870 lines
30 KiB
JavaScript
870 lines
30 KiB
JavaScript
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/*!
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* jQuery & Zepto Lazy - v1.7.6
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* http://jquery.eisbehr.de/lazy/
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*
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* Copyright 2012 - 2017, Daniel 'Eisbehr' Kern
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*
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* Dual licensed under the MIT and GPL-2.0 licenses:
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* http://www.opensource.org/licenses/mit-license.php
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* http://www.gnu.org/licenses/gpl-2.0.html
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*
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* $("img.lazy").lazy();
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*/
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;(function(window, undefined) {
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"use strict";
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// noinspection JSUnresolvedVariable
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/**
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* library instance - here and not in construct to be shorter in minimization
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* @return void
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*/
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var $ = window.jQuery || window.Zepto,
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/**
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* unique plugin instance id counter
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* @type {number}
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*/
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lazyInstanceId = 0,
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/**
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* helper to register window load for jQuery 3
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* @type {boolean}
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*/
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windowLoaded = false;
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/**
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* make lazy available to jquery - and make it a bit more case-insensitive :)
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* @access public
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* @type {function}
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* @param {object} settings
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* @return void
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*/
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$.fn.Lazy = $.fn.lazy = function(settings) {
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return new LazyPlugin(this, settings);
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};
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/**
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* helper to add plugins to lazy prototype configuration
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* @access public
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* @type {function}
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* @param {string|Array} names
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* @param {string|Array} [elements]
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* @param {function} loader
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* @return void
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*/
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$.Lazy = $.lazy = function(names, elements, loader) {
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// make second parameter optional
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if( $.isFunction(elements) ) {
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loader = elements;
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elements = [];
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}
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// exit here if parameter is not a callable function
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if( !$.isFunction(loader) ) {
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return;
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}
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// make parameters an array of names to be sure
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names = $.isArray(names) ? names : [names];
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elements = $.isArray(elements) ? elements : [elements];
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var config = LazyPlugin.prototype.config,
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forced = config._f || (config._f = {});
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// add the loader plugin for every name
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for( var i = 0, l = names.length; i < l; i++ ) {
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if( config[names[i]] === undefined || $.isFunction(config[names[i]]) ) {
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config[names[i]] = loader;
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}
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}
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// add forced elements loader
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for( var c = 0, a = elements.length; c < a; c++ ) {
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forced[elements[c]] = names[0];
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}
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};
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/**
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* contains all logic and the whole element handling
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* is packed in a private function outside class to reduce memory usage, because it will not be created on every plugin instance
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* @access private
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* @type {function}
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* @param {LazyPlugin} instance
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* @param {object} config
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* @param {object|Array} items
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* @param {object} events
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* @param {string} namespace
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* @return void
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*/
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function _executeLazy(instance, config, items, events, namespace) {
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/**
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* a helper to trigger the 'onFinishedAll' callback after all other events
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* @access private
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* @type {number}
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*/
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var _awaitingAfterLoad = 0,
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/**
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* visible content width
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* @access private
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* @type {number}
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*/
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_actualWidth = -1,
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/**
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* visible content height
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* @access private
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* @type {number}
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*/
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_actualHeight = -1,
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/**
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* determine possibly detected high pixel density
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* @access private
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* @type {boolean}
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*/
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_isRetinaDisplay = false,
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_afterLoad = "afterLoad",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_load = "load",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_error = "error",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_img = "img",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_src = "src",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_srcset = "srcset",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_sizes = "sizes",
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/**
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* dictionary entry for better minimization
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* @access private
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* @type {string}
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*/
