Flat leaf Proxy

[VRonin]

I have a model (QStandardItemModel actually) with a list of data (10 columns) each row data contains the sum off all children items. so it's a very basic tree with just one level. now I'd like to display all child items of all the tree nodes in a flat table. To achieve it I thought about a ProxyModel. Here is what I did:

#ifndef CHILDTABLEPROXY_H
#define CHILDTABLEPROXY_H

#include <QAbstractProxyModel>

class ChildTableProxy : public QAbstractProxyModel
{
   Q_OBJECT

public:
   ChildTableProxy(QObject *parent);
   virtual QModelIndex mapToSource(const QModelIndex& proxyIndex) const override;
   virtual QModelIndex mapFromSource(const QModelIndex& sourceIndex) const override;
   virtual int rowCount(const QModelIndex& parent = QModelIndex()) const override;
   virtual int columnCount(const QModelIndex& parent = QModelIndex()) const override;
   virtual bool insertColumns(int column, int count, const QModelIndex& parent = QModelIndex())override;
   virtual bool insertRows(int row, int count, const QModelIndex& parent = QModelIndex())override;
   virtual bool removeColumns(int column, int count, const QModelIndex& parent = QModelIndex())override;
   virtual bool removeRows(int row, int count, const QModelIndex& parent = QModelIndex())override;
   virtual QItemSelection mapSelectionToSource(const QItemSelection& selection) const override;
   virtual QItemSelection mapSelectionFromSource(const QItemSelection& selection) const override;
   virtual QModelIndex parent(const QModelIndex& child) const override;
   virtual QModelIndex index(int row, int column, const QModelIndex &parent = QModelIndex()) const override;
   virtual QVariant data(const QModelIndex & proxyIndex, int role = Qt::DisplayRole) const override;
protected:
   virtual QModelIndex getSourceIndex(int row, int column) const;
};

#endif // CHILDTABLEPROXY_H

#include "ChildTableProxy.h"
#include <QItemSelection>
ChildTableProxy::ChildTableProxy(QObject *parent)
    : QAbstractProxyModel(parent)
{}



QModelIndex ChildTableProxy::mapFromSource(const QModelIndex& sourceIndex) const
{
    if (!sourceIndex.isValid())
        return QModelIndex();
    if (!sourceIndex.parent().isValid())
        return QModelIndex();
    int row = sourceIndex.row();
    for (int i = 0; i < sourceIndex.parent().row(); ++i)
        row += sourceIndex.model()->rowCount(sourceIndex.model()->index(i, 0));
    return index(row, sourceIndex.column());
}

int ChildTableProxy::rowCount(const QModelIndex& parent) const
{
    if (parent.isValid())
        return 0;
    int result = 0;
    for (int i = 0; i < sourceModel()->rowCount();++i){
        result += sourceModel()->rowCount(sourceModel()->index(i, 0));
    }
    return result;
}

int ChildTableProxy::columnCount(const QModelIndex& parent) const
{
    if (parent.isValid())
        return 0;
    return sourceModel()->columnCount();
}

bool ChildTableProxy::insertColumns(int, int, const QModelIndex&)
{
    return false;
}

bool ChildTableProxy::insertRows(int , int , const QModelIndex&)
{
    return false;
}

bool ChildTableProxy::removeColumns(int , int , const QModelIndex& )
{
    return false;
}

bool ChildTableProxy::removeRows(int , int , const QModelIndex&  )
{
    return false;
}

QItemSelection ChildTableProxy::mapSelectionToSource(const QItemSelection& selection) const
{
    QItemSelection result;
    const QModelIndexList allSelected = selection.indexes();
    for (auto i = allSelected.constBegin(); i != allSelected.constEnd(); ++i) {
        const QModelIndex mapped = mapToSource(*i);
        result.select(mapped, mapped);
    }
    return result;
}

QItemSelection ChildTableProxy::mapSelectionFromSource(const QItemSelection& selection) const
{
    QItemSelection result;
    const QModelIndexList allSelected = selection.indexes();
    for (auto i = allSelected.constBegin(); i != allSelected.constEnd(); ++i) {
        const QModelIndex mapped = mapFromSource(*i);
        result.select(mapped, mapped);
    }
    return result;
}

QModelIndex ChildTableProxy::parent(const QModelIndex&) const
{
    return QModelIndex();
}

QModelIndex ChildTableProxy::index(int row, int column, const QModelIndex &parent) const
{
    if (parent.isValid())
        return QModelIndex();
    QModelIndex sourceIdx = getSourceIndex(row,column);
    if(!sourceIdx.isValid())
        return QModelIndex();
    return createIndex(row, column, sourceIdx.internalPointer());
}

QVariant ChildTableProxy::data(const QModelIndex & proxyIndex, int role) const
{
    return sourceModel()->data(mapToSource(proxyIndex),role);
}

QModelIndex ChildTableProxy::getSourceIndex(int row, int column) const
{
    if (row < 0 || column < 0 || column >= columnCount())
        return QModelIndex();
    for (int i = 0; i < sourceModel()->rowCount(); ++i) {
        if (row >= sourceModel()->rowCount(sourceModel()->index(i, 0)))
            row -= sourceModel()->rowCount(sourceModel()->index(i, 0));
        else
            return sourceModel()->index(row, column, sourceModel()->index(i, 0));
    }
    // row>rowCount()
    return QModelIndex();
    
}
QModelIndex ChildTableProxy::mapToSource(const QModelIndex& proxyIndex) const
{
    if (!proxyIndex.isValid())
        return QModelIndex();
    if (proxyIndex.parent().isValid())
        return QModelIndex();
    return getSourceIndex(proxyIndex.row(), proxyIndex.column());
}

Unfortunately, despite rowcount returning the correct number, data is never called with a row greater than 0. What am I doing wrong?
Thanks in advance

[GeorgePTVS]

How are you viewing the model?