reveal.js

	 * @param {Number} v The vertical index of the slide to show
	 */
	function navigateTo( h, v ) {
		slide( h, v );
	}
	
	function navigateLeft() {
		// Prioritize hiding fragments
		if( overviewIsActive() || previousFragment() === false ) {
			slide( indexh - 1, 0 );
		}
	}
	function navigateRight() {
		// Prioritize revealing fragments
		if( overviewIsActive() || nextFragment() === false ) {
			slide( indexh + 1, 0 );
		}
	}
	function navigateUp() {
		// Prioritize hiding fragments
		if( overviewIsActive() || previousFragment() === false ) {
			slide( indexh, indexv - 1 );
		}
	}
	function navigateDown() {
		// Prioritize revealing fragments
		if( overviewIsActive() || nextFragment() === false ) {
			slide( indexh, indexv + 1 );
		}
	}

	/**
	 * Navigates backwards, prioritized in the following order:
	 * 1) Previous fragment
	 * 2) Previous vertical slide
	 * 3) Previous horizontal slide
	 */
	function navigatePrev() {
		// Prioritize revealing fragments
		if( previousFragment() === false ) {
			if( availableRoutes().up ) {
				navigateUp();
			}
			else {
				// Fetch the previous horizontal slide, if there is one
				var previousSlide = document.querySelector( '.reveal .slides>section.past:nth-child(' + indexh + ')' );

				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, or specified, slide
		getIndices: function( slide ) {
			// By default, return the current indices
			var h = indexh,
				v = indexv;

			// If a slide is specified, return the indices of that slide
			if( slide ) {
				var isVertical = !!slide.parentNode.nodeName.match( /section/gi );
				var slideh = isVertical ? slide.parentNode : slide;

				// Select all horizontal slides
				var horizontalSlides = Array.prototype.slice.call( document.querySelectorAll( HORIZONTAL_SLIDES_SELECTOR ) );

				// Now that we know which the horizontal slide is, get its index
				h = Math.max( horizontalSlides.indexOf( slideh ), 0 );

				// If this is a vertical slide, grab the vertical index
				if( isVertical ) {
					v = Math.max( Array.prototype.slice.call( slide.parentNode.children ).indexOf( slide ), 0 );
				}
			}

			return { h: h, v: v };
		},

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