I'm trying to implement my own model/delegate where the model returns pointers to a QHash<QString, QString> *. I've called Q_DECLARE_METATYPE in order to register the new type and have also called qRegisterMetaType<MyType>("MyType"). Unfortunately, when I try to convert the call to index.data(Qt:isplayType) into <QHash<QString, QString> *, all I seem to get back is a null pointer...

Qt Code: 
  1. typedef QHash<QString, QString>* MyType; 
  2. Q_DECLARE_METATYPE(MyType)
  3.  
  4. class MyDelegate : public QItemDelegate
  5. {
  6.   Q_OBJECT
  7.  
  8.  public:
  9.   MyDelegate(QWidget *parent = 0);
  10.  
  11.   virtual void paint(QPainter *painter, const QStyleOptionViewItem &option, 
  12. 		     const QModelIndex &index) const;
  13. };
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So the declaration above helped me get the code to compile.

Qt Code: 
  1. MyDelegate::MyDelegate(QWidget *parent)
  2.   :QItemDelegate(parent)
  3. {
  4.   qRegisterMetaType<MyType>("MyType");
  5. }
  6.  
  7. void MyDelegate::paint(QPainter *painter, const QStyleOptionViewItem &option, 
  8. 		     const QModelIndex &index) const
  9. {
  10.   QRect rect = option.rect;
  11.  
  12.   QHash<QString, QString> * t = 0;
  13.   t = qVariantValue<QHash<QString, QString>*>(index.data(Qt::DisplayRole));
  14.   if(t != 0)
  15.     {
  16.       std::cout << "T size: " << t->size() << std::endl;
  17.     }
  18.  
  19.   if(option.state & QStyle::State_Selected)
  20.     {
  21.       painter->fillRect(rect, option.palette.highlight());
  22.     }
  23.   else
  24.     {
  25.       QItemDelegate::paint(painter, option, index);
  26.     }
  27. }
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Now something is going wrong on lines 12 and 13. Perhaps something about my data declaration below is incorrect? Of course I'm expecting that I should now have a handle on that index in the model. If I did, then I would proceed to format everything in the paint call.

Qt Code: 
  1. QVariant CustomModel::data(const QModelIndex &index, int role)const
  2. {
  3.   if(!index.isValid())
  4.     {
  5.       return QVariant();
  6.     }
  7.   if(role == Qt::TextAlignmentRole)
  8.     {
  9.       return int(Qt::AlignRight | Qt::AlignVCenter);
  10.     } 
  11.   else if (role == Qt::DisplayRole)
  12.     {
  13.       //Returning a pointer to the QHash<QString, QString> so just 
  14.       //cast back and then use the data in the view.
  15.       return tableData.at(index.row());
  16.     }
  17.   return QVariant();  
  18. }
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Thanks for taking your time