public void HandleTagMenuActivate (object sender, EventArgs args)
{
MenuItem parent = sender as MenuItem ?? uimanager.GetWidget ("/ui/menubar1/edit2/remove_tag") as MenuItem;
if (parent != null && parent.Submenu is PhotoTagMenu) {
PhotoTagMenu menu = (PhotoTagMenu)parent.Submenu;
menu.Populate (SelectedPhotos ());
}
}