text: /*! Picturefill - Responsive Images that work today.
  *  Author: Scott Jehl, Filament Group, 2012 ( new proposal implemented by Shawn Jansepar )
  *  License: MIT/GPLv2
  *  Spec: http://picture.responsiveimages.org/
  */
  (function( w, doc ) {
  	// Enable strict mode
  	"use strict";
  
  	// If picture is supported, well, that's awesome. Let's get outta here...
  	if ( w.HTMLPictureElement ) {
  		w.picturefill = function() { };
  		return;
  	}
  
  	// HTML shim|v it for old IE (IE9 will still need the HTML video tag workaround)
  	doc.createElement( "picture" );
  
  	// local object for method references and testing exposure
  	var pf = {};
  
  	// namespace
  	pf.ns = "picturefill";
  
  	// srcset support test
  	pf.srcsetSupported = "srcset" in doc.createElement( "img" );
  	pf.sizesSupported = w.HTMLImageElement.sizes;
  
  	// just a string trim workaround
  	pf.trim = function( str ) {
  		return str.trim ? str.trim() : str.replace( /^\s+|\s+$/g, "" );
  	};
  
  	// just a string endsWith workaround
  	pf.endsWith = function( str, suffix ) {
  		return str.endsWith ? str.endsWith( suffix ) : str.indexOf( suffix, str.length - suffix.length ) !== -1;
  	};
  
  	/**
  	 * Shortcut method for https://w3c.github.io/webappsec/specs/mixedcontent/#restricts-mixed-content ( for easy overriding in tests )
  	 */
  	pf.restrictsMixedContent = function() {
  		return w.location.protocol === "https:";
  	};
  	/**
  	 * Shortcut method for matchMedia ( for easy overriding in tests )
  	 */
  	pf.matchesMedia = function( media ) {
  		return w.matchMedia && w.matchMedia( media ).matches;
  	};
  
  	/**
  	 * Shortcut method for `devicePixelRatio` ( for easy overriding in tests )
  	 */
  	pf.getDpr = function() {
  		return ( w.devicePixelRatio || 1 );
  	};
  
  	/**
  	 * Get width in css pixel value from a "length" value
  	 * http://dev.w3.org/csswg/css-values-3/#length-value
  	 */
  	pf.getWidthFromLength = function( length ) {
  		// If a length is specified and doesn’t contain a percentage, and it is greater than 0 or using `calc`, use it. Else, use the `100vw` default.
  		length = length && length.indexOf( "%" ) > -1 === false && ( parseFloat( length ) > 0 || length.indexOf( "calc(" ) > -1 ) ? length : "100vw";
  		/**
  		* If length is specified in  `vw` units, use `%` instead since the div we’re measuring
  		* is injected at the top of the document.
  		*
  		* TODO: maybe we should put this behind a feature test for `vw`?
  		*/
  		length = length.replace( "vw", "%" );
  
  		// Create a cached element for getting length value widths
  		if ( !pf.lengthEl ) {
  			pf.lengthEl = doc.createElement( "div" );
  			doc.documentElement.insertBefore( pf.lengthEl, doc.documentElement.firstChild );
  		}
  
  		// Positioning styles help prevent padding/margin/width on `html` from throwing calculations off.
  		pf.lengthEl.style.cssText = "position: absolute; left: 0; width: " + length + ";";
  
  		if ( pf.lengthEl.offsetWidth <= 0 ) {
  			// Something has gone wrong. `calc()` is in use and unsupported, most likely. Default to `100vw` (`100%`, for broader support.):
  			pf.lengthEl.style.cssText = "width: 100%;";
  		}
  
  		return pf.lengthEl.offsetWidth;
  	};
  
  	// container of supported mime types that one might need to qualify before using
  	pf.types =  {};
  
  	// Add support for standard mime types.
  	pf.types["image/jpeg"] = true;
  	pf.types["image/gif"] = true;
  	pf.types["image/png"] = true;
  
  	// test svg support
  	pf.types[ "image/svg+xml" ] = doc.implementation.hasFeature("http://www.w3.org/TR/SVG11/feature#Image", "1.1");
  
