Bootstrap Tooltip源码分析
/* ======================================================================== * Bootstrap: tooltip.js v3.3.7 * http://getbootstrap.com/javascript/#tooltip * Inspired by the original jQuery.tipsy by Jason Frame * ======================================================================== * Copyright 2011-2016 Twitter, Inc. * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE) * ======================================================================== */ +function ($) { 'use strict'; // TOOLTIP PUBLIC CLASS DEFINITION // =============================== var Tooltip = function (element, options) {//tooltip 构造函数 element:当前dom元素 options:一般是false(除非option是对象) this.type = null this.options = null this.enabled = null this.timeout = null this.hoverState = null this.$element = null this.inState = null this.init('tooltip', element, options)//在构造函数中直接初始化 这里传入tooltip 可能是为了扩展 } Tooltip.VERSION = '3.3.7' Tooltip.TRANSITION_DURATION = 150 //过度时间 Tooltip.DEFAULTS = {//默认配置 animation: true, placement: 'top', selector: false, template: '<div class="tooltip" role="tooltip"><div class="tooltip-arrow"></div><div class="tooltip-inner"></div></div>', trigger: 'hover focus', title: '', delay: 0, html: false, container: false, viewport: { selector: 'body', padding: 0 } } Tooltip.prototype.init = function (type, element, options) {//初始化 this.enabled = true this.type = type //tooltip this.$element = $(element) this.options = this.getOptions(options)//合并参数:DEFAULTS ,data- he options 然后返回,噢还有daly //function: 传入elemlent,object:传入sleector或 paddding 二元表达式是在$()里进行的 $viewport为jquery元素 this.$viewport = this.options.viewport && $($.isFunction(this.options.viewport) ? this.options.viewport.call(this, this.$element) : (this.options.viewport.selector || this.options.viewport)) this.inState = { click: false, hover: false, focus: false }//默认是这样的,????往下看 if (this.$element[0] instanceof document.constructor && !this.options.selector) {//不能是document的实例,即不能是document对象,那么手动出错 throw new Error('`selector` option must be specified when initializing ' + this.type + ' on the window.document object!') } var triggers = this.options.trigger.split(' ')//把触发条件弄成数组 ['hover','foxus'] 这是默认的配置 for (var i = triggers.length; i--;) {//注册事件:默认的话是注册hover focus 对应的事件 监听函数为this.enter和this.leave ,也可以注册click:监听函数为this.toggle var trigger = triggers[i] if (trigger == 'click') { this.$element.on('click.' + this.type, this.options.selector, $.proxy(this.toggle, this)) } else if (trigger != 'manual') { var eventIn = trigger == 'hover' ? 'mouseenter' : 'focusin' var eventOut = trigger == 'hover' ? 'mouseleave' : 'focusout' this.$element.on(eventIn + '.' + this.type, this.options.selector, $.proxy(this.enter, this)) this.$element.on(eventOut + '.' + this.type, this.options.selector, $.proxy(this.leave, this)) } } this.options.selector ? (this._options = $.extend({}, this.options, { trigger: 'manual', selector: '' })) : this.fixTitle() } Tooltip.prototype.getDefaults = function () { return Tooltip.DEFAULTS } Tooltip.prototype.getOptions = function (options) { options = $.extend({}, this.getDefaults(), this.$element.data(), options)//主要是参数合并 if (options.delay && typeof options.delay == 'number') {//延迟的话,把delay初始化为对象 options.delay = { show: options.delay, hide: options.delay } } return options } Tooltip.prototype.getDelegateOptions = function () { var options = {} var defaults = this.getDefaults() this._options && $.each(this._options, function (key, value) { if (defaults[key] != value) options[key] = value }) return options } Tooltip.prototype.enter = function (obj) {//tooltip触发时候的执行方法 var self = obj instanceof this.constructor ? obj : $(obj.currentTarget).data('bs.' + this.type) if (!self) {//什么时候为null先不管,先往下看 self = new this.constructor(obj.currentTarget, this.getDelegateOptions()) $(obj.currentTarget).data('bs.' + this.type, self) } if (obj instanceof $.Event) {//obj是$.Event的实例的话执行,就是obj是不是事件对象 self.inState[obj.type == 'focusin' ? 'focus' : 'hover'] = true //把触发的状态搞成true,(默认是false) } if (self.tip().hasClass('in') || self.hoverState == 'in') {//有in class 或 hoverState 为in 即已经显示了所以返回 但是无论怎么样都会初始化self.