[ Solved ] a QTableView/QAbstractTableModel problem, please help

[lvdong]

I used a QTableView and an editable QAbstractTableModel subclass to display a large dataset.
But when I double click an item, the original data of the item is gone,
how can I edit the orginal data.
thanks.

model.h

class Model : public QAbstractTableModel
{
    Q_OBJECT
 
public:
    Model(QObject *parent = 0);
 
    void setSourceData(const QString &fileName);  // to get data
 
    int rowCount(const QModelIndex &parent) const;
    int columnCount(const QModelIndex &parent) const;
    QVariant data(const QModelIndex &index, int role) const;
    bool setData(const QModelIndex &index, const QVariant &value,
                 int role);
    QVariant headerData(int section, Qt::Orientation orientation,
                        int role) const;
    Qt::ItemFlags flags(const QModelIndex &index) const;
 
private:
    QStringList rowNames;
    QStringList columnNames;
    QVector<QVector<int> > dataset;
};

class Model : public QAbstractTableModel
{
    Q_OBJECT

public:
    Model(QObject *parent = 0);

    void setSourceData(const QString &fileName);  // to get data

    int rowCount(const QModelIndex &parent) const;
    int columnCount(const QModelIndex &parent) const;
    QVariant data(const QModelIndex &index, int role) const;
    bool setData(const QModelIndex &index, const QVariant &value,
                 int role);
    QVariant headerData(int section, Qt::Orientation orientation,
                        int role) const;
    Qt::ItemFlags flags(const QModelIndex &index) const;

private:
    QStringList rowNames;
    QStringList columnNames;
    QVector<QVector<int> > dataset;
};

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model.cpp(fragment)

void Model::setSourceData(const QString &fileName)(const QString &fileName)
{
// read in data using QTextStream
}
 
QVariant Model::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();
 
    if (role == Qt::TextAlignmentRole)
    {
        return int(Qt::AlignRight | Qt::AlignVCenter);
    }
    else if (role == Qt::DisplayRole)
    {
        return dataset[index.row()][index.column()];
    }
// problem solved, I forgot the Qt::EditRole
    return QVariant();
}
 
bool Model::setData(const QModelIndex &index,
                        const QVariant &value, int role)
{
    if (index.isValid() && role == Qt::EditRole)
    {
        if (value.toString().isEmpty()) return false;
        dataset[index.row()][index.column()] = value.toInt();
        QModelIndex transposedIndex = createIndex(index.column(),
                                                  index.row());
        emit dataChanged(index, index);
        emit dataChanged(transposedIndex, transposedIndex);
        return true;
    }
    return false;
}
 
Qt::ItemFlags CityModel::flags(const QModelIndex &index) const
{
    Qt::ItemFlags flags = QAbstractItemModel::flags(index);
    flags |= (Qt::ItemIsEditable
             |Qt::ItemIsSelectable
             |Qt::ItemIsUserCheckable
             |Qt::ItemIsEnabled
             |Qt::ItemIsDragEnabled
             |Qt::ItemIsDropEnabled);
    return flags;
}

void Model::setSourceData(const QString &fileName)(const QString &fileName)
{
// read in data using QTextStream
}

QVariant Model::data(const QModelIndex &index, int role) const
{
    if (!index.isValid())
        return QVariant();

    if (role == Qt::TextAlignmentRole)
    {
        return int(Qt::AlignRight | Qt::AlignVCenter);
    }
    else if (role == Qt::DisplayRole)
    {
        return dataset[index.row()][index.column()];
    }
// problem solved, I forgot the Qt::EditRole
    return QVariant();
}

bool Model::setData(const QModelIndex &index,
                        const QVariant &value, int role)
{
    if (index.isValid() && role == Qt::EditRole)
    {
        if (value.toString().isEmpty()) return false;
        dataset[index.row()][index.column()] = value.toInt();
        QModelIndex transposedIndex = createIndex(index.column(),
                                                  index.row());
        emit dataChanged(index, index);
        emit dataChanged(transposedIndex, transposedIndex);
        return true;
    }
    return false;
}

Qt::ItemFlags CityModel::flags(const QModelIndex &index) const
{
    Qt::ItemFlags flags = QAbstractItemModel::flags(index);
    flags |= (Qt::ItemIsEditable
             |Qt::ItemIsSelectable
             |Qt::ItemIsUserCheckable
             |Qt::ItemIsEnabled
             |Qt::ItemIsDragEnabled
             |Qt::ItemIsDropEnabled);
    return flags;
}

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main.cpp(fragment)

Model model;
model.setSourceData("data.txt");
QTableView tableView;
tableView.setModel(&model);

Model model;
model.setSourceData("data.txt");
QTableView tableView;
tableView.setModel(&model);

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[franz]

What does your model's data() function return for Qt::EditRole?

Also, please use the code tags for chunks of code.

[lvdong]

thanks, I forgot the EditRole.

[wojiaoguowei]

3q for your help! I do as you do!

QVariant Model::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();

if (role == Qt::TextAlignmentRole)
{
return int(Qt::AlignRight | Qt::AlignVCenter);
}
else if (role == Qt:isplayRole)
{
// problem solved, I forgot the Qt::EditRole
return dataset[index.row()][index.column()];
}
else if(role == Qt::EditRole)
{
QString str = dataset[index.row()][index.column()];
return str;
}

return QVariant();
}