modal.js对应的是bs的模态框组件。该组件主要有以下特点:
- 并不是绝对居中于浏览器窗口,而是水平居中,同时顶部距离浏览器顶部有一定的距离,其原因是因为modal框的内容可能出现滚动,垂直居中不太可能,它没有做成模态框内部滚动的效果;
- 动画是通过css3的translate实现的:transform: translate(0, -25%);
- 遮罩层的元素不是包含在modal里面的,而是与modal元素平级,都是body元素的子元素
- 不支持在已弹出的modal上继续弹框,主要是遮罩层叠加的问题
- 该组件内部包含一些如网页宽度计算,浏览器滚动条计算的函数,有一些学习的价值
- 事件监听这一块写的不太合理,混杂在各个具体的方法中,而不是统一地在一处管理
以下是具体代码,解释都以注释的形式说明,bs官方给出的例子中包含的html和css,再多看几遍注释,应该能很好地理解该组件的实现:
/* ======================================================================== * Bootstrap: modal.js v3.3.4 * http://getbootstrap.com/javascript/#modals * ======================================================================== * Copyright 2011-2015 Twitter, Inc. * Licensed under MIT (https://github.com/twbs/bootstrap/blob/master/LICENSE) * ======================================================================== */ +function ($) { ‘use strict‘; // MODAL CLASS DEFINITION // ====================== var Modal = function (element, options) { this.options = options this.$body = $(document.body) this.$element = $(element) //.modal对应的元素 this.$dialog = this.$element.find(‘.modal-dialog‘) this.$backdrop = null //遮罩元素,如果没有这个元素,在IE9下,被模态窗口覆盖的链接、按钮仍能继续点击 this.isShown = null this.originalBodyPad = null //保留body元素原来的padding值 this.scrollbarWidth = 0 this.ignoreBackdropClick = false //是否忽略遮罩元素上的点击,默认的情况是点击遮罩会隐藏modal元素 //异步加载模态窗口的内容,如果通过remote配置了异步加载地址的话 if (this.options.remote) { this.$element .find(‘.modal-content‘) .load(this.options.remote, $.proxy(function () { this.$element.trigger(‘loaded.bs.modal‘) }, this)) } } Modal.VERSION = ‘3.3.4‘ Modal.TRANSITION_DURATION = 300 Modal.BACKDROP_TRANSITION_DURATION = 150 Modal.DEFAULTS = { backdrop: true,//是否需要遮罩 keyboard: true,//是否支持按esc键时隐藏模态窗口 show: true//是否在$(..).modal()的时候立即弹出模态窗口 } Modal.prototype.toggle = function (_relatedTarget) { return this.isShown ? this.hide() : this.show(_relatedTarget) } Modal.prototype.show = function (_relatedTarget) { var that = this var e = $.Event(‘show.bs.modal‘, { relatedTarget: _relatedTarget }) this.$element.trigger(e) if (this.isShown || e.isDefaultPrevented()) return this.isShown = true this.checkScrollbar() this.setScrollbar() this.$body.addClass(‘modal-open‘)//设置overflow:hidden,在body元素溢出时隐藏body元素的滚动条 this.escape() this.resize() //模态框的关闭按钮 this.$element.on(‘click.dismiss.bs.modal‘, ‘[data-dismiss="modal"]‘, $.proxy(this.hide, this)) //点击dialog的时候不会触发hide this.$dialog.on(‘mousedown.dismiss.bs.modal‘, function () { that.$element.one(‘mouseup.dismiss.bs.modal‘, function (e) { if ($(e.target).is(that.$element)) that.ignoreBackdropClick = true }) }) //先处理遮罩元素,再调用回调显示modal元素 this.backdrop(function () { var transition = $.support.transition && that.$element.hasClass(‘fade‘) if (!that.$element.parent().length) { that.$element.appendTo(that.$body) // don‘t move modals dom position } that.$element .show() .scrollTop(0)//有可能有溢出,每次弹出的时候都滚到最顶部 that.adjustDialog() if (transition) { that.$element[0].offsetWidth // force reflow } //force reflow 跟浏览器渲染有关,虽然这样会有损性能,但是如果不这么调用的话,有可能z-index的渲染会有问题, //因为浏览器对dom处理的缓存机制 //触发动画 that.$element .addClass(‘in‘) .attr(‘aria-hidden‘, false) that.enforceFocus() var e = $.Event(‘shown.bs.modal‘, { relatedTarget: _relatedTarget }) transition ? that.$dialog // wait for modal to slide in .one(‘bsTransitionEnd‘, function () { that.$element.trigger(‘focus‘).trigger(e) }) .emulateTransitionEnd(Modal.TRANSITION_DURATION) : that.