/**
 * responsive menu
 * version: 0.2.1
 * url: private
 * description: a drop-down responsive menu for responsive layouts
 * requires: jquery
 * optional: modernizr
 * author: jbowyers
 * copyright: 2014-2015 jbowyers
 * license: this file is part of responsive menu.
 * responsive menu is free software: you can redistribute it and/or modify
 * it under the terms of the gnu general public license as published by
 * the free software foundation, either version 3 of the license, or
 * (at your option) any later version.
 *
 * responsive menu is distributed in the hope that it will be useful,
 * but without any warranty; without even the implied warranty of
 * merchantability or fitness for a particular purpose.  see the
 * gnu general public license for more details.
 *
 * you should have received a copy of the gnu general public license
 * along with this program.  if not, see http://www.gnu.org/licenses/
 */

;(function( $, window, document, math, undefined ) {

    'use strict';
    var pluginname = 'rmenu';

    /**
     * the plugin
     * @param {object} el - the menu container typically a nav element
     * @param {object} options - plugin options object litteral
     * @returns {plugin}
     * @constructor
     */
    var plugin = function( el, options ) {

        // clone this object
        var o = this;

        /**
         * initialize option defaults and set options =============================
         * @type {{minwidth: string, togglesel: string, menusel: string, menuitemssel: string, transitionspeed: number, animatebool: string, acceleratebool: string}}
         */
        o.optionsinit = {

            /**
             * minimum width for expanded layout in pixels - string should match media query in css file
             * must be in pixels and include px units if not using modernizr.
             * @default '769px'
             */
            minwidth: '769px',

            /**
             * the opening and closing speed of the menus in milliseconds
             * @default 400
             */
            transitionspeed: 400,

            /**
             * the jquery easing function - used with jquery transitions
             * @default 'swing'
             * @options 'swing', 'linear'
             */
            jqueryeasing: 'swing',

            /**
             * the css3 transitions easing function - used with css3 transitions
             * @default 'ease'
             */
            css3easing: 'ease',

            /**
             * use button as toggle link - instead of text
             * @default true
             */
            togglebtnbool: true,

            /**
             * the toggle link selector
             * @default '.rm-toggle'
             */
            togglesel: '.rm-toggle',

            /**
             * the menu/sub-menu selector
             * @default 'ul'
             */
            menusel: 'ul',

            /**
             * the menu items selector
             * @default 'li'
             */
            menuitemssel: 'li',

            /**
             * use css3 animation/transitions boolean
             * @default true
             * do not use animation/transitions: false
             */
            animatebool: true,

            /**
             * force gpu acceleration boolean
             * @default false
             * do not force: false
             */
            acceleratebool: false,

            /**
             * the setup complete callback function
             * @default 'false'
             */
            setupcallback: false,

            /**
             * the tabindex start value - integer
             * @default 1
             */
            tabindexstart: 1,

            /**
             * use development mode - outputs information to console
             * @default false
             */
            developmentmode: false
        };
        o.options = $.extend( {}, o.optionsinit, options );

        // define public objects and vars =========================================

        // toggle link object
        o.tbutton = $( o.options.togglesel );

        // the class applied to the toggle link element to make it a button
        o.tbuttonclass = 'rm-button';

        // the class applied to the toggle link element when it is visible
        o.tbuttonshowclass = 'rm-show';

        // the class applied to the toggle link element when it is visible
        o.tbuttonactiveclass = 'rm-active';

        // nav element object - contains the menus
        o.el = $( el );

        // the class the plugin adds to the nav element
        o.navelementclass = 'rm-nav';

        // container object - contains everything - the nav element and toggle link
        o.container = o.el.parent();

        // the class the plugin adds to the container of the nav element
        o.containerclass = 'rm-container';

        // the class applied to container element to trigger expanded layout
        o.expandedclass = 'rm-layout-expanded';

        // the class applied to container element to trigger contracted layout
        o.contractedclass = 'rm-layout-contracted';

        // the class that is removed from the toggle and nav element when js is supported
        o.nojsclass = 'rm-nojs';

        // all menu elements
        o.menus = o.el.find( o.options.menusel );

        // the class applied to all menu elements
        o.menuclass = 'rm-menu';

        // top level menu object - contains the menus
        o.topmenu = o.el.children( o.options.menusel );

        // the class the plugin adds to the top menu element
        o.topmenuclass = 'rm-top-menu';

