Merge pull request #2300 from mw75/master

Resize Event

README.md

@@ -42,6 +42,7 @@ reveal.js comes with a broad range of features including [nested slides](https:/
   - [Fullscreen mode](#fullscreen-mode)
   - [Embedded media](#embedded-media)
   - [Stretching elements](#stretching-elements)
+  - [Resize Event](#resize-event)
   - [postMessage API](#postmessage-api)
 - [PDF Export](#pdf-export)
 - [Theming](#theming)
@@ -991,6 +992,14 @@ Limitations:
 - Only direct descendants of a slide section can be stretched
 - Only one descendant per slide section can be stretched
 
+### Resize Event
+
+When reveal.js changes the scale of the slides it fires an resize event. You can subscribe to the event to resize your elements accordingly.
+
+```javascript
+Reveal.addEventListener( 'resize', function( event ) { /* console.log(event.scale,event.oldscale,event.size); */ } );
+```
+
 ### postMessage API
 
 The framework has a built-in postMessage API that can be used when communicating with a presentation inside of another window. Here's an example showing how you'd make a reveal.js instance in the given window proceed to slide 2:

js/reveal.js

@@ -2104,6 +2104,7 @@
 				dom.slides.style.height = size.height + 'px';
 
 				// Determine scale of content to fit within available space
+				var oldscale =scale;
 				scale = Math.min( size.presentationWidth / size.width, size.presentationHeight / size.height );
 
 				// Respect max/min scale settings
@@ -2169,6 +2170,13 @@
 
 				}
 
+				if( oldscale!==scale ){
+					dispatchEvent( 'resize', {
+						'oldscale': oldscale,
+						'scale': scale,
+						'size': size
+					} );
+				}
 			}
 
 			updateProgress();