eidolon/static/js/picturefill.js

1513 lines
43 KiB
JavaScript
Executable File

/*! Picturefill - v3.0.0-rc1 - 2015-08-21
* http://scottjehl.github.io/picturefill
* Copyright (c) 2015 https://github.com/scottjehl/picturefill/blob/master/Authors.txt; Licensed MIT
*/
/*! Gecko-Picture - v1.0
* https://github.com/scottjehl/picturefill/tree/3.0/src/plugins/gecko-picture
* Firefox's early picture implementation (prior to FF41) is static and does
* not react to viewport changes. This tiny module fixes this.
*/
(function(window) {
/*jshint eqnull:true */
var ua = navigator.userAgent;
if ( window.HTMLPictureElement && ((/ecko/).test(ua) && ua.match(/rv\:(\d+)/) && RegExp.$1 < 41) ) {
addEventListener("resize", (function() {
var timer;
var dummySrc = document.createElement("source");
var fixRespimg = function(img) {
var source, sizes;
var picture = img.parentNode;
if (picture.nodeName.toUpperCase() === "PICTURE") {
source = dummySrc.cloneNode();
picture.insertBefore(source, picture.firstElementChild);
setTimeout(function() {
picture.removeChild(source);
});
} else if (!img._pfLastSize || img.offsetWidth > img._pfLastSize) {
img._pfLastSize = img.offsetWidth;
sizes = img.sizes;
img.sizes += ",100vw";
setTimeout(function() {
img.sizes = sizes;
});
}
};
var findPictureImgs = function() {
var i;
var imgs = document.querySelectorAll("picture > img, img[srcset][sizes]");
for (i = 0; i < imgs.length; i++) {
fixRespimg(imgs[i]);
}
};
var onResize = function() {
clearTimeout(timer);
timer = setTimeout(findPictureImgs, 99);
};
var mq = window.matchMedia && matchMedia("(orientation: landscape)");
var init = function() {
onResize();
if (mq && mq.addListener) {
mq.addListener(onResize);
}
};
dummySrc.srcset = "data:image/gif;base64,R0lGODlhAQABAAAAACH5BAEKAAEALAAAAAABAAEAAAICTAEAOw==";
if (/^[c|i]|d$/.test(document.readyState || "")) {
init();
} else {
document.addEventListener("DOMContentLoaded", init);
}
return onResize;
})());
}
})(window);
/*! Picturefill - v3.0.0-beta
* http://scottjehl.github.io/picturefill
* Copyright (c) 2015 https://github.com/scottjehl/picturefill/blob/master/Authors.txt;
* License: MIT
*/
(function( window, document, undefined ) {
// Enable strict mode
"use strict";
// HTML shim|v it for old IE (IE9 will still need the HTML video tag workaround)
document.createElement( "picture" );
var warn, eminpx, alwaysCheckWDescriptor, evalId;
// local object for method references and testing exposure
var pf = {};
var noop = function() {};
var image = document.createElement( "img" );
var getImgAttr = image.getAttribute;
var setImgAttr = image.setAttribute;
var removeImgAttr = image.removeAttribute;
var docElem = document.documentElement;
var types = {};
var cfg = {
//resource selection:
algorithm: ""
};
var srcAttr = "data-pfsrc";
var srcsetAttr = srcAttr + "set";
// ua sniffing is done for undetectable img loading features,
// to do some non crucial perf optimizations
var ua = navigator.userAgent;
var supportAbort = (/rident/).test(ua) || ((/ecko/).test(ua) && ua.match(/rv\:(\d+)/) && RegExp.$1 > 35 );
var curSrcProp = "currentSrc";
var regWDesc = /\s+\+?\d+(e\d+)?w/;
var regSize = /(\([^)]+\))?\s*(.+)/;
var setOptions = window.picturefillCFG;
/**
* Shortcut property for https://w3c.github.io/webappsec/specs/mixedcontent/#restricts-mixed-content ( for easy overriding in tests )
*/
// baseStyle also used by getEmValue (i.e.: width: 1em is important)
var baseStyle = "position:absolute;left:0;visibility:hidden;display:block;padding:0;border:none;font-size:1em;width:1em;overflow:hidden;clip:rect(0px, 0px, 0px, 0px)";
var fsCss = "font-size:100%!important;";
var isVwDirty = true;
var cssCache = {};
var sizeLengthCache = {};
var DPR = window.devicePixelRatio;
var units = {
px: 1,
"in": 96
};
var anchor = document.createElement( "a" );
/**
* alreadyRun flag used for setOptions. is it true setOptions will reevaluate
* @type {boolean}
*/
var alreadyRun = false;
// Reusable, non-"g" Regexes
// (Don't use \s, to avoid matching non-breaking space.)
var regexLeadingSpaces = /^[ \t\n\r\u000c]+/,
regexLeadingCommasOrSpaces = /^[, \t\n\r\u000c]+/,
regexLeadingNotSpaces = /^[^ \t\n\r\u000c]+/,
regexTrailingCommas = /[,]+$/,
regexNonNegativeInteger = /^\d+$/,
// ( Positive or negative or unsigned integers or decimals, without or without exponents.
// Must include at least one digit.
// According to spec tests any decimal point must be followed by a digit.
// No leading plus sign is allowed.)