        // the class applied to menu/sub-menu element when menu is expanded
        o.menuexpandedclass = 'rm-menu-expanded';

        // the class applied to menu/sub-menu element when menu is hidden
        o.menuhiddenclass = 'accessibly-hidden';

        // the class the plugin adds to the menu elements when calculating height
        o.menucalcclass = 'rm-calculate';

        // the class applied to all menu items
        o.menuitemclass = 'rm-menu-item';

        // the focused parent element
        o.itemfocused = false;

        // the class applied to menu items that contain a sub-menu
        o.parentclass = 'rm-parent';

        // the class applied to a menu item when its menu is expanded
        o.itemhoverclass = 'rm-hover';

        // the class applied to the first menu item
        o.itemfirst = 'rm-first';

        // the class applied to the last menu item
        o.itemlast = 'rm-last';

        // the class applied to the second to last menu item
        o.item2ndlast = 'rm-2nd-last';

        // the css3 animate class variable
        o.animateclass = 'rm-css-animate';

        // the css3 animate boolean
        o.animatebool = o.options.animatebool;

        // the gpu accelerate class variable
        o.accelerateclass = 'rm-accelerate';

        // the gpu accelerate boolean
        o.acceleratebool = o.options.acceleratebool;

        // the touchmove boolean - did a touchmove event just occur
        o.touchmovebool = false;

        // resize and pause hover event timer function
        o.timer = false;

        // the window width - used to verify a window width change
        o.windowwidth = $( window ).width();


        /**
         * initiate plugin =========================================
         * @returns {plugin}
         */
        o.init = function() { // should only be called once

            // set up the plugin
            o.setup();

            // window event handlers
            $( window ).on({

                // reset on screen resize
                'resize': function() {

                    // test if width has resized - as opposed to height
                    if ($( window ).width() !== o.windowwidth) {

                        // update the window width
                        o.windowwidth = $( window ).width();

                        // adjust layout
                        cleartimeout( o.timer );
                        o.timer = settimeout( o.adjust, 500 );

                    }
                }
            });

            // run setupcallback function
            if ( typeof( o.options.setupcallback ) === "function" ) {
                o.options.setupcallback();
            }

            return this;
        };

        /**
         * setup plugin ============================================================
         * @returns {plugin}
         */
        o.setup = function() { // can be called again to reset plugin

            // add the container class to the nav element's parent element
            o.container.addclass( o.containerclass );

            // add rm-button class if using button
            if ( o.options.togglebtnbool ) {
                o.tbutton.addclass( o.tbuttonclass );
            } else {
                o.tbutton.removeclass( o.tbuttonclass );
            }

            // remove o.nojsclass class and add click event to toggle link
            o.tbutton
                .removeclass( o.nojsclass )
                .off( 'mousedown.rm focusin.rm click.rm' )

                // use mousedown and focus to trigger toggle
                .on( 'mousedown.rm focusin.rm', tbuttonfocus )

                // disable click events
                .on( 'click.rm', tbuttonclick )

                .attr( 'tabindex', 0 )
            ;

            // add menu class and make submenus accessibly hidden
            o.menus
                .addclass( o.menuclass )
                .attr( 'aria-hidden', 'false' )
                .hide();

            // add top menu class
            o.topmenu.addclass( o.topmenuclass );

            // adjust o.animatebool
            if ( o.animatebool ) { // using css3 transitions

                // check if transitions and acceleration are supported
                if ( typeof modernizr !== 'undefined' ) { // test with modernizr
                    if ( !modernizr.csstransitions ) {
                        o.animatebool = false;
                        o.acceleratebool = false;
                    } else if ( !modernizr.csstransforms3d ) {
                        o.acceleratebool = false;
                    }
                } else if ( !transitionssupported() ) {
                    o.animatebool = false;
                    o.acceleratebool = false;
                } else if ( !transform3dsupported()  ) {
                    o.acceleratebool = false;
                }
            } else {
                o.acceleratebool = false;
            }

            // add animate and accelerate classes if css3 animation
            if ( o.animatebool ) {
                o.menus.addclass( o.animateclass );
                if ( o.acceleratebool ) {
                    o.menus.addclass( o.accelerateclass );
                }
            }

            // add and remove classes and click events
            o.el
                .removeclass( o.nojsclass )
                .addclass( o.navelementclass )
                .off( 'focusin.rm focusout.rm click.rm touchend.rm touchmove.rm' )