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_backgroundImage = "background-image";
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/**
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* initialize plugin
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* bind loading to events or set delay time to load all items at once
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* @access private
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* @return void
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*/
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function _initialize() {
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// detect actual device pixel ratio
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// noinspection JSUnresolvedVariable
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_isRetinaDisplay = window.devicePixelRatio > 1;
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// prepare all initial items
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items = _prepareItems(items);
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// if delay time is set load all items at once after delay time
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if( config.delay >= 0 ) {
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setTimeout(function() {
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_lazyLoadItems(true);
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}, config.delay);
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}
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// if no delay is set or combine usage is active bind events
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if( config.delay < 0 || config.combined ) {
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// create unique event function
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events.e = _throttle(config.throttle, function(event) {
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// reset detected window size on resize event
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if( event.type === "resize" ) {
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_actualWidth = _actualHeight = -1;
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}
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// execute 'lazy magic'
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_lazyLoadItems(event.all);
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});
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// create function to add new items to instance
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events.a = function(additionalItems) {
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additionalItems = _prepareItems(additionalItems);
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items.push.apply(items, additionalItems);
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};
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// create function to get all instance items left
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events.g = function() {
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// filter loaded items before return in case internal filter was not running until now
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return (items = $(items).filter(function() {
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return !$(this).data(config.loadedName);
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}));
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};
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// create function to force loading elements
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events.f = function(forcedItems) {
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for( var i = 0; i < forcedItems.length; i++ ) {
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// only handle item if available in current instance
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// use a compare function, because Zepto can't handle object parameter for filter
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// var item = items.filter(forcedItems[i]);
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/* jshint loopfunc: true */
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var item = items.filter(function() {
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return this === forcedItems[i];
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});
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if( item.length ) {
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_lazyLoadItems(false, item);
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}
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}
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};
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// load initial items
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_lazyLoadItems();
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// bind lazy load functions to scroll and resize event
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// noinspection JSUnresolvedVariable
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$(config.appendScroll).on("scroll." + namespace + " resize." + namespace, events.e);
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}
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}
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/**
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* prepare items before handle them
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* @access private
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* @param {Array|object|jQuery} items
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* @return {Array|object|jQuery}
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*/
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function _prepareItems(items) {
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// fetch used configurations before loops
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var defaultImage = config.defaultImage,
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placeholder = config.placeholder,
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imageBase = config.imageBase,
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srcsetAttribute = config.srcsetAttribute,
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loaderAttribute = config.loaderAttribute,
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forcedTags = config._f || {};
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// filter items and only add those who not handled yet and got needed attributes available
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items = $(items).filter(function() {
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var element = $(this),
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tag = _getElementTagName(this);
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return !element.data(config.handledName) &&
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(element.attr(config.attribute) || element.attr(srcsetAttribute) || element.attr(loaderAttribute) || forcedTags[tag] !== undefined);
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})
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// append plugin instance to all elements
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.data("plugin_" + config.name, instance);
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for( var i = 0, l = items.length; i < l; i++ ) {
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var element = $(items[i]),
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tag = _getElementTagName(items[i]),
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elementImageBase = element.attr(config.imageBaseAttribute) || imageBase;
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// generate and update source set if an image base is set
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if( tag === _img && elementImageBase && element.attr(srcsetAttribute) ) {
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element.attr(srcsetAttribute, _getCorrectedSrcSet(element.attr(srcsetAttribute), elementImageBase));
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}
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// add loader to forced element types
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if( forcedTags[tag] !== undefined && !element.attr(loaderAttribute) ) {
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element.attr(loaderAttribute, forcedTags[tag]);
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}
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// set default image on every element without source
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if( tag === _img && defaultImage && !element.attr(_src) ) {
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element.attr(_src, defaultImage);
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}
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// set placeholder on every element without background image
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else if( tag !== _img && placeholder && (!element.css(_backgroundImage) || element.css(_backgroundImage) === "none") ) {
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element.css(_backgroundImage, "url('" + placeholder + "')");
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}
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}
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return items;
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}