// https://html.spec.whatwg.org/multipage/infrastructure.html#valid-floating-point-number
regexFloatingPoint = /^-?(?:[0-9]+|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?$/;
var on = function(obj, evt, fn, capture) {
if ( obj.addEventListener ) {
obj.addEventListener(evt, fn, capture || false);
} else if ( obj.attachEvent ) {
obj.attachEvent( "on" + evt, fn);
}
};
/**
* simple memoize function:
*/
var memoize = function(fn) {
var cache = {};
return function(input) {
if ( !(input in cache) ) {
cache[ input ] = fn(input);
}
return cache[ input ];
};
};
// UTILITY FUNCTIONS
// Manual is faster than RegEx
// http://jsperf.com/whitespace-character/5
function isSpace(c) {
return (c === "\u0020" || // space
c === "\u0009" || // horizontal tab
c === "\u000A" || // new line
c === "\u000C" || // form feed
c === "\u000D"); // carriage return
}
/**
* gets a mediaquery and returns a boolean or gets a css length and returns a number
* @param css mediaqueries or css length
* @returns {boolean|number}
*
* based on: https://gist.github.com/jonathantneal/db4f77009b155f083738
*/
var evalCSS = (function() {
var regLength = /^([\d\.]+)(em|vw|px)$/;
var replace = function() {
var args = arguments, index = 0, string = args[0];
while (++index in args) {
string = string.replace(args[index], args[++index]);
}
return string;
};
var buildStr = memoize(function(css) {
return "return " + replace((css || "").toLowerCase(),
// interpret `and`
/\band\b/g, "&&",
// interpret `,`
/,/g, "||",
// interpret `min-` as >=
/min-([a-z-\s]+):/g, "e.$1>=",
// interpret `max-` as <=
/max-([a-z-\s]+):/g, "e.$1<=",
//calc value
/calc([^)]+)/g, "($1)",
// interpret css values
/(\d+[\.]*[\d]*)([a-z]+)/g, "($1 * e.$2)",
//make eval less evil
/^(?!(e.[a-z]|[0-9\.&=|><\+\-\*\(\)\/])).*/ig, ""
) + ";";
});
return function(css, length) {
var parsedLength;
if (!(css in cssCache)) {
cssCache[css] = false;
if (length && (parsedLength = css.match( regLength ))) {
cssCache[css] = parsedLength[ 1 ] * units[parsedLength[ 2 ]];
} else {
/*jshint evil:true */
try{
cssCache[css] = new Function("e", buildStr(css))(units);
} catch(e) {}
/*jshint evil:false */
}
}
return cssCache[css];
};
})();
var setResolution = function( candidate, sizesattr ) {
if ( candidate.w ) { // h = means height: || descriptor.type === 'h' do not handle yet...
candidate.cWidth = pf.calcListLength( sizesattr || "100vw" );
candidate.res = candidate.w / candidate.cWidth ;
} else {
candidate.res = candidate.d;
}
return candidate;
};
/**
*
* @param opt
*/
var picturefill = function( opt ) {
var elements, i, plen;
var options = opt || {};
if ( options.elements && options.elements.nodeType === 1 ) {
if ( options.elements.nodeName.toUpperCase() === "IMG" ) {
options.elements = [ options.elements ];
} else {
options.context = options.elements;
options.elements = null;
}
}
elements = options.elements || pf.qsa( (options.context || document), ( options.reevaluate || options.reselect ) ? pf.sel : pf.selShort );
if ( (plen = elements.length) ) {
pf.setupRun( options );
alreadyRun = true;
// Loop through all elements
for ( i = 0; i < plen; i++ ) {
pf.fillImg(elements[ i ], options);
}
pf.teardownRun( options );
}
};
/**
* outputs a warning for the developer
* @param {message}
* @type {Function}
*/
warn = ( window.console && console.warn ) ?
function( message ) {
console.warn( message );
} :
noop
;
if ( !(curSrcProp in image) ) {
curSrcProp = "src";
}
// Add support for standard mime types.
types[ "image/jpeg" ] = true;
types[ "image/gif" ] = true;
types[ "image/png" ] = true;
function detectTypeSupport( type, typeUri ) {
// based on Modernizr's lossless img-webp test
// note: asynchronous
var image = new window.Image();
image.onerror = function() {
types[ type ] = false;
picturefill();
};
image.onload = function() {
types[ type ] = image.width === 1;
picturefill();
};
image.src = typeUri;
return "pending";
}
// test svg support
types[ "image/svg+xml" ] = document.implementation.hasFeature( "http://wwwindow.w3.org/TR/SVG11/feature#Image", "1.1" );
/**
* updates the internal vW property with the current viewport width in px
*/
function updateMetrics() {
isVwDirty = false;
DPR = window.devicePixelRatio;
cssCache = {};
sizeLengthCache = {};
pf.DPR = DPR || 1;
units.width = Math.max(window.innerWidth || 0, docElem.clientWidth);
units.height = Math.max(window.innerHeight || 0, docElem.clientHeight);
units.vw = units.width / 100;
units.vh = units.height / 100;
evalId = [ units.height, units.width, DPR ].join("-");
units.em = pf.getEmValue();
units.rem = units.em;
}
function chooseLowRes( lowerValue, higherValue, dprValue, isCached ) {
var bonusFactor, tooMuch, bonus, meanDensity;
//experimental
if (cfg.algorithm === "saveData" ){
if ( lowerValue > 2.7 ) {
meanDensity = dprValue + 1;
} else {
tooMuch = higherValue - dprValue;
bonusFactor = Math.pow(lowerValue - 0.6, 1.5);
bonus = tooMuch * bonusFactor;
if (isCached) {
bonus += 0.1 * bonusFactor;
}
meanDensity = lowerValue + bonus;
}
} else {
meanDensity = (dprValue > 1) ?
