mPopupTopExceedNotification.NotifySignal().Connect( this, &Decorator::Impl::PopUpLeavesTopBoundary );
mPopupBottomExceedNotification.NotifySignal().Connect( this, &Decorator::Impl::PopUpLeavesBottomBoundary );
mPopupTopExceedNotification.NotifySignal().Connect( this, &Decorator::Impl::PopUpLeavesTopBoundary );
mPopupBottomExceedNotification.NotifySignal().Connect( this, &Decorator::Impl::PopUpLeavesBottomBoundary );