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/**
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* the 'lazy magic' - check all items
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* @access private
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* @param {boolean} [allItems]
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* @param {object} [forced]
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* @return void
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*/
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function _lazyLoadItems(allItems, forced) {
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// skip if no items where left
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if( !items.length ) {
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// destroy instance if option is enabled
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if( config.autoDestroy ) {
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// noinspection JSUnresolvedFunction
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instance.destroy();
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}
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return;
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}
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var elements = forced || items,
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loadTriggered = false,
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imageBase = config.imageBase || "",
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srcsetAttribute = config.srcsetAttribute,
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handledName = config.handledName;
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// loop all available items
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for( var i = 0; i < elements.length; i++ ) {
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// item is at least in loadable area
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if( allItems || forced || _isInLoadableArea(elements[i]) ) {
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var element = $(elements[i]),
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tag = _getElementTagName(elements[i]),
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attribute = element.attr(config.attribute),
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elementImageBase = element.attr(config.imageBaseAttribute) || imageBase,
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customLoader = element.attr(config.loaderAttribute);
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// is not already handled
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if( !element.data(handledName) &&
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// and is visible or visibility doesn't matter
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(!config.visibleOnly || element.is(":visible")) && (
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// and image source or source set attribute is available
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(attribute || element.attr(srcsetAttribute)) && (
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// and is image tag where attribute is not equal source or source set
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(tag === _img && (elementImageBase + attribute !== element.attr(_src) || element.attr(srcsetAttribute) !== element.attr(_srcset))) ||
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// or is non image tag where attribute is not equal background
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(tag !== _img && elementImageBase + attribute !== element.css(_backgroundImage))
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) ||
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// or custom loader is available
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customLoader ))
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{
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// mark element always as handled as this point to prevent double handling
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loadTriggered = true;
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element.data(handledName, true);
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// load item
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_handleItem(element, tag, elementImageBase, customLoader);
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}
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}
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}
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// when something was loaded remove them from remaining items
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if( loadTriggered ) {
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items = $(items).filter(function() {
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return !$(this).data(handledName);
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});
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}
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}
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/**
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* load the given element the lazy way
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* @access private
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* @param {object} element
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* @param {string} tag
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* @param {string} imageBase
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* @param {function} [customLoader]
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* @return void
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*/
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function _handleItem(element, tag, imageBase, customLoader) {
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// increment count of items waiting for after load
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++_awaitingAfterLoad;
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// extended error callback for correct 'onFinishedAll' handling
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var errorCallback = function() {
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_triggerCallback("onError", element);
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_reduceAwaiting();
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// prevent further callback calls
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errorCallback = $.noop;
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};
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// trigger function before loading image
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_triggerCallback("beforeLoad", element);
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|
|
// fetch all double used data here for better code minimization
|
||
|
|
var srcAttribute = config.attribute,
|
||
|
|
srcsetAttribute = config.srcsetAttribute,
|
||
|
|
sizesAttribute = config.sizesAttribute,
|
||
|
|
retinaAttribute = config.retinaAttribute,
|
||
|
|
removeAttribute = config.removeAttribute,
|
||
|
|
loadedName = config.loadedName,
|
||
|
|
elementRetina = element.attr(retinaAttribute);
|
||
|
|
|
||
|
|
// handle custom loader
|
||
|
|
if( customLoader ) {
|
||
|
|
// on load callback
|
||
|
|
var loadCallback = function() {
|
||
|
|
// remove attribute from element
|
||
|
|
if( removeAttribute ) {
|
||
|
|
element.removeAttr(config.loaderAttribute);
|
||
|
|
}
|
||
|
|
|
||
|
|
// mark element as loaded
|
||
|
|
element.data(loadedName, true);
|
||
|
|
|
||
|
|
// call after load event
|
||
|
|
_triggerCallback(_afterLoad, element);
|
||
|
|
|
||
|
|
// remove item from waiting queue and possibly trigger finished event
|
||
|
|
// it's needed to be asynchronous to run after filter was in _lazyLoadItems
|
||
|
|
setTimeout(_reduceAwaiting, 1);
|
||
|
|
|
||
|
|
// prevent further callback calls
|
||
|
|
loadCallback = $.noop;
|
||
|
|
};
|
||
|
|
|
||
|
|
// bind error event to trigger callback and reduce waiting amount
|
||
|
|
element.off(_error).one(_error, errorCallback)
|
||
|
|
|
||
|
|
// bind after load callback to element
|
||
|
|
.one(_load, loadCallback);
|
||
|
|
|
||
|
|
// trigger custom loader and handle response
|
||
|
|
if( !_triggerCallback(customLoader, element, function(response) {
|
||
|
|
if( response ) {
|
||
|
|
element.off(_load);
|
||
|
|
loadCallback();
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
element.off(_error);
|
||
|
|
errorCallback();
|
||
|
|
}
|
||
|
|
})) element.trigger(_error);
|
||
|
|
}
|
||
|
|
|
||
|
|
// handle images
|
||
|
|
else {
|
||
|
|
// create image object
|
||
|
|
var imageObj = $(new Image());
|
||
|
|
|
||
|
|
// bind error event to trigger callback and reduce waiting amount
|
||
|
|
imageObj.one(_error, errorCallback)
|
||
|
|
|
||
|
|
// bind after load callback to image
|
||
|
|
.one(_load, function() {
|
||
|
|
// remove element from view
|
||
|
|
element.hide();
|
||
|
|
|
||
|
|
// set image back to element
|
||
|
|
// do it as single 'attr' calls, to be sure 'src' is set after 'srcset'
|
||
|
|
if( tag === _img ) {
|
||
|
|
element.attr(_sizes, imageObj.attr(_sizes))
|
||
|
|
.attr(_srcset, imageObj.attr(_srcset))
|
||
|
|
.attr(_src, imageObj.attr(_src));
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
element.css(_backgroundImage, "url('" + imageObj.attr(_src) + "')");
|
||
|
|
}
|
||
|
|
|
||
|
|
// bring it back with some effect!