$tip self.hoverState = 'in' return } clearTimeout(self.timeout)//清除定时器 self.hoverState = 'in'//改为in 因为已经开始让tooltip显示了 if (!self.options.delay || !self.options.delay.show) return self.show()//不延迟的话直接调用show方法,否则执行下面的定时器进行延迟 self.timeout = setTimeout(function () {//进行延迟 if (self.hoverState == 'in') self.show() }, self.options.delay.show) } Tooltip.prototype.isInStateTrue = function () { for (var key in this.inState) { if (this.inState[key]) return true } return false } Tooltip.prototype.leave = function (obj) { var self = obj instanceof this.constructor ? obj : $(obj.currentTarget).data('bs.' + this.type) if (!self) { self = new this.constructor(obj.currentTarget, this.getDelegateOptions()) $(obj.currentTarget).data('bs.' + this.type, self) } if (obj instanceof $.Event) { self.inState[obj.type == 'focusout' ? 'focus' : 'hover'] = false } if (self.isInStateTrue()) return clearTimeout(self.timeout) self.hoverState = 'out' if (!self.options.delay || !self.options.delay.hide) return self.hide() self.timeout = setTimeout(function () { if (self.hoverState == 'out') self.hide() }, self.options.delay.hide) } Tooltip.prototype.show = function () { var e = $.Event('show.bs.' + this.type) if (this.hasContent() && this.enabled) {//有title数据的时候才执行显示工作 this.$element.trigger(e)//触发show事件,但还没插入文档所以不会显示,往下看 var inDom = $.contains(this.$element[0].ownerDocument.documentElement, this.$element[0])//判断是否在文档中 ?不太懂,先放下 if (e.isDefaultPrevented() || !inDom) return//默认已经取消 或者是不在dom中 var that = this var $tip = this.tip()//得到tootle的jquery对象 var tipId = this.getUID(this.type)//为tip创建一个id(内部集成了去重处理), this.setContent()//设置 为$tip里填充title数据 $tip.attr('id', tipId)//设置id(因为都是一个对象引用,从哪里设置都一样) this.$element.attr('aria-describedby', tipId)//设置一个标记 if (this.options.animation) $tip.addClass('fade') var placement = typeof this.options.placement == 'function' ?//提取显示方向 this.options.placement.call(this, $tip[0], this.$element[0]) : this.options.placement var autoToken = /\s?auto?\s?/i var autoPlace = autoToken.test(placement)//判断方向是否是auto if (autoPlace) placement = placement.replace(autoToken, '') || 'top'//有auto的话为top $tip .detach()//从dom结构中删除,但是不冲jquery对象中删除 .css({ top: 0, left: 0, display: 'block' })//设置基本的css属性,先让定位在左上角 .addClass(placement) .data('bs.' + this.type, this) this.options.container ? $tip.appendTo(this.options.container) : $tip.insertAfter(this.$element)//默认加在触发元素的后面,到目前,在$element后已经可以看到dom元素(按f12看)现在在左上角上,但是透明度为0(即看不到) this.$element.trigger('inserted.bs.' + this.type)//这是一个不确定的事件 var pos = this.getPosition()// var actualWidth = $tip[0].offsetWidth// var actualHeight = $tip[0].offsetHeight// if (autoPlace) {//auto 的情况 var orgPlacement = placement var viewportDim = this.getPosition(this.$viewport) placement = placement == 'bottom' && pos.bottom + actualHeight > viewportDim.bottom ? 'top' : placement == 'top' && pos.top - actualHeight < viewportDim.top ? 'bottom' : placement == 'right' && pos.right + actualWidth > viewportDim.width ? 'left' : placement == 'left' && pos.left - actualWidth < viewportDim.left ? 'right' : placement $tip .removeClass(orgPlacement) .addClass(placement) } var calculatedOffset = this.getCalculatedOffset(placement, pos, actualWidth, actualHeight)//计算toop该在哪个位置显示 this.applyPlacement(calculatedOffset, placement)//把计算后的状态应用到实际 var complete = function () { var prevHoverState = that.hoverState that.$element.trigger('shown.bs.' + that.type) that.hoverState = null if (prevHoverState == 'out') that.leave(that) } $.support.transition && this.$tip.hasClass('fade') ? $tip .one('bsTransitionEnd', complete) .emulateTransitionEnd(Tooltip.TRANSITION_DURATION) : complete() } } Tooltip.prototype.applyPlacement = function (offset, placement) { var $tip = this.tip() var width = $tip[0].offsetWidth var height = $tip[0].offsetHeight // manually read margins because getBoundingClientRect includes difference var marginTop = parseInt($tip.css('margin-top'), 10) var marginLeft = parseInt($tip.css('margin-left'), 10) // we must check for NaN for ie 8/9 if (isNaN(marginTop)) marginTop = 0 if (isNaN(marginLeft)) marginLeft = 0 offset.top += marginTop// 加上toop自己的margin 