Register C++ class derived from QAbstractListModel

realroot

I am following the examples here: https://www.qt.io/product/qt6/qml-book/ch17-qtcpp-cpp-models#a-simple-model.

MyClass.h

class MyClass : public QAbstractListModel
{
...

But I cannot register the class:

error: static assertion failed: It is not possible to register an abstract type with qmlRegisterType. Maybe you wanted qmlRegisterUncreatableType or qmlRegisterInterface?

It works if I derive from QObject, I can compile the code and use the class in main.qml.
I also tried to use QML_ELEMENT.

The class is used for a ListView, as the example so I am supposed to use a QAbstractListModel right?

Why can't I use it?

sierdzio

@realroot said in Register C++ class derived from QAbstractListModel:

Why can't I use it?

Impossible to say for sure without seeing more code.

My guesses:

you forgot about Q_OBJECT macro
you did not reimplement abstract methods from QAbstractListModel (this is precisely what this error tells you)

As the documentation say:

When subclassing QAbstractListModel, you must provide implementations of the rowCount() and data() functions

realroot

The error message is not so clear.

I did not make the implementations of the rowCount() and data() functions, thanks.

I am replacing the configuration file that it is a QML file.
I am not sure about the implementation.

I have a ListView whose elements are ListView.
ListViews have a few properties and the inner one has ListElements:

import QtQuick

Item {
    id: config

    //Inner ListView
    Item {
        id: w001
        property bool defAutomatic: true
        property int sets: 1
        property string woName: "30 seconds"
        property bool initPrep: true

        property int exTotal: w001timers.count
        property alias timers: w001timers
        property int setTotal: w001timers.setTotal
        property int woTotal: w001timers.woTotal

        ListModel {
            id: w001timers
            property int sets: w001.sets
            property string woName: w001.woName
            property bool initPrep: w001.initPrep
            property int setTotal: {
                for (var i = 0; i < count; i++) {
                    setTotal += get(i).countdownValue;
                }
            }
            property int woTotal: setTotal * sets

            ListElement {
                automatic: true
                countdownValue: 30
                timerName: "go"
                prepare: false
            }
        }
    }
...

I am adding a C++ back end to save/load/edit the configuration, using only QML works but that looks like suitable for C++.
I thinking about saving it as json.

Any suggestion? I am a beginner.
Should I submit a new topic?

realroot

Moved here https://forum.qt.io/topic/154442/convert-qml-file-to-json.