|
||
|
|
element[config.effect](config.effectTime);
|
||
|
|
|
||
|
|
// remove attribute from element
|
||
|
|
if( removeAttribute ) {
|
||
|
|
element.removeAttr(srcAttribute + " " + srcsetAttribute + " " + retinaAttribute + " " + config.imageBaseAttribute);
|
||
|
|
|
||
|
|
// only remove 'sizes' attribute, if it was a custom one
|
||
|
|
if( sizesAttribute !== _sizes ) {
|
||
|
|
element.removeAttr(sizesAttribute);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// mark element as loaded
|
||
|
|
element.data(loadedName, true);
|
||
|
|
|
||
|
|
// call after load event
|
||
|
|
_triggerCallback(_afterLoad, element);
|
||
|
|
|
||
|
|
// cleanup image object
|
||
|
|
imageObj.remove();
|
||
|
|
|
||
|
|
// remove item from waiting queue and possibly trigger finished event
|
||
|
|
_reduceAwaiting();
|
||
|
|
});
|
||
|
|
|
||
|
|
// set sources
|
||
|
|
// do it as single 'attr' calls, to be sure 'src' is set after 'srcset'
|
||
|
|
var imageSrc = (_isRetinaDisplay && elementRetina ? elementRetina : element.attr(srcAttribute)) || "";
|
||
|
|
imageObj.attr(_sizes, element.attr(sizesAttribute))
|
||
|
|
.attr(_srcset, element.attr(srcsetAttribute))
|
||
|
|
.attr(_src, imageSrc ? imageBase + imageSrc : null);
|
||
|
|
|
||
|
|
// call after load even on cached image
|
||
|
|
imageObj.complete && imageObj.trigger(_load); // jshint ignore : line
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* check if the given element is inside the current viewport or threshold
|
||
|
|
* @access private
|
||
|
|
* @param {object} element
|
||
|
|
* @return {boolean}
|
||
|
|
*/
|
||
|
|
function _isInLoadableArea(element) {
|
||
|
|
var elementBound = element.getBoundingClientRect(),
|
||
|
|
direction = config.scrollDirection,
|
||
|
|
threshold = config.threshold,
|
||
|
|
vertical = // check if element is in loadable area from top
|
||
|
|
((_getActualHeight() + threshold) > elementBound.top) &&
|
||
|
|
// check if element is even in loadable are from bottom
|
||
|
|
(-threshold < elementBound.bottom),
|
||
|
|
horizontal = // check if element is in loadable area from left
|
||
|
|
((_getActualWidth() + threshold) > elementBound.left) &&
|
||
|
|
// check if element is even in loadable area from right
|
||
|
|
(-threshold < elementBound.right);
|
||
|
|
|
||
|
|
if( direction === "vertical" ) {
|
||
|
|
return vertical;
|
||
|
|
}
|
||
|
|
else if( direction === "horizontal" ) {
|
||
|
|
return horizontal;
|
||
|
|
}
|
||
|
|
|
||
|
|
return vertical && horizontal;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* receive the current viewed width of the browser
|
||
|
|
* @access private
|
||
|
|
* @return {number}
|
||
|
|
*/
|
||
|
|
function _getActualWidth() {
|
||
|
|
return _actualWidth >= 0 ? _actualWidth : (_actualWidth = $(window).width());
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* receive the current viewed height of the browser
|
||
|
|
* @access private
|
||
|
|
* @return {number}
|
||
|
|
*/
|
||
|
|
function _getActualHeight() {
|
||
|
|
return _actualHeight >= 0 ? _actualHeight : (_actualHeight = $(window).height());
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* get lowercase tag name of an element
