Menubar / navigation menu with single-level submenus rendered in the top
layer. Compose with <MenuItem> for leaf items and <MenuSubmenu> for
items that open a flyout. The enhancer wires roving tabindex,
orientation-aware arrow navigation, typeahead, and submenu toggling; the
open submenu is the component's value (from <MenuSubmenu value>,
defaulting to the index).
Menubar / navigation menu with single-level submenus rendered in the top layer. Compose with
<MenuItem>for leaf items and<MenuSubmenu>for items that open a flyout. The enhancer wires roving tabindex, orientation-aware arrow navigation, typeahead, and submenu toggling; the open submenu is the component's value (from<MenuSubmenu value>, defaulting to the index).