BootStrap Tooltip插件源码解析

BootStrap Tooltip插件源码解析

Tooltip插件可以让你把要显示的内容以弹出框的形式来展示，如：

因为自己在工作的过程中，用到了Tooltip这个插件，并且当时正想学习一下元素定位的问题，如：提示框显示的位置就是触发提示框元素的位置，可以配置在上、下、左、右等位置，所以就去看了源码。对于整个插件源码没有看全，但也学到了许多的知识点。能力有限，可能其中有认识错误的地方，以后再补充吧

1 使用方法不介绍 ，可以参照

Bootstrap 提示工具（Tooltip）插件

2 源码解析

+function ($) {

'use strict';

// TOOLTIP PUBLIC CLASS DEFINITION

// ===============================

var Tooltip = function (element, options) {

this.type =

this.options =

this.enabled =

this.timeout =

this.hoverState =

this.$element = null

this.init('tooltip', element, options)

}

Tooltip.VERSION = '3.3.0'

Tooltip.TRANSITION_DURATION = 150

//默认参数

Tooltip.DEFAULTS = {

animation: true,

placement: 'top',

selector: false,

template: '

trigger: 'hover focus',

title: '',

delay: 0,

html: false,

container: false,

viewport: {

selector: 'body',

padding: 0

}

}

//初始化

Tooltip.prototype.init = function (type, element, options) {

this.enabled = true

this.type = type

this.$element = $(element)

//初始化参数

this.options = this.getOptions(options)

this.$viewport = this.options.viewport && $(this.options.viewport.selector || this.options.viewport)

//多个触发器 即触发函数

var triggers = this.options.trigger.split(' ')

for (var i = triggers.length; i--;) {

var trigger = triggers[i]

if (trigger == 'click') {

//绑定事件处理程序

//事件命名空间 'click.tooltip'

//触发时执行$.proxy(this.toggle, this)返回的函数

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

}

//获得初始化参数

Tooltip.prototype.getOptions = function (options) {

// this.$element.data() data-key = value 形式的属性获取

// 返回一个对象{key:value}

// options > 元素属性 > 默认

options = $.extend({}, this.getDefaults(), this.$element.data(), options)

//delay 为数字 特殊处理

//delay 为对象 delay:{ show: 500, hide: 100 }

if (options.delay && typeof options.delay == 'number') {

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

}

//提示框显示

Tooltip.prototype.enter = function (obj) {

//obj是否是tooltip的实例

var self = obj instanceof this.constructor ?

obj : $(obj.currentTarget).data('bs.' + this.type)

//$tip.is(':visible') 该div是否可见

//可见时 只更新状态 然后直接返回

if (self && self.$tip && self.$tip.is(':visible')) {

self.hoverState = 'in'

return

}

//self 不存在

if (!self) {

self = new this.constructor(obj.currentTarget, this.getDelegateOptions())

$(obj.currentTarget).data('bs.' + this.type, self)

}

//上次点击延时未显示 则取消显示

clearTimeout(self.timeout)

//设置状态

self.hoverState = 'in'

//delay: 数字 (默认 0) 或 对象 { show: 500, hide: 100 }

//没有delay delay.show 时 直接显示

if (!self.options.delay || !self.options.delay.show) return self.show()

//延时显示 self.options.delay.show:延时时间

self.timeout = setTimeout(function () {

if (self.hoverState == 'in') self.show()

}, self.options.delay.show)

}

//提示框隐藏

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)

}

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)

}

//提示框显示核心方法

Tooltip.prototype.show = function () {

console.info(this)

var e = $.Event('show.bs.' + this.type)

if (this.hasContent() && this.enabled) {

this.$element.trigger(e)

//判断是否在根节点中

//this.$element[0] 转换为DOM对象

//.ownerDocument Document文档对象

//.documentElement 根节点 HTML标签

//$.contains 一个DOM节点是否包含另一个DOM节点。

var inDom = $.contains(this.$element[0].ownerDocument.documentElement, this.$element[0])

//调用preventDefault 或 不在根节点 return

//事件对象中是否调用过 event.preventDefault()