Math.sqrt(lowerValue * higherValue) :
lowerValue;
}
return meanDensity > dprValue;
}
function applyBestCandidate( img ) {
var srcSetCandidates;
var matchingSet = pf.getSet( img );
var evaluated = false;
if ( matchingSet !== "pending" ) {
evaluated = evalId;
if ( matchingSet ) {
srcSetCandidates = pf.setRes( matchingSet );
pf.applySetCandidate( srcSetCandidates, img );
}
}
img[ pf.ns ].evaled = evaluated;
}
function ascendingSort( a, b ) {
return a.res - b.res;
}
function setSrcToCur( img, src, set ) {
var candidate;
if ( !set && src ) {
set = img[ pf.ns ].sets;
set = set && set[set.length - 1];
}
candidate = getCandidateForSrc(src, set);
if ( candidate ) {
src = pf.makeUrl(src);
img[ pf.ns ].curSrc = src;
img[ pf.ns ].curCan = candidate;
if ( !candidate.res ) {
setResolution( candidate, candidate.set.sizes );
}
}
return candidate;
}
function getCandidateForSrc( src, set ) {
var i, candidate, candidates;
if ( src && set ) {
candidates = pf.parseSet( set );
src = pf.makeUrl(src);
for ( i = 0; i < candidates.length; i++ ) {
if ( src === pf.makeUrl(candidates[ i ].url) ) {
candidate = candidates[ i ];
break;
}
}
}
return candidate;
}
function getAllSourceElements( picture, candidates ) {
var i, len, source, srcset;
// SPEC mismatch intended for size and perf:
// actually only source elements preceding the img should be used
// also note: don't use qsa here, because IE8 sometimes doesn't like source as the key part in a selector
var sources = picture.getElementsByTagName( "source" );
for ( i = 0, len = sources.length; i < len; i++ ) {
source = sources[ i ];
source[ pf.ns ] = true;
srcset = source.getAttribute( "srcset" );
// if source does not have a srcset attribute, skip
if ( srcset ) {
candidates.push( {
srcset: srcset,
media: source.getAttribute( "media" ),
type: source.getAttribute( "type" ),
sizes: source.getAttribute( "sizes" )
} );
}
}
}
/**
* Srcset Parser
* By Alex Bell | MIT License
*
* @returns Array [{url: _, d: _, w: _, h:_, set:_(????)}, ...]
*
* Based super duper closely on the reference algorithm at:
* https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-srcset-attribute
*/
// 1. Let input be the value passed to this algorithm.
// (TO-DO : Explain what "set" argument is here. Maybe choose a more
// descriptive & more searchable name. Since passing the "set" in really has
// nothing to do with parsing proper, I would prefer this assignment eventually
// go in an external fn.)
function parseSrcset(input, set) {
function collectCharacters(regEx) {
var chars,
match = regEx.exec(input.substring(pos));
if (match) {
chars = match[ 0 ];
pos += chars.length;
return chars;
}
}
var inputLength = input.length,
url,
descriptors,
currentDescriptor,
state,
c,
// 2. Let position be a pointer into input, initially pointing at the start
// of the string.
pos = 0,
// 3. Let candidates be an initially empty source set.
candidates = [];
/**
* Adds descriptor properties to a candidate, pushes to the candidates array
* @return undefined
*/
// (Declared outside of the while loop so that it's only created once.
// (This fn is defined before it is used, in order to pass JSHINT.
// Unfortunately this breaks the sequencing of the spec comments. :/ )
function parseDescriptors() {
// 9. Descriptor parser: Let error be no.
var pError = false,
// 10. Let width be absent.
// 11. Let density be absent.
// 12. Let future-compat-h be absent. (We're implementing it now as h)
w, d, h, i,
candidate = {},
desc, lastChar, value, intVal, floatVal;
// 13. For each descriptor in descriptors, run the appropriate set of steps
// from the following list:
for (i = 0 ; i < descriptors.length; i++) {
desc = descriptors[ i ];
lastChar = desc[ desc.length - 1 ];
value = desc.substring(0, desc.length - 1);
intVal = parseInt(value, 10);
floatVal = parseFloat(value);
// If the descriptor consists of a valid non-negative integer followed by
// a U+0077 LATIN SMALL LETTER W character
if (regexNonNegativeInteger.test(value) && (lastChar === "w")) {
// If width and density are not both absent, then let error be yes.
if (w || d) {pError = true;}
// Apply the rules for parsing non-negative integers to the descriptor.
// If the result is zero, let error be yes.
// Otherwise, let width be the result.
if (intVal === 0) {pError = true;} else {w = intVal;}
// If the descriptor consists of a valid floating-point number followed by
// a U+0078 LATIN SMALL LETTER X character
} else if (regexFloatingPoint.test(value) && (lastChar === "x")) {
// If width, density and future-compat-h are not all absent, then let error
// be yes.
if (w || d || h) {pError = true;}
// Apply the rules for parsing floating-point number values to the descriptor.
