Insert data after setModel on QAbstractTableModel

Question

My model is a subclass of QAbstractTableModel and I have overridden some methods to make this work.

class UserModel: public QAbstractTableModel
{
    Q_OBJECT
public:
    UserModel(QList<User> users, QObject *parent = Q_NULLPTR);

    int rowCount(const QModelIndex &) const override
    {

        return users.size();
    }
    int columnCount(const QModelIndex &) const override
    {
        return 3;
    }

    QVariant data(const QModelIndex &index, int role) const override
    {
        if(role == Qt::DisplayRole)
        {
            User user = users.at(index.row());
            QVariant data[] = { user.getFirstname(), user.getLastname() , user.getAge() };
            return data[index.column()];
        }

        return {};
    }


    void sort(int column, Qt::SortOrder order) override
    {
        auto fnSort = [](const User & u1, const User & u2){ return u1.getFirstname() < u2.getFirstname(); };
        auto lnSort = [](const User & u1, const User & u2){ return u1.getLastname() < u2.getLastname(); };
        auto agSort = [](const User & u1, const User & u2){ return u1.getAge() < u2.getAge(); };

        std::function<bool (const User &, const User &)>  sortFn[] = {fnSort, lnSort, agSort};
        std::sort(users.begin(), users.end(), sortFn[column]);

        if(order == Qt::DescendingOrder)
        {
            std::reverse(users.begin(), users.end());
        }
    }


    bool insertRows(int position, int rows, const QModelIndex &index) override
    {
        Q_UNUSED(index);
        beginInsertRows(QModelIndex(), position, position + rows - 1);

        for (int row = 0; row < rows; ++row)
            users.insert(position, {User()});

        endInsertRows();
        return true;
    }


    bool setData(const QModelIndex &index, const QVariant &value, int role) override
    {
        if (index.isValid() && role == Qt::EditRole) {
            int row = index.row();

            User u = users.value(row);

            if (index.column() == 0)
                u.setFirstname(value.toString());
            else if (index.column() == 1)
                u.setLastname(value.toString());
            else
                return false;

            users.replace(row, u);
            emit(dataChanged(index, index));

            return true;
        }

        return false;
    }


    Qt::ItemFlags flags(const QModelIndex &index) const override
    {
        return Qt::ItemIsEditable | QAbstractTableModel::flags(index);
    }

    QVariant headerData(int section, Qt::Orientation orientation, int role) const override
    {
        if (role == Qt::DisplayRole && orientation == Qt::Horizontal) {
            switch (section) {
            case 0:
                return QString("firstname");
            case 1:
                return QString("lastname");
            case 2:
                return QString("age");
            }
        }
        return QVariant();
    }

signals:
    void editCompleted(const QString &);

private:

    QList<User> users;



};

#endif // USERMODEL_H

with that, i see my table:

this->model = new UserModel(users, this);
this->m_proxy->setSourceModel(this->model);
this->ui->tableView->setModel(this->m_proxy);

I try to make my model work with something like:

this->model->addSomethingToMyModel(newUser);

Seems to be LOOOOOOT more complicated. Can you help me a bit ? I have based my code on the AdressBook exemple

Answer 1

You can add a function like this to the model class:

void append(const User & user)
{
    int row = _users.size();
    insertRows(row, 1, QModelIndex());
    _users[row] = user;
    emit(dataChanged(index(row, 0), index(row, 2)));
}

then downcast the table model to use it:

UserModel * model = dynamic_cast<UserModel*>(myTableView->model());
model->append(newUser);