text: /* global screenReaderText */
  /**
   * Theme functions file.
   *
   * Contains handlers for navigation and widget area.
   */
  
  ( function( $ ) {
  	var $body, $window, $sidebar, resizeTimer,
  		secondary, button;
  
  	function initMainNavigation( container ) {
  		// Add dropdown toggle that display child menu items.
  		container.find( '.menu-item-has-children > a' ).after( '<button class="dropdown-toggle" aria-expanded="false">' + screenReaderText.expand + '</button>' );
  
  		// Toggle buttons and submenu items with active children menu items.
  		container.find( '.current-menu-ancestor > button' ).addClass( 'toggle-on' );
  		container.find( '.current-menu-ancestor > .sub-menu' ).addClass( 'toggled-on' );
  
  		container.find( '.dropdown-toggle' ).click( function( e ) {
  			var _this = $( this );
  			e.preventDefault();
  			_this.toggleClass( 'toggle-on' );
  			_this.next( '.children, .sub-menu' ).toggleClass( 'toggled-on' );
  			_this.attr( 'aria-expanded', _this.attr( 'aria-expanded' ) === 'false' ? 'true' : 'false' );
  			_this.html( _this.html() === screenReaderText.expand ? screenReaderText.collapse : screenReaderText.expand );
  		} );
  	}
  	initMainNavigation( $( '.main-navigation' ) );
  
  	// Re-initialize the main navigation when it is updated, persisting any existing submenu expanded states.
  	$( document ).on( 'customize-preview-menu-refreshed', function( e, params ) {
  		if ( 'primary' === params.wpNavMenuArgs.theme_location ) {
  			initMainNavigation( params.newContainer );
  
  			// Re-sync expanded states from oldContainer.
  			params.oldContainer.find( '.dropdown-toggle.toggle-on' ).each(function() {
  				var containerId = $( this ).parent().prop( 'id' );
  				$( params.newContainer ).find( '#' + containerId + ' > .dropdown-toggle' ).triggerHandler( 'click' );
  			});
  		}
  	});
  
  	secondary = $( '#secondary' );
  	button = $( '.site-branding' ).find( '.secondary-toggle' );
  
  	// Enable menu toggle for small screens.
  	( function() {
  		var menu, widgets, social;
  		if ( ! secondary.length || ! button.length ) {
  			return;
  		}
  
  		// Hide button if there are no widgets and the menus are missing or empty.
  		menu    = secondary.find( '.nav-menu' );
  		widgets = secondary.find( '#widget-area' );
  		social  = secondary.find( '#social-navigation' );
  		if ( ! widgets.length && ! social.length && ( ! menu.length || ! menu.children().length ) ) {
  			button.hide();
  			return;
  		}
  
  		button.on( 'click.twentyfifteen', function() {
  			secondary.toggleClass( 'toggled-on' );
  			secondary.trigger( 'resize' );
  			$( this ).toggleClass( 'toggled-on' );
  			if ( $( this, secondary ).hasClass( 'toggled-on' ) ) {
  				$( this ).attr( 'aria-expanded', 'true' );
  				secondary.attr( 'aria-expanded', 'true' );
  			} else {
  				$( this ).attr( 'aria-expanded', 'false' );
  				secondary.attr( 'aria-expanded', 'false' );
  			}
  		} );
  	} )();
  
  	/**
  	 * Add or remove ARIA attributes.
  	 *
  	 * Uses jQuery's width() function to determine the size of the window and add
  	 * the default ARIA attributes for the menu toggle if it's visible.
  	 *
  	 * @since Twenty Fifteen 1.1
  	 */
  	function onResizeARIA() {
  		if ( 955 > $window.width() ) {
  			button.attr( 'aria-expanded', 'false' );
  			secondary.attr( 'aria-expanded', 'false' );
  			button.attr( 'aria-controls', 'secondary' );
  		} else {
  			button.removeAttr( 'aria-expanded' );
  			secondary.removeAttr( 'aria-expanded' );
  			button.removeAttr( 'aria-controls' );
  		}
  	}
  
  	// Sidebar scrolling.
  	function resizeAndScroll() {
  		var windowPos = $window.scrollTop(),
  			windowHeight = $window.height(),
  			sidebarHeight = $sidebar.height(),
  			bodyHeight = $body.height();
  
  		if( 955 < $window.width() && bodyHeight > sidebarHeight && ( windowPos + windowHeight ) >= sidebarHeight ) {
  			$sidebar.css({
  				position: 'fixed',
  				bottom: sidebarHeight > windowHeight ? 0 : 'auto'
  			});
  		} else {
  			$sidebar.css('position', 'relative');
  		}
  	}
  
  	$( document ).ready( function() {
  		$body          = $( document.body );
  		$window        = $( window );
  		$sidebar       = $( '#sidebar' ).first();
  
  		$window
  			.on( 'scroll.twentyfifteen', resizeAndScroll )
  			.on( 'load.twentyfifteen', onResizeARIA )
  			.on( 'resize.twentyfifteen', function() {
  				clearTimeout( resizeTimer );
  				resizeTimer = setTimeout( resizeAndScroll, 500 );
  				onResizeARIA();
  			} );
  		$sidebar.on( 'click.twentyfifteen keydown.twentyfifteen', 'button', resizeAndScroll );
  
  		for ( var i = 0; i < 6; i++ ) {
  			setTimeout( resizeAndScroll, 100 * i );
  		}
  	} );
  
  } )( jQuery );
  