// If the result is less than zero, let error be yes. Otherwise, let density
// be the result.
if (floatVal < 0) {pError = true;} else {d = floatVal;}
// If the descriptor consists of a valid non-negative integer followed by
// a U+0068 LATIN SMALL LETTER H character
} else if (regexNonNegativeInteger.test(value) && (lastChar === "h")) {
// If height and density are not both absent, then let error be yes.
if (h || d) {pError = true;}
// Apply the rules for parsing non-negative integers to the descriptor.
// If the result is zero, let error be yes. Otherwise, let future-compat-h
// be the result.
if (intVal === 0) {pError = true;} else {h = intVal;}
// Anything else, Let error be yes.
} else {pError = true;}
} // (close step 13 for loop)
// 15. If error is still no, then append a new image source to candidates whose
// URL is url, associated with a width width if not absent and a pixel
// density density if not absent. Otherwise, there is a parse error.
if (!pError) {
candidate.url = url;
if (w) { candidate.w = w;}
if (d) { candidate.d = d;}
if (h) { candidate.h = h;}
if (!h && !d && !w) {candidate.d = 1;}
if (candidate.d === 1) {set.has1x = true;}
candidate.set = set;
candidates.push(candidate);
}
} // (close parseDescriptors fn)
/**
* Tokenizes descriptor properties prior to parsing
* Returns undefined.
* (Again, this fn is defined before it is used, in order to pass JSHINT.
* Unfortunately this breaks the logical sequencing of the spec comments. :/ )
*/
function tokenize() {
// 8.1. Descriptor tokeniser: Skip whitespace
collectCharacters(regexLeadingSpaces);
// 8.2. Let current descriptor be the empty string.
currentDescriptor = "";
// 8.3. Let state be in descriptor.
state = "in descriptor";
while (true) {
// 8.4. Let c be the character at position.
c = input.charAt(pos);
// Do the following depending on the value of state.
// For the purpose of this step, "EOF" is a special character representing
// that position is past the end of input.
// In descriptor
if (state === "in descriptor") {
// Do the following, depending on the value of c:
// Space character
// If current descriptor is not empty, append current descriptor to
// descriptors and let current descriptor be the empty string.
// Set state to after descriptor.
if (isSpace(c)) {
if (currentDescriptor) {
descriptors.push(currentDescriptor);
currentDescriptor = "";
state = "after descriptor";
}
// U+002C COMMA (,)
// Advance position to the next character in input. If current descriptor
// is not empty, append current descriptor to descriptors. Jump to the step
// labeled descriptor parser.
} else if (c === ",") {
pos += 1;
if (currentDescriptor) {
descriptors.push(currentDescriptor);
}
parseDescriptors();
return;
// U+0028 LEFT PARENTHESIS (()
// Append c to current descriptor. Set state to in parens.
} else if (c === "\u0028") {
currentDescriptor = currentDescriptor + c;
state = "in parens";
// EOF
// If current descriptor is not empty, append current descriptor to
// descriptors. Jump to the step labeled descriptor parser.
} else if (c === "") {
if (currentDescriptor) {
descriptors.push(currentDescriptor);
}
parseDescriptors();
return;
// Anything else
// Append c to current descriptor.
} else {
currentDescriptor = currentDescriptor + c;
}
// (end "in descriptor"
// In parens
} else if (state === "in parens") {
// U+0029 RIGHT PARENTHESIS ())
// Append c to current descriptor. Set state to in descriptor.
if (c === ")") {
currentDescriptor = currentDescriptor + c;
state = "in descriptor";
// EOF
// Append current descriptor to descriptors. Jump to the step labeled
// descriptor parser.
} else if (c === "") {
descriptors.push(currentDescriptor);
parseDescriptors();
return;
// Anything else
// Append c to current descriptor.
} else {
currentDescriptor = currentDescriptor + c;
}
// After descriptor
} else if (state === "after descriptor") {
// Do the following, depending on the value of c:
// Space character: Stay in this state.
if (isSpace(c)) {
// EOF: Jump to the step labeled descriptor parser.
} else if (c === "") {
parseDescriptors();
return;
// Anything else
// Set state to in descriptor. Set position to the previous character in input.
} else {
state = "in descriptor";
pos -= 1;
}
}
// Advance position to the next character in input.
pos += 1;
// Repeat this step.
} // (close while true loop)
}
// 4. Splitting loop: Collect a sequence of characters that are space
// characters or U+002C COMMA characters. If any U+002C COMMA characters
// were collected, that is a parse error.
while (true) {
collectCharacters(regexLeadingCommasOrSpaces);
// 5. If position is past the end of input, return candidates and abort these steps.
if (pos >= inputLength) {
return candidates; // (we're done, this is the sole return path)
}
// 6. Collect a sequence of characters that are not space characters,
// and let that be url.
url = collectCharacters(regexLeadingNotSpaces);
// 7. Let descriptors be a new empty list.
descriptors = [];
// 8. If url ends with a U+002C COMMA character (,), follow these substeps:
// (1). Remove all trailing U+002C COMMA characters from url. If this removed
// more than one character, that is a parse error.
if (url.slice(-1) === ",") {
url = url.replace(regexTrailingCommas, "");
// (Jump ahead to step 9 to skip tokenization and just push the candidate).
parseDescriptors();
// Otherwise, follow these substeps:
} else {
tokenize();
} // (close else of step 8)
// 16. Return to the step labeled splitting loop.
} // (Close of big while loop.)
