The correct solution is to not modify a model from an other thread.
You could either use invokeMethod or emit a signal and connect it to a function in the main thread to add data to your model.

@qtMJ Consider also whether you need a thread at all. If you need timed actions use QTimer. It's not a good programming practice to use while loop and sleep in a Qt application.

https://arunpkqt.wordpress.com/2016/12/08/qml-list-view-sort-and-filter/

To my model I added from the example

class FilterProxyModel : public QSortFilterProxyModel

and in my main.cpp I changed to following code

FilterProxyModel filterModel;
filterModel.setSourceModel(&model);

QQmlApplicationEngine engine;
QQmlContext* ctxt = engine.rootContext();
ctxt->setContextProperty("myModel", &filterModel);
engine.load(QUrl(QStringLiteral("qrc:/main.qml")));

And in my QML I changed to ApplicationWindow and put my ListView in a ColumnLayout.

And now when it works as I wanted, I can continue and try to understand why...

Thanks for all help and if you think this solution is good, I can mark this post as solved
and continue with my project?

/MJ

The only code I added to the example is my thread that I start in main.cpp before
QQuickView view;

And run like this (Here model is moved as a global, even tryed to pass it as pointer)

void myThread::run()
{
int i=0;
while (1) {
model.addAnimal(Animal("Animal" + QString::number(++i), "Medium"));
msleep(1000);
}
}

And in my QML I just added

Connections{
target: myModel
onRowsInserted: console.log("rows were inserted")
}

and the text shows up in my consol every second.

void AnimalModel::addAnimal(const Animal &animal)
{
    beginInsertRows(QModelIndex(), rowCount(), rowCount());
    m_animals << animal;
    endInsertRows();
}

and if you call it to add animals to list it should send signals automatically and the view should be updated. You can try to catch the signal in QML:

Connections{
target: myModelObjectWhichWasSetAsContextProperty
onRowsInserted: console.log("rows were inserted")
}

If it works there's something wrong with the view.

I found this AbstractItemModel Example,
http://doc.qt.io/qt-5/qtquick-models-abstractitemmodel-example.html

I passed
AnimalModel model;
to my thread, and I managed to add to the list, but the view only update my ListView if I resize the window.
Is this right way to go, and how can I update my view?

/MJ