var board: [Int]

    init() {

       board = [Int](count:finalSquare +1,repeatedValue: 0 )

       board[03]= +08;board[06] = +11;board[09] = +09;board[10] = +02

       board[14]= -10;board[19] = -11;board[22] = -02;board[24] = -08

    }

    var delegate: DiceGameDelegate?

    func play() {

       square = 0

       delegate?.gameDidStart(self)

       gameLoop: while square != finalSquare{

           let diceRoll = dice.roll()

           delegate?.game(self,didStartNewTurnWithDiceRoll: diceRoll)

           switch square + diceRoll {

               case finalSquare: breakgameLoop

               case let newSquare wherenewSquare > finalSquare: continue gameLoop

               default:

                   square+= diceRoll

                   square+= board[square]

           }

       }

       delegate?.gameDidEnd(self)

    }

    func test(){ println("Testing!")}

}

 

//**************************************************************

//

// DiceGameTracker实现了DiceGameDelegate协议的方法要求，用于跟踪游戏过程

//跟踪时，传递被跟踪对象DiceGame过来给DiceGameTracker调用，也就是代理DiceGame

//进行另外的工作（游戏跟踪）

//

//**************************************************************

class DiceGameTracker:DiceGameDelegate{

    var numberOfTurns = 0

    func gameDidStart(game: DiceGame){

       numberOfTurns =0

       if game isSnakesAndLadders {

           println("Starteda new game of蛇与梯子!")

       }

       if letgameon = game as? SnakesAndLadders{

           gameon.test()

       }

       println("the game is usinga\(game.dice.sides)-sides dice")

    }

    func game(game: DiceGame,didStartNewTurnWithDiceRoll diceRoll:Int) {

        ++numberOfTurns

       println("Rollednumber = \(diceRoll)")

    }

    func gameDidEnd(game: DiceGame){

       println("The game lastedfor\(numberOfTurns) turns")

    }

}

 

let tracker =DiceGameTracker()

let game =SnakesAndLadders()

game.delegate =tracker

game.play()

 

//运行结果：

//Started a new game of蛇与梯子!

//Testing!

//thegame is using a 7-sides dice

//Rollednumber = 3

//Rollednumber = 4

//Rollednumber = 2

//Rollednumber = 4

//Rollednumber = 3

//Rollednumber = 4

//Rollednumber = 1

//Rollednumber = 6

//Rollednumber = 4

//Thegame lasted for 9 turns