-QPointF ChatItem::mapToLine(const QPointF &p) const { return p + pos(); }
-QPointF ChatItem::mapFromLine(const QPointF &p) const { return p - pos(); }
-// relative to the ChatLine
-QPointF ChatItem::mapToScene(const QPointF &p) const { return chatLine()->mapToScene(p /* + pos() */); }
-QPointF ChatItem::mapFromScene(const QPointF &p) const { return chatLine()->mapFromScene(p) /* - pos() */; }
-