  	// test webp support, only when the markup calls for it
  	pf.types[ "image/webp" ] = function() {
  		// based on Modernizr's lossless img-webp test
  		// note: asynchronous
  		var img = new w.Image(),
  			type = "image/webp";
  
  		img.onerror = function() {
  			pf.types[ type ] = false;
  			picturefill();
  		};
  		img.onload = function() {
  			pf.types[ type ] = img.width === 1;
  			picturefill();
  		};
  		img.src = "data:image/webp;base64,UklGRh4AAABXRUJQVlA4TBEAAAAvAAAAAAfQ//73v/+BiOh/AAA=";
  	};
  
  	/**
  	 * Takes a source element and checks if its type attribute is present and if so, supported
  	 * Note: for type tests that require a async logic,
  	 * you can define them as a function that'll run only if that type needs to be tested. Just make the test function call picturefill again when it is complete.
  	 * see the async webp test above for example
  	 */
  	pf.verifyTypeSupport = function( source ) {
  		var type = source.getAttribute( "type" );
  		// if type attribute exists, return test result, otherwise return true
  		if ( type === null || type === "" ) {
  			return true;
  		} else {
  			// if the type test is a function, run it and return "pending" status. The function will rerun picturefill on pending elements once finished.
  			if ( typeof( pf.types[ type ] ) === "function" ) {
  				pf.types[ type ]();
  				return "pending";
  			} else {
  				return pf.types[ type ];
  			}
  		}
  	};
  
  	/**
  	* Parses an individual `size` and returns the length, and optional media query
  	*/
  	pf.parseSize = function( sourceSizeStr ) {
  		var match = /(\([^)]+\))?\s*(.+)/g.exec( sourceSizeStr );
  		return {
  			media: match && match[1],
  			length: match && match[2]
  		};
  	};
  
  	/**
  	 * Takes a string of sizes and returns the width in pixels as a number
  	 */
  	pf.findWidthFromSourceSize = function( sourceSizeListStr ) {
  		// Split up source size list, ie ( max-width: 30em ) 100%, ( max-width: 50em ) 50%, 33%
  		//                            or (min-width:30em) calc(30% - 15px)
  		var sourceSizeList = pf.trim( sourceSizeListStr ).split( /\s*,\s*/ ),
  			winningLength;
  
  		for ( var i = 0, len = sourceSizeList.length; i < len; i++ ) {
  			// Match <media-condition>? length, ie ( min-width: 50em ) 100%
  			var sourceSize = sourceSizeList[ i ],
  				// Split "( min-width: 50em ) 100%" into separate strings
  				parsedSize = pf.parseSize( sourceSize ),
  				length = parsedSize.length,
  				media = parsedSize.media;
  
  			if ( !length ) {
  				continue;
  			}
  			if ( !media || pf.matchesMedia( media ) ) {
  				// if there is no media query or it matches, choose this as our winning length
  				// and end algorithm
  				winningLength = length;
  				break;
  			}
  		}
  
  		// pass the length to a method that can properly determine length
  		// in pixels based on these formats: http://dev.w3.org/csswg/css-values-3/#length-value
  		return pf.getWidthFromLength( winningLength );
  	};
  
  	pf.parseSrcset = function( srcset ) {
  		/**
  		* A lot of this was pulled from Boris Smus’ parser for the now-defunct WHATWG `srcset`
  		* https://github.com/borismus/srcset-polyfill/blob/master/js/srcset-info.js
  		*
  		* 1. Let input (`srcset`) be the value passed to this algorithm.
  		* 2. Let position be a pointer into input, initially pointing at the start of the string.
  		* 3. Let raw candidates be an initially empty ordered list of URLs with associated 
  		*    unparsed descriptors. The order of entries in the list is the order in which entries 
  		*    are added to the list.
  		*/
  		var candidates = [];
  
  		while ( srcset !== "" ) {
  			srcset = srcset.replace(/^\s+/g,"");
  
  			// 5. Collect a sequence of characters that are not space characters, and let that be url.
  			var pos = srcset.search(/\s/g),
  				url, descriptor = null;
  
  			if ( pos !== -1 ) {
  				url = srcset.slice( 0, pos );
  
  				var last = url[ url.length - 1 ];
  
  				// 6. If url ends with a U+002C COMMA character (,), remove that character from url
  				// and let descriptors be the empty string. Otherwise, follow these substeps
  				// 6.1. If url is empty, then jump to the step labeled descriptor parser.
  
  				if ( last === "," || url === "" ) {
  					url = url.replace(/,+$/, "");
  					descriptor = "";
  				}
  				srcset = srcset.slice( pos + 1 );
  
