| var $get = 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 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;
}
}
}
}
//容器對象,滑動對象,切換數量
var SlideTrans = function(container, slider, count, options) {
this._slider = $get(slider);
this._container = $get(container); //容器對象
this._timer = null; //定時器
this._count = Math.abs(count); //切換數量
this._target = 0; //目標值
this._t = this._b = this._c = 0; //tween參數
this.Index = 0; //當前索引
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
//樣式設置
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 = {
//設置默認屬性
SetOptions: function(options) {
this.options = {//默認值
Vertical: true, //是否垂直方向（方向不能改）
Auto: false, //是否自動
Change: 0, //改變量
Duration: 50, //滑動持續時間
Time: 10, //滑動延時
Pause: 2000, //停頓時間(Auto爲true時有效)
onStart: function() { }, //開始轉換時執行
onFinish: function() { }, //完成轉換時執行
Tween: Tween.Quart.easeOut//tween算子
};
Extend(this.options, options || {});
},
//開始切換
Run: function(index) {
//修正index
index == undefined && (index = this.Index);
index < 0 && (index = this._count - 1) || index >= this._count && (index = 0);
//設置參數
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();
},
//移動
Move: function() {
clearTimeout(this._timer);
//未到達目標繼續移動不然進行下一次滑動
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));
}
},
//移動到
MoveTo: function(i) {
this._slider.style[this._css] = i + "px";
},
//下一個
Next: function() {
this.Run(++this.Index);
},
//上一個
Previous: function() {
this.Run(--this.Index);
},
//中止
Stop: function() {
clearTimeout(this._timer); this.MoveTo(this._target);
}
};
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