Having the generic qt_itemFired: as action would result in the whole
submenu tree closing if an item with a sub-menu was clicked on. This
is not how native applications behave. They respond by immediately
opening the submenu, or do nothing if the menu is already open.
By using submenuAction: as the selector we achieve the same behavior.
A complication here is that for some reason we defer associating the
submenu NSMenu to an NSMenuItem until QCocoaMenu::setAttachedItem(),
instead of doing it in QCocoaMenuItem::setMenu(), or even as part of
QCocoaMenuItem::sync().
As a result, AppKit's NSMenuValidation logic will conclude that the
item does neither have a submenu, nor a valid target/selector combo
to be validated, and will explicitly disable the item. This can be
debugged by passing -NSTrackMenuValidation YES to the application.
To work around this we explicitly enable the item once we have set
a valid submenu for the item.
Pick-to: 6.5 6.6
Fixes: QTBUG-114199
Change-Id: I7178e7687066b3fe082454c512ec9c7eab3bded4
Reviewed-by: Timur Pocheptsov <timur.pocheptsov@qt.io>
Reviewed-by: Tor Arne Vestbø <tor.arne.vestbo@qt.io>
c8473c0903