                // use focus to trigger menu item focus/hover behaviour
                .on( 'focusin.rm', o.options.menuitemssel, itemfocus )

                // de-focus menu on focus out
                .on( 'focusout.rm', o.topmenu, menublur )

                // use click and touchend to trigger click behaviour
                .on( 'click.rm touchend.rm', o.options.menuitemssel, itemclick )

                // set touchmovebool to true on touchmove event
                .on( 'touchmove.rm', o.options.menuitemssel, touchmove )
                .find( o.options.menuitemssel )
                    .each( function(i) {
                        var $el = $( this );
                        $el
                            .addclass( o.menuitemclass)
                            .children( 'a' ).attr( 'tabindex', 0 )
                        ;
                        if ( $el.is( ':first-child') ) {
                            $el.addclass( o.itemfirst );
                        }
                        if ( $el.is( ':last-child') ) {
                            $el.addclass( o.itemlast )
                                .prev().addclass( o.item2ndlast );
                        }
                    })
                    .addback()
                    .removeclass( o.parentclass )
                    .has( o.options.menusel )
                        .addclass( o.parentclass )
            ;

            // apply initial layout and adjustments
            o.adjust();

            return this;
        };

        /**
         * adjust plugin ============================================================
         * @param {string} minwidth  - the min-width value (including units)
         * minwidth must be in pixels if not using modernizr. should match media query in css file
         */
        o.adjust = function( minwidth ) {

            // get the breakpoint minimum width
            minwidth = typeof minwidth !== 'undefined' ? minwidth : o.options.minwidth;

            // check browser width - set menu layout
            if ( typeof modernizr !== 'undefined' && modernizr.mq('only all') ) { // mqs supported - test with modernizr
                if ( o.options.developmentmode ) {
                    console.log( 'modernizr: mq supported' );
                }
                if ( !modernizr.mq( '( min-width: ' + minwidth + ' )' ) ) {
                    o.layoutcontracted();
                } else {
                    o.layoutexpanded();
                }

            } else { // unable to detect mq support - test width using outerwidth - less reliable
                if ( o.options.developmentmode ) {
                    console.log( 'unable to detect mq support' );
                }
                if ( $( window ).outerwidth() < parseint( minwidth ) ) {
                    o.layoutcontracted();
                } else {
                    o.layoutexpanded();
                }
            }
        };

        // external helper functions ===============================================

        /**
         * contracted layout
         * @returns {plugin}
         */
        o.layoutcontracted = function() {

            if ( !o.container.hasclass( o.contractedclass ) ) { // not contracted

                // contract any expanded siblings and their children
                menublur( { 'type': 'layoutcontracted' } );

                // apply contracted class
                o.container
                    .removeclass( o.expandedclass )
                    .addclass( o.contractedclass )
                    .find( '.' + o.itemhoverclass ).removeclass( o.itemhoverclass );

                if ( o.animatebool ) { // using css3 transitions

                    // recalculate menu heights
                    o.calculateheights();
                }

                // remove hover events
                o.el.off( 'mouseenter.le mouseleave.le' );

                // show toggle link and setup topmenu
                o.tbutton.addclass( o.tbuttonshowclass );
                if ( !o.tbutton.hasclass( o.tbuttonactiveclass ) ) { // topmenu not active

                    // hide topmenu
                    o.topmenu
                        .addclass( o.menuhiddenclass )
                        .show()
                        .removeclass( o.menuexpandedclass )
                    ;
                } else { // topmenu is active

                    // show topmenu
                    o.topmenu
                        .removeclass( o.menuhiddenclass )
                        .show()
                        .addclass( o.menuexpandedclass );
                    if ( o.animatebool ) { // using css3 transitions
                        o.topmenu
                            .css({
                                'max-height': 'none'
                            })
                        ;
                    }
                }
            }

            if ( o.options.developmentmode ) {
                console.log( 'responsive-menu: contracted layout' );
            }
            return this;
        };

        /**
         * expanded layout
         * @returns {plugin}
         */
        o.layoutexpanded = function() {

            if ( !o.container.hasclass( o.expandedclass ) ) { // not expanded

                // contract any expanded siblings and their children
                menublur( { 'type': 'layoutexpanded' } );

                // apply expanded class to container
                o.container
                    .removeclass( o.contractedclass )
                    .addclass( o.expandedclass  )
                    .find( '.' + o.itemhoverclass ).removeclass( o.itemhoverclass );

                if ( o.animatebool ) { // using css3 transitions

                    // recalculate menu heights
                    o.calculateheights();
                }

