design help with QList in an interface

[tbscope]

If both storeChannelItem and newsChannelItem are based on QObject, then just store a QObject in your storeChannel and newsChannel.
Otherwise, why won't you return a list of storeChannelItems and newsChannelItems via getItems() ?

[helloworld]

You could use templates:

template <typename T>
class ChannelInterface
{
public:
  virtual QList<T*> getItems() = 0;
};
 
class storeChannelItem
{
    // ...
};
 
class newsChannelItem
{
    // ...
};
 
class storeChannel : public QObject, public ChannelInterface<storeChannelItem>
{
    QList<storeChannelItem*> items;
public:
    QList<storeChannelItem*> getItems();
};
 
class newsChannel : public QObject, public ChannelInterface<newsChannelItem>
{
    QList<newsChannelItem*> items;
public:
    QList<newsChannelItem*> getItems();
};

template <typename T>
class ChannelInterface
{
public:
  virtual QList<T*> getItems() = 0;
};

class storeChannelItem
{
    // ...
};

class newsChannelItem
{
    // ...
};

class storeChannel : public QObject, public ChannelInterface<storeChannelItem>
{
    QList<storeChannelItem*> items;
public:
    QList<storeChannelItem*> getItems();
};

class newsChannel : public QObject, public ChannelInterface<newsChannelItem>
{
    QList<newsChannelItem*> items;
public:
    QList<newsChannelItem*> getItems();
};

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EDIT: Don't forget to define a virtual destructor in your interface also:

template <typename T>
class ChannelInterface
{
public:
  virtual ~ChannelInterface() {}
  virtual QList<T*> getItems() = 0;
};

template <typename T>
class ChannelInterface
{
public:
  virtual ~ChannelInterface() {}
  virtual QList<T*> getItems() = 0;
};

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