#include <QAbstractListModel>
#include <QApplication>
#include <QDebug>
#include <QLayout>
#include <QListView>
#include <QMainWindow>
#include <QScopedPointer>
#include <QSortFilterProxyModel>
#include <QTimer>
#include <QVector>

class CategoryModel : public QAbstractListModel {
    Q_OBJECT
    QVector<QString> cache{"foo", "bar"};
public:
    virtual int rowCount(const QModelIndex &parent) const override;
    virtual QVariant data(const QModelIndex &index, int role) const override;
};

#include "main.moc"

int CategoryModel::rowCount(const QModelIndex &) const {
    return cache.size();
}

QVariant CategoryModel::data(const QModelIndex &index, int role) const {
    if (role == Qt::DisplayRole || role == Qt::EditRole) {
        return cache[index.row()];
    }
    return QVariant();
}

int main(int argc, char *argv[]) {
    QApplication app(argc, argv);
    QMainWindow widget;

    CategoryModel model;
    QSortFilterProxyModel proxy;
    proxy.setSourceModel(&model);
    QListView view;
    view.setModel(&proxy);
    view.selectionModel()->select(model.index(0), QItemSelectionModel::ClearAndSelect);
    QObject::connect(view.selectionModel(), &QItemSelectionModel::selectionChanged, [&model](){
        qDebug() << "selection changed";
        emit model.dataChanged(model.index(0), model.index(0));
        qDebug() << "dataChanged";
    });
    QTimer::singleShot(0, [&proxy](){
        proxy.setFilterFixedString("fizz");
    });

    widget.setCentralWidget(&view);
    widget.show();
    return app.exec();
}