qd-changjing/public/leaflet/libs/vanilla-lazyload/10.6.0/lazyload.js

272 lines
10 KiB
JavaScript

/*!
* Copyright© lazyload
* lazyload v10.6.0 (https://verlok.github.io/lazyload)
* github: https://github.com/verlok/lazyload
* license: MIT
*
*/var _extends = Object.assign || function (target) { for (var i = 1; i < arguments.length; i++) { var source = arguments[i]; for (var key in source) { if (Object.prototype.hasOwnProperty.call(source, key)) { target[key] = source[key]; } } } return target; };
var _typeof = typeof Symbol === "function" && typeof Symbol.iterator === "symbol" ? function (obj) { return typeof obj; } : function (obj) { return obj && typeof Symbol === "function" && obj.constructor === Symbol && obj !== Symbol.prototype ? "symbol" : typeof obj; };
(function (global, factory) {
(typeof exports === 'undefined' ? 'undefined' : _typeof(exports)) === 'object' && typeof module !== 'undefined' ? module.exports = factory() : typeof define === 'function' && define.amd ? define(factory) : global.LazyLoad = factory();
})(this, function () {
'use strict';
var getInstanceSettings = function getInstanceSettings(customSettings) {
var defaultSettings = {
elements_selector: "img",
container: document,
threshold: 300,
data_src: "src",
data_srcset: "srcset",
class_loading: "loading",
class_loaded: "loaded",
class_error: "error",
callback_load: null,
callback_error: null,
callback_set: null,
callback_enter: null
};
return _extends({}, defaultSettings, customSettings);
};
var dataPrefix = "data-";
var getData = function getData(element, attribute) {
return element.getAttribute(dataPrefix + attribute);
};
var setData = function setData(element, attribute, value) {
return element.setAttribute(dataPrefix + attribute, value);
};
var purgeElements = function purgeElements(elements) {
return elements.filter(function (element) {
return !getData(element, "was-processed");
});
};
/* Creates instance and notifies it through the window element */
var createInstance = function createInstance(classObj, options) {
var event;
var eventString = "LazyLoad::Initialized";
var instance = new classObj(options);
try {
// Works in modern browsers
event = new CustomEvent(eventString, { detail: { instance: instance } });
} catch (err) {
// Works in Internet Explorer (all versions)
event = document.createEvent("CustomEvent");
event.initCustomEvent(eventString, false, false, { instance: instance });
}
window.dispatchEvent(event);
};
/* Auto initialization of one or more instances of lazyload, depending on the
options passed in (plain object or an array) */
var autoInitialize = function autoInitialize(classObj, options) {
if (!options.length) {
// Plain object
createInstance(classObj, options);
} else {
// Array of objects
for (var i = 0, optionsItem; optionsItem = options[i]; i += 1) {
createInstance(classObj, optionsItem);
}
}
};
var setSourcesForPicture = function setSourcesForPicture(element, settings) {
var dataSrcSet = settings.data_srcset;
var parent = element.parentNode;
if (!parent || parent.tagName !== "PICTURE") {
return;
}
for (var i = 0, pictureChild; pictureChild = parent.children[i]; i += 1) {
if (pictureChild.tagName === "SOURCE") {
var sourceSrcset = getData(pictureChild, dataSrcSet);
if (sourceSrcset) {
pictureChild.setAttribute("srcset", sourceSrcset);
}
}
}
};
var setSources = function setSources(element, settings) {
var dataSrc = settings.data_src,
dataSrcSet = settings.data_srcset;
var tagName = element.tagName;
var elementSrc = getData(element, dataSrc);
if (tagName === "IMG") {
setSourcesForPicture(element, settings);
var imgSrcset = getData(element, dataSrcSet);
if (imgSrcset) {
element.setAttribute("srcset", imgSrcset);
}
if (elementSrc) {
element.setAttribute("src", elementSrc);
}
return;
}
if (tagName === "IFRAME") {
if (elementSrc) {
element.setAttribute("src", elementSrc);
}
return;
}
if (elementSrc) {
element.style.backgroundImage = 'url("' + elementSrc + '")';
}
};
var runningOnBrowser = typeof window !== "undefined";
var supportsIntersectionObserver = runningOnBrowser && "IntersectionObserver" in window;
var supportsClassList = runningOnBrowser && "classList" in document.createElement("p");
