useRootOverlay property
final
Whether the menu panel should be rendered in the root Overlay.
When true, the menu is mounted in the root overlay. Rendering the menu in the root overlay prevents the menu from being obscured by other widgets.
When false, the menu is rendered in the nearest ancestor Overlay.
Submenus will always use the same overlay as their top-level ancestor, so setting a useRootOverlay value on a submenu will have no effect.
Defaults to false.
Implementation
final bool useRootOverlay;