                // re-apply mouse events
                o.el.off( 'mouseenter.le mouseleave.le' )

                    // add mouseenter to all menu items to trigger focus
                    .on( 'mouseenter.le', o.options.menuitemssel, itemfocus )

                    // add mouseleave to trigger focus when re-entering parent of expanded menu
                    .on( 'mouseleave.le', o.options.menuitemssel, itemleave )

                    // add mouseleave on topmenu to trigger menu blur
                    .on( 'mouseleave.le', o.topmenu, menublur )
                ;

                // show menu - hide toggle link
                o.tbutton.removeclass( o.tbuttonshowclass );
                o.topmenu.removeclass( o.menuhiddenclass )
                    .show()
                    .addclass( o.menuexpandedclass );
                if ( o.animatebool ) { // using css3 transitions
                    o.topmenu
                        .css({
                            'max-height': 'none',
                            'overflow': 'visible'
                        })
                    ;
                }
            }
            if ( o.options.developmentmode ) {
                console.log( 'responsive-menu: expanded layout' );
            }
            return this;
        };

        /**
         * calculate the heights of each submenu and store in data object, reset styles
         * used when css3 transitions are enabled
         * @returns {plugin}
         */
        o.calculateheights = function() {

            // unstyle menus to original state to measure heights and then reapply styles
            o.menus
                .addclass( o.menucalcclass )
                .removeclass( o.menuexpandedclass )
                .attr( 'style', '' )
                .show( 0 );

            // reselect to force application of styles
            o.menus.each( function () {
                    var $el = $( this );
                    $el
                        .data( 'height', $el.height() )
                    ;
                })
                .css( {
                    'max-height': '0'
                })
                .removeclass( o.menucalcclass )
            ;
            return this;
        };

        /**
         * toggle visibility of entire menu
         * @param {object} el - the toggle link element
         */
        o.togglemenu = function( el ) {

            // contract all sub-menus
            contract( o.topmenu );

            if ( !o.topmenu.hasclass( o.menuhiddenclass ) ) { // topmenu is visible

                // hide topmenu
                $( el ).removeclass( o.tbuttonactiveclass );
                contract( o.container );

            } else { // menu is hidden

                // show topmenu
                $( el ).addclass( o.tbuttonactiveclass );
                o.topmenu.removeclass( o.menuhiddenclass );
                if ( o.animatebool ) { // using css3 transitions
                    o.topmenu.css( 'max-height', '0' );
                } else { // use jquery animation
                    o.topmenu.hide( 0 );
                }
                expand( o.el );
            }

        };

        // internal event handler functions ===============================================

        /**
         * toggle btn focus and mousedown event handler
         * @param {event} e - event object
         */
        var tbuttonfocus = function( e ) {

            e.stoppropagation();

            var $el = $( e.target );

            cleartimeout( o.timer );
            o.timer = settimeout( function () {
                o.togglemenu( e.target );
            }, 100 );
        };

        /**
         * toggle btn click event handler
         * @param {event} e - event object
         */
        var tbuttonclick = function( e ) {

            e.preventdefault();
            e.stoppropagation();
        };

        /**
         * item click and touchend event handler
         * @param {event} e - event object
         */
        var itemclick = function( e ) {

            var $el = $( e.currenttarget );

            e.stoppropagation();

            if ( ( $el.hasclass( o.itemhoverclass ) || !$el.hasclass( o.parentclass ) ) && !o.touchmovebool ) {
                location.href = $el.children( 'a' ).attr('href');
                menublur( e );
            } else if ( e.type !== 'touchend' ) {
                e.preventdefault();
            }

            o.touchmovebool = false;
        };

        /**
         * menu item focus and mouseenter event handler -
         * triggers: focus, mouseenter
         * @param {event} e - event object
         */
        var itemfocus = function( e ) {

            // get current target before it changes
            var $el = $( e.currenttarget );

            e.stoppropagation();

            // add focus if item does not have focus
            if ( e.type !== 'focusin' ) {
                $el.children( 'a' ).not( ':focus' ).focus();
            }
            o.itemfocused = $el;

            cleartimeout( o.timer );
            o.timer = settimeout( function () {

                // expand topmenu if toggle button is active and menu is contracted
                if ( o.tbutton.hasclass( o.tbuttonshowclass ) && !o.tbutton.hasclass( o.tbuttonactiveclass )) {
                    o.togglemenu( o.tbutton.get(0) );
                }

