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pbakaus · Aug 30, 2012 · 4f75dce · 4f75dce
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diff --git a/css/main.css b/css/main.css
@@ -0,0 +1,54 @@
+body {
+	font-family: Open Sans, sans-serif;
+	font-size: 0.9em;
+	color: #333;
+
+
+	background-image: url(data:image/png;base64,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);
+}
+
+section {
+	max-width: 710px;
+	margin: 0 auto;
+}
+
+.sub {
+	height: 210px;
+}
+
+.sub > * {
+	float: left;
+}
+
+pre {
+	background: #333;
+	color: #eee;
+	padding: 10px;
+}
+
+canvas {
+	background: #eee;
+}
+
+h1 {
+	border-bottom: 1px solid #fff;
+	clear: both;
+	margin-top: 1em;
+	text-shadow: 1px 1px 0px white;
+}
+
+p {
+	color: #555;
+	line-height: 1.4em;
+}
+
+strong {
+	font-weight: 600;
+}
+
+h1::after {
+	content: '';
+	width: 100%;
+	display: block;
+	border-bottom: 1px solid rgba(30,30,30,0.4);
+}
diff --git a/index.html b/index.html
@@ -0,0 +1,113 @@
+<!DOCTYPE html>
+<html>
+	<head>
+		<meta charset="utf-8">
+		<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
+		<title>Domvas!</title>
+
+		<link href='http://fonts.googleapis.com/css?family=Open+Sans:400,600,300' rel='stylesheet' type='text/css'>
+		<link rel="stylesheet" href="css/main.css">
+
+		<style type="text/css">
+
+			#dom {
+				font-family: Arial;
+				border: 5px solid rgba(0,0,0,0.2);
+				border-radius: 10px;
+				width: 260px;
+				padding: 5px 20px;
+				background: #4f8eff;
+
+				text-shadow: 1px 1px 0 #264782;
+				line-height: 1.4em;
+
+				margin: 20px;
+			}
+
+			#dom p {
+				color: rgba(255,255,255,0.8);
+			}
+
+			#dom strong {
+				color: #fff;
+				font-style: italic;
+			}
+
+		</style>
+</head>
+<body>
+
+	<section>
+
+		<h1>Domvas!</h1>
+
+		<p><strong>Domvas implements the missing piece that connects the DOM and Canvas</strong>. It gives to the ability to take arbitrary DOM content and paint it to a Canvas of your choice.</p>
+
+		<p>That dialog that is a pain to layout in Canvas but needs to be animated? Yep. Always wanted to use CSS transforms in Canvas? Yep. I think you get the idea.</p>
+
+		<h1>Demo</h1>
+
+		<div class="sub">
+
+			<div style='font-size:30px' id="dom">
+				<p>EHRMAGERD <strong>DOM IN CANVAS</strong>!</p>
+			</div>
+
+			<canvas id="test" width="350" height="206"></canvas>
+
+		</div>
+
+		<h1>Usage</h1>
+
+		<pre>
+var canvas = document.getElementById("test");
+var context = canvas.getContext('2d');
+
+domvas.toImage(document.getElementById("dom"), function() {
+	context.drawImage(this, 20, 20);
+});
+		</pre>
+
+		<p>Extended documentation:</p>
+
+		<pre>
+domvas.toImage(domElement, readyCallback, width, height, left, top);
+		</pre>		
+
+		<h1>How it works</h1>
+
+		<p>Domvas uses a feature of SVG that allows you to embed XHTML content into the SVG – and as you might know, the actual SVG can be used as a data uri, and therefore behaves like a standard image.</p>
+
+		<p>I have written about this technique in 2008 <a href="http://paulbakaus.com/2008/08/19/css-transforms-for-firefox/">when I brought CSS transforms to browsers that did not have them</a>. It took a little more experimentation to transform it into a reusable plugin: HTML content needs to be serialized to XML, and all styles have to be inlined.</p>
+
+		<h1>Caveats</h1>
+
+			<ul>
+				<li><strong>Internet Explorer</strong> is not supported, at it doesn't support the foreignObject tag in SVG.</li>
+				<li>SVG's foreignObject is subject to strong security – meaning any external content will likely fail (i.e. iframes, web fonts)</li>
+				<li>The DOM object is <strong>not linked, but copied</strong> – if you change the style of the DOM object, it will not automatically update in Canvas</li>
+				<li>Content outside the bounding box of the element will be cut of per default if painted to Canvas. Don't worry though, simply pass a more confortable offset to the toImage function (see above)</li>
+			</ul>
+
+		<h1>Credits / License</h1>
+
+		<p>&copy;2012 Paul Bakaus. Licensed under MIT. Reach out on <a href='http://twitter.com/pbakaus'>Twitter</a>!</p>
+
+
+	</section>
+
+	<script src="src/domvas.js"></script>
+	<script>
+
+		var canvas = document.getElementById("test");
+		var context = canvas.getContext('2d');
+
+		domvas.toImage(document.getElementById("dom"), function() {
+			// Look ma, I just converted this element to an image and can now to funky stuff!
