onSubMenuVisibilityChanged method
Implementation
void onSubMenuVisibilityChanged(MenuItem item, bool visible) {
if (!visible && (item == _submenuParent)) {
_submenuParent = null;
if (_isMouseDriven) return;
// Refocus the previous active item if any as long as the whole menu
// isn't closing.
if (_menuRoot.visible) {
_focusActiveItem();
}
}
}