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respimage.js
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respimage.js
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/*! respimage - v1.4.2 - 2015-08-22
Licensed MIT */
!function(window, document, undefined) {
"use strict";
function trim(str) {
return str.trim ? str.trim() : str.replace(/^\s+|\s+$/g, "");
}
function updateMetrics() {
var dprM;
isVwDirty = !1, DPR = window.devicePixelRatio, cssCache = {}, sizeLengthCache = {},
dprM = (DPR || 1) * cfg.xQuant, cfg.uT || (cfg.maxX = Math.max(1.3, cfg.maxX), dprM = Math.min(dprM, cfg.maxX),
ri.DPR = dprM), 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, units.em = ri.getEmValue(), units.rem = units.em,
lazyFactor = cfg.lazyFactor / 2, lazyFactor = lazyFactor * dprM + lazyFactor, substractCurRes = .4 + .1 * dprM,
lowTreshHold = .5 + .2 * dprM, partialLowTreshHold = .5 + .25 * dprM, tMemory = dprM + 1.3,
(isLandscape = units.width > units.height) || (lazyFactor *= .9), supportAbort && (lazyFactor *= .9),
evalID = [ units.width, units.height, dprM ].join("-");
}
function chooseLowRes(lowRes, diff, dpr) {
var add = diff * Math.pow(lowRes - .4, 1.9);
return isLandscape || (add /= 1.3), lowRes += add, lowRes > dpr;
}
function applyBestCandidate(img) {
var srcSetCandidates, matchingSet = ri.getSet(img), evaluated = !1;
"pending" != matchingSet && (evaluated = evalID, matchingSet && (srcSetCandidates = ri.setRes(matchingSet),
evaluated = ri.applySetCandidate(srcSetCandidates, img))), img[ri.ns].evaled = evaluated;
}
function ascendingSort(a, b) {
return a.res - b.res;
}
function setSrcToCur(img, src, set) {
var candidate;
return !set && src && (set = img[ri.ns].sets, set = set && set[set.length - 1]),
candidate = getCandidateForSrc(src, set), candidate && (src = ri.makeUrl(src), img[ri.ns].curSrc = src,
img[ri.ns].curCan = candidate, candidate.res || setResolution(candidate, candidate.set.sizes)),
candidate;
}
function getCandidateForSrc(src, set) {
var i, candidate, candidates;
if (src && set) for (candidates = ri.parseSet(set), src = ri.makeUrl(src), i = 0; i < candidates.length; i++) if (src == ri.makeUrl(candidates[i].url)) {
candidate = candidates[i];
break;
}
return candidate;
}
function getAllSourceElements(picture, candidates) {
var i, len, source, srcset, sources = picture.getElementsByTagName("source");
for (i = 0, len = sources.length; len > i; i++) source = sources[i], source[ri.ns] = !0,
srcset = source.getAttribute("srcset"), srcset && candidates.push({
srcset: srcset,
media: source.getAttribute("media"),
type: source.getAttribute("type"),
sizes: source.getAttribute("sizes")
});
}
var lowTreshHold, partialLowTreshHold, isLandscape, lazyFactor, tMemory, substractCurRes, eminpx, alwaysCheckWDescriptor, resizeThrottle, evalID, ri = {}, noop = function() {}, image = document.createElement("img"), getImgAttr = image.getAttribute, setImgAttr = image.setAttribute, removeImgAttr = image.removeAttribute, docElem = document.documentElement, types = {}, cfg = {
xQuant: 1,
lazyFactor: .4,
maxX: 2
}, srcAttr = "data-pfsrc", srcsetAttr = srcAttr + "set", reflowBug = "webkitBackfaceVisibility" in docElem.style, ua = navigator.userAgent, supportAbort = /rident/.test(ua) || /ecko/.test(ua) && ua.match(/rv\:(\d+)/) && RegExp.$1 > 35, curSrcProp = "currentSrc", regWDesc = /\s+\+?\d+(e\d+)?w/, regSize = /((?:\([^)]+\)(?:\s*and\s*|\s*or\s*|\s*not\s*)?)+)?\s*(.+)/, regDescriptor = /^([\+eE\d\.]+)(w|x)$/, regHDesc = /\s*\d+h\s*/, setOptions = window.respimgCFG, baseStyle = ("https:" == location.protocol,
"position:absolute;left:0;visibility:hidden;display:block;padding:0;border:none;font-size:1em;width:1em;overflow:hidden;clip:rect(0px, 0px, 0px, 0px)"), fsCss = "font-size:100%!important;", isVwDirty = !0, cssCache = {}, sizeLengthCache = {}, DPR = window.devicePixelRatio, units = {
px: 1,
"in": 96
}, anchor = document.createElement("a"), alreadyRun = !1, on = function(obj, evt, fn, capture) {
