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ofi.js
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ofi.js
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/*! npm.im/object-fit-images 3.2.4 */
var objectFitImages = (function () {
'use strict';
var OFI = 'fregante:object-fit-images';
var propRegex = /(object-fit|object-position)\s*:\s*([-.\w\s%]+)/g;
var testImg = typeof Image === 'undefined' ? {style: {'object-position': 1}} : new Image();
var supportsObjectFit = 'object-fit' in testImg.style;
var supportsObjectPosition = 'object-position' in testImg.style;
var supportsOFI = 'background-size' in testImg.style;
var supportsCurrentSrc = typeof testImg.currentSrc === 'string';
var nativeGetAttribute = testImg.getAttribute;
var nativeSetAttribute = testImg.setAttribute;
var autoModeEnabled = false;
function createPlaceholder(w, h) {
return ("data:image/svg+xml,%3Csvg xmlns='http://www.w3.org/2000/svg' width='" + w + "' height='" + h + "'%3E%3C/svg%3E");
}
function polyfillCurrentSrc(el) {
if (el.srcset && !supportsCurrentSrc && window.picturefill) {
var pf = window.picturefill._;
// parse srcset with picturefill where currentSrc isn't available
if (!el[pf.ns] || !el[pf.ns].evaled) {
// force synchronous srcset parsing
pf.fillImg(el, {reselect: true});
}
if (!el[pf.ns].curSrc) {
// force picturefill to parse srcset
el[pf.ns].supported = false;
pf.fillImg(el, {reselect: true});
}
// retrieve parsed currentSrc, if any
el.currentSrc = el[pf.ns].curSrc || el.src;
}
}
function getStyle(el) {
var style = getComputedStyle(el).fontFamily;
var parsed;
var props = {};
while ((parsed = propRegex.exec(style)) !== null) {
props[parsed[1]] = parsed[2];
}
return props;
}
function setPlaceholder(img, width, height) {
// Default: fill width, no height
var placeholder = createPlaceholder(width || 1, height || 0);
// Only set placeholder if it's different
if (nativeGetAttribute.call(img, 'src') !== placeholder) {
nativeSetAttribute.call(img, 'src', placeholder);
}
}
function onImageReady(img, callback) {
// naturalWidth is only available when the image headers are loaded,
// this loop will poll it every 100ms.
if (img.naturalWidth) {
callback(img);
} else {
setTimeout(onImageReady, 100, img, callback);
}
}
function fixOne(el) {
var style = getStyle(el);
var ofi = el[OFI];
style['object-fit'] = style['object-fit'] || 'fill'; // default value
// Avoid running where unnecessary, unless OFI had already done its deed
if (!ofi.img) {
// fill is the default behavior so no action is necessary
if (style['object-fit'] === 'fill') {
return;
}
// Where object-fit is supported and object-position isn't (Safari < 10)
if (
!ofi.skipTest && // unless user wants to apply regardless of browser support
supportsObjectFit && // if browser already supports object-fit
!style['object-position'] // unless object-position is used
) {
return;
}
}
// keep a clone in memory while resetting the original to a blank
if (!ofi.img) {
ofi.img = new Image(el.width, el.height);
ofi.img.srcset = nativeGetAttribute.call(el, "data-ofi-srcset") || el.srcset;
ofi.img.src = nativeGetAttribute.call(el, "data-ofi-src") || el.src;
// preserve for any future cloneNode calls
// https://github.com/fregante/object-fit-images/issues/53
nativeSetAttribute.call(el, "data-ofi-src", el.src);
if (el.srcset) {
nativeSetAttribute.call(el, "data-ofi-srcset", el.srcset);
}
setPlaceholder(el, el.naturalWidth || el.width, el.naturalHeight || el.height);
// remove srcset because it overrides src
if (el.srcset) {
el.srcset = '';
}
try {
keepSrcUsable(el);
} catch (err) {
if (window.console) {
console.warn('https://bit.ly/ofi-old-browser');
}
}
}
polyfillCurrentSrc(ofi.img);
el.style.backgroundImage = "url(\"" + ((ofi.img.currentSrc || ofi.img.src).replace(/"/g, '\\"')) + "\")";
el.style.backgroundPosition = style['object-position'] || 'center';
el.style.backgroundRepeat = 'no-repeat';
el.style.backgroundOrigin = 'content-box';
if (/scale-down/.test(style['object-fit'])) {
onImageReady(ofi.img, function () {
if (ofi.img.naturalWidth > el.width || ofi.img.naturalHeight > el.height) {
el.style.backgroundSize = 'contain';
} else {
el.style.backgroundSize = 'auto';
}
});
} else {
el.style.backgroundSize = style['object-fit'].replace('none', 'auto').replace('fill', '100% 100%');
}
onImageReady(ofi.img, function (img) {
setPlaceholder(el, img.naturalWidth, img.naturalHeight);
});
}
function keepSrcUsable(el) {
var descriptors = {
get: function get(prop) {
return el[OFI].img[prop ? prop : 'src'];
},
set: function set(value, prop) {
el[OFI].img[prop ? prop : 'src'] = value;
nativeSetAttribute.call(el, ("data-ofi-" + prop), value); // preserve for any future cloneNode
fixOne(el);
return value;
}
};
Object.defineProperty(el, 'src', descriptors);
Object.defineProperty(el, 'currentSrc', {
get: function () { return descriptors.get('currentSrc'); }
});
Object.defineProperty(el, 'srcset', {
get: function () { return descriptors.get('srcset'); },
set: function (ss) { return descriptors.set(ss, 'srcset'); }
});
}
function hijackAttributes() {
function getOfiImageMaybe(el, name) {
return el[OFI] && el[OFI].img && (name === 'src' || name === 'srcset') ? el[OFI].img : el;
}
if (!supportsObjectPosition) {
HTMLImageElement.prototype.getAttribute = function (name) {
return nativeGetAttribute.call(getOfiImageMaybe(this, name), name);
};
HTMLImageElement.prototype.setAttribute = function (name, value) {
return nativeSetAttribute.call(getOfiImageMaybe(this, name), name, String(value));
};
}
}
function fix(imgs, opts) {
var startAutoMode = !autoModeEnabled && !imgs;
opts = opts || {};
imgs = imgs || 'img';
if ((supportsObjectPosition && !opts.skipTest) || !supportsOFI) {
return false;
}
// use imgs as a selector or just select all images
if (imgs === 'img') {
imgs = document.getElementsByTagName('img');
} else if (typeof imgs === 'string') {
imgs = document.querySelectorAll(imgs);
} else if (!('length' in imgs)) {
imgs = [imgs];
}
// apply fix to all
for (var i = 0; i < imgs.length; i++) {
imgs[i][OFI] = imgs[i][OFI] || {
skipTest: opts.skipTest
};
fixOne(imgs[i]);
}
if (startAutoMode) {
document.body.addEventListener('load', function (e) {
if (e.target.tagName === 'IMG') {
fix(e.target, {
skipTest: opts.skipTest
});
}
}, true);
autoModeEnabled = true;
imgs = 'img'; // reset to a generic selector for watchMQ
}
// if requested, watch media queries for object-fit change
if (opts.watchMQ) {
window.addEventListener('resize', fix.bind(null, imgs, {
skipTest: opts.skipTest
}));
}
}
fix.supportsObjectFit = supportsObjectFit;
fix.supportsObjectPosition = supportsObjectPosition;
hijackAttributes();
return fix;
}());