QML/C++ Master/Detail ComboBox/Listview

[lqsa]

On Qt 5.7, Quick Controls 2.0, I have a master ComboBox with a slave ListView. How can the slave change when the user changes the ComboBox selection?

For exemple:

Imagine that I have a list of persons, and every person has a list of cars:
- Person1 - car1, car2, car3
- Person2 - car4
- Person3 - car5, car6, car7, car8
- Person4 - car9, car10
...

The persons must appears on ComboBox and when the users selects a person, the Listview must show person's cars.

I've tried this, but the carsRole is never called on data member, so the ListView doesn't show anything.

QML:

ComboBox {
	    textRole: "name"
            model: personsModel
	}
	ListView {
		model: personsModel.cars
	}

ComboBox {
	    textRole: "name"
            model: personsModel
	}
	ListView {
		model: personsModel.cars
	}

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C++

enum PersonsRoles {
    nameRole = Qt::UserRole + 1,
    carsRole
};
 
QVariant PersonsModel::data(const QModelIndex &index, int role) const
{
    int row = index.row();
    if ((row < 0) || (row >= _persons.size())) {
        return QVariant();
    }
    switch (role) {
    case nameRole:
        return _persons.at(row);
    case carsRole: {        
        return QVariant::fromValue(new CarsModel(row));
    }
    }
    return QVariant();
}
 
QHash<int, QByteArray> PersonsModel::roleNames() const
{
    QHash<int, QByteArray> roles;
    roles[nameRole] = "name";
    roles[carsRole] = "cars";
    return roles;
}

enum PersonsRoles {
    nameRole = Qt::UserRole + 1,
    carsRole
};

QVariant PersonsModel::data(const QModelIndex &index, int role) const
{
    int row = index.row();
    if ((row < 0) || (row >= _persons.size())) {
        return QVariant();
    }
    switch (role) {
    case nameRole:
        return _persons.at(row);
    case carsRole: {        
        return QVariant::fromValue(new CarsModel(row));
    }
    }
    return QVariant();
}

QHash<int, QByteArray> PersonsModel::roleNames() const
{
    QHash<int, QByteArray> roles;
    roles[nameRole] = "name";
    roles[carsRole] = "cars";
    return roles;
}

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