fix(list): removed keypress event listener from first child on destroy

fixes #5842

  Closes #7057

Author: EladBezalel

src/components/list/list.js

@@ -248,19 +248,21 @@ function mdListItemDirective($mdAria, $mdConstant, $mdUtil, $timeout) {
           }
         }
 
-        if (!hasClick && !proxies.length) {
-          firstChild && firstChild.addEventListener('keypress', function(e) {
-            if (e.target.nodeName != 'INPUT' && e.target.nodeName != 'TEXTAREA' && !e.target.isContentEditable) {
-              var keyCode = e.which || e.keyCode;
-              if (keyCode == $mdConstant.KEY_CODE.SPACE) {
-                if (firstChild) {
-                  firstChild.click();
-                  e.preventDefault();
-                  e.stopPropagation();
-                }
+        var firstChildKeypressListener = function(e) {
+          if (e.target.nodeName != 'INPUT' && e.target.nodeName != 'TEXTAREA' && !e.target.isContentEditable) {
+            var keyCode = e.which || e.keyCode;
+            if (keyCode == $mdConstant.KEY_CODE.SPACE) {
+              if (firstChild) {
+                firstChild.click();
+                e.preventDefault();
+                e.stopPropagation();
               }
             }
-          });
+          }
+        };
+
+        if (!hasClick && !proxies.length) {
+          firstChild && firstChild.addEventListener('keypress', firstChildKeypressListener);
         }
 
         $element.off('click');
@@ -278,6 +280,10 @@ function mdListItemDirective($mdAria, $mdConstant, $mdUtil, $timeout) {
             }
           });
         }
+
+        $scope.$on('$destroy', function () {
+          firstChild && firstChild.removeEventListener('keypress', firstChildKeypressListener);
+        });
       }
     }
   };