#include <QtGui>

class PanelModel : public QAbstractListModel
{
    Q_OBJECT
public:
    PanelModel(QObject *parent = 0) : QAbstractListModel(parent) { m_elements << "a" << "b" << "c" << "d"; }
    int rowCount(const QModelIndex &parent = QModelIndex()) const { return m_elements.count(); }
    QVariant data(const QModelIndex &index, int role = Qt::DisplayRole) const
    {    
        if (!index.isValid())
            return QVariant();

        if (index.row() < m_elements.count()) {
            if ( role == Qt::DisplayRole )
                return m_elements.at( index.row() );
        }

        return QVariant();
    }
public slots:
    void move() 
    {
        m_elements[0] = "e";
        m_elements[1] = "f";
        m_elements[2] = "g";
        m_elements[3] = "h";
        emit dataChanged(index(2, 0, QModelIndex()), index(3, 0, QModelIndex()));
    }
private:    
    QStringList m_elements;
};

#include "main.moc"

int main(int argc, char *argv[])
{
    QApplication app(argc, argv);
    PanelModel aPanelModel;
    QWidget w;
    QVBoxLayout *vbox = new QVBoxLayout;
    QListView *lv = new QListView;
    QTreeView *tv = new QTreeView;
    QPushButton *pb = new QPushButton("Update");
    vbox->addWidget(lv);
    vbox->addWidget(tv);
    vbox->addWidget(pb);
    lv->setModel(&aPanelModel);
    tv->setModel(&aPanelModel);
    w.setLayout(vbox);
    QObject::connect(pb, SIGNAL(clicked()), &aPanelModel, SLOT(move()));
    w.show();
    return app.exec();
}