performance improvement for exposeAsideWhen directive that also fixes…

… issue ionic-team#3600

js/angular/directive/exposeAsideWhen.js

@@ -23,7 +23,6 @@
  * the most common use-case. However, for added flexibility, any valid media query could be added
  * as the value, such as `(min-width:600px)` or even multiple queries such as
  * `(min-width:750px) and (max-width:1200px)`.
-
  * @usage
  * ```html
  * <ion-side-menus>
@@ -39,12 +38,21 @@
  * For a complete side menu example, see the
  * {@link ionic.directive:ionSideMenus} documentation.
  */
-IonicModule.directive('exposeAsideWhen', ['$window', function($window) {
+
+IonicModule.directive('exposeAsideWhen', ['$window', function($window) { 
   return {
     restrict: 'A',
     require: '^ionSideMenus',
     link: function($scope, $element, $attr, sideMenuCtrl) {
 
+      // Setup a match media query listener that triggers a ui change only when a change
+      // in media matching status occurs
+      var mq = $attr.exposeAsideWhen == 'large' ? '(min-width:768px)' : $attr.exposeAsideWhen;
+      var mql = $window.matchMedia(mq);
+      mql.addListener(function (mql) {
+        onResize();
+      })
+
       function checkAsideExpose() {
         var mq = $attr.exposeAsideWhen == 'large' ? '(min-width:768px)' : $attr.exposeAsideWhen;
         sideMenuCtrl.exposeAside($window.matchMedia(mq).matches);
@@ -61,14 +69,6 @@ IonicModule.directive('exposeAsideWhen', ['$window', function($window) {
       }, 300, false);
 
       $scope.$evalAsync(checkAsideExpose);
-
-      ionic.on('resize', onResize, $window);
-
-      $scope.$on('$destroy', function() {
-        ionic.off('resize', onResize, $window);
-      });
-
     }
   };
-}]);
-
+}]);