Qt - reduce duplication between two QAbstractListModel subclasses - c++

Question

I've written two QAbstractListModel subclasses:
class Model1: public QAbstractListModel {
Q_OBJECT
public:
int rowCount(const QModelIndex& parent=QModelIndex()) const;
QVariant data(const QModelIndex& index, int role) const;
void clear();
private:
QVector<Obj1*> m_items;
};
and
class Model2: public QAbstractListModel {
Q_OBJECT
public:
int rowCount(const QModelIndex& parent=QModelIndex()) const;
QVariant data(const QModelIndex& index, int role) const;
void clear();
private:
QVector<Obj2*> m_items;
};
In addition, these two classes have a slot AddObj() which is dependent on the pointer used (Obj1* or Obj2*).
The matter is, constructors and destructors are the same, and so are rowCount and clear (they do the exact same thing). The only differences are in data and in what m_items is.
What's the best strategy to reduce duplication here? I tried with a base class:
class ModelBase: public QAbstractListModel {
Q_OBJECT
ModelBase(QObject* parent=0);
~ModelBase();
public:
virtual int rowCount(const QModelIndex& parent=QModelIndex()) const;
virtual QVariant data(const QModelIndex& index, int role) const = 0;
virtual void clear();
private:
QVector<QString*> m_items; // dummy vector
};
and then have the other classes derive from it:
class ModelDerived1: public ModelBase {
Q_OBJECT
public:
ModelDerived1(QObject* parent=0);
~ModelDerived1();
QVariant data(const QModelIndex& index, int role) const = 0;
private:
QVector<Obj1*> m_items;
};
The problem is that in such a case the derived class's data function is never called when this model is attached to a view.
Nevertheless, the derived class data() is not called (I put in debug statements, and they are never executed).
What am I doing wrong here?

Answer 1

EDIT: The solution is not what I posted here. In fact, it was completely off. The issue is in the rowCount function and in the private m_items QVector.
rowCount, if not present, calls the superclass method, which does not use the private m_items element from the derived class, but it uses the one from the superclass, which being dummy, returns always a size of 0, and thus data never gets called.