}
/*
* Sizes Parser
*
* By Alex Bell | MIT License
*
* Non-strict but accurate and lightweight JS Parser for the string value <img sizes="here">
*
* Reference algorithm at:
* https://html.spec.whatwg.org/multipage/embedded-content.html#parse-a-sizes-attribute
*
* Most comments are copied in directly from the spec
* (except for comments in parens).
*
* Grammar is:
* <source-size-list> = <source-size># [ , <source-size-value> ]? | <source-size-value>
* <source-size> = <media-condition> <source-size-value>
* <source-size-value> = <length>
* http://www.w3.org/html/wg/drafts/html/master/embedded-content.html#attr-img-sizes
*
* E.g. "(max-width: 30em) 100vw, (max-width: 50em) 70vw, 100vw"
* or "(min-width: 30em), calc(30vw - 15px)" or just "30vw"
*
* Returns the first valid <css-length> with a media condition that evaluates to true,
* or "100vw" if all valid media conditions evaluate to false.
*
*/
function parseSizes(strValue) {
// (Percentage CSS lengths are not allowed in this case, to avoid confusion:
// https://html.spec.whatwg.org/multipage/embedded-content.html#valid-source-size-list
// CSS allows a single optional plus or minus sign:
// http://www.w3.org/TR/CSS2/syndata.html#numbers
// CSS is ASCII case-insensitive:
// http://www.w3.org/TR/CSS2/syndata.html#characters )
// Spec allows exponential notation for <number> type:
// http://dev.w3.org/csswg/css-values/#numbers
var regexCssLengthWithUnits = /^(?:[+-]?[0-9]+|[0-9]*\.[0-9]+)(?:[eE][+-]?[0-9]+)?(?:ch|cm|em|ex|in|mm|pc|pt|px|rem|vh|vmin|vmax|vw)$/i;
// (This is a quick and lenient test. Because of optional unlimited-depth internal
// grouping parens and strict spacing rules, this could get very complicated.)
var regexCssCalc = /^calc\((?:[0-9a-z \.\+\-\*\/\(\)]+)\)$/i;
var i;
var unparsedSizesList;
var unparsedSizesListLength;
var unparsedSize;
var lastComponentValue;
var size;
// UTILITY FUNCTIONS
// (Toy CSS parser. The goals here are:
// 1) expansive test coverage without the weight of a full CSS parser.
// 2) Avoiding regex wherever convenient.
// Quick tests: http://jsfiddle.net/gtntL4gr/3/
// Returns an array of arrays.)
function parseComponentValues(str) {
var chrctr;
var component = "";
var componentArray = [];
var listArray = [];
var parenDepth = 0;
var pos = 0;
var inComment = false;
function pushComponent() {
if (component) {
componentArray.push(component);
component = "";
}
}
function pushComponentArray() {
if (componentArray[0]) {
listArray.push(componentArray);
componentArray = [];
}
}
// (Loop forwards from the beginning of the string.)
while (true) {
chrctr = str.charAt(pos);
if (chrctr === "") { // ( End of string reached.)
pushComponent();
pushComponentArray();
return listArray;
} else if (inComment) {
if ((chrctr === "*") && (str[pos + 1] === "/")) { // (At end of a comment.)
inComment = false;
pos += 2;
pushComponent();
continue;
} else {
pos += 1; // (Skip all characters inside comments.)
continue;
}
} else if (isSpace(chrctr)) {
// (If previous character in loop was also a space, or if
// at the beginning of the string, do not add space char to
// component.)
if ( (str.charAt(pos - 1) && isSpace( str.charAt(pos - 1) ) ) || !component ) {
pos += 1;
continue;
} else if (parenDepth === 0) {
pushComponent();
pos +=1;
continue;
} else {
// (Replace any space character with a plain space for legibility.)
chrctr = " ";
}
} else if (chrctr === "(") {
parenDepth += 1;
} else if (chrctr === ")") {
parenDepth -= 1;
} else if (chrctr === ",") {
pushComponent();
pushComponentArray();
pos += 1;
continue;
} else if ( (chrctr === "/") && (str.charAt(pos + 1) === "*") ) {
inComment = true;
pos += 2;
continue;
}
component = component + chrctr;
pos += 1;
}
}
function isValidNonNegativeSourceSizeValue(s) {
if (regexCssLengthWithUnits.test(s) && (parseFloat(s) >= 0)) {return true;}
if (regexCssCalc.test(s)) {return true;}
// ( http://www.w3.org/TR/CSS2/syndata.html#numbers says:
// "-0 is equivalent to 0 and is not a negative number." which means that
// unitless zero and unitless negative zero must be accepted as special cases.)
if ((s === "0") || (s === "-0") || (s === "+0")) {return true;}
return false;
}
// When asked to parse a sizes attribute from an element, parse a
// comma-separated list of component values from the value of the element's
// sizes attribute (or the empty string, if the attribute is absent), and let
// unparsed sizes list be the result.
// http://dev.w3.org/csswg/css-syntax/#parse-comma-separated-list-of-component-values
unparsedSizesList = parseComponentValues(strValue);
unparsedSizesListLength = unparsedSizesList.length;
// For each unparsed size in unparsed sizes list:
for (i = 0; i < unparsedSizesListLength; i++) {
unparsedSize = unparsedSizesList[i];
// 1. Remove all consecutive <whitespace-token>s from the end of unparsed size.
// ( parseComponentValues() already omits spaces outside of parens. )
// If unparsed size is now empty, that is a parse error; continue to the next
// iteration of this algorithm.