                // expand menu
                if ( $el.hasclass( o.parentclass ) ) {

                    if ( !$el.hasclass( o.itemhoverclass ) ) {

                        // contract any expanded siblings and their children
                        contract( $el.parent() );

                        expand( $el );
                    }
                } else {
                    // contract any expanded siblings and their children
                    contract( $el.parent() );
                }
            }, 100 );
        };

        /**
         * touchmove event handler
         * @param {event} e - event object
         */
        var touchmove = function( e ) {
            o.touchmovebool = true;
        };

        /**
         * topmenu mouseleave and foucusout event handler
         * triggers: mouseleave, focusout
         * @param {event} e - event object
         */
        var menublur = function( e ) {

            // define event type if e is undefined
            e = e || { 'type': 'callback' };

            cleartimeout( o.timer );
            o.timer = settimeout( function () {

                if ( o.itemfocused ) {
                    o.itemfocused.children( 'a' ).blur();
                    o.itemfocused = false;
                }
                contract( o.topmenu );
            }, 100 );
        };

        /**
         * sub-menu item mouseleave event handler - used with expanded layout
         * triggers: mouseleave
         * @param {event} e - event object
         */
        var itemleave = function( e ) {

            // get current target before it changes
            var $el = $( e.currenttarget );

            cleartimeout( o.timer );
            o.timer = settimeout( function () {

                // focus the parent element of the expanded menu
                $el.parent().parent().children( 'a' ).focus();
            }, 100 );
        };

        /**
         * the css3 transition end contract event handler - used to add call-back functions to css3 transitions
         * @param {event} e - event object
         */
        var transitionendcontract = function( e ) {

            if ( e.originalevent.propertyname === 'max-height' ) {

                var $el = $( e.currenttarget );
                e.stoppropagation();

                // menu contracted
                $el
                    .css( {
                        'transition': '',
                        'max-height': '0',
                        'overflow': 'hidden'
                    } )
                    .removeclass( o.menuexpandedclass )
                    .off( 'transitionend webkittransitionend otransitionend mstransitionend' )
                    .parent().find( '.' + o.itemhoverclass ).addback().removeclass( o.itemhoverclass )
                ;

                if ( $el.hasclass( o.topmenuclass ) ) { // is topmenu

                    // accessibly hide topmenu
                    $el
                        .addclass( o.menuhiddenclass )
                        .show( 0 );
                }

                // scroll to expanded menu
                scrollmenu( o.itemfocused );
            }
        };

        /**
         * the css3 transition end expand event handler - used to add call-back functions to css3 transitions
         * @param {event} e - event object
         */
        var transitionendexpand = function( e ) {

            if ( e.originalevent.propertyname === 'max-height' ) {
                var $el = $( e.currenttarget );
                e.stoppropagation();

                // menu expanded
                $el
                    .removeclass( o.menuhiddenclass )
                    .css( {
                        'transition': '',
                        'max-height': 'none',
                        'overflow': 'visible'
                    } )
                    .addclass( o.menuexpandedclass )
                    .off( 'transitionend webkittransitionend otransitionend mstransitionend' )
                ;
                $el.parent( '.' + o.parentclass ).addclass( o.itemhoverclass );

                // scroll to expanded menu
                scrollmenu( o.itemfocused );
            }
        };

        // internal helper functions ===============================================

        /**
         * contract sub-menus
         * @param {object} $parent - the parent element of the menu item initiating the event
         */
        var contract = function( $parent ) {

            var $menus = $parent.find( o.options.menusel );

            if ( o.animatebool ) { // using css3 transitions

                // set max-height to height of each expanded menu
                $menus.each( function(){
                    var $el = $( this );
                    if ( $el.height() !== 0 ) {
                        $el
                            .css({
                                'max-height': $el.height(),
                                'transition': 'max-height ' + string( o.options.transitionspeed / 1000 ) + 's ' + o.options.css3easing,
                                'overflow': 'hidden'
                            })
                            .on( 'transitionend webkittransitionend otransitionend mstransitionend', transitionendcontract )
                        ;
                    } else {
                        $menus.not( $el );
                    }
                });

                // must force a redraw so transition will occur
                $menus.hide(0).show(0);

                // contract menu
                $menus
                    .css({
                        'max-height': '0'
                    })
                    .removeclass( o.menuexpandedclass )
                ;

