Newby questions about QML models

[Willem Ferguson]

On 01/02/2016 20:46, Tomaz Canabrava wrote:
> I can have a class DiveComputers that is a model based on 
> QAbstractListModel, since any dive can have zero or more dive 
> computers, I can have the method DiveComputers *diveComputers() on the 
> class Dive as a Q_PROPERTY, and I can access it in QML via:
>
> ListView {
>     id: diveList
>     model : diveListModel
>     delegate {
>         ListView {
>             id: diveComputerList
>             model: dive.diveComputers
>         }
>     }
> }
>
Tomaz,
Your email above is extremely informative. I deal with two-way 
communication between the QML and C++. The above allows the QML to see a 
model on the C++ side. This takes care of getting data drom the C++ to 
the QML. I also use a signal emitted by the QML to update the model 
within C++, something as follows:

Class DownloadManager

     Q_PROPERTY(QStringListModel *vendorModel READ getVendorModel WRITE 
setVendorModel NOTIFY vendorChanged)
    .......

signals:
     void vendorChanged();    // notification from C++ to QML

public slots:
     void newVendorSlot(const QString &vendortext);// meant for incoming 
signal from QML. I need to connect this to the QML.


The middle two lines above allow communication of the vendorModel to the 
QML. The bottom line above allows the C++ to receive the signal from the 
QML. Normally, using QtQuickView I would have connected the QML signal 
to the C++ slot as follows:

     QObject *dcSelectPanel = view.rootObject();
QObject::connect(dcSelectPanel,SIGNAL(vendorChangedSignal(QString)),
&DownloadManager,SLOT(newVendorSlot(QString)));

But within the present context it looks like view.rootObject() is not 
easily accessible and I need an alternative way of connecting the QML 
signal to the C++ slot. Any suggestions? I have spent considerable time 
scanning for a discussion on this issue and cannot find any text. In 
QmlManager, many slots are created but I see no connect construct. I 
hope I am making sense?
Kind regards,
willem