因为位置不包过外边框 offset.left += marginLeft // $.fn.offset doesn't round pixel values // so we use setOffset directly with our own function B-0 用jquery内部的方法来指定top和left,是对jquery有多熟啊, 这段还真是不好理解,回头看 $.offset.setOffset($tip[0], $.extend({ using: function (props) { $tip.css({ top: Math.round(props.top), left: Math.round(props.left) }) } }, offset), 0) $tip.addClass('in')//目前就显示了 // check to see if placing tip in new offset caused the tip to resize itself var actualWidth = $tip[0].offsetWidth var actualHeight = $tip[0].offsetHeight if (placement == 'top' && actualHeight != height) { offset.top = offset.top + height - actualHeight } var delta = this.getViewportAdjustedDelta(placement, offset, actualWidth, actualHeight)//得到视口调整三角,什么意思 if (delta.left) offset.left += delta.left else offset.top += delta.top var isVertical = /top|bottom/.test(placement) var arrowDelta = isVertical ? delta.left * 2 - width + actualWidth : delta.top * 2 - height + actualHeight var arrowOffsetPosition = isVertical ? 'offsetWidth' : 'offsetHeight' $tip.offset(offset) this.replaceArrow(arrowDelta, $tip[0][arrowOffsetPosition], isVertical) } Tooltip.prototype.replaceArrow = function (delta, dimension, isVertical) { this.arrow() .css(isVertical ? 'left' : 'top', 50 * (1 - delta / dimension) + '%') .css(isVertical ? 'top' : 'left', '') } Tooltip.prototype.setContent = function () { var $tip = this.tip()//得到dom节点 var title = this.getTitle()//得到数据 $tip.find('.tooltip-inner')[this.options.html ? 'html' : 'text'](title)//这里是判断是用$().html(),形式还是$().text()方式填入title数据 $tip.removeClass('fade in top bottom left right')//移除这些可能有的class } Tooltip.prototype.hide = function (callback) { var that = this var $tip = $(this.$tip) var e = $.Event('hide.bs.' + this.type) function complete() { if (that.hoverState != 'in') $tip.detach() if (that.$element) { // TODO: Check whether guarding this code with this `if` is really necessary. that.$element .removeAttr('aria-describedby') .trigger('hidden.bs.' + that.type) } callback && callback() } this.$element.trigger(e) if (e.isDefaultPrevented()) return $tip.removeClass('in') $.support.transition && $tip.hasClass('fade') ? $tip .one('bsTransitionEnd', complete) .emulateTransitionEnd(Tooltip.TRANSITION_DURATION) : complete() this.hoverState = null return this } Tooltip.prototype.fixTitle = function () { var $e = this.$element if ($e.attr('title') || typeof $e.attr('data-original-title') != 'string') { $e.attr('data-original-title', $e.attr('title') || '').attr('title', '') } } Tooltip.prototype.hasContent = function () { return this.getTitle() } Tooltip.prototype.getPosition = function ($element) {//得到任意元素的位置(默认为触发元素) $element = $element || this.$element var el = $element[0] var isBody = el.tagName == 'BODY' var elRect = el.getBoundingClientRect()// 这个方法返回一个矩形对象,包含四个属性:left、top、right和bottom。分别表示元素各边与页面上边和左边的距离。(包括宽高) 但是right,bottom和css中的理解有点不一样 if (elRect.width == null) {//兼容ie8,没有height和with的情况 // width and height are missing in IE8, so compute them manually; see https://github.com/twbs/bootstrap/issues/14093 elRect = $.extend({}, elRect, { width: elRect.right - elRect.left, height: elRect.bottom - elRect.top }) } var isSvg = window.SVGElement && el instanceof window.SVGElement//是否为svg // Avoid using $.offset() on SVGs since it gives incorrect results in jQuery 3. // See https://github.com/twbs/bootstrap/issues/20280 var elOffset = isBody ? { top: 0, left: 0 } : (isSvg ? null : $element.offset())//获取匹配元素在当前视口的相对偏移。 var scroll = { scroll: isBody ? document.documentElement.scrollTop || document.body.scrollTop : $element.scrollTop() }//获取滚动条高度 var outerDims = isBody ? { width: $(window).width(), height: $(window).height() } : null//is body时要做怎么多处理 return $.extend({}, elRect, scroll, outerDims, elOffset)//都掺和一下,为了保险 主要还是 el.getBoundingClientRect() $element.offset() } Tooltip.prototype.getCalculatedOffset = function (placement, pos, actualWidth, actualHeight) {//获取计算后的样式,即:tooptip 应该在哪个位置显示 这是一套固定算法,算出如何在其中间位置显示 return placement == 'bottom' ? { top: pos.top + pos.height, left: pos.left + pos.width / 2 - actualWidth / 2 } : placement == 'top' ? { top: pos.top - actualHeight, left: pos.left + pos.width / 2 - actualWidth / 2 } : placement == 'left' ? { top: pos.top + pos.height / 2 - actualHeight / 2, left: pos.left - actualWidth } : /* placement == 'right' */ { top: pos.top + pos.height / 2 - actualHeight / 2, left: pos.left + pos.width } } Tooltip.prototype.getViewportAdjustedDelta = function (placement, pos, actualWidth, actualHeight) { var delta = { top: 0, left: 0 } if (!this.