Add tab navigation to Editor context menus and popups

#3676

Source/Editor/GUI/ContextMenu/ContextMenuBase.cs

@@ -108,6 +108,11 @@ namespace FlaxEditor.GUI.ContextMenu
         /// </summary>
         public bool UseInput = true;
 
+        /// <summary>
+        /// Optional flag that can disable UI navigation (tab/enter).
+        /// </summary>
+        public bool UseNavigation = true;
+
         /// <summary>
         /// Initializes a new instance of the <see cref="ContextMenuBase"/> class.
         /// </summary>
@@ -594,6 +599,21 @@ namespace FlaxEditor.GUI.ContextMenu
             case KeyboardKeys.Escape:
                 Hide();
                 return true;
+            case KeyboardKeys.Return:
+                if (UseNavigation && Root?.FocusedControl != null)
+                {
+                    Root.SubmitFocused();
+                    return true;
+                }
+                break;
+            case KeyboardKeys.Tab:
+                if (UseNavigation && Root != null)
+                {
+                    bool shiftDown = Root.GetKey(KeyboardKeys.Shift);
+                    Root.Navigate(shiftDown ? NavDirection.Previous : NavDirection.Next);
+                    return true;
+                }
+                break;
             }
             return false;
         }