// ( parseComponentValues() won't push an empty array. )
// 2. If the last component value in unparsed size is a valid non-negative
// <source-size-value>, let size be its value and remove the component value
// from unparsed size. Any CSS function other than the calc() function is
// invalid. Otherwise, there is a parse error; continue to the next iteration
// of this algorithm.
// http://dev.w3.org/csswg/css-syntax/#parse-component-value
lastComponentValue = unparsedSize[unparsedSize.length - 1];
if (isValidNonNegativeSourceSizeValue(lastComponentValue)) {
size = lastComponentValue;
unparsedSize.pop();
} else {
continue;
}
// 3. Remove all consecutive <whitespace-token>s from the end of unparsed
// size. If unparsed size is now empty, return size and exit this algorithm.
// If this was not the last item in unparsed sizes list, that is a parse error.
if (unparsedSize.length === 0) {
return size;
}
// 4. Parse the remaining component values in unparsed size as a
// <media-condition>. If it does not parse correctly, or it does parse
// correctly but the <media-condition> evaluates to false, continue to the
// next iteration of this algorithm.
// (Parsing all possible compound media conditions in JS is heavy, complicated,
// and the payoff is unclear. Is there ever an situation where the
// media condition parses incorrectly but still somehow evaluates to true?
// Can we just rely on the browser/polyfill to do it?)
unparsedSize = unparsedSize.join(" ");
if (!(pf.matchesMedia( unparsedSize ) ) ) {
continue;
}
// 5. Return size and exit this algorithm.
return size;
}
// If the above algorithm exhausts unparsed sizes list without returning a
// size value, return 100vw.
return "100vw";
}
// namespace
pf.ns = ("pf" + new Date().getTime()).substr(0, 9);
// srcset support test
pf.supSrcset = "srcset" in image;
pf.supSizes = "sizes" in image;
pf.supPicture = !!window.HTMLPictureElement;
if (pf.supSrcset && pf.supPicture && !pf.supSizes) {
(function(image2) {
image.srcset = "data:,a";
image2.src = "data:,a";
pf.supSrcset = image.complete === image2.complete;
pf.supPicture = pf.supSrcset && pf.supPicture;
})(document.createElement("img"));
}
// using pf.qsa instead of dom traversing does scale much better,
// especially on sites mixing responsive and non-responsive images
pf.selShort = "picture>img,img[srcset]";
pf.sel = pf.selShort;
pf.cfg = cfg;
if ( pf.supSrcset ) {
pf.sel += ",img[" + srcsetAttr + "]";
}
/**
* Shortcut property for `devicePixelRatio` ( for easy overriding in tests )
*/
pf.DPR = (DPR || 1 );
pf.u = units;
// container of supported mime types that one might need to qualify before using
pf.types = types;
alwaysCheckWDescriptor = pf.supSrcset && !pf.supSizes;
pf.setSize = noop;
/**
* Gets a string and returns the absolute URL
* @param src
* @returns {String} absolute URL
*/
pf.makeUrl = memoize(function(src) {
anchor.href = src;
return anchor.href;
});
/**
* Gets a DOM element or document and a selctor and returns the found matches
* Can be extended with jQuery/Sizzle for IE7 support
* @param context
* @param sel
* @returns {NodeList}
*/
pf.qsa = function(context, sel) {
return context.querySelectorAll(sel);
};
/**
* Shortcut method for matchMedia ( for easy overriding in tests )
* wether native or pf.mMQ is used will be decided lazy on first call
* @returns {boolean}
*/
pf.matchesMedia = function() {
if ( window.matchMedia && (matchMedia( "(min-width: 0.1em)" ) || {}).matches ) {
pf.matchesMedia = function( media ) {
return !media || ( matchMedia( media ).matches );
};
} else {
pf.matchesMedia = pf.mMQ;
}
return pf.matchesMedia.apply( this, arguments );
};
/**
* A simplified matchMedia implementation for IE8 and IE9
* handles only min-width/max-width with px or em values
* @param media
* @returns {boolean}
*/
pf.mMQ = function( media ) {
return media ? evalCSS(media) : true;
};
/**
* Returns the calculated length in css pixel from the given sourceSizeValue
* http://dev.w3.org/csswg/css-values-3/#length-value
* intended Spec mismatches:
* * Does not check for invalid use of CSS functions
* * Does handle a computed length of 0 the same as a negative and therefore invalid value
* @param sourceSizeValue
* @returns {Number}
*/
pf.calcLength = function( sourceSizeValue ) {
var value = evalCSS(sourceSizeValue, true) || false;
if (value < 0) {
value = false;
}
return value;
};
/**
* Takes a type string and checks if its supported
*/
pf.supportsType = function( type ) {
return ( type ) ? types[ type ] : true;
};
/**
* Parses a sourceSize into mediaCondition (media) and sourceSizeValue (length)
* @param sourceSizeStr
* @returns {*}
*/
pf.parseSize = memoize(function( sourceSizeStr ) {
var match = ( sourceSizeStr || "" ).match(regSize);
return {
media: match && match[1],
length: match && match[2]
};
});
pf.parseSet = function( set ) {
if ( !set.cands ) {
set.cands = parseSrcset(set.srcset, set);
}
return set.cands;