$element.trigger(‘focus‘).trigger(e) }) } //关闭modal Modal.prototype.hide = function (e) { if (e) e.preventDefault() e = $.Event(‘hide.bs.modal‘) this.$element.trigger(e) if (!this.isShown || e.isDefaultPrevented()) return this.isShown = false this.escape() this.resize() $(document).off(‘focusin.bs.modal‘) //开始进行关闭动画,移除show的时候绑定的事件监听器 this.$element .removeClass(‘in‘) .attr(‘aria-hidden‘, true) .off(‘click.dismiss.bs.modal‘) .off(‘mouseup.dismiss.bs.modal‘) this.$dialog.off(‘mousedown.dismiss.bs.modal‘) $.support.transition && this.$element.hasClass(‘fade‘) ? this.$element .one(‘bsTransitionEnd‘, $.proxy(this.hideModal, this)) .emulateTransitionEnd(Modal.TRANSITION_DURATION) : this.hideModal() } //focusin事件支持代理,focus事件不支持,enforceFocus方法的目的是 //当document捕获到focusin事件时,说明内部有元素获得了焦点 //假如这个焦点元素不在modal元素内,那么强制触发modal元素focus事件,使其获得焦点 Modal.prototype.enforceFocus = function () { $(document) .off(‘focusin.bs.modal‘) // guard against infinite focus loop .on(‘focusin.bs.modal‘, $.proxy(function (e) { if (this.$element[0] !== e.target && !this.$element.has(e.target).length) { this.$element.trigger(‘focus‘) } }, this)) } //ESC键的处理,show与hide方法都会调用 Modal.prototype.escape = function () { if (this.isShown && this.options.keyboard) { this.$element.on(‘keydown.dismiss.bs.modal‘, $.proxy(function (e) { e.which == 27 && this.hide() }, this)) } else if (!this.isShown) { this.$element.off(‘keydown.dismiss.bs.modal‘) } } //widnow resize的处理 Modal.prototype.resize = function () { if (this.isShown) { $(window).on(‘resize.bs.modal‘, $.proxy(this.handleUpdate, this)) } else { $(window).off(‘resize.bs.modal‘) } } Modal.prototype.hideModal = function () { var that = this this.$element.hide() this.backdrop(function () { that.$body.removeClass(‘modal-open‘)//恢复溢出 that.resetAdjustments()//取消modal元素的左右padding that.resetScrollbar()//重置body元素的padding-right that.$element.trigger(‘hidden.bs.modal‘) }) } //删除遮罩元素 Modal.prototype.removeBackdrop = function () { this.$backdrop && this.$backdrop.remove() this.$backdrop = null } //遮罩处理 Modal.prototype.backdrop = function (callback) { var that = this var animate = this.$element.hasClass(‘fade‘) ? ‘fade‘ : ‘‘ if (this.isShown && this.options.backdrop) { var doAnimate = $.support.transition && animate this.$backdrop = $(‘<div class="modal-backdrop ‘ + animate + ‘" />‘) .appendTo(this.$body) this.$element.on(‘click.dismiss.bs.modal‘, $.proxy(function (e) { //如果点的是dialog就返回 if (this.ignoreBackdropClick) { this.ignoreBackdropClick = false return } if (e.target !== e.currentTarget) return //如果options.backdrop配置不是static,那么点的空白部分时就会隐藏modal this.options.backdrop == ‘static‘ ? this.$element[0].focus() : this.hide() }, this)) if (doAnimate) this.$backdrop[0].offsetWidth // force reflow this.$backdrop.addClass(‘in‘) if (!callback) return doAnimate ? this.$backdrop .one(‘bsTransitionEnd‘, callback) .emulateTransitionEnd(Modal.BACKDROP_TRANSITION_DURATION) : callback() } else if (!this.isShown && this.$backdrop) { this.$backdrop.removeClass(‘in‘) var callbackRemove = function () { that.removeBackdrop() callback && callback() } $.support.transition && this.$element.hasClass(‘fade‘) ? this.$backdrop .one(‘bsTransitionEnd‘, callbackRemove) .emulateTransitionEnd(Modal.BACKDROP_TRANSITION_DURATION) : callbackRemove() } else if (callback) { callback() } } // these following methods are used to handle overflowing modals Modal.prototype.handleUpdate = function () { this.adjustDialog() } //在show的时候,以及浏览器窗口调整的时候调用,目的是: //在body溢出而modal没有溢出的时候,给modal添加padding-right //在body没有溢出而modal溢出的时候,给modal添加padding-left //目的还是为了让modal元素水平居中于浏览器窗口中 Modal.prototype.adjustDialog = function () { var modalIsOverflowing = this.