Conductor and conductor text item : minor change about how the text is save to xml

git-svn-id: svn+ssh://svn.tuxfamily.org/svnroot/qet/qet/trunk@3485 bfdf4180-ca20-0410-9c96-a3a8aa849046

sources/qetgraphicsitem/diagramtextitem.cpp

@@ -79,6 +79,16 @@ Diagram *DiagramTextItem::diagram() const {
 	return(qobject_cast<Diagram *>(scene()));
 }
 
+/**
+ * @brief DiagramTextItem::toXml
+ * This method do nothing and return an empty DomElement
+ * This is used to be inherited by child class
+ * @return
+ */
+QDomElement DiagramTextItem::toXml(QDomDocument &) const {
+	return QDomElement();
+}
+
 /**
 	@return l'angle de rotation actuel de ce texte
 */