https://vandraught.com/wp-content/themes/mayosis/js/sticky.js?ver=1.0

1/*
2* HeadsUp 1.5.6
3* @author Kyle Foster (@hkfoster)
4* @license MIT
5*/
6;(function( window, document, undefined ) {
7
8  'use strict';
9
10  // Extend function
11  function extend( a, b ) {
12    for( var key in b ) {
13      if( b.hasOwnProperty( key ) ) {
14        a[ key ] = b[ key ];
15      }
16    }
17    return a;
18  }
19
20  // Throttle function (https://bit.ly/1eJxOqL)
21  function throttle( fn, threshhold, scope ) {
22    threshhold || ( threshhold = 250 );
23    var previous, deferTimer;
24    return function () {
25      var context = scope || this,
26          current = Date.now(),
27          args    = arguments;
28      if ( previous && current < previous + threshhold ) {
29        clearTimeout( deferTimer );
30        deferTimer = setTimeout( function () {
31        previous   = current;
32        fn.apply( context, args );
33        }, threshhold );
34      } else {
35        previous = current;
36        fn.apply( context, args );
37      }
38    };
39  }
40
41  // Class management functions
42  function classReg( className ) {
43    return new RegExp( '(^|\\s+)' + className + '(\\s+|$)' );
44  }
45
46  function hasClass( el, cl ) {
47    return classReg( cl ).test( el.className );
48  }
49
50  function addClass( el, cl ) {
51    if ( !hasClass( el, cl ) ) {
52      el.className = el.className + ' ' + cl;
53    }
54  }
55
56  function removeClass( el, cl ) {
57    el.className = el.className.replace( classReg( cl ), ' ' );
58  }
59
60  // Main function definition
61  function headsUp( selector, options ) {
62    this.selector = document.querySelector( selector );
63    this.options  = extend( this.defaults, options );
64    this.init();
65  }
66
67  // Overridable defaults
68  headsUp.prototype = {
69    defaults : {
70      delay       : 0,
71      sensitivity : 20
72    },
73
74    // Init function
75    init : function( selector ) {
76
77      var self         = this,
78          options      = self.options,
79          selector     = self.selector,
80          oldScrollY   = 0, 
81          winHeight;
82
83      // Resize handler function
84      function resizeHandler() {
85        winHeight = window.innerHeight;
86        return winHeight;
87      }
88
89      // Scroll handler function
90      function scrollHandler() {
91
92        // Scoped variables
93        var newScrollY = window.pageYOffset,
94            docHeight  = document.body.scrollHeight,
95            pastDelay  = newScrollY > options.delay,
96            goingDown  = newScrollY > oldScrollY,
97            fastEnough = newScrollY < oldScrollY - options.sensitivity,
98            rockBottom = newScrollY < 0 || newScrollY + winHeight >= docHeight;
99
100        // Where the magic happens
101        if ( pastDelay && goingDown ) {
102          addClass( selector, 'heads-up' );
103        } else if ( !goingDown && fastEnough && !rockBottom || !pastDelay ) {
104          removeClass( selector, 'heads-up' );
105        }
106
107        // Keep on keeping on
108        oldScrollY = newScrollY;
109      }
110
111      // Attach listeners
112      if ( selector ) {
113        
114        // Trigger initial resize
115        resizeHandler();
116
117        // Resize function listener
118        window.addEventListener( 'resize', throttle( resizeHandler ), false );
119
120        // Scroll function listener
121        window.addEventListener( 'scroll', throttle( scrollHandler, 100 ), false );
122      }
123    }
124  };
125
126  window.headsUp = headsUp;
127
128})( window, document );
129
130// Instantiate HeadsUp
131new headsUp( '.smartenble' );