QAbstractListModel return a QObject and use it in qml?

[bkamps]

Hi,

I want to use the QAbstractListModel to fill a QML ListView and to set some properties of the ListView. But I also want to access the properties of the elements in my AbstractListModel.

For Example:

@class MyClass : public QObject
{
Q_OBJECT
Q_PROPERTY(int number READ Number WRITE SetNumber NOTIFY NumberChanged)
}@

@class MyClassListModel : public QAbstractListModel
{
Q_OBJECT

public:
MyClassListModel(QObject *parent = 0)
: QAbstractListModel(parent){}

int rowCount(const QModelIndex &parent = QModelIndex()) const;
QVariant data(const QModelIndex &index, int role) const;

private:
QList<MyClass*> mMyClasses
}@

@QVariant MyClassListModel::data(const QModelIndex &index, int role) const
{
if (!index.isValid())
return QVariant();

if (index.row() >= stringList.size())
    return QVariant();

if (role == Qt::DisplayRole)
    return mMyClasses.at(index.row());  
else
    return QVariant();

}@

return mMyClasses.at(index.row()); >>>>>>>>> Compiler tells me I cannot return this because it's not a QVariant. Not even when I register this class with Q_DECLARE_METATYPE(MyClass).

How is this possible?

This is the situation I want to archieve:

I have read somewhere you can "return" a (pointer) QObject from data() which then is set in the QML Listview (as a delegate).

If you then notify a property of that c++ QObject (MyClass number) the property will change in the QML ListView delegate.

If the property of one of my c++ objects in the list changes I don't want to refresh the whole QML ListView (or add/remove rows) but only update the properties of that object.

The QML object can then redraw itself instead of redrawing the whole list.

[andre]

What do you expect? You are returning a pointer to a MyClass object. You can wrap that in a QVariant if you want. You can not put an actual QObject in a QVariant, as that would require copying and QObjects can not be copied.

[bkamps]

This is the situation I want to archieve:

I have read somewhere you can “return” a (pointer) QObject from data() which then is set in the QML Listview (as a delegate).

If you then notify a property of that c++ QObject (MyClass number) the property will change in the QML ListView delegate.

If the property of one of my c++ objects in the list changes I don’t want to refresh the whole QML ListView (or add/remove rows) but only update the properties of that object.

The QML object can then redraw itself instead of redrawing the whole list.

[mbrasser]

Hi,

I'd suggest trying https://qt.gitorious.org/qt-labs/qml-object-model -- it has all of the underlying model stuff already implemented for you -- you just need to provide it with the list of objects.

Regards,
Michael