  				// 6.2. Collect a sequence of characters that are not U+002C COMMA characters (,), and 
  				// let that be descriptors.
  				if ( descriptor === null ) {
  					var descpos = srcset.indexOf(",");
  					if ( descpos !== -1 ) {
  						descriptor = srcset.slice( 0, descpos );
  						srcset = srcset.slice( descpos + 1 );
  					} else {
  						descriptor = srcset;
  						srcset = "";
  					}
  				}
  			} else {
  				url = srcset;
  				srcset = "";
  			}
  
  			// 7. Add url to raw candidates, associated with descriptors.
  			if ( url || descriptor ) {
  				candidates.push({
  					url: url,
  					descriptor: descriptor
  				});
  			}
  		}
  		return candidates;
  	};
  
  	pf.parseDescriptor = function( descriptor, sizesattr ) {
  		// 11. Descriptor parser: Let candidates be an initially empty source set. The order of entries in the list 
  		// is the order in which entries are added to the list.
  		var sizes = sizesattr || "100vw",
  			sizeDescriptor = descriptor && descriptor.replace(/(^\s+|\s+$)/g, ""),
  			widthInCssPixels = pf.findWidthFromSourceSize( sizes ),
  			resCandidate;
  
  			if ( sizeDescriptor ) {
  				var splitDescriptor = sizeDescriptor.split(" ");
  
  				for (var i = splitDescriptor.length + 1; i >= 0; i--) {
  					if ( splitDescriptor[ i ] !== undefined ) {
  						var curr = splitDescriptor[ i ],
  							lastchar = curr && curr.slice( curr.length - 1 );
  
  						if ( ( lastchar === "h" || lastchar === "w" ) && !pf.sizesSupported ) {
  							resCandidate = parseFloat( ( parseInt( curr, 10 ) / widthInCssPixels ) );
  						} else if ( lastchar === "x" ) {
  							var res = curr && parseFloat( curr, 10 );
  							resCandidate = res && !isNaN( res ) ? res : 1;
  						}
  					}
  				}
  			}
  		return resCandidate || 1;
  	};
  
  	/**
  	 * Takes a srcset in the form of url/
  	 * ex. "images/pic-medium.png 1x, images/pic-medium-2x.png 2x" or
  	 *     "images/pic-medium.png 400w, images/pic-medium-2x.png 800w" or
  	 *     "images/pic-small.png"
  	 * Get an array of image candidates in the form of
  	 *      {url: "/foo/bar.png", resolution: 1}
  	 * where resolution is http://dev.w3.org/csswg/css-values-3/#resolution-value
  	 * If sizes is specified, resolution is calculated
  	 */
  	pf.getCandidatesFromSourceSet = function( srcset, sizes ) {
  		var candidates = pf.parseSrcset( srcset ),
  			formattedCandidates = [];
  
  		for ( var i = 0, len = candidates.length; i < len; i++ ) {
  			var candidate = candidates[ i ];
  
  			formattedCandidates.push({
  				url: candidate.url,
  				resolution: pf.parseDescriptor( candidate.descriptor, sizes )
  			});
  		}
  		return formattedCandidates;
  	};
  
  	/*
  	 * if it's an img element and it has a srcset property,
  	 * we need to remove the attribute so we can manipulate src
  	 * (the property's existence infers native srcset support, and a srcset-supporting browser will prioritize srcset's value over our winning picture candidate)
  	 * this moves srcset's value to memory for later use and removes the attr
  	 */
  	pf.dodgeSrcset = function( img ) {
  		if ( img.srcset ) {
  			img[ pf.ns ].srcset = img.srcset;
  			img.removeAttribute( "srcset" );
  		}
  	};
  
  	/*
  	 * Accept a source or img element and process its srcset and sizes attrs
  	 */
  	pf.processSourceSet = function( el ) {
  		var srcset = el.getAttribute( "srcset" ),
  			sizes = el.getAttribute( "sizes" ),
  			candidates = [];
  
