Navigation menu block: dissapearing submenus is disorienting

[enriquesanchez]

This issue comes from the the accessibility test performed by the Accessibility team (#20369). One of the issues raised was that having submenus appear and disappear depending on child block selection can be disorienting.

Having the nested links disappear when the subblock was not selected was disorienting. It made me believe that somehow my sublinks had been deleted.

I understand that the UI is replicating the front-end behavior, but I expect that not everyone will understand it. Also, users of assistive technology will probably find it disorienting.

[enriquesanchez]

If we can't have sub-menus visible at all times (because we want to keep a 1:1 similarity between the editor and the front-end), I think we could make it more obvious that there is a sub-menu.

This perhaps means increasing the size of the sub-menu icon (the little triangle), or using a different icon that communicates the existence of a sub-menu in a better way.

[noisysocks]

#22107 addressed this.