C++ (Qt)
class TextItem: public QGraphicsTextItem 
{
...
public:
  enum { TEXT = UserType + 4 };
  int type() const { return TEXT; }
 
protected:
  void mouseDoubleClickEvent(QGraphicsSceneMouseEvent * event);
}
 
void TextItem::mousePressEvent(QGraphicsSceneMouseEvent * event)
{
  setTextInteractionFlags(Qt::TextEditorInteraction);
  setFocus();
 
  QGraphicsTextItem::mousePressEvent(event);
}
 

C++ (Qt)
class Group1: public QGraphicsItemGroup
{
...
public:
 void paint(QPainter *painter, const QStyleOptionGraphicsItem * option, QWidget *widget);
 QRectF boundingRect() const;
 
private:
 Group2 group2;
}
 
Group1::Group1(QGraphicsItem *parent) : QGraphicsItem(parent)
{
    addToGroup(group2);
}
 
void Group1::paint(QPainter *painter, const QStyleOptionGraphicsItem * option, QWidget *widget)
{
   group2.setPos(5,5);
   ...
}
 

C++ (Qt)
class Group2: public QGraphicsItemGroup
{
...
public:
 void paint(QPainter *painter, const QStyleOptionGraphicsItem * option, QWidget *widget);
 QRectF boundingRect() const;
 
private:
 TextItem *txtiIem;
}
 
Group2::Group2(QGraphicsItem *parent) : QGraphicsItem(parent)
{
  textItem = new TextItem("Hello");
  addToGroup(textItem);
}
 
void Group2::paint(QPainter *painter, const QStyleOptionGraphicsItem * option, QWidget *widget)
{
  textItem->setPos(10,10);
}
 

C++ (Qt)
class Scene : public QGraphicsScene
{
...
protected:
 void mousePressEvent(QGraphicsSceneMouseEvent * event);
 
private:
 Group1 group1;
}
 
Сцена и обработчик нажатия мыши
Scene::Scene(QObject*parent) : QGraphicsScene(parent)
{
   addItem(&group1);
   group1.setPos(10, 10)
}
 
//Обработка события нажатия мыши на сцене
void Scene::mousePressEvent(QGraphicsSceneMouseEvent * event)
{
 
 QGraphicsItem *item = itemAt(event->scenePos());
 //если это TextItem
 if(item && item->type() == TextItem::TEXT){
   sendEvent(item,event);
 }
 
}
 

Scene::Scene(QObject*parent) : QGraphicsScene(parent)
{
   TextItem *textItem = new TextItem("fjgkjfgfd");
   addItem(textItem);
   textItem->setPos(10, 10);
}