  		// if it's an img element, use the cached srcset property (defined or not)
  		if ( el.nodeName.toUpperCase() === "IMG" && el[ pf.ns ] && el[ pf.ns ].srcset ) {
  			srcset = el[ pf.ns ].srcset;
  		}
  
  		if ( srcset ) {
  			candidates = pf.getCandidatesFromSourceSet( srcset, sizes );
  		}
  		return candidates;
  	};
  
  	pf.applyBestCandidate = function( candidates, picImg ) {
  		var candidate,
  			length,
  			bestCandidate;
  
  		candidates.sort( pf.ascendingSort );
  
  		length = candidates.length;
  		bestCandidate = candidates[ length - 1 ];
  
  		for ( var i = 0; i < length; i++ ) {
  			candidate = candidates[ i ];
  			if ( candidate.resolution >= pf.getDpr() ) {
  				bestCandidate = candidate;
  				break;
  			}
  		}
  
  		if ( bestCandidate && !pf.endsWith( picImg.src, bestCandidate.url ) ) {
  			if ( pf.restrictsMixedContent() && bestCandidate.url.substr(0, "http:".length).toLowerCase() === "http:" ) {
  				if ( typeof console !== undefined ) {
  					console.warn( "Blocked mixed content image " + bestCandidate.url );
  				}
  			} else {
  				picImg.src = bestCandidate.url;
  				// currentSrc attribute and property to match
  				// http://picture.responsiveimages.org/#the-img-element
  				picImg.currentSrc = picImg.src;
  			}
  		}
  	};
  
  	pf.ascendingSort = function( a, b ) {
  		return a.resolution - b.resolution;
  	};
  
  	/*
  	 * In IE9, <source> elements get removed if they aren't children of
  	 * video elements. Thus, we conditionally wrap source elements
  	 * using <!--[if IE 9]><video style="display: none;"><![endif]-->
  	 * and must account for that here by moving those source elements
  	 * back into the picture element.
  	 */
  	pf.removeVideoShim = function( picture ) {
  		var videos = picture.getElementsByTagName( "video" );
  		if ( videos.length ) {
  			var video = videos[ 0 ],
  				vsources = video.getElementsByTagName( "source" );
  			while ( vsources.length ) {
  				picture.insertBefore( vsources[ 0 ], video );
  			}
  			// Remove the video element once we're finished removing its children
  			video.parentNode.removeChild( video );
  		}
  	};
  
  	/*
  	 * Find all `img` elements, and add them to the candidate list if they have
  	 * a `picture` parent, a `sizes` attribute in basic `srcset` supporting browsers,
  	 * a `srcset` attribute at all, and they haven’t been evaluated already.
  	 */
  	pf.getAllElements = function() {
  		var elems = [],
  			imgs = doc.getElementsByTagName( "img" );
  
  		for ( var h = 0, len = imgs.length; h < len; h++ ) {
  			var currImg = imgs[ h ];
  
  			if ( currImg.parentNode.nodeName.toUpperCase() === "PICTURE" ||
  				( currImg.getAttribute( "srcset" ) !== null ) || currImg[ pf.ns ] && currImg[ pf.ns ].srcset !== null ) {
  					elems.push( currImg );
  			}
  		}
  		return elems;
  	};
  
  	pf.getMatch = function( img, picture ) {
  		var sources = picture.childNodes,
  			match;
  
  		// Go through each child, and if they have media queries, evaluate them
  		for ( var j = 0, slen = sources.length; j < slen; j++ ) {
  			var source = sources[ j ];
  
  			// ignore non-element nodes
  			if ( source.nodeType !== 1 ) {
  				continue;
  			}
  
  			// Hitting the `img` element that started everything stops the search for `sources`.
  			// If no previous `source` matches, the `img` itself is evaluated later.
  			if ( source === img ) {
  				return match;
  			}
  
  			// ignore non-`source` nodes
  			if ( source.nodeName.toUpperCase() !== "SOURCE" ) {
  				continue;
  			}
  			// if it's a source element that has the `src` property set, throw a warning in the console
  			if ( source.getAttribute( "src" ) !== null && typeof console !== undefined ){
  				console.warn("The `src` attribute is invalid on `picture` `source` element; instead, use `srcset`.");
  			}
  
  			var media = source.getAttribute( "media" );
  
  			// if source does not have a srcset attribute, skip
  			if ( !source.getAttribute( "srcset" ) ) {
  				continue;
  			}
  
  			// if there's no media specified, OR w.matchMedia is supported
  			if ( ( !media || pf.matchesMedia( media ) ) ) {
  				var typeSupported = pf.verifyTypeSupport( source );
  
  				if ( typeSupported === true ) {
  					match = source;
  					break;
  				} else if ( typeSupported === "pending" ) {
  					return false;
  				}
  			}
  		}
  
  		return match;
  	};
  
  	function picturefill( opt ) {
  		var elements,
  			element,
  			parent,
  			firstMatch,
  			candidates,
  
  		options = opt || {};
  		elements = options.elements || pf.getAllElements();
  
