How to access C++ model from QML ListView

[sly110]

I am using the drawer control to navigate between various qml pages displayed in a stackview. I have a model in C++ exposed to QML as a QListProperty. The C++ class containing this property is instantiated in main.cpp and set as a context property. My drawer has delegate Buttons each associated with a Key class in the QList. Each button should display the 'title' QString in each Key object. Error in QML debugger is qrc:/main.qml:191:23: Unable to assign [undefined] to QString qrc:/main.qml: 191

How do I set the text property in the ListView / delegate?

Also when the drawer button is clicked a slot in the C++ should be called with the Key source QString. How will this be defined in QML.

Thank you for any help.

   //nav drawer
    Drawer {
        id: drawer
        width: Math.min(window.width, window.height) / 3 * 2
        height: window.height
        background: Rectangle {  //add fill to drawer
            anchors.fill: parent
            color: "white"
        }
        ListView {
            id: listView
            currentIndex: -1
            anchors.fill: parent
            model: QML_MAIN.KeyModel     //c++ model

            delegate: Button {
                id: buttonDelegate
                width: parent.width - 2
                height: window.height / 6
                text: listView.model.title

                contentItem: Text {
                    text: buttonDelegate.text
                    font: buttonDelegate.font
                    opacity: 1.0
                    color: "white"
                    horizontalAlignment: Text.AlignHCenter
                    verticalAlignment: Text.AlignVCenter
                    elide: Text.ElideRight
                }
                background: Rectangle {
                    color: "blue"
                    border.width: 2
                    border.color: "white"
                }
                highlighted: ListView.isCurrentItem
                onClicked: {
                        console.log("Drawer Clicked")
//                       QML_MAIN.cppNavSlot(QML_MAIN.model.target)

                }
            } //button delegate
            ScrollIndicator.vertical: ScrollIndicator { }
        } //listview
    } //nav drawer

//------------------------------------------------------------------------------
// class QmlMain
//------------------------------------------------------------------------------
class QmlMain : public QObject
{
    Q_OBJECT

    Q_PROPERTY  (QString Id READ getId NOTIFY idChanged)
    Q_PROPERTY  (QString Title READ getTitle NOTIFY titleChanged)
    Q_PROPERTY  (QString Source READ getSource NOTIFY sourceChanged)
//SLY TODO:
//    Q_PROPERTY(QString icon READ icon WRITE setIcon NOTIFY iconChanged)
//    Q_PROPERTY(QString target READ target WRITE setTarget NOTIFY targetChanged)

    Q_PROPERTY  (QUrl Help READ gethelpUrl NOTIFY helpUrlChanged)
    Q_PROPERTY  (QString StatusText READ getStatusText WRITE setStatusText NOTIFY statusTextChanged)

    Q_PROPERTY  (QQmlListProperty<Key> KeyModel READ readKeyModel NOTIFY keyModelChanged)
...
  QList<Key *> _keyModel;

class Key : public QObject
{
    Q_OBJECT


public:

    Key(QObject *parent = 0);
    Key(const QString &id, const QString &type, const QString &title, const QString &icon, const QString &target, QObject *parent = 0);

//    Key(const Key &key, QObject *parent = 0);     //my public copy constructor
//    Key &operator=( const Key& key );

    ~Key();

    QString id;
    QString type;
    QString title;
    QString icon;
    QString target;


};


class Nav : public QObject
{
    Q_OBJECT


public:
    Nav(QObject *parent = 0);
    Nav(const QString &pid, const QString &ptitle, QObject *parent = 0);
    ~Nav();

//    Nav(const Nav &nav, QObject *parent = 0);    //my public copy constructor
//    Nav &operator=( const Nav& nav );



    QString id;
    QString title;
    QString source;
    QList <Key *> keys;
    QList <int> milestones;
};


#endif // KEYDATA_H

[sly110]

Apparently the included class must have Q_PROPERTY defined for items intended to be bound to QML.
At least it is working now. I will mark as solved in case this helps someone else.