var QQ = function() {
// 公用函数
function T$(id) { return document.getElementById(id); }
function T$$(root, tag) { return (root || document).getElementsByTagName(tag); }
function $extend(des, src) { for(var p in src) { des[p] = src[p]; } return des; }
function $each(arr, callback, thisp) {
if (arr.forEach) {arr.forEach(callback, thisp);}
else { for (var i = 0, len = arr.length; i < len; i++) callback.call(thisp, arr[i], i, arr);}
}
function currentStyle(elem, style) {
return elem.currentStyle || document.defaultView.getComputedStyle(elem, null);
}
// 缓动类
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;
}
}
}
}

// 主类构造函数
var scrollTrans = function(cid, sid, count, config) {
var self = this;
if (!(self instanceof scrollTrans)) {
return new scrollTrans(cid, sid, count, config);
}
self.container = T$(cid);
self.scroller = T$(sid);
if (!(self.container || self.scroller)) {
return;
}
self.config = $extend(defaultConfig, config || {});
self.index = 0;
self.timer = null;
self.count = count;
self.step = self.scroller.offsetWidth / count;
};

// 默认配置
var defaultConfig = {
trigger: 1, // 触发方式1:click other: mouseover
auto: true, // 是否自动切换
tween: Tween.Quart.easeOut, // 默认缓动类
Time: 10, // 滑动延时
duration: 50, // 切换时间
pause: 3000, // 停顿时间
start: function() {}, // 切换开始执行函数
end: function() {} // 切换结束执行函数
};

scrollTrans.prototype = {
constructor: scrollTrans,
transform: function(index) {
var self = this;
index == undefined && (index = self.index);
index < 0 && (index = self.count - 1) || index >= self.count && (index = 0);
self.time = 0;
self.target = -Math.abs(self.step) * (self.index = index);
self.begin = parseInt(currentStyle(self.scroller)['left']);
self.change = self.target - self.begin;
self.duration = self.config.duration;
self.start();
self.run();
},

run: function() {
var self = this;
clearTimeout(self.timer);
if (self.change && self.time < self.duration) {
self.moveTo(Math.round(self.config.tween(self.time++, self.begin, self.change, self.duration)));
self.timer = setTimeout(function() {self.run()}, self.config.Time);
} else {
self.moveTo(self.target);
self.config.auto && (self.timer = setTimeout(function() {self.next()}, self.config.pause));
}
},

moveTo: function(i) {
this.scroller.style.left = i + 'px';
},

next: function() {
this.transform(++this.index);
}
};

return {
scroll: function(cid, sid, count, config) {
window.onload = function() {
var frag = document.createDocumentFragment(),
nums = [];
for (var i = 0; i < count; i++) {
var li = document.createElement('li');
(nums[i] = frag.appendChild(document.createElement('li'))).innerHTML = i + 1;
}
T$('page').appendChild(frag);

// 调用主类
var st = scrollTrans(cid, sid, count, config);
$each(nums, function(o, i) {
o[st.config.trigger == 1 ? 'onclick' : 'onmouseover'] = function() { o.className = 'on'; st.transform(i); }
o.onmouseout = function() { o.className = ''; st.transform();}
});
st.start = function() {
$each(nums, function(o, i) {
o.className = st.index == i ? 'on' : '';
});
};
st.transform();
}
}
}
}();

QQ.scroll('container', 'scroller', 5, {trigger: 0});

var defaultConfig = {
trigger: 1, // 触发方式 1:click 其余: mouseover
auto: true, // 是否自动切换
tween: Tween.Quart.easeOut, // 默认缓动类
Time: 10, // 滑动延时
duration: 50, // 切换时间
pause: 3000, // 停顿时间
start: function() {}, // 切换开始执行函数
end: function() {} // 切换结束执行函数
};

QQ.scroll('container' /*外部容器ID*/, 'scroller'/*滑动容器ID*/, 5/*切换图片数目*/, {trigger: 0} /*默认配置*/);