            } else { // use jquery animation

                // contract menus
                $menus.each( function() {

                    var $el = $( this );

                    if ( $el.height() !== 0 ) {

                        $el
                            .slideup( o.options.transitionspeed, o.options.jqueryeasing, function () {

                                $el
                                    .css( 'overflow', 'visible' )
                                    .removeclass( o.menuexpandedclass )
                                    .parent( '.' + o.parentclass )
                                    .removeclass( o.itemhoverclass )
                                ;

                                if ( $el.hasclass( o.topmenuclass ) ) {
                                    o.topmenu.addclass( o.menuhiddenclass );
                                }

                                // scroll to expanded menu
                                scrollmenu( o.itemfocused );
                            })
                        ;
                    }
                });
            }
        };

        /**
         * expand sub-menu
         * @param {object} $el - the menu item initiating the event
         */
        var expand = function( $el ) {

            // define menu
            var $menu = $el.children( o.options.menusel );

            // remove hover class from siblings
            $el.siblings( '.' + o.itemhoverclass )
                .removeclass( o.itemhoverclass );

            if ( o.animatebool ) { // using css3 transitions

                // expand menu
                $menu
                    .css({
                        'transition': 'max-height ' + string( o.options.transitionspeed / 1000 ) + 's ' + o.options.css3easing,
                        'max-height': $menu.data('height')
                    })
                    .on( 'transitionend webkittransitionend otransitionend mstransitionend', transitionendexpand )
                ;
            } else { // use jquery animation

                // expand menu
                $menu
                    .slidedown( o.options.transitionspeed, o.options.jqueryeasing, function() {
                        $el.addclass( o.itemhoverclass );
                        $menu
                            .addclass( o.menuexpandedclass )
                            .css( 'overflow','visible' )
                        ;
                        console.log('jquery expand');

                        // scroll to expanded menu
                        scrollmenu( o.itemfocused );
                    })
                ;
            }
        };

        // initialize ----------------------------------------------------------------
        o.init( el );

        return this;
    };

    /**
     * create plugin obects
     * @param {object} options - plugin options
     * @returns {*}
     */
    $.fn[ pluginname ] = function( options ) {

        // return collection of elements
        return this.each( function() {
            var $el = $( this );
            if ( !$el.data( pluginname ) ) {
                $el.data( pluginname, new plugin( this, options ) );
            }
        });
    };

    // out of scope private functions ==================================================

    /**
     * test for transform3d support
     * @returns {boolean}
     */
    var transform3dsupported = function() {
        var el = document.createelement('p'),
            has3d,
            transforms = {
                'webkittransform':'-webkit-transform',
                'otransform':'-o-transform',
                'mstransform':'-ms-transform',
                'moztransform':'-moz-transform',
                'transform':'transform'
            };

        // add it to the body to get the computed style
        document.body.insertbefore(el, null);

        for(var t in transforms){
            if( el.style[t] !== undefined ){
                el.style[t] = 'translate3d(1px,1px,1px)';
                has3d = window.getcomputedstyle(el).getpropertyvalue(transforms[t]);
            }
        }

        document.body.removechild(el);

        return (has3d !== undefined && has3d.length > 0 && has3d !== "none");
    };

    /**
     * test for css3 transitions support
     * @returns {boolean}
     */
    var transitionssupported = function() {
        var b = document.body || document.documentelement,
            s = b.style,
            p = 'transition';

        if (typeof s[p] === 'string') { return true; }

        // tests for vendor specific prop
        var v = ['moz', 'webkit', 'webkit', 'khtml', 'o', 'ms'];
        p = p.charat(0).touppercase() + p.substr(1);

        for (var i=0; i<v.length; i++) {
            if (typeof s[v[i] + p] === 'string') { return true; }
        }

        return false;
    };

    /**
     * scroll menu into viewport if off screen
     * @returns {boolean}
     */
    var scrollmenu = function( $el ) {

        if ( $el.length ) {

            var viewtop = $( window ).scrolltop();
            var viewbottom = viewtop + $( window ).height();
            var boundstop = $el.offset().top;
            var boundsbottom = boundstop + $el.outerheight();

            if ( boundsbottom > viewbottom || boundstop < viewtop ) {
                $( 'html, body' ).animate( { scrolltop: boundstop }, 'slow' );
            }
        }
    };

})( jquery, window, document, math );