https://www.registroimprese.it/o/registroimprese-theme/js/plugins/jquery.menu-anchor.js?v=2015-09-13

1(function($) {
2
3    $.MenuAnchor = function(elem, options) {
4        var self = this;
5        var docu = $('body');
6
7        // default settings
8        self.settings = $.extend({
9            window: window.top,
10            pluralId: 'menu-anchor-',
11            contentPostfix: '-content',
12            scroll: true
13        }, options);
14
15        self.scroll = true;
16
17        self.init = function() {
18            
19            $(elem).find('[id^=' +  self.settings.pluralId + ']').each(function(i, e) {
20                // event click
21                $(e).click(function(evt) {
22                    evt.preventDefault();
23                    if (self.settings.scroll){
24                    	console.log("self.scroll = false")
25                    	self.scroll = false;
26                    }
27                        
28
29                    var pos = $('#' + e.id + self.settings.contentPostfix).offset();
30                    console.log(pos.top);
31
32                    $(self.settings.window.document).find('html, body').animate(
33                            {scrollTop: pos.top - 60},
34                    {duration: 'slow',
35                        complete: function() {
36                            if (self.settings.scroll)
37                                self.scroll = true;
38                            self.setSelectedLink(e.id);
39                        },
40                        error: function() {
41                            if (self.settings.scroll)
42                                self.scroll = true;
43                             self.setSelectedLink(e.id);
44                        }
45                    }
46                    );
47                });
48            });
49            
50            // scroll event
51            if (self.settings.scroll) {
52                $(self.settings.window).scroll(function() {
53                    if (self.scroll) {
54                        self.setSelectedLink();
55                    }
56                });
57            }
58
59        };
60
61        self.setSelectedLink = function(anchorId) {
62            var currPos = -1;
63            var currId = '';
64
65            $(elem).find('[id^=' + self.settings.pluralId + ']').each(function(i, e) {
66                if (typeof  self.settings.window !== 'undefined') {
67                    // remove selected class
68                    if ($('#' + e.id).hasClass('selected')) {
69                        $('#' + e.id).removeClass('selected');
70                    }
71
72                    var xOffset = $('#' + e.id + self.settings.contentPostfix).offset();
73
74                    var yOffset = self.settings.window.pageYOffset;
75
76                    var scrPos = xOffset.top - yOffset;
77
78                    if ((scrPos >= 0 && currPos >= scrPos) || currPos <= 0 || currId === '') {
79                        currPos = scrPos;
80                        currId = e.id;
81                    }
82                }
83
84            });
85
86            if (anchorId)
87                currId = anchorId;
88
89            if (currId !== '')
90                $('#' + currId).addClass('selected');
91            
92        };
93
94        self.init();
95        self.setSelectedLink();
96    };
97
98    $.fn.MenuAnchor = function(options) {
99        return this.each(function() {
100            (new $.MenuAnchor(this, options));
101        });
102    };
103}(jQuery));