/*! Picturefill - v2.1.0 - 2014-07-25
* http://scottjehl.github.io/picturefill
* Copyright (c) 2014 https://github.com/scottjehl/picturefill/blob/master/Authors.txt; Licensed MIT */
/*! matchMedia() polyfill - Test a CSS media type/query in JS. Authors & copyright (c) 2012: Scott Jehl, Paul Irish, Nicholas Zakas, David Knight. Dual MIT/BSD license */
window.matchMedia || (window.matchMedia = function() {
"use strict";
// For browsers that support matchMedium api such as IE 9 and webkit
var styleMedia = (window.styleMedia || window.media);
// For those that don't support matchMedium
if (!styleMedia) {
var style = document.createElement('style'),
script = document.getElementsByTagName('script')[0],
info = null;
style.type = 'text/css';
style.id = 'matchmediajs-test';
script.parentNode.insertBefore(style, script);
// 'style.currentStyle' is used by IE <= 8 and 'window.getComputedStyle' for all other browsers
info = ('getComputedStyle' in window) && window.getComputedStyle(style, null) || style.currentStyle;
styleMedia = {
matchMedium: function(media) {
var text = '@media ' + media + '{ #matchmediajs-test { width: 1px; } }';
// 'style.styleSheet' is used by IE <= 8 and 'style.textContent' for all other browsers
if (style.styleSheet) {
style.styleSheet.cssText = text;
} else {
style.textContent = text;
}
// Test if media query is true or false
return info.width === '1px';
}
};
}
return function(media) {
return {
matches: styleMedia.matchMedium(media || 'all'),
media: media || 'all'
};
};
}());
/*! 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 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 no length was specified, or it is 0 or negative, default to `100vw` (per the spec).
length = length && ( 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 ) ) {
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 );