QIdentityProxyModel display empty rows - c++

Question

I've implemented QIdentityProxyModel like this:
class ProxyModel : public QIdentityProxyModel
{
Q_OBJECT
public:
ProxyModel(QObject *parent)
{
entriesPerPage = 3;
page = 1;
}
inline int getEntriesPerPage() const
{ return entriesPerPage; }
inline void setEntriesPerPage(int value)
{ entriesPerPage = value; }
inline qint64 getPage() const
{ return page; }
inline void setPage(const qint64 &value)
{ page = value; }
inline int rowCount(const QModelIndex &parent = QModelIndex()) const override{
Q_UNUSED(parent)
if(!sourceModel())
return 0;
return entriesPerPage * page <= sourceModel()->rowCount()
? entriesPerPage
: sourceModel()->rowCount() - entriesPerPage * (page - 1);
}
inline int columnCount(const QModelIndex &parent = QModelIndex()) const override{
Q_UNUSED(parent);
return 6;
}
QModelIndex ProxyModel::mapFromSource(const QModelIndex &sourceIndex) const
{
if(!sourceModel() && !proxyIndex.isValid())
return QModelIndex();
return sourceIndex.isValid()
? createIndex(sourceIndex.row() % entriesPerPage, sourceIndex.column(), sourceIndex.internalPointer())
: QModelIndex();
}
QModelIndex ProxyModel::mapToSource(const QModelIndex &proxyIndex) const
{
if(!sourceModel() && !proxyIndex.isValid())
return QModelIndex();
QModelIndex remapped = createIndex(proxyIndex.row() ,
proxyIndex.column(),
proxyIndex.internalPointer());
return QIdentityProxyModel::mapToSource(remapped);
}
private:
int entriesPerPage;
qint64 page;
};
When I insert a row in the sourceModel() with index more then entriesPerPage, view displays empty rows, so that row number is more then entriesPerPage, although rowCount() return number equal to entriesPerPage.
How can I get rid of empty rows?

Answer 1

First. It is a bad practice to override rowCount/mapFromSource for QIdentityProxyModel. I propose you to use QAbstractProxyModel to have more clear code.
Main. Your problem is in getEntriesPerPage/setPage methods. You need to call beginResetModel/endResetModel after updating such data.
inline void setPage(const qint64 &value)
{
beginResetModel();
page = value;
endResetModel();
}
Offtopic: it is pretty cool, that you have to code with Qt in BSUIR. Who is your teacher?