obj.addEventListener ? obj.addEventListener(evt, fn, capture || !1) : obj.attachEvent && obj.attachEvent("on" + evt, fn);
}, memoize = function(fn) {
var cache = {};
return function(input) {
return input in cache || (cache[input] = fn(input)), cache[input];
};
}, evalCSS = function() {
var regLength = /^([\d\.]+)(em|vw|px)$/, replace = function() {
for (var args = arguments, index = 0, string = args[0]; ++index in args; ) string = string.replace(args[index], args[++index]);
return string;
}, buidlStr = memoize(function(css) {
return "return " + replace((css || "").toLowerCase(), /\band\b/g, "&&", /,/g, "||", /min-([a-z-\s]+):/g, "e.$1>=", /max-([a-z-\s]+):/g, "e.$1<=", /calc([^)]+)/g, "($1)", /(\d+[\.]*[\d]*)([a-z]+)/g, "($1 * e.$2)", /^(?!(e.[a-z]|[0-9\.&=|><\+\-\*\(\)\/])).*/gi, "");
});
return function(css, length) {
var parsedLength;
if (!(css in cssCache)) if (cssCache[css] = !1, length && (parsedLength = css.match(regLength))) cssCache[css] = parsedLength[1] * units[parsedLength[2]]; else try {
cssCache[css] = new Function("e", buidlStr(css))(units);
} catch (e) {}
return cssCache[css];
};
}(), setResolution = function(candidate, sizesattr) {
return candidate.w ? (candidate.cWidth = ri.calcListLength(sizesattr || "100vw"),
candidate.res = candidate.w / candidate.cWidth) : candidate.res = candidate.x, candidate;
}, respimage = function(opt) {
var elements, i, plen, options = opt || {};
if (options.elements && 1 == options.elements.nodeType && ("IMG" == options.elements.nodeName.toUpperCase() ? options.elements = [ options.elements ] : (options.context = options.elements,
options.elements = null)), options.reparse && (options.reevaluate = !0, window.console && console.warn && console.warn("reparse was renamed to reevaluate!")),
elements = options.elements || ri.qsa(options.context || document, options.reevaluate || options.reselect ? ri.sel : ri.selShort),
plen = elements.length) {
for (ri.setupRun(options), alreadyRun = !0, i = 0; plen > i; i++) ri.fillImg(elements[i], options);
ri.teardownRun(options);
}
}, parseDescriptor = memoize(function(descriptor) {
var descriptorObj = [ 1, "x" ], parsedDescriptor = trim(descriptor || "");
return parsedDescriptor && (parsedDescriptor = parsedDescriptor.replace(regHDesc, ""),
descriptorObj = parsedDescriptor.match(regDescriptor) ? [ 1 * RegExp.$1, RegExp.$2 ] : !1),
descriptorObj;
});
if (curSrcProp in image || (curSrcProp = "src"), types["image/jpeg"] = !0, types["image/gif"] = !0,
types["image/png"] = !0, types["image/svg+xml"] = document.implementation.hasFeature("http://wwwindow.w3.org/TR/SVG11/feature#Image", "1.1"),
ri.ns = ("ri" + new Date().getTime()).substr(0, 9), ri.supSrcset = "srcset" in image,
ri.supSizes = "sizes" in image, ri.supPicture = !!window.HTMLPictureElement, ri.supSrcset && ri.supPicture && !ri.supSizes && !function(image2) {
image.srcset = "data:,a", image2.src = "data:,a", ri.supSrcset = image.complete === image2.complete,
ri.supPicture = ri.supSrcset && ri.supPicture;
}(document.createElement("img")), ri.selShort = "picture>img,img[srcset]", ri.sel = ri.selShort,
ri.cfg = cfg, ri.supSrcset && (ri.sel += ",img[" + srcsetAttr + "]"), ri.DPR = DPR || 1,
ri.u = units, ri.types = types, alwaysCheckWDescriptor = ri.supSrcset && !ri.supSizes,
ri.setSize = noop, ri.makeUrl = memoize(function(src) {
return anchor.href = src, anchor.href;
}), ri.qsa = function(context, sel) {
return context.querySelectorAll(sel);
}, ri.matchesMedia = function() {
return ri.matchesMedia = window.matchMedia && (matchMedia("(min-width: 0.1em)") || {}).matches ? function(media) {
return !media || matchMedia(media).matches;
} : ri.mMQ, ri.matchesMedia.apply(this, arguments);
}, ri.mMQ = function(media) {
return media ? evalCSS(media) : !0;
}, ri.calcLength = function(sourceSizeValue) {
var value = evalCSS(sourceSizeValue, !0) || !1;
return 0 > value && (value = !1), value;
}, ri.supportsType = function(type) {
return type ? types[type] : !0;
}, ri.parseSize = memoize(function(sourceSizeStr) {
var match = (sourceSizeStr || "").match(regSize);
return {
media: match && match[1],