//event.preventDefault():阻止元素发生默认的行为

//如 当点击提交按钮时阻止对表单的提交 、 阻止以下 URL 的链接

if (e.isDefaultPrevented() || !inDom) return

var that = this

var $tip = this.tip()

var tipId = this.getUID(this.type)

//设置提示框的title

this.setContent()

$tip.attr('id', tipId)

this.$element.attr('aria-describedby', tipId)

//参数animation

if (this.options.animation) $tip.addClass('fade')

//参数placement 提示框的位置 top bottom left right

var placement = typeof this.options.placement == 'function' ?

this.options.placement.call(this, $tip[0], this.$element[0]) :

this.options.placement

// 判断placement是否包含"auto"

var autoToken = /\s?auto?\s?/i

var autoPlace = autoToken.test(placement)

//包含 "auto"时

if (autoPlace) placement = placement.replace(autoToken, '') || 'top'

$tip

//detach() 删除匹配的对象 与remove()不同的是，所有绑定的事件、附加的数据等都会保留下来

.detach()

.css({ top: 0, left: 0, display: 'block' })

.addClass(placement)

.data('bs.' + this.type, this)

//参数 container 向指定元素添加该提示框

//没有 添加到当前元素后面

this.options.container ? $tip.appendTo(this.options.container) : $tip.insertAfter(this.$element)

//位置对象pos pos = {top: , right: , bottom: , left: , width: ,scroll:}

var pos = this.getPosition()

//提示框自身实际的 width height

var actualWidth = $tip[0].offsetWidth

var actualHeight = $tip[0].offsetHeight

if (autoPlace) {

var orgPlacement = placement

var $container = this.options.container ? $(this.options.container) : this.$element.parent()

var containerDim = this.getPosition($container)

placement = placement == 'bottom' && pos.bottom + actualHeight > containerDim.bottom ? 'top' :

placement == 'top' && pos.top - actualHeight < containerDim.top ? 'bottom' :

placement == 'right' && pos.right + actualWidth > containerDim.width ? 'left' :

placement == 'left' && pos.left - actualWidth < containerDim.left ? 'right' :

placement

$tip

.removeClass(orgPlacement)

.addClass(placement)

}

//计算提示框的偏移量 {top: , left: }

var calculatedOffset = this.getCalculatedOffset(placement, pos, actualWidth, actualHeight)

//应用并设置偏移量

this.applyPlacement(calculatedOffset, placement)

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

//获得提示框自身的外边距的值

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

//是否是非数字

if (isNaN(marginTop)) marginTop = 0

if (isNaN(marginLeft)) marginLeft = 0

//计算的偏移量 + 自身的外边距

offset.top = offset.top + marginTop

offset.left = offset.left + marginLeft

// $.fn.offset doesn't round pixel values

// so we use setOffset directly with our own function B-0

// 应用了offset.setOffset方法，传入了using参数，因为offset设置值的时候，不能四舍五入

$.offset.setOffset($tip[0], $.extend({

using: function (props) {

$tip.css({

top: Math.round(props.top),

left: Math.round(props.left)

})

}

}, offset), 0)

//添加 in class 让提示框显示

$tip.addClass('in')

// check to see if placing tip in new offset caused the tip to resize itself

//获取显示后的提示框的宽和高 检查是否调整了自身的大小

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)

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, isHorizontal) {

this.arrow()

.css(isHorizontal ? 'left' : 'top', 50 * (1 - delta / dimension) + '%')

.css(isHorizontal ? 'top' : 'left', '')

}

//设置提示框的title

Tooltip.prototype.setContent = function () {

//div

var $tip = this.tip()

var title = this.getTitle()

$tip.find('.tooltip-inner')[this.options.html ? 'html' : 'text'](title)

$tip.removeClass('fade in top bottom left right')

}

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()

that.$element

.removeAttr('aria-describedby')

.trigger('hidden.bs.' + that.type)

callback && callback()

}

this.$element.trigger(e)

if (e.isDefaultPrevented()) return

$tip.removeClass('in')

$.support.transition && this.$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()

}

//获取位置

Tooltip.prototype.getPosition = function ($element) {

//不传入 则为当前点击元素

$element = $element || this.$element

//转换为DOM对象

var el = $element[0]

//是否是body元素

var isBody = el.tagName == 'BODY'

