Jquery高亮显示文本中重要的关键字

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

 

英文地址：http://5thirtyone.com/archives/2206

Demo地址：http://5thirtyone.com/sandbox/samples/fadefocus/

Demo下载：http://5thirtyone.com/sandbox/samples/fadefocus/all.zip