$viewport) return delta// $viewport 为body的jquery对象 var viewportPadding = this.options.viewport && this.options.viewport.padding || 0 var viewportDimensions = this.getPosition(this.$viewport)//获取body的rect矩阵位置 if (/right|left/.test(placement)) { var topEdgeOffset = pos.top - viewportPadding - viewportDimensions.scroll var bottomEdgeOffset = pos.top + viewportPadding - viewportDimensions.scroll + actualHeight if (topEdgeOffset < viewportDimensions.top) { // top overflow delta.top = viewportDimensions.top - topEdgeOffset } else if (bottomEdgeOffset > viewportDimensions.top + viewportDimensions.height) { // bottom overflow delta.top = viewportDimensions.top + viewportDimensions.height - bottomEdgeOffset } } else {//top 或bootem时 var leftEdgeOffset = pos.left - viewportPadding var rightEdgeOffset = pos.left + viewportPadding + actualWidth if (leftEdgeOffset < viewportDimensions.left) { // left overflow delta.left = viewportDimensions.left - leftEdgeOffset } else if (rightEdgeOffset > viewportDimensions.right) { // right overflow delta.left = viewportDimensions.left + viewportDimensions.width - rightEdgeOffset } } return delta } Tooltip.prototype.getTitle = function () { var title var $e = this.$element var o = this.options title = $e.attr('data-original-title')//优先提取 html属性里面的title || (typeof o.title == 'function' ? o.title.call($e[0]) : o.title)//也可以在配置参数时指定title的回调函数 return title } Tooltip.prototype.getUID = function (prefix) { do prefix += ~~(Math.random() * 1000000)//~~ 位操作符一直没研究透,汗颜。。 while (document.getElementById(prefix))//去重处理 return prefix } Tooltip.prototype.tip = function () { if (!this.$tip) { this.$tip = $(this.options.template) if (this.$tip.length != 1) { throw new Error(this.type + ' `template` option must consist of exactly 1 top-level element!') } } return this.$tip } Tooltip.prototype.arrow = function () { return (this.$arrow = this.$arrow || this.tip().find('.tooltip-arrow')) } Tooltip.prototype.enable = function () { this.enabled = true } Tooltip.prototype.disable = function () { this.enabled = false } Tooltip.prototype.toggleEnabled = function () { this.enabled = !this.enabled } Tooltip.prototype.toggle = function (e) { var self = this if (e) { self = $(e.currentTarget).data('bs.' + this.type) if (!self) { self = new this.constructor(e.currentTarget, this.getDelegateOptions()) $(e.currentTarget).data('bs.' + this.type, self) } } if (e) { self.inState.click = !self.inState.click if (self.isInStateTrue()) self.enter(self) else self.leave(self) } else { self.tip().hasClass('in') ? self.leave(self) : self.enter(self) } } Tooltip.prototype.destroy = function () { var that = this clearTimeout(this.timeout) this.hide(function () { that.$element.off('.' + that.type).removeData('bs.' + that.type) if (that.$tip) { that.$tip.detach() } that.$tip = null that.$arrow = null that.$viewport = null that.$element = null }) } // TOOLTIP PLUGIN DEFINITION // ========================= function Plugin(option) {//jquery 插件的入口方法 return this.each(function () {//each 在这里就很有意义了,如果选择器选到n个元素,就可以挨个初始化了 var $this = $(this) var data = $this.data('bs.tooltip') var options = typeof option == 'object' && option //option 是object时才付给option否则为false if (!data && /destroy|hide/.test(option)) return //有data时 return 或者有destroy或hide时返回 if (!data) $this.data('bs.tooltip', (data = new Tooltip(this, options)))//初始化data并数据缓存,下次直接使用 new Tooltip(this, options))这里已经执行了大部分功能,可以跟过去看看 if (typeof option == 'string') data[option]() }) } var old = $.fn.tooltip $.fn.tooltip = Plugin $.fn.tooltip.Constructor = Tooltip // TOOLTIP NO CONFLICT // =================== $.fn.tooltip.noConflict = function () { $.fn.tooltip = old return this } }(jQuery); //显示:校正状态为true self.inState,