ECOM-4945 Fixed Shift-Tab on menu

TNL-5437 Reverted to no RequireJS

lms/static/js/my_courses_dropdown.js

-(function(require) {
+$(document).ready(function() {
     'use strict';
 
-    require([
-        'jquery',
-        'edx-ui-toolkit/js/utils/constants'
-    ], function($, constants) {
     // define variables for code legibility
     var $dropdownMenuToggle = $('.dropdown');
     var $dropdownMenu = $('.dropdown-menu');
     var menuItems = $dropdownMenu.find('.dropdown-menuitem');
 
+    var keyCodes = {
+        leftArrow: 37,
+        upArrow: 38,
+        rightArrow: 39,
+        downArrow: 40,
+        tab: 9,
+        escape: 27,
+        space: 32
+    };
+
+
     // bind menu toggle click for later use
     $dropdownMenuToggle.toggle(function() {
         $dropdownMenu.addClass('expanded').find('.dropdown-menuitem').first()
@@ -20,10 +27,10 @@
         $dropdownMenuToggle.removeClass('active').attr('aria-expanded', 'false').focus();
     });
 
-        // catch keypresses when focused on dropdownMenuToggle (we only care about spacebar keypresses here)
+    // catch keypresses when focused on $dropdownMenuToggle (we only care about spacebar keypresses here)
     $dropdownMenuToggle.on('keydown', function(event) {
         // if space key pressed
-            if (event.which === constants.keyCodes.space) {
+        if (event.which === keyCodes.space) {
             $dropdownMenuToggle.click();
             event.preventDefault();
         }
@@ -43,20 +50,20 @@
         var itemToFocusIndex;
 
         // if space key pressed
-            if (event.which === constants.keyCodes.space) {
+        if (event.which === keyCodes.space) {
             $dropdownMenuToggle.click();
             event.preventDefault();
         }
 
         // if escape key pressed
-            if (event.which === constants.keyCodes.esc) {
+        if (event.which === keyCodes.escape) {
             $dropdownMenuToggle.click();
             event.preventDefault();
         }
 
         // if up arrow key pressed or shift+tab else down key or tab is pressed
-            if (event.which === constants.keyCodes.up || event.which === constants.keyCodes.left ||
-                (event.which === constants.keyCodes.tab && event.shiftKey)) {
+        if (event.which === keyCodes.upArrow || event.which === keyCodes.leftArrow ||
+            (event.which === keyCodes.tab && event.shiftKey)) {
             // if first item go to last
             if (focusedItemIndex === 0) {
                 menuItems.last().focus();
@@ -65,8 +72,8 @@
                 menuItems.get(itemToFocusIndex).focus();
             }
             event.preventDefault();
-            } else if (event.which === constants.keyCodes.down || event.which === constants.keyCodes.right ||
-                event.which === constants.keyCodes.tab) {
+        } else if (event.which === keyCodes.downArrow || event.which === keyCodes.rightArrow ||
+            event.which === keyCodes.tab) {
             // if last item go to first
             if (focusedItemIndex === numberOfMenuItems - 1) {
                 menuItems.first().focus();
@@ -78,10 +85,9 @@
         }
     }
 
-        // catch keypresses when inside dropdownMenu
+    // catch keypresses when inside $dropdownMenu
     // (we want to catch spacebar; escape; up arrow or shift+tab; and down arrow or tab)
     $dropdownMenu.on('keydown', function(event) {
         catchKeyPress($(this), event);
     });
-    });
-}).call(this, require || RequireJS.require);
+});