#include <QListView>
#include <QApplication>

class MyModel : public QAbstractListModel {
public:
    int rows;
    MyModel() {
        rows = 300000;
    }
    int rowCount(const QModelIndex&) const {
        return rows;
    }
    QVariant data(const QModelIndex& index,int role) const {
        if (role==Qt::DisplayRole)
            return index.row()*index.row();
        return QVariant();
    }

};

int main(int argc,char**argv) {
    QApplication app(argc,argv);
    MyModel m;
    QListView v;
    v.setLayoutMode(QListView::Batched);
    v.setModel(&m);
    v.show();
    return app.exec();
}