公司主要客户是外国人，主要交流语言是英语，公司里的人都使用一口流利的中国式英语进行对话，中国式英语在不正式场合没什么问题，大家都听得懂即可。可惜，我不会，所以接下来得好好练习英语口语了。相信我能够坚持下来，起码把中国式英语学会。
以前都是jQuery或者zepto（移动端）布局完事，后来公司要求pc端移动端兼容，然后想到bootstrap，当然，公司项目很小，小外包公司嘛。所以浏览器兼容跟随bootstrap新版本走，不支持css3的全部没戏。
软件行业都有外包公司技术深度不够（就是菜）说法，作为小外包公司，深有体会。但我想改变现状，所以打起源码主意，其实研究好的源码，会学到很多知识。
今天来研究下 carousel.js轮播插件源码，依然会是简单的源码解读，大神绕道。
/* ========================================================================
* Bootstrap: carousel.js v3.3.7
* http://getbootstrap.com/javascript/#carousel
* ========================================================================
* Copyright 2011-2016 Twitter, Inc.
* Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE)
* ======================================================================== */
+function ($) {
'use strict';//严格模式，能够限制一些js代码弊端，糟粕，为新js标准铺路
// CAROUSEL CLASS DEFINITION
// =========================
//Carousel类构造函数
var Carousel = function (element, options) {
this.$element = $(element)//选择Dom元素
this.$indicators = this.$element.find('.carousel-indicators')//找到含有carousel-indicators类名的元素（轮播切换下标）
this.options = options//选项
this.paused = null //暂停切换
this.sliding = null //滑动
this.interval = null //每个轮播图切换时间间隔
this.$active = null //活动图片标示（展示那张轮播图）
this.$items = null //图片数量
this.options.keyboard && this.$element.on('keydown.bs.carousel', $.proxy(this.keydown, this))
this.options.pause == 'hover' && !('ontouchstart' in document.documentElement) && this.$element
.on('mouseenter.bs.carousel', $.proxy(this.pause, this))
.on('mouseleave.bs.carousel', $.proxy(this.cycle, this))
}
Carousel.VERSION = '3.3.7'//Carousel插件版本号，跟随bootstrap版本号
Carousel.TRANSITION_DURATION = 600 //图片过渡时间600ms
//插件默认图片切换时间5000ms，鼠标经过暂停，连续播放，按键（鼠标左键）控制true
Carousel.DEFAULTS = {
interval: 5000,
pause: 'hover',
wrap: true,
keyboard: true
}
//左右按键切换轮播图
Carousel.prototype.keydown = function (e) {
//正则验证事件目标名字是否含有input或者textarea（忽略大小写）有就返回
//也就是说鼠标要点击到左右切换按钮(a标签)才能够使用左右按键控制切换,点击轮播图，input控件，文本区域都不行
if (/input|textarea/i.test(e.target.tagName)) return
switch (e.which) {
case 37: this.prev(); break
case 39: this.next(); break
default: return
}
//阻止事件冒泡
e.preventDefault()
}
//轮播图循环播放控制
Carousel.prototype.cycle = function (e) {
e || (this.paused = false) //类似于if(e||(this.paused = false)){}
this.interval && clearInterval(this.interval)//如果this.interval为true，则清空计时器
//if(this.options.interval&&!this.paused){this.interval = setInterval($.proxy(this.next, this), this.options.interval)}
//bootstrap插件中用来代替if else惯用技巧
this.options.interval
&& !this.paused
&& (this.interval = setInterval($.proxy(this.next, this), this.options.interval))
return this //返回this
}
//得到当前活跃的图片下标
Carousel.prototype.getItemIndex = function (item) {
this.$items = item.parent().children('.item')
return this.$items.index(item || this.$active)
}
//滑动方向控制
Carousel.prototype.getItemForDirection = function (direction, active) {
var activeIndex = this.getItemIndex(active)
var willWrap = (direction == 'prev' && activeIndex === 0)
|| (direction == 'next' && activeIndex == (this.$items.length - 1))
if (willWrap && !this.options.wrap) return active
var delta = direction == 'prev' ? -1 : 1
var itemIndex = (activeIndex + delta) % this.$items.length
return this.$items.eq(itemIndex)
}
//切换到目标图片
Carousel.prototype.to = function (pos) {
var that = this
var activeIndex = this.getItemIndex(this.$active = this.$element.find('.item.active'))
if (pos > (this.$items.length - 1) || pos < 0) return
if (this.sliding) return this.$element.one('slid.bs.carousel', function () { that.to(pos) }) // yes, "slid"
if (activeIndex == pos) return this.pause().cycle()
return this.slide(pos > activeIndex ? 'next' : 'prev', this.$items.eq(pos))
}
//暂停滑动
Carousel.prototype.pause = function (e) {