var addClass = function addClass(element, className) {
if (supportsClassList) {
element.classList.add(className);
return;
}
element.className += (element.className ? " " : "") + className;
};
var removeClass = function removeClass(element, className) {
if (supportsClassList) {
element.classList.remove(className);
return;
}
element.className = element.className.replace(new RegExp("(^|\\s+)" + className + "(\\s+|$)"), " ").replace(/^\s+/, "").replace(/\s+$/, "");
};
var callCallback = function callCallback(callback, argument) {
if (callback) {
callback(argument);
}
};
var loadString = "load";
var errorString = "error";
var removeListeners = function removeListeners(element, loadHandler, errorHandler) {
element.removeEventListener(loadString, loadHandler);
element.removeEventListener(errorString, errorHandler);
};
var addOneShotListeners = function addOneShotListeners(element, settings) {
var onLoad = function onLoad(event) {
onEvent(event, true, settings);
removeListeners(element, onLoad, onError);
};
var onError = function onError(event) {
onEvent(event, false, settings);
removeListeners(element, onLoad, onError);
};
element.addEventListener(loadString, onLoad);
element.addEventListener(errorString, onError);
};
var onEvent = function onEvent(event, success, settings) {
var element = event.target;
removeClass(element, settings.class_loading);
addClass(element, success ? settings.class_loaded : settings.class_error); // Setting loaded or error class
callCallback(success ? settings.callback_load : settings.callback_error, element); // Calling loaded or error callback
};
var revealElement = function revealElement(element, settings) {
callCallback(settings.callback_enter, element);
if (["IMG", "IFRAME"].indexOf(element.tagName) > -1) {
addOneShotListeners(element, settings);
addClass(element, settings.class_loading);
}
setSources(element, settings);
setData(element, "was-processed", true);
callCallback(settings.callback_set, element);
};
/* entry.isIntersecting needs fallback because is null on some versions of MS Edge, and
entry.intersectionRatio is not enough alone because it could be 0 on some intersecting elements */
var isIntersecting = function isIntersecting(element) {
return element.isIntersecting || element.intersectionRatio > 0;
};
var LazyLoad = function LazyLoad(customSettings, elements) {
this._settings = getInstanceSettings(customSettings);
this._setObserver();
this.update(elements);
};
LazyLoad.prototype = {
_setObserver: function _setObserver() {
var _this = this;
if (!supportsIntersectionObserver) {
return;
}
var settings = this._settings;
var observerSettings = {
root: settings.container === document ? null : settings.container,
rootMargin: settings.threshold + "px"
};
var revealIntersectingElements = function revealIntersectingElements(entries) {
entries.forEach(function (entry) {
if (isIntersecting(entry)) {
var element = entry.target;
revealElement(element, _this._settings);
_this._observer.unobserve(element);
}
});
_this._elements = purgeElements(_this._elements);
};
this._observer = new IntersectionObserver(revealIntersectingElements, observerSettings);
},
update: function update(elements) {
var _this2 = this;
var settings = this._settings;
var nodeSet = elements || settings.container.querySelectorAll(settings.elements_selector);
this._elements = purgeElements(Array.prototype.slice.call(nodeSet)); // nodeset to array for IE compatibility
if (this._observer) {
this._elements.forEach(function (element) {
_this2._observer.observe(element);
});
return;
}
// Fallback: load all elements at once
this._elements.forEach(function (element) {
revealElement(element, settings);
});
this._elements = purgeElements(this._elements);
},
destroy: function destroy() {
var _this3 = this;
if (this._observer) {
purgeElements(this._elements).forEach(function (element) {
_this3._observer.unobserve(element);
});
this._observer = null;
}
this._elements = null;
this._settings = null;
}
};
/* Automatic instances creation if required (useful for async script loading!) */
var autoInitOptions = window.lazyLoadOptions;
if (runningOnBrowser && autoInitOptions) {
autoInitialize(LazyLoad, autoInitOptions);
}
return LazyLoad;
});