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