Reimplemented QStandardItem. Drag&Drop

[Miga]

Hello!
I would like to realize drag&drop with reimplemented QStandardItemModel. QStandardItem also reimplemented. It looks like:

class _DLL_PREFIX_ TMyItem : public QStandardItem
        {
            public:
                virtual QVariant data(int role = Qt::UserRole + 1) const;
                virtual void setData(const QVariant &value, int role = Qt::UserRole + 1);
 
            private:
                 TElementData *m_pElementData;
}
 
QVariant TMyItem::data(int role) const
{
    if (role == Qt::UserRole+1) 
    {
         return QVariant::fromValue(m_pElementData);  
    }
    return QStandardItem::data(role);    
}
 
void TMyItem::setData(const QVariant &value, int role)
{
    if (role == Qt::UserRole+1) 
    {
        ASSERT(value.canConvert<TElementData *>())
        m_pElementData = value.value<TElementData*>()->clone();
         return;         
    }
 
    QStandardItem::setData(value, role);
}

class _DLL_PREFIX_ TMyItem : public QStandardItem
        {
            public:
                virtual QVariant data(int role = Qt::UserRole + 1) const;
                virtual void setData(const QVariant &value, int role = Qt::UserRole + 1);

            private:
                 TElementData *m_pElementData;
}

QVariant TMyItem::data(int role) const
{
    if (role == Qt::UserRole+1) 
    {
         return QVariant::fromValue(m_pElementData);  
    }
    return QStandardItem::data(role);    
}

void TMyItem::setData(const QVariant &value, int role)
{
    if (role == Qt::UserRole+1) 
    {
        ASSERT(value.canConvert<TElementData *>())
        m_pElementData = value.value<TElementData*>()->clone();
         return;         
    }
      
    QStandardItem::setData(value, role);
}

To copy to clipboard, switch view to plain text mode 

When I try to drag an element within the model (to reorder elements) I find out that user data is not copied (m_pElementData = NULL in the dropped element). I think I should reimplement some other functions to make all this work correctly. But I'm not quite sure what functions and in what classes. It seems to me that: QStandardItemModel::mimeData(...), maybe QStandardItemModel::itemData (...)? Something else?

Thanks in advance.

[Miga]

So, maybe this will be useful for somebody. The following was done.
TMyModel : public QStandardItemModel
Reimplemented metods: itemData, setItemData, data, setData.
TMyItem : public QStandardItem
Reimplemented methods: data, setData

Don't forget:

Q_DECLARE_METATYPE(TElementData*)
 
qRegisterMetaType<TElementData*>("TDataPtr");
qRegisterMetaTypeStreamOperators<TElementData*>("TDataPtr");

Q_DECLARE_METATYPE(TElementData*)

qRegisterMetaType<TElementData*>("TDataPtr");
qRegisterMetaTypeStreamOperators<TElementData*>("TDataPtr");

To copy to clipboard, switch view to plain text mode 

Realize functions:

QDataStream &operator<<(QDataStream &Out, const TElementData* pElement)
QDataStream &operator>>(QDataStream &In, TElementData* &pElement)

QDataStream &operator<<(QDataStream &Out, const TElementData* pElement)
QDataStream &operator>>(QDataStream &In, TElementData* &pElement)

To copy to clipboard, switch view to plain text mode