|
||
|
|
* @access private
|
||
|
|
* @param {object} element
|
||
|
|
* @returns {string}
|
||
|
|
*/
|
||
|
|
function _getElementTagName(element) {
|
||
|
|
return element.tagName.toLowerCase();
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* prepend image base to all srcset entries
|
||
|
|
* @access private
|
||
|
|
* @param {string} srcset
|
||
|
|
* @param {string} imageBase
|
||
|
|
* @returns {string}
|
||
|
|
*/
|
||
|
|
function _getCorrectedSrcSet(srcset, imageBase) {
|
||
|
|
if( imageBase ) {
|
||
|
|
// trim, remove unnecessary spaces and split entries
|
||
|
|
var entries = srcset.split(",");
|
||
|
|
srcset = "";
|
||
|
|
|
||
|
|
for( var i = 0, l = entries.length; i < l; i++ ) {
|
||
|
|
srcset += imageBase + entries[i].trim() + (i !== l - 1 ? "," : "");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
return srcset;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* helper function to throttle down event triggering
|
||
|
|
* @access private
|
||
|
|
* @param {number} delay
|
||
|
|
* @param {function} callback
|
||
|
|
* @return {function}
|
||
|
|
*/
|
||
|
|
function _throttle(delay, callback) {
|
||
|
|
var timeout,
|
||
|
|
lastExecute = 0;
|
||
|
|
|
||
|
|
return function(event, ignoreThrottle) {
|
||
|
|
var elapsed = +new Date() - lastExecute;
|
||
|
|
|
||
|
|
function run() {
|
||
|
|
lastExecute = +new Date();
|
||
|
|
// noinspection JSUnresolvedFunction
|
||
|
|
callback.call(instance, event);
|
||
|
|
}
|
||
|
|
|
||
|
|
timeout && clearTimeout(timeout); // jshint ignore : line
|
||
|
|
|
||
|
|
if( elapsed > delay || !config.enableThrottle || ignoreThrottle ) {
|
||
|
|
run();
|
||
|
|
}
|
||
|
|
else {
|
||
|
|
timeout = setTimeout(run, delay - elapsed);
|
||
|
|
}
|
||
|
|
};
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* reduce count of awaiting elements to 'afterLoad' event and fire 'onFinishedAll' if reached zero
|
||
|
|
* @access private
|
||
|
|
* @return void
|
||
|
|
*/
|
||
|
|
function _reduceAwaiting() {
|
||
|
|
--_awaitingAfterLoad;
|
||
|
|
|
||
|
|
// if no items were left trigger finished event
|
||
|
|
if( !items.length && !_awaitingAfterLoad ) {
|
||
|
|
_triggerCallback("onFinishedAll");
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* single implementation to handle callbacks, pass element and set 'this' to current instance
|
||
|
|
* @access private
|
||
|
|
* @param {string|function} callback
|
||
|
|
* @param {object} [element]
|
||
|
|
* @param {*} [args]
|
||
|
|
* @return {boolean}
|
||
|
|
*/
|
||
|
|
function _triggerCallback(callback, element, args) {
|
||
|
|
if( (callback = config[callback]) ) {
|
||
|
|
// jQuery's internal '$(arguments).slice(1)' are causing problems at least on old iPads
|
||
|
|
// below is shorthand of 'Array.prototype.slice.call(arguments, 1)'
|
||
|
|
callback.apply(instance, [].slice.call(arguments, 1));
|
||
|
|
return true;
|
||
|
|
}
|
||
|
|
|
||
|
|
return false;
|
||
|
|
}
|
||
|
|
|
||
|
|
// if event driven or window is already loaded don't wait for page loading
|
||
|
|
if( config.bind === "event" || windowLoaded ) {
|
||
|
|
_initialize();
|
||
|
|
}
|
||
|
|
|
||
|
|
// otherwise load initial items and start lazy after page load