};
/**
* returns 1em in css px for html/body default size
* function taken from respondjs
* @returns {*|number}
*/
pf.getEmValue = function() {
var body;
if ( !eminpx && (body = document.body) ) {
var div = document.createElement( "div" ),
originalHTMLCSS = docElem.style.cssText,
originalBodyCSS = body.style.cssText;
div.style.cssText = baseStyle;
// 1em in a media query is the value of the default font size of the browser
// reset docElem and body to ensure the correct value is returned
docElem.style.cssText = fsCss;
body.style.cssText = fsCss;
body.appendChild( div );
eminpx = div.offsetWidth;
body.removeChild( div );
//also update eminpx before returning
eminpx = parseFloat( eminpx, 10 );
// restore the original values
docElem.style.cssText = originalHTMLCSS;
body.style.cssText = originalBodyCSS;
}
return eminpx || 16;
};
/**
* Takes a string of sizes and returns the width in pixels as a number
*/
pf.calcListLength = function( sourceSizeListStr ) {
// Split up source size list, ie ( max-width: 30em ) 100%, ( max-width: 50em ) 50%, 33%
//
// or (min-width:30em) calc(30% - 15px)
if ( !(sourceSizeListStr in sizeLengthCache) || cfg.uT ) {
var winningLength = pf.calcLength( parseSizes( sourceSizeListStr ) );
sizeLengthCache[ sourceSizeListStr ] = !winningLength ? units.width : winningLength;
}
return sizeLengthCache[ sourceSizeListStr ];
};
/**
* Takes a candidate object with a srcset property 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, res is calculated
*/
pf.setRes = function( set ) {
var candidates;
if ( set ) {
candidates = pf.parseSet( set );
for ( var i = 0, len = candidates.length; i < len; i++ ) {
setResolution( candidates[ i ], set.sizes );
}
}
return candidates;
};
pf.setRes.res = setResolution;
pf.applySetCandidate = function( candidates, img ) {
if ( !candidates.length ) {return;}
var candidate,
i,
j,
length,
bestCandidate,
curSrc,
curCan,
isSameSet,
candidateSrc,
abortCurSrc;
var imageData = img[ pf.ns ];
var dpr = pf.DPR;
curSrc = imageData.curSrc || img[curSrcProp];
curCan = imageData.curCan || setSrcToCur(img, curSrc, candidates[0].set);
// if we have a current source, we might either become lazy or give this source some advantage
if ( curCan && curCan.set === candidates[ 0 ].set ) {
// if browser can abort image request and the image has a higher pixel density than needed
// and this image isn't downloaded yet, we skip next part and try to save bandwidth
abortCurSrc = (supportAbort && !img.complete && curCan.res - 0.1 > dpr);
if ( !abortCurSrc ) {
curCan.cached = true;
// if current candidate is "best", "better" or "okay",
// set it to bestCandidate
if ( curCan && isSameSet && curCan.res >= dpr ) {
bestCandidate = curCan;
}
}
}
if ( !bestCandidate ) {
candidates.sort( ascendingSort );
length = candidates.length;
bestCandidate = candidates[ length - 1 ];
for ( i = 0; i < length; i++ ) {
candidate = candidates[ i ];
if ( candidate.res >= dpr ) {
j = i - 1;
// we have found the perfect candidate,
// but let's improve this a little bit with some assumptions ;-)
if (candidates[ j ] &&
(abortCurSrc || curSrc !== pf.makeUrl( candidate.url )) &&
chooseLowRes(candidates[ j ].res, candidate.res, dpr, candidates[ j ].cached)) {
bestCandidate = candidates[ j ];
} else {
bestCandidate = candidate;
}
break;
}
}
}
if ( bestCandidate ) {
candidateSrc = pf.makeUrl( bestCandidate.url );
imageData.curSrc = candidateSrc;
imageData.curCan = bestCandidate;
if ( candidateSrc !== curSrc ) {
pf.setSrc( img, bestCandidate );
}
pf.setSize( img );
}
};
pf.setSrc = function( img, bestCandidate ) {
var origWidth;
img.src = bestCandidate.url;
// although this is a specific Safari issue, we don't want to take too much different code paths
if ( bestCandidate.set.type === "image/svg+xml" ) {
origWidth = img.style.width;
img.style.width = (img.offsetWidth + 1) + "px";
// next line only should trigger a repaint
// if... is only done to trick dead code removal
if ( img.offsetWidth + 1 ) {
img.style.width = origWidth;
}
}
};
pf.getSet = function( img ) {
var i, set, supportsType;
var match = false;
var sets = img [ pf.ns ].sets;
for ( i = 0; i < sets.length && !match; i++ ) {
set = sets[i];
if ( !set.srcset || !pf.matchesMedia( set.media ) || !(supportsType = pf.supportsType( set.type )) ) {
continue;
}
if ( supportsType === "pending" ) {
set = supportsType;
}
match = set;
break;
}
return match;
};
pf.parseSets = function( element, parent, options ) {
var srcsetAttribute, imageSet, isWDescripor, srcsetParsed;
var hasPicture = parent && parent.nodeName.toUpperCase() === "PICTURE";
var imageData = element[ pf.ns ];
if ( imageData.src === undefined || options.src ) {
imageData.src = getImgAttr.call( element, "src" );
if ( imageData.src ) {
setImgAttr.call( element, srcAttr, imageData.src );
} else {
removeImgAttr.call( element, srcAttr );
}
}
if ( imageData.srcset === undefined || options.srcset || !pf.supSrcset || element.srcset ) {
