/*!
 * headroom.js v0.9.3 - give your page some headroom. hide your header until you need it
 * copyright (c) 2016 nick williams - http://wicky.nillia.ms/headroom.js
 * license: mit
 */

!function(a,b){"use strict";"function"==typeof define&&define.amd?define([],b):"object"==typeof exports?module.exports=b():a.headroom=b()}(this,function(){"use strict";function a(a){this.callback=a,this.ticking=!1}function b(a){return a&&"undefined"!=typeof window&&(a===window||a.nodetype)}function c(a){if(arguments.length<=0)throw new error("missing arguments in extend function");var d,e,f=a||{};for(e=1;e<arguments.length;e++){var g=arguments[e]||{};for(d in g)"object"!=typeof f[d]||b(f[d])?f[d]=f[d]||g[d]:f[d]=c(f[d],g[d])}return f}function d(a){return a===object(a)?a:{down:a,up:a}}function e(a,b){b=c(b,e.options),this.lastknownscrolly=0,this.elem=a,this.tolerance=d(b.tolerance),this.classes=b.classes,this.offset=b.offset,this.scroller=b.scroller,this.initialised=!1,this.onpin=b.onpin,this.onunpin=b.onunpin,this.ontop=b.ontop,this.onnottop=b.onnottop,this.onbottom=b.onbottom,this.onnotbottom=b.onnotbottom}var f={bind:!!function(){}.bind,classlist:"classlist"in document.documentelement,raf:!!(window.requestanimationframe||window.webkitrequestanimationframe||window.mozrequestanimationframe)};return window.requestanimationframe=window.requestanimationframe||window.webkitrequestanimationframe||window.mozrequestanimationframe,a.prototype={constructor:a,update:function(){this.callback&&this.callback(),this.ticking=!1},requesttick:function(){this.ticking||(requestanimationframe(this.rafcallback||(this.rafcallback=this.update.bind(this))),this.ticking=!0)},handleevent:function(){this.requesttick()}},e.prototype={constructor:e,init:function(){return e.cutsthemustard?(this.debouncer=new a(this.update.bind(this)),this.elem.classlist.add(this.classes.initial),settimeout(this.attachevent.bind(this),100),this):void 0},destroy:function(){var a=this.classes;this.initialised=!1,this.elem.classlist.remove(a.unpinned,a.pinned,a.top,a.nottop,a.initial),this.scroller.removeeventlistener("scroll",this.debouncer,!1)},attachevent:function(){this.initialised||(this.lastknownscrolly=this.getscrolly(),this.initialised=!0,this.scroller.addeventlistener("scroll",this.debouncer,!1),this.debouncer.handleevent())},unpin:function(){var a=this.elem.classlist,b=this.classes;!a.contains(b.pinned)&&a.contains(b.unpinned)||(a.add(b.unpinned),a.remove(b.pinned),this.onunpin&&this.onunpin.call(this))},pin:function(){var a=this.elem.classlist,b=this.classes;a.contains(b.unpinned)&&(a.remove(b.unpinned),a.add(b.pinned),this.onpin&&this.onpin.call(this))},top:function(){var a=this.elem.classlist,b=this.classes;a.contains(b.top)||(a.add(b.top),a.remove(b.nottop),this.ontop&&this.ontop.call(this))},nottop:function(){var a=this.elem.classlist,b=this.classes;a.contains(b.nottop)||(a.add(b.nottop),a.remove(b.top),this.onnottop&&this.onnottop.call(this))},bottom:function(){var a=this.elem.classlist,b=this.classes;a.contains(b.bottom)||(a.add(b.bottom),a.remove(b.notbottom),this.onbottom&&this.onbottom.call(this))},notbottom:function(){var a=this.elem.classlist,b=this.classes;a.contains(b.notbottom)||(a.add(b.notbottom),a.remove(b.bottom),this.onnotbottom&&this.onnotbottom.call(this))},getscrolly:function(){return void 0!==this.scroller.pageyoffset?this.scroller.pageyoffset:void 0!==this.scroller.scrolltop?this.scroller.scrolltop:(document.documentelement||document.body.parentnode||document.body).scrolltop},getviewportheight:function(){return window.innerheight||document.documentelement.clientheight||document.body.clientheight},getelementphysicalheight:function(a){return math.max(a.offsetheight,a.clientheight)},getscrollerphysicalheight:function(){return this.scroller===window||this.scroller===document.body?this.getviewportheight():this.getelementphysicalheight(this.scroller)},getdocumentheight:function(){var a=document.body,b=document.documentelement;return math.max(a.scrollheight,b.scrollheight,a.offsetheight,b.offsetheight,a.clientheight,b.clientheight)},getelementheight:function(a){return math.max(a.scrollheight,a.offsetheight,a.clientheight)},getscrollerheight:function(){return this.scroller===window||this.scroller===document.body?this.getdocumentheight():this.getelementheight(this.scroller)},isoutofbounds:function(a){var b=0>a,c=a+this.getscrollerphysicalheight()>this.getscrollerheight();return b||c},toleranceexceeded:function(a,b){return math.abs(a-this.lastknownscrolly)>=this.tolerance[b]},shouldunpin:function(a,b){var c=a>this.lastknownscrolly,d=a>=this.offset;return c&&d&&b},shouldpin:function(a,b){var c=a<this.lastknownscrolly,d=a<=this.offset;return c&&b||d},update:function(){var a=this.getscrolly(),b=a>this.lastknownscrolly?"down":"up",c=this.toleranceexceeded(a,b);this.isoutofbounds(a)||(a<=this.offset?this.top():this.nottop(),a+this.getviewportheight()>=this.getscrollerheight()?this.bottom():this.notbottom(),this.shouldunpin(a,c)?this.unpin():this.shouldpin(a,c)&&this.pin(),this.lastknownscrolly=a)}},e.options={tolerance:{up:0,down:0},offset:0,scroller:window,classes:{pinned:"headroom--pinned",unpinned:"headroom--unpinned",top:"headroom--top",nottop:"headroom--not-top",bottom:"headroom--bottom",notbottom:"headroom--not-bottom",initial:"headroom"}},e.cutsthemustard="undefined"!=typeof f&&f.raf&&f.bind&&f.classlist,e});