https://ykhospital.com.cn/Content/Areas/Common/scripts/jquery.lazyload.js

1/*
2 * Lazy Load - jQuery plugin for lazy loading images
3 *
4 * Copyright (c) 2007-2013 Mika Tuupola
5 *
6 * Licensed under the MIT license:
7 *
8 * Project home:
9 *
10 * Version: 1.9.3
11 *
12 */
13
14(function($, window, document, undefined) {
15 var $window = $(window);
16
17 $.fn.lazyload = function(options) {
18 var elements = this;
19 var $container;
20 var settings = {
21 threshold  : 0,
22 failure_limit  : 0,
23 event  : "scroll",
24 effect : "show",
25 container  : window,
26 data_attribute : "original",
27 skip_invisible : true,
28 appear : null,
29 load : null,
30 placeholder: "js/grey.gif"
31 };
32
33 function update() {
34 var counter = 0;
35
36 elements.each(function() {
37 var $this = $(this);
38 if (settings.skip_invisible && !$this.is(":visible")) {
39 return;
40 }
41 if ($.abovethetop(this, settings) ||
42 $.leftofbegin(this, settings)) {
43 /* Nothing. */
44 } else if (!$.belowthefold(this, settings) &&
45 !$.rightoffold(this, settings)) {
46 $this.trigger("appear");
47 /* if we found an image we'll load, reset the counter */
48 counter = 0;
49 } else {
50 if (++counter > settings.failure_limit) {
51 return false;
52 }
53 }
54 });
55
56 }
57
58 if(options) {
59 /* Maintain BC for a couple of versions. */
60 if (undefined !== options.failurelimit) {
61 options.failure_limit = options.failurelimit;
62 delete options.failurelimit;
63 }
64 if (undefined !== options.effectspeed) {
65 options.effect_speed = options.effectspeed;
66 delete options.effectspeed;
67 }
68
69 $.extend(settings, options);
70 }
71
72 /* Cache container as jQuery as object. */
73 $container = (settings.container === undefined ||
74 settings.container === window) ? $window : $(settings.container);
75
76 /* Fire one scroll event per scroll. Not one scroll event per image. */
77 if (0 === settings.event.indexOf("scroll")) {
78 $container.bind(settings.event, function() {
79 return update();
80 });
81 }
82
83 this.each(function() {
84 var self = this;
85 var $self = $(self);
86
87 self.loaded = false;
88
89 /* If no src attribute given use data:uri. */
90 if ($self.attr("src") === undefined || $self.attr("src") === false) {
91 if ($self.is("img")) {
92 $self.attr("src", settings.placeholder);
93 }
94 }
95
96 /* When appear is triggered load original image. */
97 $self.one("appear", function() {
98 if (!this.loaded) {
99 if (settings.appear) {
100 var elements_left = elements.length;
101 settings.appear.call(self, elements_left, settings);
102 }
103 $("<img />")
104 .bind("load", function() {
105
106 var original = $self.attr("data-" + settings.data_attribute);
107 $self.hide();
108 if ($self.is("img")) {
109 $self.attr("src", original);
110 } else {
111 $self.css("background-image", "url('" + original + "')");
112 }
113 $self[settings.effect](settings.effect_speed);
114
115 self.loaded = true;
116
117 /* Remove image from array so it is not looped next time. */
118 var temp = $.grep(elements, function(element) {
119 return !element.loaded;
120 });
121 elements = $(temp);
122
123 if (settings.load) {
124 var elements_left = elements.length;
125 settings.load.call(self, elements_left, settings);
126 }
127 })
128 .attr("src", $self.attr("data-" + settings.data_attribute));
129 }
130 });
131
132 /* When wanted event is triggered load original image */
133 /* by triggering appear. */
134 if (0 !== settings.event.indexOf("scroll")) {
135 $self.bind(settings.event, function() {
136 if (!self.loaded) {
137 $self.trigger("appear");
138 }
139 });
140 }
141 });
142
143 /* Check if something appears when window is resized. */
144 $window.bind("resize", function() {
145 update();
146 });
147
148 /* With IOS5 force loading images when navigating with back button. */
149 /* Non optimal workaround. */
150 if ((/(?:iphone|ipod|ipad).*os 5/gi).test(navigator.appVersion)) {
151 $window.bind("pageshow", function(event) {
152 if (event.originalEvent && event.originalEvent.persisted) {
153 elements.each(function() {
154 $(this).trigger("appear");
155 });
156 }
157 });
158 }
159
160 /* Force initial check if images should appear. */
161 $(document).ready(function() {
162 update();
163 });
164
165 return this;
166 };
167
168 /* Convenience methods in jQuery namespace.  */
169 /* Use as $.belowthefold(element, {threshold : 100, container : window}) */
170
171 $.belowthefold = function(element, settings) {
172 var fold;
173
174 if (settings.container === undefined || settings.container === window) {
175 fold = (window.innerHeight ? window.innerHeight : $window.height()) + $window.scrollTop();
176 } else {
177 fold = $(settings.container).offset().top + $(settings.container).height();
178 }
179
180 return fold <= $(element).offset().top - settings.threshold;
181 };
182
183 $.rightoffold = function(element, settings) {
184 var fold;
185
186 if (settings.container === undefined || settings.container === window) {
187 fold = $window.width() + $window.scrollLeft();
188 } else {
189 fold = $(settings.container).offset().left + $(settings.container).width();
190 }
191
192 return fold <= $(element).offset().left - settings.threshold;
193 };
194
195 $.abovethetop = function(element, settings) {
196 var fold;
197
198 if (settings.container === undefined || settings.container === window) {
199 fold = $window.scrollTop();
200 } else {
201 fold = $(settings.container).offset().top;
202 }
203
204 return fold >= $(element).offset().top + settings.threshold + $(element).height();
205 };
206
207 $.leftofbegin = function(element, settings) {
208 var fold;
209
210 if (settings.container === undefined || settings.container === window) {
211 fold = $window.scrollLeft();
212 } else {
213 fold = $(settings.container).offset().left;
214 }
215
216 return fold >= $(element).offset().left + settings.threshold + $(element).width();
217 };
218
219 $.inviewport = function(element, settings) {
220  return !$.rightoffold(element, settings) && !$.leftofbegin(element, settings) &&
221 !$.belowthefold(element, settings) && !$.abovethetop(element, settings);
222  };
223
224 /* Custom selectors for your convenience.  */
225 /* Use as $("img:below-the-fold").something() or */
226 /* $("img").filter(":below-the-fold").something() which is faster */
227
228 $.extend($.expr[":"], {