reveal.js

		// Toggles the "black screen" mode on/off
		togglePause: togglePause,

		// State checks
		isOverview: isOverview,
		isPaused: isPaused,

		// Adds or removes all internal event listeners (such as keyboard)
		addEventListeners: addEventListeners,
		removeEventListeners: removeEventListeners,

		// Returns the indices of the current, or specified, slide
		getIndices: getIndices,

		// Returns the slide at the specified index, y is optional
		getSlide: function( x, y ) {
			var horizontalSlide = document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR )[ x ];
			var verticalSlides = horizontalSlide && horizontalSlide.querySelectorAll( 'section' );

			if( typeof y !== 'undefined' ) {
				return verticalSlides ? verticalSlides[ y ] : undefined;
			}

			return horizontalSlide;
		},

		// Returns the previous slide element, may be null
		getPreviousSlide: function() {
			return previousSlide;
		},

		// Returns the current slide element
		getCurrentSlide: function() {
			return currentSlide;
		},

		// Returns the current scale of the presentation content
		getScale: function() {
			return scale;
		},

		// Returns the current configuration object
		getConfig: function() {
			return config;
		},

		// Helper method, retrieves query string as a key/value hash
		getQueryHash: function() {
			var query = {};

			location.search.replace( /[A-Z0-9]+?=(\w*)/gi, function(a) {
				query[ a.split( '=' ).shift() ] = a.split( '=' ).pop();
			} );

			return query;
		},

		// Returns true if we're currently on the first slide
		isFirstSlide: function() {
			return document.querySelector( SLIDES_SELECTOR + '.past' ) == null ? true : false;
		},

		// Returns true if we're currently on the last slide
		isLastSlide: function() {
			if( currentSlide && currentSlide.classList.contains( '.stack' ) ) {
				return currentSlide.querySelector( SLIDES_SELECTOR + '.future' ) == null ? true : false;
			}
			else {
				return document.querySelector( SLIDES_SELECTOR + '.future' ) == null ? true : false;
			}
		},

		// Forward event binding to the reveal DOM element
		addEventListener: function( type, listener, useCapture ) {
			if( 'addEventListener' in window ) {
				( dom.wrapper || document.querySelector( '.reveal' ) ).addEventListener( type, listener, useCapture );
			}
		},
		removeEventListener: function( type, listener, useCapture ) {
			if( 'addEventListener' in window ) {
				( dom.wrapper || document.querySelector( '.reveal' ) ).removeEventListener( type, listener, useCapture );
			}
		}
	};

})();