reveal.js

/*!
 * reveal.js
 * http://lab.hakim.se/reveal-js
 * MIT licensed
 *
 * Copyright (C) 2011-2012 Hakim El Hattab, http://hakim.se
 */
var Reveal = (function(){

	'use strict';

	var SLIDES_SELECTOR = '.reveal .slides section',
		HORIZONTAL_SLIDES_SELECTOR = '.reveal .slides>section',
		VERTICAL_SLIDES_SELECTOR = '.reveal .slides>section.present>section',
		HOME_SLIDE_SELECTOR = '.reveal .slides>section:first-child',

		// Configurations defaults, can be overridden at initialization time
		config = {
			// Display controls in the bottom right corner
			controls: true,

			// Display a presentation progress bar
			progress: true,

			// Push each slide change to the browser history
			history: false,

			// Enable keyboard shortcuts for navigation
			keyboard: true,

			// Enable the slide overview mode
			overview: true,

			// Vertical centering of slides
			center: true,

			// Loop the presentation
			loop: false,

			// Change the presentation direction to be RTL
			rtl: false,

			// Number of milliseconds between automatically proceeding to the
			// next slide, disabled when set to 0, this value can be overwritten
			// by using a data-autoslide attribute on your slides
			autoSlide: 0,

			// Enable slide navigation via mouse wheel
			mouseWheel: false,

			// Apply a 3D roll to links on hover
			rollingLinks: true,

			// Theme (see /css/theme)
			theme: null,

			// Transition style
			transition: 'default', // default/cube/page/concave/zoom/linear/fade/none

			// Script dependencies to load
			dependencies: []
		},

		// Stores if the next slide should be shown automatically
		// after n milliseconds
		autoSlide = config.autoSlide,

		// The horizontal and verical index of the currently active slide
		indexh = 0,
		indexv = 0,

		// The previous and current slide HTML elements
		previousSlide,
		currentSlide,

		// Slides may hold a data-state attribute which we pick up and apply
		// as a class to the body. This list contains the combined state of
		// all current slides.
		state = [],

		// Cached references to DOM elements
		dom = {},

		// Detect support for CSS 3D transforms
		supports3DTransforms =  'WebkitPerspective' in document.body.style ||
								'MozPerspective' in document.body.style ||
								'msPerspective' in document.body.style ||
								'OPerspective' in document.body.style ||
								'perspective' in document.body.style,

		supports2DTransforms =  'WebkitTransform' in document.body.style ||
								'MozTransform' in document.body.style ||
								'msTransform' in document.body.style ||
								'OTransform' in document.body.style ||
								'transform' in document.body.style,

		// Throttles mouse wheel navigation
		mouseWheelTimeout = 0,

		// An interval used to automatically move on to the next slide
		autoSlideTimeout = 0,

		// Delays updates to the URL due to a Chrome thumbnailer bug
		writeURLTimeout = 0,

		// A delay used to activate the overview mode
		activateOverviewTimeout = 0,

		// A delay used to deactivate the overview mode
		deactivateOverviewTimeout = 0,

		// Holds information about the currently ongoing touch input
		touch = {
			startX: 0,
			startY: 0,
			startSpan: 0,
			startCount: 0,
			handled: false,
			threshold: 80
		};

	/**
	 * Starts up the presentation if the client is capable.
	 */
	function initialize( options ) {
		if( ( !supports2DTransforms && !supports3DTransforms ) ) {
			document.body.setAttribute( 'class', 'no-transforms' );

			// If the browser doesn't support core features we won't be
			// using JavaScript to control the presentation
			return;
		}

		// Force a layout when the whole page, incl fonts, has loaded
		window.addEventListener( 'load', layout, false );

		// Copy options over to our config object
		extend( config, options );

		// Hide the address bar in mobile browsers
		hideAddressBar();

		// Loads the dependencies and continues to #start() once done
		load();

	}

	/**
	 * Finds and stores references to DOM elements which are
	 * required by the presentation. If a required element is
	 * not found, it is created.
	 */
	function setupDOM() {
		// Cache references to key DOM elements
		dom.theme = document.querySelector( '#theme' );
		dom.wrapper = document.querySelector( '.reveal' );
		dom.slides = document.querySelector( '.reveal .slides' );

		// Progress bar
		if( !dom.wrapper.querySelector( '.progress' ) && config.progress ) {
			var progressElement = document.createElement( 'div' );
			progressElement.classList.add( 'progress' );
			progressElement.innerHTML = '<span></span>';
			dom.wrapper.appendChild( progressElement );
		}

		// Arrow controls
		if( !dom.wrapper.querySelector( '.controls' ) && config.controls ) {
			var controlsElement = document.createElement( 'aside' );
			controlsElement.classList.add( 'controls' );
			controlsElement.innerHTML = '<div class="navigate-left"></div>' +
										'<div class="navigate-right"></div>' +
										'<div class="navigate-up"></div>' +
										'<div class="navigate-down"></div>';
			dom.wrapper.appendChild( controlsElement );
		}

		// Presentation background element
		if( !dom.wrapper.querySelector( '.state-background' ) ) {
			var backgroundElement = document.createElement( 'div' );
			backgroundElement.classList.add( 'state-background' );
			dom.wrapper.appendChild( backgroundElement );
		}

		// Overlay graphic which is displayed during the paused mode
		if( !dom.wrapper.querySelector( '.pause-overlay' ) ) {
			var pausedElement = document.createElement( 'div' );
			pausedElement.classList.add( 'pause-overlay' );
			dom.wrapper.appendChild( pausedElement );
		}

		// Cache references to elements
		dom.progress = document.querySelector( '.reveal .progress' );
		dom.progressbar = document.querySelector( '.reveal .progress span' );

		if ( config.controls ) {
			dom.controls = document.querySelector( '.reveal .controls' );

			// There can be multiple instances of controls throughout the page
			dom.controlsLeft = toArray( document.querySelectorAll( '.navigate-left' ) );