//获取元素各边与页面上边和左边的距离 left right top bottom height width

var elRect = el.getBoundingClientRect()

//兼容IE8 没有 width height 则计算

if (elRect.width == null) {

// 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 })

}

//当前元素相对于文档的偏移量

var elOffset = isBody ? { top: 0, left: 0 } : $element.offset()

//垂直滚动条的距离

//document.documentElement.scrollTop 和 document.body.scrollTop 浏览器兼容

var scroll = { scroll: isBody ? document.documentElement.scrollTop || document.body.scrollTop : $element.scrollTop() }

var outerDims = isBody ? { width: $(window).width(), height: $(window).height() } : null

//合并

return $.extend({}, elRect, scroll, outerDims, elOffset)

}

//计算偏移量

Tooltip.prototype.getCalculatedOffset = function (placement, pos, actualWidth, actualHeight) {

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 }

//默认参数

//viewport: {

// selector: 'body',

// padding: 0

//}

//默认的话 this.$viewport = 'body'

if (!this.$viewport) return delta

var viewportPadding = this.options.viewport && this.options.viewport.padding || 0

//this.$viewport = 'body' width height为 window的

var viewportDimensions = this.getPosition(this.$viewport)

console.info(viewportDimensions)

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 {

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.width) { // right overflow

delta.left = viewportDimensions.left + viewportDimensions.width - rightEdgeOffset

}

}

return delta

}

//提示框的title

Tooltip.prototype.getTitle = function () {

var title

var $e = this.$element

var o = this.options

//先获取当前元素的data-original-title属性

//否则获取参数title

title = $e.attr('data-original-title')

|| (typeof o.title == 'function' ? o.title.call($e[0]) : o.title)

return title

}

//随机生成唯一id 0 -- 100000 id值

Tooltip.prototype.getUID = function (prefix) {

//~~ 去掉小数部分

do prefix += ~~(Math.random() * 1000000)

while (document.getElementById(prefix))

return prefix

}

//生成提示框的div

//不存在 则用模板

//

Tooltip.prototype.tip = function () {

return (this.$tip = this.$tip || $(this.options.template))

}

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

}

//click 事件触发时执行的函数

Tooltip.prototype.toggle = function (e) {

//this tooltip实例对象

var self = this

if (e) {

//e.currentTarget 返回注册该事件处理程序的元素

self = $(e.currentTarget).data('bs.' + this.type)

if (!self) {

self = new this.constructor(e.currentTarget, this.getDelegateOptions())

$(e.currentTarget).data('bs.' + this.type, self)

}

}

//判断提示框当前的状态

//true 当前显示 需要隐藏

//false 相反

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)

})

}

// TOOLTIP PLUGIN DEFINITION

// =========================

function Plugin(option) {

return this.each(function () {

var $this = $(this)

//所选元素是否有 key为:bs.tooltip 对应的value值

var data = $this.data('bs.tooltip')

//option为对象 options:option

//option为字符串 则是方法 options:false

var options = typeof option == 'object' && option

//option是对象 执行初始化 ，并提供了选择器

var selector = options && options.selector

//是destroy 方法 不执行

if (!data && option == http://'destroy') return

//tooltip初始化

if (selector) {

//存在选择器，则将当前点击元素 bs.tooltip = {} 即去掉Tooltip实例

if (!data) $this.data('bs.tooltip', (data = {}))

//给选择器加上Tooltip实例

if (!data[selector]) data[selector] = new Tooltip(this, options)

} else {

//没有value值时，则加上 bs.tooltip = data(new Tooltip(this, options))

if (!data) $this.data('bs.tooltip', (data = new Tooltip(this, options)))

}

//执行方法

if (typeof option == 'string') data[option]()

})

}

//缓存以前$.fn上的tooltip

var old = $.fn.tooltip

//添加到jquery对象上

$.fn.tooltip = Plugin

$.fn.tooltip.Constructor = Tooltip

// TOOLTIP NO CONFLICT

// ===================

//tooltip冲突时 调用该方法

//var other = $("#aa").tooltip().noConflict();

$.fn.tooltip.noConflict = function () {

$.fn.tooltip = old

return this

}

}(jQuery);

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