length: match && match[2]
};
}), ri.parseSet = function(set) {
if (!set.cands) {
var pos, url, descriptor, last, descpos, can, srcset = set.srcset;
for (set.cands = []; srcset; ) srcset = srcset.replace(/^\s+/g, ""), pos = srcset.search(/\s/g),
descriptor = null, -1 != pos ? (url = srcset.slice(0, pos), last = url.charAt(url.length - 1),
"," != last && url || (url = url.replace(/,+$/, ""), descriptor = ""), srcset = srcset.slice(pos + 1),
null == descriptor && (descpos = srcset.indexOf(","), -1 != descpos ? (descriptor = srcset.slice(0, descpos),
srcset = srcset.slice(descpos + 1)) : (descriptor = srcset, srcset = ""))) : (url = srcset,
srcset = ""), url && (descriptor = parseDescriptor(descriptor)) && (can = {
url: url.replace(/^,+/, ""),
set: set
}, can[descriptor[1]] = descriptor[0], "x" == descriptor[1] && 1 == descriptor[0] && (set.has1x = !0),
set.cands.push(can));
}
return set.cands;
}, ri.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, docElem.style.cssText = fsCss, body.style.cssText = fsCss,
body.appendChild(div), eminpx = div.offsetWidth, body.removeChild(div), eminpx = parseFloat(eminpx, 10),
docElem.style.cssText = originalHTMLCSS, body.style.cssText = originalBodyCSS;
}
return eminpx || 16;
}, ri.calcListLength = function(sourceSizeListStr) {
if (!(sourceSizeListStr in sizeLengthCache) || cfg.uT) {
var sourceSize, parsedSize, length, media, i, len, sourceSizeList = trim(sourceSizeListStr).split(/\s*,\s*/), winningLength = !1;
for (i = 0, len = sourceSizeList.length; len > i && (sourceSize = sourceSizeList[i],
parsedSize = ri.parseSize(sourceSize), length = parsedSize.length, media = parsedSize.media,
!length || !ri.matchesMedia(media) || (winningLength = ri.calcLength(length)) === !1); i++) ;
sizeLengthCache[sourceSizeListStr] = winningLength ? winningLength : units.width;
}
return sizeLengthCache[sourceSizeListStr];
}, ri.setRes = function(set) {
var candidates;
if (set) {
candidates = ri.parseSet(set);
for (var i = 0, len = candidates.length; len > i; i++) setResolution(candidates[i], set.sizes);
}
return candidates;
}, ri.setRes.res = setResolution, ri.applySetCandidate = function(candidates, img) {
if (candidates.length) {
var candidate, dpr, i, j, diff, length, bestCandidate, curSrc, curCan, isSameSet, candidateSrc, abortCurSrc, oldRes, imageData = img[ri.ns], evaled = evalID, lazyF = lazyFactor, sub = substractCurRes;
if (curSrc = imageData.curSrc || img[curSrcProp], curCan = imageData.curCan || setSrcToCur(img, curSrc, candidates[0].set),
dpr = ri.DPR, oldRes = curCan && curCan.res, !bestCandidate && curSrc && (abortCurSrc = supportAbort && !img.complete && curCan && oldRes - .2 > dpr,
abortCurSrc || curCan && !(tMemory > oldRes) || (curCan && dpr > oldRes && oldRes > lowTreshHold && (partialLowTreshHold > oldRes && (lazyF *= .8,
sub += .04 * dpr), curCan.res += lazyF * Math.pow(oldRes - sub, 2)), isSameSet = !imageData.pic || curCan && curCan.set == candidates[0].set,
curCan && isSameSet && curCan.res >= dpr && (bestCandidate = curCan))), !bestCandidate) for (oldRes && (curCan.res = curCan.res - (curCan.res - oldRes) / 2),
candidates.sort(ascendingSort), length = candidates.length, bestCandidate = candidates[length - 1],
i = 0; length > i; i++) if (candidate = candidates[i], candidate.res >= dpr) {
j = i - 1, bestCandidate = candidates[j] && (diff = candidate.res - dpr) && (abortCurSrc || curSrc != ri.makeUrl(candidate.url)) && chooseLowRes(candidates[j].res, diff, dpr) ? candidates[j] : candidate;
break;
}
return oldRes && (curCan.res = oldRes), bestCandidate && (candidateSrc = ri.makeUrl(bestCandidate.url),
imageData.curSrc = candidateSrc, imageData.curCan = bestCandidate, candidateSrc != curSrc && ri.setSrc(img, bestCandidate),
ri.setSize(img)), evaled;
}
}, ri.setSrc = function(img, bestCandidate) {
var origStyle;
img.src = bestCandidate.url, reflowBug && (origStyle = img.style.zoom, img.style.zoom = "0.999",
img.style.zoom = origStyle);
}, ri.getSet = function(img) {
var i, set, supportsType, match = !1, sets = img[ri.ns].sets;