|
||
|
|
else {
|
||
|
|
// noinspection JSUnresolvedVariable
|
||
|
|
$(window).on(_load + "." + namespace, _initialize);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* lazy plugin class constructor
|
||
|
|
* @constructor
|
||
|
|
* @access private
|
||
|
|
* @param {object} elements
|
||
|
|
* @param {object} settings
|
||
|
|
* @return {object|LazyPlugin}
|
||
|
|
*/
|
||
|
|
function LazyPlugin(elements, settings) {
|
||
|
|
/**
|
||
|
|
* this lazy plugin instance
|
||
|
|
* @access private
|
||
|
|
* @type {object|LazyPlugin|LazyPlugin.prototype}
|
||
|
|
*/
|
||
|
|
var _instance = this,
|
||
|
|
|
||
|
|
/**
|
||
|
|
* this lazy plugin instance configuration
|
||
|
|
* @access private
|
||
|
|
* @type {object}
|
||
|
|
*/
|
||
|
|
_config = $.extend({}, _instance.config, settings),
|
||
|
|
|
||
|
|
/**
|
||
|
|
* instance generated event executed on container scroll or resize
|
||
|
|
* packed in an object to be referenceable and short named because properties will not be minified
|
||
|
|
* @access private
|
||
|
|
* @type {object}
|
||
|
|
*/
|
||
|
|
_events = {},
|
||
|
|
|
||
|
|
/**
|
||
|
|
* unique namespace for instance related events
|
||
|
|
* @access private
|
||
|
|
* @type {string}
|
||
|
|
*/
|
||
|
|
_namespace = _config.name + "-" + (++lazyInstanceId);
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* wrapper to get or set an entry from plugin instance configuration
|
||
|
|
* much smaller on minify as direct access
|
||
|
|
* @access public
|
||
|
|
* @type {function}
|
||
|
|
* @param {string} entryName
|
||
|
|
* @param {*} [value]
|
||
|
|
* @return {LazyPlugin|*}
|
||
|
|
*/
|
||
|
|
_instance.config = function(entryName, value) {
|
||
|
|
if( value === undefined ) {
|
||
|
|
return _config[entryName];
|
||
|
|
}
|
||
|
|
|
||
|
|
_config[entryName] = value;
|
||
|
|
return _instance;
|
||
|
|
};
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* add additional items to current instance
|
||
|
|
* @access public
|
||
|
|
* @param {Array|object|string} items
|
||
|
|
* @return {LazyPlugin}
|
||
|
|
*/
|
||
|
|
_instance.addItems = function(items) {
|
||
|
|
_events.a && _events.a($.type(items) === "string" ? $(items) : items); // jshint ignore : line
|
||
|
|
return _instance;
|
||
|
|
};
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* get all left items of this instance
|
||
|
|
* @access public
|
||
|
|
* @returns {object}
|
||
|
|
*/
|
||
|
|
_instance.getItems = function() {
|
||
|
|
return _events.g ? _events.g() : {};
|
||
|
|
};
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* force lazy to load all items in loadable area right now
|
||
|
|
* by default without throttle
|
||
|
|
* @access public
|
||
|
|
* @type {function}
|
||
|
|
* @param {boolean} [useThrottle]
|
||
|
|
* @return {LazyPlugin}
|
||
|
|
*/
|
||
|
|
_instance.update = function(useThrottle) {
|
||
|
|
_events.e && _events.e({}, !useThrottle); // jshint ignore : line
|
||
|
|
return _instance;
|
||
|
|
};
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* force element(s) to load directly, ignoring the viewport
|
||
|
|
* @access public
|
||
|
|
* @param {Array|object|string} items
