Preventing drop/drag outside the main window

[ucomesdag]

void floorBoard::dragMoveEvent(QDragMoveEvent *event)
{
	QByteArray data = event->mimeData()->data("text/uri-list");
	QString uri(data);
 
	if ( event->mimeData()->hasFormat("application/x-stompbox") ||
		uri.contains(".syx", Qt::CaseInsensitive) &&
		event->answerRect().intersects(this->geometry()) ) 
	{
        if (children().contains(event->source())) 
		{
            event->setDropAction(Qt::MoveAction);
			event->accept();
        } else {
            event->acceptProposedAction();
        };
    } else {
        event->ignore();
    };
};

void floorBoard::dragMoveEvent(QDragMoveEvent *event)
{
	QByteArray data = event->mimeData()->data("text/uri-list");
	QString uri(data);
	
	if ( event->mimeData()->hasFormat("application/x-stompbox") ||
		uri.contains(".syx", Qt::CaseInsensitive) &&
		event->answerRect().intersects(this->geometry()) ) 
	{
        if (children().contains(event->source())) 
		{
            event->setDropAction(Qt::MoveAction);
			event->accept();
        } else {
            event->acceptProposedAction();
        };
    } else {
        event->ignore();
    };
};

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I tried with adding event->answerRect().intersects(this->geometry()) but you can still drag items outside the mainwindow?

Bit lost here, I want the drag to stop when we are outside the window but it is still active when moving over other apps like firefox.