e || (this.paused = true)
if (this.$element.find('.next, .prev').length && $.support.transition) {
this.$element.trigger($.support.transition.end)
this.cycle(true)
}
this.interval = clearInterval(this.interval)
return this
}
//下一张图片
Carousel.prototype.next = function () {
if (this.sliding) return
return this.slide('next')
}
//上一张图片
Carousel.prototype.prev = function () {
if (this.sliding) return
return this.slide('prev')
}
//轮播切换具体实现，添加active 下一张图片滑动方向，鼠标暂停等等
Carousel.prototype.slide = function (type, next) {
var $active = this.$element.find('.item.active')
var $next = next || this.getItemForDirection(type, $active)
var isCycling = this.interval
var direction = type == 'next' ? 'left' : 'right'
var that = this
if ($next.hasClass('active')) return (this.sliding = false)
var relatedTarget = $next[0]
var slideEvent = $.Event('slide.bs.carousel', {
relatedTarget: relatedTarget,
direction: direction
})
this.$element.trigger(slideEvent)
if (slideEvent.isDefaultPrevented()) return
this.sliding = true
isCycling && this.pause()
if (this.$indicators.length) {
this.$indicators.find('.active').removeClass('active')
var $nextIndicator = $(this.$indicators.children()[this.getItemIndex($next)])
$nextIndicator && $nextIndicator.addClass('active')
}
var slidEvent = $.Event('slid.bs.carousel', { relatedTarget: relatedTarget, direction: direction }) // yes, "slid"
if ($.support.transition && this.$element.hasClass('slide')) {
$next.addClass(type)
$next[0].offsetWidth // force reflow
$active.addClass(direction)
$next.addClass(direction)
$active
.one('bsTransitionEnd', function () {
$next.removeClass([type, direction].join(' ')).addClass('active')
$active.removeClass(['active', direction].join(' '))
that.sliding = false
setTimeout(function () {
that.$element.trigger(slidEvent)
}, 0)
})
.emulateTransitionEnd(Carousel.TRANSITION_DURATION)
} else {
$active.removeClass('active')
$next.addClass('active')
this.sliding = false
this.$element.trigger(slidEvent)
}
isCycling && this.cycle()
return this
}
// CAROUSEL PLUGIN DEFINITION
// ==========================
//Carousel插件定义
function Plugin(option) {
return this.each(function () {
var $this = $(this)
var data = $this.data('bs.carousel')
var options = $.extend({}, Carousel.DEFAULTS, $this.data(), typeof option == 'object' && option)
var action = typeof option == 'string' ? option : options.slide
if (!data) $this.data('bs.carousel', (data = new Carousel(this, options)))
if (typeof option == 'number') data.to(option)
else if (action) data[action]()
else if (options.interval) data.pause().cycle()
})
}
var old = $.fn.carousel
$.fn.carousel = Plugin
$.fn.carousel.Constructor = Carousel
// CAROUSEL NO CONFLICT
// ====================
//防止冲突noConflict，目的是释放$控制权
$.fn.carousel.noConflict = function () {
$.fn.carousel = old
return this
}
// CAROUSEL DATA-API
// =================
//点击句柄绑定
var clickHandler = function (e) {
var href
var $this = $(this)
var $target = $($this.attr('data-target') || (href = $this.attr('href')) && href.replace(/.*(?=#[^\s]+$)/, '')) // strip for ie7
if (!$target.hasClass('carousel')) return
var options = $.extend({}, $target.data(), $this.data())
var slideIndex = $this.attr('data-slide-to')
if (slideIndex) options.interval = false
Plugin.call($target, options)
if (slideIndex) {
$target.data('bs.carousel').to(slideIndex)
}
e.preventDefault()
}
$(document)
.on('click.bs.carousel.data-api', '[data-slide]', clickHandler)
.on('click.bs.carousel.data-api', '[data-slide-to]', clickHandler)
$(window).on('load', function () {
$('[data-ride="carousel"]').each(function () {
var $carousel = $(this)
Plugin.call($carousel, $carousel.data())
})
})
}(jQuery);
由于时间以及个人技术问题，有些具体的来不及写注释，放到有空再来修改编辑了。目前先这样，晚安！