support for custom slide number formatting #965

README.md

@@ -572,7 +572,16 @@ By default, Reveal is configured with [highlight.js](http://softwaremaniacs.org/
 If you would like to display the page number of the current slide you can do so using the ```slideNumber``` configuration value.
 
 ```javascript
+// Shows the slide number using default formatting
 Reveal.configure({ slideNumber: true });
+
+// Slide number formatting can be configured using these variables:
+//  h: current slide's horizontal index
+//  v: current slide's vertical index
+//  c: current slide index (flattened)
+//  t: total number of slides (flattened)
+Reveal.configure({ slideNumber: 'c / t' });
+
 ```
 
 

js/reveal.js

@@ -2331,19 +2331,33 @@
 
 	/**
 	 * Updates the slide number div to reflect the current slide.
+	 *
+	 * Slide number format can be defined as a string using the
+	 * following variables:
+	 *  h: current slide's horizontal index
+	 *  v: current slide's vertical index
+	 *  c: current slide index (flattened)
+	 *  t: total number of slides (flattened)
 	 */
 	function updateSlideNumber() {
 
 		// Update slide number if enabled
 		if( config.slideNumber && dom.slideNumber) {
 
-			// Display the number of the page using 'indexh - indexv' format
-			var indexString = indexh;
-			if( indexv > 0 ) {
-				indexString += ' - ' + indexv;
+			// Default to only showing the current slide number
+			var format = 'c';
+
+			// Check if a custom slide number format is available
+			if( typeof config.slideNumber === 'string' ) {
+				format = config.slideNumber;
 			}
 
-			dom.slideNumber.innerHTML = indexString;
+			var totalSlides = getTotalSlides();
+
+			dom.slideNumber.innerHTML = format.replace( /h/g, indexh )
+												.replace( /v/g, indexv )
+												.replace( /c/g, Math.round( getProgress() * totalSlides ) + 1 )
+												.replace( /t/g, totalSlides + 1 );
 		}
 
 	}