|
||
|
|
* @return {LazyPlugin}
|
||
|
|
*/
|
||
|
|
_instance.force = function(items) {
|
||
|
|
_events.f && _events.f($.type(items) === "string" ? $(items) : items); // jshint ignore : line
|
||
|
|
return _instance;
|
||
|
|
};
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* force lazy to load all available items right now
|
||
|
|
* this call ignores throttling
|
||
|
|
* @access public
|
||
|
|
* @type {function}
|
||
|
|
* @return {LazyPlugin}
|
||
|
|
*/
|
||
|
|
_instance.loadAll = function() {
|
||
|
|
_events.e && _events.e({all: true}, true); // jshint ignore : line
|
||
|
|
return _instance;
|
||
|
|
};
|
||
|
|
|
||
|
|
// noinspection JSUndefinedPropertyAssignment
|
||
|
|
/**
|
||
|
|
* destroy this plugin instance
|
||
|
|
* @access public
|
||
|
|
* @type {function}
|
||
|
|
* @return undefined
|
||
|
|
*/
|
||
|
|
_instance.destroy = function() {
|
||
|
|
// unbind instance generated events
|
||
|
|
// noinspection JSUnresolvedFunction, JSUnresolvedVariable
|
||
|
|
$(_config.appendScroll).off("." + _namespace, _events.e);
|
||
|
|
// noinspection JSUnresolvedVariable
|
||
|
|
$(window).off("." + _namespace);
|
||
|
|
|
||
|
|
// clear events
|
||
|
|
_events = {};
|
||
|
|
|
||
|
|
return undefined;
|
||
|
|
};
|
||
|
|
|
||
|
|
// start using lazy and return all elements to be chainable or instance for further use
|
||
|
|
// noinspection JSUnresolvedVariable
|
||
|
|
_executeLazy(_instance, _config, elements, _events, _namespace);
|
||
|
|
return _config.chainable ? elements : _instance;
|
||
|
|
}
|
||
|
|
|
||
|
|
/**
|
||
|
|
* settings and configuration data
|
||
|
|
* @access public
|
||
|
|
* @type {object}
|
||
|
|
*/
|
||
|
|
LazyPlugin.prototype.config = {
|
||
|
|
// general
|
||
|
|
name : "lazy",
|
||
|
|
chainable : true,
|
||
|
|
autoDestroy : true,
|
||
|
|
bind : "load",
|
||
|
|
threshold : 500,
|
||
|
|
visibleOnly : false,
|
||
|
|
appendScroll : window,
|
||
|
|
scrollDirection : "both",
|
||
|
|
imageBase : null,
|
||
|
|
defaultImage : "data:image/gif;base64,R0lGODlhAQABAIAAAP///wAAACH5BAEAAAAALAAAAAABAAEAAAICRAEAOw==",
|
||
|
|
placeholder : null,
|
||
|
|
delay : -1,
|
||
|
|
combined : false,
|
||
|
|
|
||
|
|
// attributes
|
||
|
|
attribute : "data-src",
|
||
|
|
srcsetAttribute : "data-srcset",
|
||
|
|
sizesAttribute : "data-sizes",
|
||
|
|
retinaAttribute : "data-retina",
|
||
|
|
loaderAttribute : "data-loader",
|
||
|
|
imageBaseAttribute : "data-imagebase",
|
||
|
|
removeAttribute : true,
|
||
|
|
handledName : "handled",
|
||
|
|
loadedName : "loaded",
|
||
|
|
|
||
|
|
// effect
|
||
|
|
effect : "show",
|
||
|
|
effectTime : 0,
|
||
|
|
|
||
|
|
// throttle
|
||
|
|
enableThrottle : true,
|
||
|
|
throttle : 250,
|
||
|
|
|
||
|
|
// callbacks
|
||
|
|
beforeLoad : undefined,
|
||
|
|
afterLoad : undefined,
|
||
|
|
onError : undefined,
|
||
|
|
onFinishedAll : undefined
|
||
|
|
};
|
||
|
|
|
||
|
|
// register window load event globally to prevent not loading elements
|
||
|
|
// since jQuery 3.X ready state is fully async and may be executed after 'load'
|
||
|
|
$(window).on("load", function() {
|
||
|
|
windowLoaded = true;
|
||
|
|
});
|
||
|
|
})(window);
|