for (i = 0; i < sets.length && !match; i++) if (set = sets[i], set.srcset && ri.matchesMedia(set.media) && (supportsType = ri.supportsType(set.type))) {
"pending" == supportsType && (set = supportsType), match = set;
break;
}
return match;
}, ri.parseSets = function(element, parent, options) {
var srcsetAttribute, imageSet, isWDescripor, srcsetParsed, hasPicture = "PICTURE" == parent.nodeName.toUpperCase(), imageData = element[ri.ns];
(imageData.src === undefined || options.src) && (imageData.src = getImgAttr.call(element, "src"),
imageData.src ? setImgAttr.call(element, srcAttr, imageData.src) : removeImgAttr.call(element, srcAttr)),
(imageData.srcset === undefined || !ri.supSrcset || element.srcset || options.srcset) && (srcsetAttribute = getImgAttr.call(element, "srcset"),
imageData.srcset = srcsetAttribute, srcsetParsed = !0), imageData.sets = [], hasPicture && (imageData.pic = !0,
getAllSourceElements(parent, imageData.sets)), imageData.srcset ? (imageSet = {
srcset: imageData.srcset,
sizes: getImgAttr.call(element, "sizes")
}, imageData.sets.push(imageSet), isWDescripor = (alwaysCheckWDescriptor || imageData.src) && regWDesc.test(imageData.srcset || ""),
isWDescripor || !imageData.src || getCandidateForSrc(imageData.src, imageSet) || imageSet.has1x || (imageSet.srcset += ", " + imageData.src,
imageSet.cands.push({
url: imageData.src,
x: 1,
set: imageSet
}))) : imageData.src && imageData.sets.push({
srcset: imageData.src,
sizes: null
}), imageData.curCan = null, imageData.curSrc = undefined, imageData.supported = !(hasPicture || imageSet && !ri.supSrcset || isWDescripor),
srcsetParsed && ri.supSrcset && !imageData.supported && (srcsetAttribute ? (setImgAttr.call(element, srcsetAttr, srcsetAttribute),
element.srcset = "") : removeImgAttr.call(element, srcsetAttr)), imageData.supported && !imageData.srcset && (!imageData.src && element.src || element.src != ri.makeUrl(imageData.src)) && (null == imageData.src ? element.removeAttribute("src") : element.src = imageData.src),
imageData.parsed = !0;
}, ri.fillImg = function(element, options) {
var parent, imageData, extreme = options.reselect || options.reevaluate;
if (element[ri.ns] || (element[ri.ns] = {}), imageData = element[ri.ns], extreme || imageData.evaled != evalID) {
if (!imageData.parsed || options.reevaluate) {
if (parent = element.parentNode, !parent) return;
ri.parseSets(element, parent, options);
}
imageData.supported ? imageData.evaled = evalID : applyBestCandidate(element);
}
}, ri.setupRun = function(options) {
(!alreadyRun || isVwDirty || DPR != window.devicePixelRatio) && (updateMetrics(),
options.elements || options.context || clearTimeout(resizeThrottle));
}, ri.supPicture ? (respimage = noop, ri.fillImg = noop) : (document.createElement("picture"),
function() {
var isDomReady, regReady = window.attachEvent ? /d$|^c/ : /d$|^c|^i/, run = function() {
var readyState = document.readyState || "";
timerId = setTimeout(run, "loading" == readyState ? 200 : 999), document.body && (isDomReady = isDomReady || regReady.test(readyState),
ri.fillImgs(), isDomReady && clearTimeout(timerId));
}, resizeEval = function() {
ri.fillImgs();
}, onResize = function() {
clearTimeout(resizeThrottle), isVwDirty = !0, resizeThrottle = setTimeout(resizeEval, 99);
}, timerId = setTimeout(run, document.body ? 0 : 20);
on(window, "resize", onResize), on(document, "readystatechange", run);
}()), ri.respimage = respimage, ri.fillImgs = respimage, ri.teardownRun = noop,
respimage._ = ri, window.respimage = window.picturefill || respimage, !window.picturefill) for (window.respimgCFG = {
ri: ri,
push: function(args) {
var name = args.shift();
"function" == typeof ri[name] ? ri[name].apply(ri, args) : (cfg[name] = args[0],
alreadyRun && ri.fillImgs({
reselect: !0
}));
}
}; setOptions && setOptions.length; ) window.respimgCFG.push(setOptions.shift());
window.picturefill || (window.picturefill = window.respimage, window.picturefillCFG || (window.picturefillCFG = window.respimgCFG));
}(window, document);