+			context.drawImage(this, 20, 20);
+		});
+
+	</script>
+
+</body>
+</html>
diff --git a/src/domvas.js b/src/domvas.js
@@ -0,0 +1,87 @@
+"use strict";
+
+(function() {
+
+	var supportsCSSText = getComputedStyle(document.body).cssText !== "";
+
+	function copyCSS(elem, origElem, log) {
+
+		var computedStyle = getComputedStyle(origElem);
+
+		if(supportsCSSText) {
+			elem.style.cssText = computedStyle.cssText;
+
+		} else {
+
+			// Really, Firefox?
+			for(var prop in computedStyle) {
+				if(isNaN(parseInt(prop, 10)) && typeof computedStyle[prop] !== 'function' && !(/^(cssText|length|parentRule)$/).test(prop)) {
+					elem.style[prop] = computedStyle[prop];
+				}
+			}
+
+		}
+
+	}
+
+	function inlineStyles(elem, origElem) {
+
+		var children = elem.querySelectorAll('*');
+		var origChildren = origElem.querySelectorAll('*');
+
+		// copy the current style to the clone
+		copyCSS(elem, origElem, 1);
+
+		// collect all nodes within the element, copy the current style to the clone
+		Array.prototype.forEach.call(children, function(child, i) {
+			copyCSS(child, origChildren[i]);
+		});
+
+		// strip margins from the outer element
+		elem.style.margin = elem.style.marginLeft = elem.style.marginTop = elem.style.marginBottom = elem.style.marginRight = '';
+
+	}
+
+	window.domvas = {
+
+		toImage: function(origElem, callback, width, height, left, top) {
+
+			left = (left || 0);
+			top = (top || 0);
+
+			var elem = origElem.cloneNode(true);
+
+			// inline all CSS (ugh..)
+			inlineStyles(elem, origElem);
+
+			// unfortunately, SVG can only eat well formed XHTML
+			elem.setAttribute("xmlns", "http://www.w3.org/1999/xhtml");
+
+			// serialize the DOM node to a String
+			var serialized = new XMLSerializer().serializeToString(elem);
+
+			// Create well formed data URL with our DOM string wrapped in SVG
+			var dataUri = "data:image/svg+xml," +
+				"<svg xmlns='http://www.w3.org/2000/svg' width='" + ((width || origElem.offsetWidth) + left) + "' height='" + ((height || origElem.offsetHeight) + top) + "'>" +
+					"<foreignObject width='100%' height='100%' x='" + left + "' y='" + top + "'>" +
+					serialized +
+					"</foreignObject>" +
+				"</svg>";
+
+			// create new, actual image
+			var img = new Image();
+			img.src = dataUri;
+
+			// when loaded, fire onload callback with actual image node
+			img.onload = function() {
+				if(callback) {
+					callback.call(this, this);
+				}
+			};
+
+		}
+
+	};
+
+})();
+
diff --git a/src/domvas.min.js b/src/domvas.min.js