//下面以一個(gè)開(kāi)燈程序演示狀態(tài)模式
//燈共用三種狀態(tài)，分別是‘關(guān)閉'，‘弱光‘和'強(qiáng)光‘。每次按下開(kāi)關(guān)按鈕都會(huì)換擋。
let OfflightState = function (light) {
    this.light = light;
}
OfflightState.prototype.buttonPressed = function () {
    console.light('弱光');
    this.light.setState(this.light.weakLightState);
}
let WeakLightState = function (light) {
    this.light = light;
}
WeakLightState.prototype.buttonPressed = function () {
    console.log('強(qiáng)光')
    this.light.setState(this.light.strongLightState);
}
let StrongLightState = function (light) {
    this.light = light;
}
StrongLightState.prototype.buttonPressed = function () {
    console.log('關(guān)閉');
    this.light.setState(this.light.offlightState)
}
let Light = function () {
    this.offlightState = new OfflightState(this); 
    this.weakLightState = new WeakLightState(this);
    this.strongLightState = new StrongLightState(this);
    this.button = null;
}
Light.prototype.init = function () { 
    let button = document.createElement('button');
    self = this;
    this.button = document.body.appendChild(button);
    this.button.innerHTML = '開(kāi)關(guān)';
    this.button.currState = this.offlightState;
    this.button.onclick = function () { 
        self.currState.buttonPressed;
    }
}
Light.prototype.setState = function (newState) {
    this.currState = newState;
}
let light = new Light();
light.init();

let googleMap = {
    show: function () {
        console.log('開(kāi)始渲染谷歌地圖');
    }
}
let baiduMap = {
    show: function () {
        console.log('開(kāi)始渲染百度地圖');
    }
}
let renderMap = function (map) {
    map.show();
}
/**
 * 以上代碼段實(shí)現(xiàn)了渲染不同地圖的功能?，F(xiàn)在假設(shè)BaiduMap的api改成了display,修改源代碼勢(shì)必不太符合開(kāi)閉原則，這時(shí)候我們可以通過(guò)新建一個(gè)適配器來(lái)達(dá)到目的
 */
let baiduMapAdapter = {
    show: function () {
        return baiduMap.display();
    }
}
renderMap(baiduMapAdapter);