srcsetAttribute = getImgAttr.call( element, "srcset" );
imageData.srcset = srcsetAttribute;
srcsetParsed = true;
}
imageData.sets = [];
if ( hasPicture ) {
imageData.pic = true;
getAllSourceElements( parent, imageData.sets );
}
if ( imageData.srcset ) {
imageSet = {
srcset: imageData.srcset,
sizes: getImgAttr.call( element, "sizes" )
};
imageData.sets.push( imageSet );
isWDescripor = (alwaysCheckWDescriptor || imageData.src) && regWDesc.test(imageData.srcset || "");
// add normal src as candidate, if source has no w descriptor
if ( !isWDescripor && imageData.src && !getCandidateForSrc(imageData.src, imageSet) && !imageSet.has1x ) {
imageSet.srcset += ", " + imageData.src;
imageSet.cands.push({
url: imageData.src,
d: 1,
set: imageSet
});
}
} else if ( imageData.src ) {
imageData.sets.push( {
srcset: imageData.src,
sizes: null
} );
}
imageData.curCan = null;
imageData.curSrc = undefined;
// if img has picture or the srcset was removed or has a srcset and does not support srcset at all
// or has a w descriptor (and does not support sizes) set support to false to evaluate
imageData.supported = !( hasPicture || ( imageSet && !pf.supSrcset ) || isWDescripor );
if ( srcsetParsed && pf.supSrcset && !imageData.supported ) {
if ( srcsetAttribute ) {
setImgAttr.call( element, srcsetAttr, srcsetAttribute );
element.srcset = "";
} else {
removeImgAttr.call( element, srcsetAttr );
}
}
if (imageData.supported && !imageData.srcset && ((!imageData.src && element.src) || element.src !== pf.makeUrl(imageData.src))) {
if (imageData.src === null) {
element.removeAttribute("src");
} else {
element.src = imageData.src;
}
}
imageData.parsed = true;
};
pf.fillImg = function(element, options) {
var imageData;
var extreme = options.reselect || options.reevaluate;
// expando for caching data on the img
if ( !element[ pf.ns ] ) {
element[ pf.ns ] = {};
}
imageData = element[ pf.ns ];
// if the element has already been evaluated, skip it
// unless `options.reevaluate` is set to true ( this, for example,
// is set to true when running `picturefill` on `resize` ).
if ( !extreme && imageData.evaled === evalId ) {
return;
}
if ( !imageData.parsed || options.reevaluate ) {
pf.parseSets( element, element.parentNode, options );
}
if ( !imageData.supported ) {
applyBestCandidate( element );
} else {
imageData.evaled = evalId;
}
};
pf.setupRun = function() {
if ( !alreadyRun || isVwDirty || (DPR !== window.devicePixelRatio) ) {
updateMetrics();
}
};
// If picture is supported, well, that's awesome.
if ( pf.supPicture ) {
picturefill = noop;
pf.fillImg = noop;
} else {
// Set up picture polyfill by polling the document
(function() {
var isDomReady;
var regReady = window.attachEvent ? /d$|^c/ : /d$|^c|^i/;
var run = function() {
var readyState = document.readyState || "";
timerId = setTimeout(run, readyState === "loading" ? 200 : 999);
if ( document.body ) {
pf.fillImgs();
isDomReady = isDomReady || regReady.test(readyState);
if ( isDomReady ) {
clearTimeout( timerId );
}
}
};
var timerId = setTimeout(run, document.body ? 9 : 99);
// Also attach picturefill on resize and readystatechange
// http://modernjavascript.blogspot.com/2013/08/building-better-debounce.html
var debounce = function(func, wait) {
var timeout, timestamp;
var later = function() {
var last = (new Date()) - timestamp;
if (last < wait) {
timeout = setTimeout(later, wait - last);
} else {
timeout = null;
func();
}
};
return function() {
timestamp = new Date();
if (!timeout) {
timeout = setTimeout(later, wait);
}
};
};
var lastClientWidth = docElem.clientHeight;
var onResize = function() {
isVwDirty = Math.max(window.innerWidth || 0, docElem.clientWidth) !== units.width || docElem.clientHeight !== lastClientWidth;
lastClientWidth = docElem.clientHeight;
if ( isVwDirty ) {
pf.fillImgs();
}
};
on( window, "resize", debounce(onResize, 99 ) );
on( document, "readystatechange", run );
})();
}
pf.picturefill = picturefill;
//use this internally for easy monkey patching/performance testing
pf.fillImgs = picturefill;
pf.teardownRun = noop;
/* expose methods for testing */
picturefill._ = pf;
window.picturefillCFG = {
pf: pf,
push: function(args) {
var name = args.shift();
if (typeof pf[name] === "function") {
pf[name].apply(pf, args);
} else {
cfg[name] = args[0];
if (alreadyRun) {
pf.fillImgs( { reselect: true } );
}
}
}
};
while (setOptions && setOptions.length) {
window.picturefillCFG.push(setOptions.shift());
}
/* expose picturefill */
window.picturefill = picturefill;
/* 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( "picturefill", function() { return picturefill; } );
}
// IE8 evals this sync, so it must be the last thing we do
if ( !pf.supPicture ) {
types[ "image/webp" ] = detectTypeSupport("image/webp", "data:image/webp;base64,UklGRkoAAABXRUJQVlA4WAoAAAAQAAAAAAAAAAAAQUxQSAwAAAABBxAR/Q9ERP8DAABWUDggGAAAADABAJ0BKgEAAQADADQlpAADcAD++/1QAA==" );
}
} )( window, document );