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<html><!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"><html xmlns="http://www.w3.org/1999/xhtml"><head><meta http-equiv="Keywords" name="Keywords"content="JavaScript, examples, JavaScript: The Definitive Guide"><title>Example 16-2 from JavaScript: The Definitive Guide, Fifth Edition</title><style>body {  font-family: arial, sans-serif}.lefttitle {  font: bold x-small arial, sans-serif;  margin: 5px;  letter-spacing: .15em;  text-transform:uppercase;}.leftcaption {  font: italic x-small sans-serif;  margin-bottom: 20px;}#banner {	font-family:sans-serif;	color:#333;	font-size:x-large;	font-weight:normal;		padding:15px;	padding-top: 3px;        border-bottom:4px double #666;}#banner h1 {	font-size: x-large;	margin: 0px;	padding: 0px;}#banner .description {	font-size:large;	margin-left: 2px;}pre {  border: solid black 1px;  background-color: #ddd;  padding: 10px;  margin: 0px;}	</style></script></head><body><div id="banner"><h1>davidflanagan.com/javascript5</h1><span class="description">Example 16-2 from<i>JavaScript: The Definitive Guide, Fifth Edition</i></span></div><div style="float: left; 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text-align: right"><a href="index.html" tppabs="http://www.davidflanagan.com/javascript5/index.html">Table of Examples</a></div><pre>/** * Shadows.js: shadowed text with CSS. *  * This module defines a single global object named Shadows. * The properties of this object are two utility functions. *  * Shadows.add(element, shadows): *   Add the specified shadows to the specified element.  The first argument *   is a document element or element id.  This element must have a single *   text node as its child.  This child is the one that will be shadowed. *   Shadows are specified with a string argument whose syntax is explained *   below. * * Shadows.addAll(root, tagname): *   Find all descendants of the specified root element that have the *   specified tagname. If any of these elements have an attribute named *   shadow, then call Shadows.add(), for the element and the value of its *   shadow attribute.  If tagname is not specified, all elements are checked. *   If root is not specified, the document object is used.  This function is *   intended to be called once, when a document is first loaded. * * Shadow Syntax *  * Shadows are specified by a string of the form [x y color]+.  That is, one * or more triplets specifying an x offset a y offset and a color.  Each of * these values must be in legal CSS format. If more than one shadow is * specified, then the first shadow specified is on the bottom, overlapped * by subsequent shadows.  For example: "4px 4px #ccc 2px 2px #aaa" */var Shadows = {};// Add shadows to a single specified elementShadows.add = function(element, shadows) {    if (typeof element == "string")        element = document.getElementById(element);    // Break the shadows string up at whitespace, first stripping off    // any leading and trailing spaces.    shadows = shadows.replace(/^\s+/, "").replace(/\s+$/, "");    var args = shadows.split(/\s+/);    // Find the text node that we are going to shadow.    // This module would be more robust if we shadowed all children.    // For simplicity, though, we're only going to do one.    var textnode = element.firstChild;        // Give the container element relative positioning, so that    // shadows can be positioned relative to it.    // We'll learn about scripting the style property in this way later.    element.style.position = "relative";    // Create the shadows    var numshadows = args.length/3;           // how many shadows?    for(var i = 0; i &lt; numshadows; i++) {     // for each one        var shadowX = args[i*3];              // get the X offset        var shadowY = args[i*3 + 1];          // the Y offset        var shadowColor = args[i*3 + 2];      // and the color arguments        // Create a new &lt;span&gt; to hold the shadow        var shadow = document.createElement("span");        // Use its style attribute to specify offset and color        shadow.setAttribute("style", "position:absolute; " +                            "left:" + shadowX + "; " +                            "top:" + shadowY + "; " +                            "color:" + shadowColor + ";");        // Add a copy of the text node to this shadow span        shadow.appendChild(textnode.cloneNode(false));        // And add the span to the container        element.appendChild(shadow);    }    // Now we put the text on top of the shadow.  First, create a &lt;span&gt;    var text = document.createElement("span");    text.setAttribute("style", "position: relative"); // position it    text.appendChild(textnode); // Move the original text node to this span    element.appendChild(text);  // And add this span to the container};// Scan the document tree at and beneath the specified root element for// elements with the specified tagname.  If any have a shadow attribute// pass it to the Shadows.add() method above to create the shadow.// If root is omitted, use the document object.  If tagname is omitted,// search all tags.Shadows.addAll = function(root, tagname) {    if (!root) root = document;   // Use whole document if no root    if (!tagname) tagname = '*';  // Use any tag if no tagname specified        var elements = root.getElementsByTagName(tagname); // Find all tags    for(var i = 0; i &lt; elements.length; i++) {           // For each tag        var shadow = elements[i].getAttribute("shadow"); // If it has a shadow        if (shadow) Shadows.add(elements[i], shadow);    // create the shadow    }};</pre><div class="lefttitle" style="padding:0px; text-align: right"><a href="index.html" tppabs="http://www.davidflanagan.com/javascript5/index.html">Table of Examples</a></div><p><script type="text/javascript">amazon_ad_tag="davidflanagancom"; amazon_ad_width="300"; amazon_ad_height="250"; amazon_ad_logo="hide";</script><script type="text/javascript" src="../../www.assoc-amazon.com/s/ads.js" tppabs="http://www.assoc-amazon.com/s/ads.js"></script></div></body></html>

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