Using a QML model from a QDeclarativeItem subclass

YetAnotherNick

Hi! I'm creating a QDeclarativeItem subclass:

@class MyGraphic : public QDeclarativeItem
{
Q_OBJECT
Q_PROPERTY(????? model READ model SET model)

public:
MyGraphic(QDeclarativeItem *parent = 0);
void paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget = 0);
...
};@

I would like to use it in QML like this:

@Rectangle {
ListModel {
id: mymodel
ListElement { type: "Oranges"; amount: 35 }
ListElement { type: "Apples"; amount: 27 }
ListElement { type: "Peaches"; amount: 12 }
}

MyGraphic {
    width: 300; height: 200
    model: mymodel
}

}@

There are plenty of examples on how to make a C++ model available in the QML world but I have found nothing on how to access a QML model from C++.

How can I access mymodel from MyGraphic (the C++ class)? Should I use QAbstractItemModel* directly in the Q_PROPERTY?

I mean something like:

@void MyGraphic::paint(QPainter *painter, const QStyleOptionGraphicsItem *option, QWidget *widget)
{
QString type = model->data(...); // model would be "mymodel" from QML
int amount = model->data(...);
// paint a graphic using the "type" and "amount" variables
}@

andre

Sounds like the same question as "this":http://developer.qt.nokia.com/forums/viewthread/2926/.

Short answer: AFAIK, this is not yet possible*, as the QML model API is private API.

*) in a supported way.

YetAnotherNick

Thanks! Seems like I will have to use a QAbstractItemModel and set it in C++. Doesn't look so pretty either but that's life.

xsacha

This is something that would be very useful.
The workaround would be too complicated.
For now, do it (i mean the model) in the C++ and then it is much easier to manipulate both in QML and C++.

syrianzoro

I have did the same as in this example, I replaced the qlist with standard model but in vain

@#include <QAbstractListModel>
#include <QStringList>

//![0]
class Animal
{
public:
Animal(const QString &type, const QString &size);
//![0]

QString type() const;
QString size() const;

private:
QString m_type;
QString m_size;
//![1]
};

class AnimalModel : public QAbstractListModel
{
Q_OBJECT
public:
enum AnimalRoles {
TypeRole = Qt::UserRole + 1,
SizeRole
};

AnimalModel(QObject *parent = 0);

//![1]

void addAnimal(const Animal &animal);

int rowCount(const QModelIndex & parent = QModelIndex()) const;

QVariant data(const QModelIndex & index, int role = Qt::DisplayRole) const;

private:
QList<Animal> m_animals;
//![2]
};@