added support for looped presentations

README.md

@@ -58,6 +58,9 @@ Reveal.initialize({
 	// If true; each slide will be pushed to the browser history
 	history: true,
 
+	// Loops the presentation, defaults to false
+	loop: false,
+
 	// Flags if mouse wheel navigation should be enabled
 	mouseWheel: true,
 
@@ -98,6 +101,7 @@ document.addEventListener( 'someState', function() {
 
 #### 1.3 (master)
 - Revised keyboard shortcuts, including ESC for overview, N for next, P for previous. Thanks [mahemoff](https://github.com/mahemoff)
+- Added support for looped presentations via config
 
 #### 1.2
 

index.html

@@ -260,6 +260,9 @@
 				// If true; each slide will be pushed to the browser history
 				history: true,
 
+				// Loops the presentation, defaults to false
+				loop: false,
+
 				// Flags if mouse wheel navigation should be enabled
 				mouseWheel: true,
 

js/reveal.js

@@ -19,10 +19,11 @@ var Reveal = (function(){
 			controls: false,
 			progress: false,
 			history: false,
-			transition: 'default',
-			theme: 'default',
+			loop: false,
 			mouseWheel: true,
-			rollingLinks: true
+			rollingLinks: true,
+			transition: 'default',
+			theme: 'default'
 		},
 
 		// Slides may hold a data-state attribute which we pick up and apply 
@@ -406,19 +407,34 @@ var Reveal = (function(){
 		
 		// Select all slides and convert the NodeList result to
 		// an array
-		var slides = Array.prototype.slice.call( document.querySelectorAll( selector ) );
+		var slides = Array.prototype.slice.call( document.querySelectorAll( selector ) ),
+			slidesLength = slides.length;
+		
+		if( slidesLength ) {
+
+			// Should the index loop?
+			if( config.loop ) {
+				index %= slidesLength;
+
+				if( index < 0 ) {
+					index = slidesLength + index;
+				}
+			}
 			
-		if( slides.length ) {
 			// Enforce max and minimum index bounds
-			index = Math.max(Math.min(index, slides.length - 1), 0);
+			index = Math.max( Math.min( index, slidesLength - 1 ), 0 );
 			
-			for( var i = 0; i < slides.length; i++ ) {
+			for( var i = 0; i < slidesLength; i++ ) {
 				var slide = slides[i];
 
 				// Optimization; hide all slides that are three or more steps 
 				// away from the present slide
 				if( overviewIsActive() === false ) {
-					slide.style.display = Math.abs( index - i ) > 3 ? 'none' : 'block';
+					// The distance loops so that it measures 1 between the first
+					// and last slides
+					var distance = Math.abs( ( index - i ) % ( slidesLength - 3 ) ) || 0;
+
+					slide.style.display = distance > 3 ? 'none' : 'block';
 				}
 
 				slides[i].classList.remove( 'past' );