$element[0].scrollHeight > document.documentElement.clientHeight this.$element.css({ paddingLeft: !this.bodyIsOverflowing && modalIsOverflowing ? this.scrollbarWidth : ‘‘, paddingRight: this.bodyIsOverflowing && !modalIsOverflowing ? this.scrollbarWidth : ‘‘ }) } //重置modal元素的左右padding,这主要是因为adjustDialog方法的调用,所以在hide的时候得还原 Modal.prototype.resetAdjustments = function () { this.$element.css({ paddingLeft: ‘‘, paddingRight: ‘‘ }) } Modal.prototype.checkScrollbar = function () { var fullWindowWidth = window.innerWidth if (!fullWindowWidth) { // workaround for missing window.innerWidth in IE8 var documentElementRect = document.documentElement.getBoundingClientRect() fullWindowWidth = documentElementRect.right - Math.abs(documentElementRect.left) } this.bodyIsOverflowing = document.body.clientWidth < fullWindowWidth//记录body元素是否有溢出 this.scrollbarWidth = this.measureScrollbar()//得到当前浏览器滚动条的宽度 } //在body发生溢出的时候,给body添加padding-right。该值等于当前浏览器滚动条的宽度加上body元素原有的padding-right //这个是在show方法调用的时候才会调的,目的是为了让modal元素完全水平居中在浏览器窗口中 Modal.prototype.setScrollbar = function () { var bodyPad = parseInt((this.$body.css(‘padding-right‘) || 0), 10) this.originalBodyPad = document.body.style.paddingRight || ‘‘ if (this.bodyIsOverflowing) this.$body.css(‘padding-right‘, bodyPad + this.scrollbarWidth) } //在hide的时候重置body元素的padding-right Modal.prototype.resetScrollbar = function () { this.$body.css(‘padding-right‘, this.originalBodyPad) } //计算当前浏览器的滚动条宽度 Modal.prototype.measureScrollbar = function () { // thx walsh var scrollDiv = document.createElement(‘div‘) scrollDiv.className = ‘modal-scrollbar-measure‘ this.$body.append(scrollDiv) var scrollbarWidth = scrollDiv.offsetWidth - scrollDiv.clientWidth this.$body[0].removeChild(scrollDiv) return scrollbarWidth } // MODAL PLUGIN DEFINITION // ======================= function Plugin(option, _relatedTarget) { return this.each(function () { var $this = $(this) var data = $this.data(‘bs.modal‘) var options = $.extend({}, Modal.DEFAULTS, $this.data(), typeof option == ‘object‘ && option) if (!data) $this.data(‘bs.modal‘, (data = new Modal(this, options))) if (typeof option == ‘string‘) data[option](_relatedTarget) else if (options.show) data.show(_relatedTarget) }) } var old = $.fn.modal $.fn.modal = Plugin $.fn.modal.Constructor = Modal // MODAL NO CONFLICT // ================= $.fn.modal.noConflict = function () { $.fn.modal = old return this } // MODAL DATA-API // ============== $(document).on(‘click.bs.modal.data-api‘, ‘[data-toggle="modal"]‘, function (e) { var $this = $(this) var href = $this.attr(‘href‘) var $target = $($this.attr(‘data-target‘) || (href && href.replace(/.*(?=#[^\s]+$)/, ‘‘))) // strip for ie7 var option = $target.data(‘bs.modal‘) ? ‘toggle‘ : $.extend({ remote: !/#/.test(href) && href }, $target.data(), $this.data()) if ($this.is(‘a‘)) e.preventDefault() $target.one(‘show.bs.modal‘, function (showEvent) { if (showEvent.isDefaultPrevented()) return // only register focus restorer if modal will actually get shown $target.one(‘hidden.bs.modal‘, function () { $this.is(‘:visible‘) && $this.trigger(‘focus‘) }) }) Plugin.call($target, option, this) }) }(jQuery);
时间: 2024-11-03 01:22:44