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webshim . ready ( 'matchMedia' , function ( $ , webshim , w , doc , undefined ) {
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try {
new Image ( ) ;
} catch ( e ) {
window . Image = function ( ) {
return document . createElement ( 'img' ) ;
} ;
}
webshim . isReady ( 'picture' , true ) ;
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// Enable strict mode
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"use strict" ;
// If picture is supported, well, that's awesome. Let's get outta here...
if ( w . HTMLPictureElement ) {
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w . picturefill = function ( ) { } ;
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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
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pf . srcsetSupported = "srcset" in doc . createElement ( "img" ) ;
pf . sizesSupported = w . HTMLImageElement . sizes ;
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// 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 ) {
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// 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" ;
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/ * *
* 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 + ";" ;
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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%;" ;
}
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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 ( /,+$/ , "" ) ;
descriptor = "" ;
}
srcset = srcset . slice ( pos + 1 ) ;
// 6.2. Collect a sequence of characters that are not U+002C COMMA characters (,), and
// let that be descriptors.
if ( descriptor === null ) {
var descpos = srcset . indexOf ( "," ) ;
if ( descpos !== - 1 ) {
descriptor = srcset . slice ( 0 , descpos ) ;
srcset = srcset . slice ( descpos + 1 ) ;
} else {
descriptor = srcset ;
srcset = "" ;
}
}
} else {
url = srcset ;
srcset = "" ;
}
// 7. Add url to raw candidates, associated with descriptors.
if ( url || descriptor ) {
candidates . push ( {
url : url ,
descriptor : descriptor
} ) ;
}
}
return candidates ;
} ;
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pf . parseDescriptor = function ( descriptor , sizesattr ) {
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// 11. Descriptor parser: Let candidates be an initially empty source set. The order of entries in the list
// is the order in which entries are added to the list.
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var sizes = sizesattr || "100vw" ,
sizeDescriptor = descriptor && descriptor . replace ( /(^\s+|\s+$)/g , "" ) ,
widthInCssPixels = pf . findWidthFromSourceSize ( sizes ) ,
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resCandidate ;
if ( sizeDescriptor ) {
var splitDescriptor = sizeDescriptor . split ( " " ) ;
for ( var i = splitDescriptor . length + 1 ; i >= 0 ; i -- ) {
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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 ;
}
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}
}
}
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return resCandidate || 1 ;
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} ;
/ * *
* 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 ;
}
}
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if ( bestCandidate && ! pf . endsWith ( picImg . src , bestCandidate . url ) ) {
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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 ) ;
}
} ;
/ *
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* 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 .
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* /
pf . getAllElements = function ( ) {
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var elems = [ ] ,
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imgs = doc . getElementsByTagName ( "img" ) ;
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for ( var h = 0 , len = imgs . length ; h < len ; h ++ ) {
var currImg = imgs [ h ] ;
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if ( currImg . parentNode . nodeName . toUpperCase ( ) === "PICTURE" ||
( currImg . getAttribute ( "srcset" ) !== null ) || currImg [ pf . ns ] && currImg [ pf . ns ] . srcset !== null ) {
elems . push ( currImg ) ;
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}
}
return elems ;
} ;
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pf . getMatch = function ( img , picture ) {
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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 ;
}
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// Hitting the `img` element that started everything stops the search for `sources`.
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// If no previous `source` matches, the `img` itself is evaluated later.
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if ( source === img ) {
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return match ;
}
// ignore non-`source` nodes
if ( source . nodeName . toUpperCase ( ) !== "SOURCE" ) {
continue ;
}
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// 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`." ) ;
}
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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 ;
} ;
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function picturefill ( opt ) {
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var elements ,
element ,
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parent ,
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firstMatch ,
candidates ,
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options = opt || { } ;
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elements = options . elements || pf . getAllElements ( ) ;
// Loop through all elements
for ( var i = 0 , plen = elements . length ; i < plen ; i ++ ) {
element = elements [ i ] ;
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parent = element . parentNode ;
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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 ;
}
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// if `img` is in a `picture` element
if ( parent . nodeName . toUpperCase ( ) === "PICTURE" ) {
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// IE9 video workaround
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pf . removeVideoShim ( parent ) ;
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// return the first match which might undefined
// returns false if there is a pending source
// TODO the return type here is brutal, cleanup
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firstMatch = pf . getMatch ( element , parent ) ;
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// 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 ;
}
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// 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 ) ;
}
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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 ) ;
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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.
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}
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// set evaluated to true to avoid unnecessary reparsing
element [ pf . ns ] . evaluated = true ;
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}
}
/ * *
* Sets up picture polyfill by polling the document and running
* the polyfill every 250 ms 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 ) ;
}
}
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runPicturefill ( ) ;
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/* expose methods for testing */
picturefill . _ = pf ;
/* expose picturefill */
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w . picturefill = picturefill ;
( function ( ) {
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webshim . isReady ( 'picture' , true ) ;
var sel = 'picture, img[srcset]' ;
webshim . addReady ( function ( context ) {
if ( context . querySelector ( sel ) ) {
window . picturefill ( ) ;
}
} ) ;
} ) ( ) ;
} ) ;
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; /*! 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'
} ;
} ;
} ( ) ) ;
/*! matchMedia() polyfill addListener/removeListener extension. Author & copyright (c) 2012: Scott Jehl. Dual MIT/BSD license */
( function ( ) {
// Bail out for browsers that have addListener support
if ( window . matchMedia && window . matchMedia ( 'all' ) . addListener ) {
return false ;
}
var localMatchMedia = window . matchMedia ,
hasMediaQueries = localMatchMedia ( 'only all' ) . matches ,
isListening = false ,
timeoutID = 0 , // setTimeout for debouncing 'handleChange'
queries = [ ] , // Contains each 'mql' and associated 'listeners' if 'addListener' is used
handleChange = function ( evt ) {
// Debounce
clearTimeout ( timeoutID ) ;
timeoutID = setTimeout ( function ( ) {
for ( var i = 0 , il = queries . length ; i < il ; i ++ ) {
var mql = queries [ i ] . mql ,
listeners = queries [ i ] . listeners || [ ] ,
matches = localMatchMedia ( mql . media ) . matches ;
// Update mql.matches value and call listeners
// Fire listeners only if transitioning to or from matched state
if ( matches !== mql . matches ) {
mql . matches = matches ;
for ( var j = 0 , jl = listeners . length ; j < jl ; j ++ ) {
listeners [ j ] . call ( window , mql ) ;
}
}
}
} , 30 ) ;
} ;
window . matchMedia = function ( media ) {
var mql = localMatchMedia ( media ) ,
listeners = [ ] ,
index = 0 ;
mql . addListener = function ( listener ) {
// Changes would not occur to css media type so return now (Affects IE <= 8)
if ( ! hasMediaQueries ) {
return ;
}
// Set up 'resize' listener for browsers that support CSS3 media queries (Not for IE <= 8)
// There should only ever be 1 resize listener running for performance
if ( ! isListening ) {
isListening = true ;
window . addEventListener ( 'resize' , handleChange , true ) ;
}
// Push object only if it has not been pushed already
if ( index === 0 ) {
index = queries . push ( {
mql : mql ,
listeners : listeners
} ) ;
}
listeners . push ( listener ) ;
} ;
mql . removeListener = function ( listener ) {
for ( var i = 0 , il = listeners . length ; i < il ; i ++ ) {
if ( listeners [ i ] === listener ) {
listeners . splice ( i , 1 ) ;
}
}
} ;
return mql ;
} ;
} ( ) ) ;
webshim . isReady ( 'matchMedia' , true ) ;