一、界面预览
鼠标放到右边的Tab按钮上，文字透明度降低，同时一段文字高亮显示，效果如下：
Demo地址：http://5thirtyone.com/sandbox/samples/fadefocus/
很绚丽的效果幺！
二、实现原理
将要高亮显示的文字加上<span>段落标记， class=”mask”的div 做为遮罩层，使此遮罩层位于文字内容之上（z-index属性，使用Jquery给段落动态添加样式类。
三、HTML代码
| <div class="wrapper"> <ul class="entity-results"> <li><a class="d1" href="#">Summary</a></li> <li><a class="d2" href="#">Avatar</a></li> <li><a class="d3" href="#">Formats</a></li> </ul> <div class="content"> <h2> Avatar (2009 film)</h2> <div class="entity-source"> <img src="images/avatar.jpg" alt="Avatar poster" /> <p> Avatar, also known as James Cameron's Avatar, is an American 3-D science fiction epic film written and directed by <a href="http://en.wikipedia.org/wiki/James_Cameron"> James Cameron</a>, and was released on December 16, 2009 by 20th Century Fox. The film is co-produced by <a href="http://en.wikipedia.org/wiki/Lightstorm_Entertainment"> Lightstorm Entertainment</a>, and <span class="d1">focuses on an epic conflict on Pandora</span>, an inhabited Earth-sized moon of Polyphemus, one of three fictional gas giants orbiting <a href="http://en.wikipedia.org/wiki/Alpha_Centauri_A">Alpha Centauri A</a>. On Pandora, human colonists and the sentient humanoid indigenous inhabitants of Pandora, the Na'vi, engage in a war over the planet's resources and the latter's continued existence. The film's title refers to <span class="d2">an avatar, a representation of a real person in a virtual world</span>.</p> <p> <span class="d3">The film was released in 2D and 3D formats</span>, along with an IMAX 3D release in selected theaters. The film is being touted as a breakthrough in terms of filmmaking technology, for its development of 3D viewing and stereoscopic filmmaking with cameras that were specially designed for the film's production.</p> <p> Read the rest of the <a href="http://en.wikipedia.org/wiki/Avatar_(2009_film)">original Wikipedia page about Avatar</a></p> <div class="mask"> </div> </div> </div> </div> |
entity-results类中显示了Tab按钮，每个按钮控制左边文字的透明度，段落文字的高亮显示。
entity-source类中有三个段落span Calss分别为d1 d2 d3，也就是高亮文字段落。
class=”mask”的空div放到最后，此Div也就是一个遮罩层。
四、CSS关键代码
| .entity-source, .entity-source span.show { position: relative; } .entity-source .mask { display: none; position: absolute; top: 0; left: 0; height: 100%; width: 100%; z-index: 1; } .entity-source span { z-index: 2; } .entity-source span.show { background: #ffc; color: #000; } |
类mask中的z-index:1 使得<div class=”mask”> 覆盖在左边文字内容之上。
z-nidex：2又使得span段落覆盖在<div class=”mask”>之上。从而显示实现了段落文字高亮显示。
五、Jquery代码
| jQuery(document).ready(function($) { // mask source 控制mask的动画效果 var maskSource = jQuery('.mask'); jQuery('.entity-results').hover(function() { maskSource.animate({opacity:0.7},1).fadeIn('750'); }, function() { maskSource.fadeOut('1000'); }); // match hover 控制段落的高亮显示 var sample1 = jQuery('span.d1'); var sample2 = jQuery('span.d2'); var sample3 = jQuery('span.d3'); jQuery('a.d1').hover(function() { sample1.addClass('show');//给段落添加类 }, function() { sample1.removeClass('show'); //移除段落类 }); jQuery('a.d2').hover(function() { sample2.addClass('show'); }, function() { sample2.removeClass('show'); }); jQuery('a.d3').hover(function() { sample3.addClass('show'); }, function() { sample3.removeClass('show'); }); }); |
动画函数animate(params, [duration], [easing], [callback])
Params：一组包含作为动画属性和终值的样式属性和及其值的集合
duration (可选)：种预定速度之一的字符串("slow", "normal", or "fast")或表示动画时长的毫秒数值(如：1000)
easing (可选)：要使用的擦除效果的名称(需要插件支持).默认jQuery提供"linear" 和 "swing".
callback (可选)：在动画完成时执行的函数
淡入效果函数：fadeIn(speed, [callback])
Speed：三种预定速度之一的字符串("slow", "normal", or "fast")或表示动画时长的毫秒数值(如：1000)
callback(可选)：(Optional) 在动画完成时执行的函数
淡出效果函数：fadeOut解释同fadeIn
