https://www.ifp-seminare.de/wp-content/themes/enfold/js/avia-snippet-sticky-header.js?ver=5.3.1.1

1(function($)
2{
3    "use strict";
4
5    $( function()
6    {
7		// decreases header size when user scrolls down
8        avia_header_size();
9    });
10
11
12    function av_change_class($element, change_method, class_name)
13	{
14		if($element[0].classList)
15		{
16			if(change_method == "add")
17			{
18				$element[0].classList.add(class_name);
19			}
20			else
21			{
22				$element[0].classList.remove(class_name);
23			}
24		}
25		else
26		{
27			if(change_method == "add")
28			{
29				$element.addClass(class_name);
30			}
31			else
32			{
33				$element.removeClass(class_name);
34			}
35		}
36	}
37
38
39	function avia_header_size()
40	{
41		var win				= $(window),
42			header          = $('.html_header_top.html_header_sticky #header'),
43			unsticktop		= $('.av_header_unstick_top');
44
45		if( ! header.length && ! unsticktop.length )
46		{
47			return;
48		}
49
50		var logo            = $('#header_main .container .logo img, #header_main .container .logo svg, #header_main .container .logo a'),
51			elements        = $('#header_main .container:not(#header_main_alternate>.container), #header_main .main_menu ul:first-child > li > a:not(.avia_mega_div a, #header_main_alternate a), #header_main #menu-item-shop .cart_dropdown_link'),
52			el_height       = $(elements).first().height(),
53			isMobile        = $.avia_utilities.isMobile,
54			scroll_top		= $('#scroll-top-link'),
55			transparent 	= header.is('.av_header_transparency'),
56			shrinking		= header.is('.av_header_shrinking'),
57			header_meta		= header.find('#header_meta'),
58			topbar_height	= header_meta.length ? header_meta.outerHeight() : 0,
59
60			set_height = function()
61            {
62				var st = win.scrollTop(),
63					newH = 0,
64					st_real = st;
65
66				if( unsticktop )
67				{
68					st -= topbar_height;
69				}
70
71				if( st < 0 )
72				{
73					st = 0;
74				}
75
76				if( shrinking && ! isMobile )
77				{
78					if( st < el_height/2 )
79					{
80						newH = el_height - st;
81						if( st <= 0 )
82						{
83							newH = el_height;
84						}
85
86						av_change_class( header, 'remove', 'header-scrolled' );
87						//header.removeClass('header-scrolled');
88					}
89					else
90					{
91						newH = el_height/2;
92						//header.addClass('header-scrolled');
93						av_change_class( header, 'add', 'header-scrolled' );
94					}
95
96					if( st - 30 < el_height )
97					{
98						av_change_class( header, 'remove', 'header-scrolled-full' );
99					}
100					else
101					{
102						av_change_class( header, 'add', 'header-scrolled-full' );
103					}
104
105
106					elements.css({'height': newH + 'px', 'lineHeight': newH + 'px'});
107					logo.css({'maxHeight': newH + 'px'});
108				}
109
110				if( unsticktop.length )
111				{
112					if( st <= 0 )
113					{
114						if( st_real <= 0 )
115						{
116							st_real = 0;
117						}
118
119						unsticktop.css({"margin-top":"-"+st_real+"px"});
120					}
121					else
122					{
123						unsticktop.css({"margin-top":"-"+topbar_height+"px"});
124					}
125				}
126
127				if( transparent )
128				{
129					if( st > 50 )
130					{
131						//header.removeClass('av_header_transparency');
132						av_change_class( header, 'remove', 'av_header_transparency' );
133					}
134					else
135					{
136						//header.addClass('av_header_transparency');
137						av_change_class( header, 'add', 'av_header_transparency' );
138					}
139				}
140
141
142            };
143
144		if( $('body').is( '.avia_deactivate_menu_resize' ) )
145		{
146			shrinking = false;
147		}
148
149		if( ! transparent && ! shrinking && ! unsticktop.length )
150		{
151			return;
152		}
153
154		win.on( 'debouncedresize',  function()
155		{
156			el_height = $( elements ).attr( 'style',"" ).first().height();
157			set_height();
158		});
159
160		win.on( 'scroll',  function()
161		{
162			window.requestAnimationFrame( set_height );
163		});
164
165		set_height();
166    }
167
168
169})(jQuery);
170