add explanatory comment

paulirish · Jan 12, 2013 · d003d45 · d003d45
1 parent 70f13fc
commit d003d45
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/matchMedia.addListener.js b/matchMedia.addListener.js
@@ -13,6 +13,8 @@
 					var list = oldMM( q ),
 						unmatchToMatch = list.matches && !last,
 						matchToUnmatch = !list.matches && last;
+
+                                        //fire callbacks only if transitioning to or from matched state
 					if( unmatchToMatch || matchToUnmatch ){
 						for( var i =0, il = listeners.length; i< il; i++ ){
 							listeners[ i ].call( ret, list );
@@ -42,4 +44,4 @@
 			return ret;
 		};
 	}
-}());
+}());