var $$ = function (id) {
            return "string" == typeof id ? document.getElementById(id) : id;
        };

        var Extend = function (destination, source) {
            for (var property in source) {
                destination[property] = source[property];
            }
            return destination;
        }

        var CurrentStyle = function (element) {
            return element.currentStyle || document.defaultView.getComputedStyle(element, null);
        }

        var Bind = function (object, fun) {
            var args = Array.prototype.slice.call(arguments).slice(2);
            return function () {
                return fun.apply(object, args.concat(Array.prototype.slice.call(arguments)));
            }
        }

        var forEach = function (array, callback, thisObject) {
            if (array.forEach) {
                array.forEach(callback, thisObject);
            } else {
                for (var i = 0, len = array.length; i < len; i++) { callback.call(thisObject, array[i], i, array); }
            }
        }

        var Tween = {
            Quart: {
                easeOut: function (t, b, c, d) {
                    return -c * ((t = t / d - 1) * t * t * t - 1) + b;
                }
            },
            Back: {
                easeOut: function (t, b, c, d, s) {
                    if (s == undefined) s = 1.70158;
                    return c * ((t = t / d - 1) * t * ((s + 1) * t + s) + 1) + b;
                }
            },
            Bounce: {
                easeOut: function (t, b, c, d) {
                    if ((t /= d) < (1 / 2.75)) {
                        return c * (7.5625 * t * t) + b;
                    } else if (t < (2 / 2.75)) {
                        return c * (7.5625 * (t -= (1.5 / 2.75)) * t + .75) + b;
                    } else if (t < (2.5 / 2.75)) {
                        return c * (7.5625 * (t -= (2.25 / 2.75)) * t + .9375) + b;
                    } else {
                        return c * (7.5625 * (t -= (2.625 / 2.75)) * t + .984375) + b;
                    }
                }
            }
        }


        //容器对象,滑动对象,切换数量
        var SlideTrans = function (container, slider, count, options) {
            this._slider = $$(slider);
            this._container = $$(container); //容器对象
            this._timer = null; //定时器
            this._count = Math.abs(count); //切换数量
            this._target = 0; //目标值
            this._t = this._b = this._c = 0; //tween参数

            this.Index = 0; //当前索引

            this.SetOptions(options);

            this.Auto = !!this.options.Auto;
            this.Duration = Math.abs(this.options.Duration);
            this.Time = Math.abs(this.options.Time);
            this.Pause = Math.abs(this.options.Pause);
            this.Tween = this.options.Tween;
            this.onStart = this.options.onStart;
            this.onFinish = this.options.onFinish;

            var bVertical = !!this.options.Vertical;
            this._css = bVertical ? "top" : "left"; //方向

            //样式设置
            var p = CurrentStyle(this._container).position;
            p == "relative" || p == "absolute" || (this._container.style.position = "relative");
            this._container.style.overflow = "hidden";
            this._slider.style.position = "absolute";

            this.Change = this.options.Change ? this.options.Change :this._slider[bVertical ? "offsetHeight" : "offsetWidth"] / this._count;
        };
        SlideTrans.prototype = {
            //设置默认属性
            SetOptions: function (options) {
                this.options = {//默认值
                    Vertical: true, //是否垂直方向（方向不能改）
                    Auto: true, //是否自动
                    Change: 0, //改变量
                    Duration: 30, //滑动持续时间
                    Time: 10, //滑动延时
                    Pause: 3000, //停顿时间(Auto为true时有效)
                    onStart: function () { }, //开始转换时执行
                    onFinish: function () { }, //完成转换时执行
                    Tween: Tween.Quart.easeOut//tween算子
                };
                Extend(this.options, options || {});
            },
            //开始切换
            Run: function (index) {
                //修正index
                index == undefined && (index = this.Index);
                index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);
                //设置参数
                this._target = -Math.abs(this.Change) * (this.Index = index);
                this._t = 0;
                this._b = parseInt(CurrentStyle(this._slider)[this.options.Vertical ? "top" : "left"]);
                this._c = this._target - this._b;

                this.onStart();
                this.Move();
            },
            //移动
            Move: function () {
                clearTimeout(this._timer);
                //未到达目标继续移动否则进行下一次滑动
                if (this._c && this._t < this.Duration) {
                    this.MoveTo(Math.round(this.Tween(this._t++, this._b, this._c, this.Duration)));
                    this._timer = setTimeout(Bind(this, this.Move), this.Time);
                } else {
                    this.MoveTo(this._target);
                    this.Auto && (this._timer = setTimeout(Bind(this, this.Next), this.Pause));
                }
            },
            //移动到
            MoveTo: function (i) {
                this._slider.style[this._css] = i + "px";
            },
            //下一个
            Next: function () {
                this.Run(++this.Index);
            },
            //上一个
            Previous: function () {
                this.Run(--this.Index);
            },
            //停止
            Stop: function () {
                clearTimeout(this._timer); this.MoveTo(this._target);
            }
        };