add zoomKey option for #700

diff --git a/plugin/zoom-js/zoom.js b/plugin/zoom-js/zoom.js
index b67ae16641864ca64cefbdca80c086ed91221991..cd5b06ff886507d036974e99fd83bca9b3a08d8a 100644 (file)
--- a/plugin/zoom-js/zoom.js
+++ b/plugin/zoom-js/zoom.js
@@ -3,7 +3,9 @@
        var isEnabled = true;
 
        document.querySelector( '.reveal' ).addEventListener( 'mousedown', function( event ) {
-               if( event.altKey && isEnabled ) {
+               var modifier = ( Reveal.getConfig().zoomKey ? Reveal.getConfig().zoomKey : 'alt' ) + 'Key';
+
+               if( event[ modifier ] && isEnabled ) {
                        event.preventDefault();
                        zoom.to({ element: event.target, pan: false });
                }