disable zoom plugin while in overview mode

plugin/zoom-js/zoom.js

 // Custom reveal.js integration
 (function(){
-	document.querySelector( '.reveal' ).addEventListener( 'click', function( event ) {
-		if( event.altKey ) {
+	var isEnabled = true;
+
+	document.querySelector( '.reveal' ).addEventListener( 'mousedown', function( event ) {
+		if( event.altKey && isEnabled ) {
 			event.preventDefault();
 			zoom.to({ element: event.target, pan: false });
 		}
 	} );
+
+	Reveal.addEventListener( 'overviewshown', function() { isEnabled = false; } );
+	Reveal.addEventListener( 'overviewhidden', function() { isEnabled = true; } );
 })();
 
 /*!
  * zoom.js 0.2 (modified version for use with reveal.js)
  * http://lab.hakim.se/zoom-js
  * MIT licensed
- * 
+ *
  * Copyright (C) 2011-2012 Hakim El Hattab, http://hakim.se
  */
 var zoom = (function(){
 
 	// The current zoom level (scale)
 	var level = 1;
-	
+
 	// The current mouse position, used for panning
 	var mouseX = 0,
 		mouseY = 0;
-	
+
 	// Timeout before pan is activated
 	var panEngageTimeout = -1,
 		panUpdateInterval = -1;
@@ -36,7 +41,7 @@ var zoom = (function(){
 								'msTransform' in document.body.style ||
 								'OTransform' in document.body.style ||
 								'transform' in document.body.style;
-    
+
 	if( supportsTransforms ) {
 		// The easing that will be applied when we zoom in/out
 		document.body.style.transition = 'transform 0.8s ease';
@@ -45,7 +50,7 @@ var zoom = (function(){
 		document.body.style.MozTransition = '-moz-transform 0.8s ease';
 		document.body.style.WebkitTransition = '-webkit-transform 0.8s ease';
 	}
-	
+
 	// Zoom out if the user hits escape
 	document.addEventListener( 'keyup', function( event ) {
 		if( level !== 1 && event.keyCode === 27 ) {
@@ -62,21 +67,21 @@ var zoom = (function(){
 	}, false );
 
 	/**
-	 * Applies the CSS required to zoom in, prioritizes use of CSS3 
+	 * Applies the CSS required to zoom in, prioritizes use of CSS3
 	 * transforms but falls back on zoom for IE.
-	 * 
-	 * @param {Number} pageOffsetX 
-	 * @param {Number} pageOffsetY 
-	 * @param {Number} elementOffsetX 
-	 * @param {Number} elementOffsetY 
-	 * @param {Number} scale 
+	 *
+	 * @param {Number} pageOffsetX
+	 * @param {Number} pageOffsetY
+	 * @param {Number} elementOffsetX
+	 * @param {Number} elementOffsetY
+	 * @param {Number} scale
 	 */
 	function magnify( pageOffsetX, pageOffsetY, elementOffsetX, elementOffsetY, scale ) {
 
 		if( supportsTransforms ) {
 			var origin = pageOffsetX +'px '+ pageOffsetY +'px',
 				transform = 'translate('+ -elementOffsetX +'px,'+ -elementOffsetY +'px) scale('+ scale +')';
-			
+
 			document.body.style.transformOrigin = origin;
 			document.body.style.OTransformOrigin = origin;
 			document.body.style.msTransformOrigin = origin;
@@ -121,7 +126,7 @@ var zoom = (function(){
 	}
 
 	/**
-	 * Pan the document when the mosue cursor approaches the edges 
+	 * Pan the document when the mosue cursor approaches the edges
 	 * of the window.
 	 */
 	function pan() {
@@ -129,7 +134,7 @@ var zoom = (function(){
 			rangeX = window.innerWidth * range,
 			rangeY = window.innerHeight * range,
 			scrollOffset = getScrollOffset();
-		
+
 		// Up
 		if( mouseY < rangeY ) {
 			window.scroll( scrollOffset.x, scrollOffset.y - ( 1 - ( mouseY / rangeY ) ) * ( 14 / level ) );
@@ -159,7 +164,7 @@ var zoom = (function(){
 	return {
 		/**
 		 * Zooms in on either a rectangle or HTML element.
-		 * 
+		 *
 		 * @param {Object} options
 		 *   - element: HTML element to zoom in on
 		 *   OR
@@ -232,7 +237,7 @@ var zoom = (function(){
 			if( currentOptions && currentOptions.element ) {
 				scrollOffset.x -= ( window.innerWidth - ( currentOptions.width * currentOptions.scale ) ) / 2;
 			}
-			
+
 			magnify( scrollOffset.x, scrollOffset.y, 0, 0, 1 );
 
 			level = 1;
@@ -241,11 +246,11 @@ var zoom = (function(){
 		// Alias
 		magnify: function( options ) { this.to( options ) },
 		reset: function() { this.out() },
-		
+
 		zoomLevel: function() {
 			return level;
 		}
 	}
-	
+
 })();