如何将文本添加到项目Qt

My problem is that i have created a class Item that paints polygones and what i want to do is to add some text to these item...Like Class in UML we got the class name and some attributs...to be more clear i want to create a simple tool form uml class with Qt and i created a class which can paint the entity but its just a simple polygone with 2 areas one for the class name and the other for the attributs,my question is how can i add the text to the polygone with the possibility to change it...please i really need some help here and thanks to everyone.My problem is that i have created a class Item