[SOLVED] How to use multiple different list element in ListView

jimcad

I can use different properties in ListElement when using QML model. The following code works properly. Arg2 is only in the first ListElement:

ListView  {
    id:listView
    height: 200
    Layout.fillWidth: true
    delegate: Rectangle {
        height: 50
        Label {
            anchors.fill: parent
            text: arg1 + " " + (arg2 === undefined ? "" : " " + arg2)
        }
    }
    model: ListModel {
        ListElement { arg1: "Elem1"; arg2: "Elem1arg2" }
        ListElement { arg1: "Elem2" }
    }
}

But I'd like to load model from C++. I have multiple inherited classes.

Here is base idea of my classes:

class Class1 : public QObject
{
  Q_PROPERTY(QString arg1...
//...
class Class2 : public Class1
  Q_PROPERTY(QStirng arg2...

I tried to use QObjectList -based model. I didn't get it working because only properties from Class1 are available:

QList<QObject*> list;
list.append(new Class1("Elem1"));
list.append(new Class2("Elem2","Elem2arg1" ));
return QVariant::fromValue(list);

How I can get properties from both classes? Or is it even possible?

p3c0

@jimcad AFAIK it should work. All the parent's properties should be visible to child.
Have you set the inherited property's value from child ?

jimcad

@p3c0 Yes, arg1 is set for both and it's visible in QML. But arg2 is available only in Class2 and it's not visible in QML. That is the problem.

p3c0

@jimcad OfCourse how would arg2 be available to Class1 ? Children inherit properties of their parents and not the other way.
You can add a check there something like:

Text {
    text : typeof model.modelData.arg2==="undefined" ? "DefaultValue" : model.modelData.arg2
}

jimcad

@p3c0 Yes, I know that. There must be something wrong in my code because this not working either:

    MyClass1{ id: class1 }
    MyClass2{ id: class2 }

    Component.onCompleted: {
        class2.arg1 = "Changed arg1"
        console.log(class2.arg1) // works ok
        class2.arg2 = "Changed arg2" // <-- Doesn't work        
        console.log(class2.arg2)
    }

Seems that all properties from inherited classes doesn't works. Here is my example project: https://www.dropbox.com/s/mi33b8ml8nctrup/qml-test.zip?dl=0

jimcad

@p3c0 I found it. It was missing Q_OBJECT macro in Class2. Now it works properly. Thanks for your advice.