MDL-74701 core: Fix popover elements are focusable even when hidden

lib/amd/src/popover_region_controller.js

@@ -129,6 +129,7 @@ define(['jquery', 'core/str', 'core/custom_interaction_events'],
         this.menuContainer.attr('aria-expanded', 'false');
         this.menuContainer.attr('aria-hidden', 'true');
         this.updateButtonAriaLabel();
+        this.updateFocusItemTabIndex();
         this.root.trigger(this.events().menuClosed);
     };
 
@@ -149,6 +150,7 @@ define(['jquery', 'core/str', 'core/custom_interaction_events'],
         this.menuContainer.attr('aria-expanded', 'true');
         this.menuContainer.attr('aria-hidden', 'false');
         this.updateButtonAriaLabel();
+        this.updateFocusItemTabIndex();
         // Resolve the promises to allow the handlers to be added
         // to the DOM, if they have been requested.
         this.promises.closeHandlers.resolve();
@@ -392,5 +394,18 @@ define(['jquery', 'core/str', 'core/custom_interaction_events'],
         }.bind(this));
     };
 
+    /**
+     * Set the appropriate tabindex attribute on the popover toggle.
+     *
+     * @method updateFocusItemTabIndex
+     */
+    PopoverRegionController.prototype.updateFocusItemTabIndex = function() {
+        if (this.isMenuOpen()) {
+            this.menuContainer.find(SELECTORS.CAN_RECEIVE_FOCUS).removeAttr('tabindex');
+        } else {
+            this.menuContainer.find(SELECTORS.CAN_RECEIVE_FOCUS).attr('tabindex', '-1');
+        }
+    };
+
     return PopoverRegionController;
 });