  		// Loop through all elements
  		for ( var i = 0, plen = elements.length; i < plen; i++ ) {
  			element = elements[ i ];
  			parent = element.parentNode;
  			firstMatch = undefined;
  			candidates = undefined;
  
  			// expando for caching data on the img
  			if ( !element[ pf.ns ] ) {
  				element[ pf.ns ] = {};
  			}
  
  			// if the element has already been evaluated, skip it
  			// unless `options.force` is set to true ( this, for example,
  			// is set to true when running `picturefill` on `resize` ).
  			if ( !options.reevaluate && element[ pf.ns ].evaluated ) {
  				continue;
  			}
  
  			// if `img` is in a `picture` element
  			if ( parent.nodeName.toUpperCase() === "PICTURE" ) {
  
  				// IE9 video workaround
  				pf.removeVideoShim( parent );
  
  				// return the first match which might undefined
  				// returns false if there is a pending source
  				// TODO the return type here is brutal, cleanup
  				firstMatch = pf.getMatch( element, parent );
  
  				// if any sources are pending in this picture due to async type test(s)
  				// remove the evaluated attr and skip for now ( the pending test will
  				// rerun picturefill on this element when complete)
  				if ( firstMatch === false ) {
  					continue;
  				}
  			} else {
  				firstMatch = undefined;
  			}
  
  			// Cache and remove `srcset` if present and we’re going to be doing `picture`/`srcset`/`sizes` polyfilling to it.
  			if ( parent.nodeName.toUpperCase() === "PICTURE" ||
  			( element.srcset && !pf.srcsetSupported ) ||
  			( !pf.sizesSupported && ( element.srcset && element.srcset.indexOf("w") > -1 ) ) ) {
  				pf.dodgeSrcset( element );
  			}
  
  			if ( firstMatch ) {
  				candidates = pf.processSourceSet( firstMatch );
  				pf.applyBestCandidate( candidates, element );
  			} else {
  				// No sources matched, so we’re down to processing the inner `img` as a source.
  				candidates = pf.processSourceSet( element );
  
  				if ( element.srcset === undefined || element[ pf.ns ].srcset ) {
  					// Either `srcset` is completely unsupported, or we need to polyfill `sizes` functionality.
  					pf.applyBestCandidate( candidates, element );
  				} // Else, resolution-only `srcset` is supported natively.
  			}
  
  			// set evaluated to true to avoid unnecessary reparsing
  			element[ pf.ns ].evaluated = true;
  		}
  	}
  
  	/**
  	 * Sets up picture polyfill by polling the document and running
  	 * the polyfill every 250ms until the document is ready.
  	 * Also attaches picturefill on resize
  	 */
  	function runPicturefill() {
  		picturefill();
  		var intervalId = setInterval( function() {
  			// When the document has finished loading, stop checking for new images
  			// https://github.com/ded/domready/blob/master/ready.js#L15
  			picturefill();
  			if ( /^loaded|^i|^c/.test( doc.readyState ) ) {
  				clearInterval( intervalId );
  				return;
  			}
  		}, 250 );
  		if ( w.addEventListener ) {
  			var resizeThrottle;
  			w.addEventListener( "resize", function() {
  				if (!w._picturefillWorking) {
  					w._picturefillWorking = true;
  					w.clearTimeout( resizeThrottle );
  					resizeThrottle = w.setTimeout( function() {
  						picturefill({ reevaluate: true });
  						w._picturefillWorking = false;
  					}, 60 );
  				}
  			}, false );
  		}
  	}
  
  	runPicturefill();
  
  	/* expose methods for testing */
  	picturefill._ = pf;
  
  	/* expose picturefill */
  	if ( typeof module === "object" && typeof module.exports === "object" ) {
  		// CommonJS, just export
  		module.exports = picturefill;
  	} else if ( typeof define === "function" && define.amd ){
  		// AMD support
  		define( function() { return picturefill; } );
  	} else if ( typeof w === "object" ) {
  		// If no AMD and we are in the browser, attach to window
  		w.picturefill = picturefill;
  	}
  
  } )( this, this.document );
  