https://magazin24.se/wp-content/themes/magazin24/js/jquery.appear.js?ver=1.1.1

1/*
2 * jQuery appear plugin
3 *
4 * Copyright (c) 2012 Andrey Sidorov
5 * licensed under MIT license.
6 *
7 * https://github.com/morr/jquery.appear/
8 *
9 * Version: 0.3.3
10 */
11(function($) {
12  var selectors = [];
13
14  var check_binded = false;
15  var check_lock = false;
16  var defaults = {
17    interval: 250,
18    force_process: false
19  }
20  var $window = $(window);
21
22  var $prior_appeared;
23
24  function process() {
25    check_lock = false;
26    for (var index = 0; index < selectors.length; index++) {
27      var $appeared = $(selectors[index]).filter(function() {
28        return $(this).is(':appeared');
29      });
30
31      $appeared.trigger('appear', [$appeared]);
32
33      if ($prior_appeared) {
34        var $disappeared = $prior_appeared.not($appeared);
35        $disappeared.trigger('disappear', [$disappeared]);
36      }
37      $prior_appeared = $appeared;
38    }
39  }
40
41  // "appeared" custom filter
42  $.expr[':']['appeared'] = function(element) {
43    var $element = $(element);
44    if (!$element.is(':visible')) {
45      return false;
46    }
47
48    var window_left = $window.scrollLeft();
49    var window_top = $window.scrollTop();
50    var offset = $element.offset();
51    var left = offset.left;
52    var top = offset.top;
53
54    if (top + $element.height() >= window_top &&
55        top - ($element.data('appear-top-offset') || 0) <= window_top + $window.height() &&
56        left + $element.width() >= window_left &&
57        left - ($element.data('appear-left-offset') || 0) <= window_left + $window.width()) {
58      return true;
59    } else {
60      return false;
61    }
62  }
63
64  $.fn.extend({
65    // watching for element's appearance in browser viewport
66    appear: function(options) {
67      var opts = $.extend({}, defaults, options || {});
68      var selector = this.selector || this;
69      if (!check_binded) {
70        var on_check = function() {
71          if (check_lock) {
72            return;
73          }
74          check_lock = true;
75
76          setTimeout(process, opts.interval);
77        };
78
79        $(window).scroll(on_check).resize(on_check);
80        check_binded = true;
81      }
82
83      if (opts.force_process) {
84        setTimeout(process, opts.interval);
85      }
86      selectors.push(selector);
87      return $(selector);
88    }
89  });
90
91  $.extend({
92    // force elements's appearance check
93    force_appear: function() {
94      if (check_binded) {
95        process();
96        return true;
97      };
98      return false;
99    }
100  });
101})(jQuery);