问从另一个模型中提取子模型？

EN

class TreeItem
{
public:
    explicit TreeItem(const QList<QVariant> &data, TreeItem *parentItem = 0);
    ~TreeItem();

    void appendChild(TreeItem *child);

    TreeItem *child(int row);
    int childCount() const;
    int columnCount() const;
    QVariant data(int column) const;
    int row() const;
    TreeItem *parentItem();

private:
    QList<TreeItem*> m_childItems;
    QList<QVariant> m_itemData;
    TreeItem *m_parentItem;
};

class TreeModel : public QAbstractItemModel
{
    Q_OBJECT

public:
    explicit TreeModel(const QString &data, QObject *parent = 0);
    ~TreeModel();

    QVariant data(const QModelIndex &index, int role) const Q_DECL_OVERRIDE;
    Qt::ItemFlags flags(const QModelIndex &index) const Q_DECL_OVERRIDE;
    QVariant headerData(int section, Qt::Orientation orientation,
                        int role = Qt::DisplayRole) const Q_DECL_OVERRIDE;
    QModelIndex index(int row, int column,
                      const QModelIndex &parent = QModelIndex()) const Q_DECL_OVERRIDE;
    QModelIndex parent(const QModelIndex &index) const Q_DECL_OVERRIDE;
    int rowCount(const QModelIndex &parent = QModelIndex()) const Q_DECL_OVERRIDE;
    int columnCount(const QModelIndex &parent = QModelIndex()) const Q_DECL_OVERRIDE;

private:
    void setupModelData(const QStringList &lines, TreeItem *parent);

    TreeItem *rootItem;
};

Item {
    width: parent.width
    height: parent.height

    ListView {
        //anchors.top: myImage.bottom
        anchors.fill: parent
        id: list
        spacing: 4
        model: treeModel

        delegate: listDelegate

    }

    Component {
        id: listDelegate
        Rectangle
        {
            id: delegateRect
            height: image.height
            width: 500
            Image {
                id: image
                source: "qrc:/icons/resources/element.ico"

            }

            Text {
                id: t
                anchors.left: image.right
                anchors.leftMargin: 20
                anchors.centerIn: delegateRect

                text: title + "/" + summary
                //text: display
            }

            MouseArea {
                anchors.fill: parent
                onClicked: {

                    list.currentIndex = index

                    console.log("Item clicked, index = " + index)

                    // I think I should change model here to sub model but how do I do it?
                    //list.model = treeModel.data(index) 
                }
            }
        }
    }
}