reveal.js

				if( previousSlide ) {
					indexv = ( previousSlide.querySelectorAll('section').length + 1 ) || 0;
					indexh --;
					slide();
				}
			}
		}
	}

	/**
	 * Same as #navigatePrev() but navigates forwards.
	 */
	function navigateNext() {
		// Prioritize revealing fragments
		if( nextFragment() === false ) {
			availableRoutes().down ? navigateDown() : navigateRight();
		}

		// If auto-sliding is enabled we need to cue up 
		// another timeout
		cueAutoSlide();
	}

	/**
	 * Toggles the slide overview mode on and off.
	 */
	function toggleOverview() {
		if( overviewIsActive() ) {
			deactivateOverview();
		}
		else {
			activateOverview();
		}
	}
	
	// Expose some methods publicly
	return {
		initialize: initialize,
		navigateTo: navigateTo,
		navigateLeft: navigateLeft,
		navigateRight: navigateRight,
		navigateUp: navigateUp,
		navigateDown: navigateDown,
		navigatePrev: navigatePrev,
		navigateNext: navigateNext,
		toggleOverview: toggleOverview,

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

		// Returns the indices of the current slide
		getIndices: function() {
			return { 
				h: indexh, 
				v: indexv 
			};
		},

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

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

		// 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;
		},

		// 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 );
			}
		}
	};
	
})();