https://transitionsofmotherhood.com/wp-content/themes/harper-theme.1.2.0/js/sticky.js?ver=1.0.0

1/*!
2 * Headhesive.js v1.2.3 - An on-demand sticky header
3 * Author: Copyright (c) Mark Goodyear <@markgdyr> <http://markgoodyear.com>
4 * Url: http://markgoodyear.com/labs/headhesive
5 * License: MIT
6 */
7(function(root, factory) {
8  if (typeof define === "function" && define.amd) {
9    define([], function() {
10      return factory();
11    });
12  } else if (typeof exports === "object") {
13    module.exports = factory();
14  } else {
15    root.Headhesive = factory();
16  }
17})(this, function() {
18  "use strict";
19  var _mergeObj = function(to, from) {
20    for (var p in from) {
21      if (from.hasOwnProperty(p)) {
22        to[p] = typeof from[p] === "object" ? _mergeObj(to[p], from[p]) : from[p];
23      }
24    }
25    return to;
26  };
27  var _throttle = function(func, wait) {
28    var _now = Date.now || function() {
29      return new Date().getTime();
30    };
31    var context, args, result;
32    var timeout = null;
33    var previous = 0;
34    var later = function() {
35      previous = _now();
36      timeout = null;
37      result = func.apply(context, args);
38      context = args = null;
39    };
40    return function() {
41      var now = _now();
42      var remaining = wait - (now - previous);
43      context = this;
44      args = arguments;
45      if (remaining <= 0) {
46        clearTimeout(timeout);
47        timeout = null;
48        previous = now;
49        result = func.apply(context, args);
50        context = args = null;
51      } else if (!timeout) {
52        timeout = setTimeout(later, remaining);
53      }
54      return result;
55    };
56  };
57  var _getScrollY = function() {
58    return window.pageYOffset !== undefined ? window.pageYOffset : (document.documentElement || document.body.parentNode || document.body).scrollTop;
59  };
60  var _getElemY = function(elem, side) {
61    var pos = 0;
62    var elemHeight = elem.offsetHeight;
63    while (elem) {
64      pos += elem.offsetTop;
65      elem = elem.offsetParent;
66    }
67    if (side === "bottom") {
68      pos = pos + elemHeight;
69    }
70    return pos;
71  };
72  var Headhesive = function(elem, options) {
73    if (!("querySelector" in document && "addEventListener" in window)) {
74      return;
75    }
76    this.visible = false;
77    this.options = {
78      offset: 1200,
79      offsetSide: "top",
80      classes: {
81        clone: "headhesive",
82        stick: "headhesive--stick",
83        unstick: "headhesive--unstick"
84      },
85      throttle: 250,
86      onInit: function() {},
87      onStick: function() {},
88      onUnstick: function() {},
89      onDestroy: function() {}
90    };
91    this.elem = typeof elem === "string" ? document.querySelector(elem) : elem;
92    this.options = _mergeObj(this.options, options);
93    this.init();
94  };
95  Headhesive.prototype = {
96    constructor: Headhesive,
97    init: function() {
98      this.clonedElem = this.elem.cloneNode(true);
99      this.clonedElem.className += " " + this.options.classes.clone;
100      document.body.insertBefore(this.clonedElem, document.body.firstChild);
101      if (typeof this.options.offset === "number") {
102        this.scrollOffset = this.options.offset;
103      } else if (typeof this.options.offset === "string") {
104        this._setScrollOffset();
105      } else {
106        throw new Error("Invalid offset: " + this.options.offset);
107      }
108      this._throttleUpdate = _throttle(this.update.bind(this), this.options.throttle);
109      this._throttleScrollOffset = _throttle(this._setScrollOffset.bind(this), this.options.throttle);
110      window.addEventListener("scroll", this._throttleUpdate, false);
111      window.addEventListener("resize", this._throttleScrollOffset, false);
112      this.options.onInit.call(this);
113    },
114    _setScrollOffset: function() {
115      if (typeof this.options.offset === "string") {
116        this.scrollOffset = _getElemY(document.querySelector(this.options.offset), this.options.offsetSide);
117      }
118    },
119    destroy: function() {
120      document.body.removeChild(this.clonedElem);
121      window.removeEventListener("scroll", this._throttleUpdate);
122      window.removeEventListener("resize", this._throttleScrollOffset);
123      this.options.onDestroy.call(this);
124    },
125    stick: function() {
126      if (!this.visible) {
127        this.clonedElem.className = this.clonedElem.className.replace(new RegExp("(^|\\s)*" + this.options.classes.unstick + "(\\s|$)*", "g"), "");
128        this.clonedElem.className += " " + this.options.classes.stick;
129        this.visible = true;
130        this.options.onStick.call(this);
131      }
132    },
133    unstick: function() {
134      if (this.visible) {
135        this.clonedElem.className = this.clonedElem.className.replace(new RegExp("(^|\\s)*" + this.options.classes.stick + "(\\s|$)*", "g"), "");
136        this.clonedElem.className += " " + this.options.classes.unstick;
137        this.visible = false;

138        this.options.onUnstick.call(this);
139      }
140    },
141    update: function() {
142      if (_getScrollY() > this.scrollOffset) {
143        this.stick();
144      } else {
145        this.unstick();
146      }
147    }
148  };
149  return Headhesive;
150  
151});