utils.js: Make isFocusable return false when tabindex is positive and…

… element is disabled (pull#1419)


This change potentially effects any example that uses the isFocusable method in the shared utility scripts (examples/js/utils.js).
Fixes a bug in isFocusable where it returned true for elements with positive tabindex even when the element is disabled.

examples/js/utils.js

@@ -64,8 +64,8 @@ aria.Utils.remove = function (item) {
 };
 
 aria.Utils.isFocusable = function (element) {
-  if (element.tabIndex > 0 || (element.tabIndex === 0 && element.getAttribute('tabIndex') !== null)) {
-    return true;
+  if (element.tabIndex < 0) {
+    return false;
   }
 
   if (element.disabled) {