#include "mainwindow.h"
#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :
    QMainWindow(parent),
    ui(new Ui::MainWindow)
{
    ui->setupUi(this);
    ui->splitter->setStretchFactor(0, 3);
    ui->splitter->setStretchFactor(1, 7);
    TabSelect item("tab");
    ui->tabsList->addItem(item);
}

MainWindow::~MainWindow()
{
    delete ui;
}

and this is my tabselect.h:

#ifndef TABSELECT_H
#define TABSELECT_H

#include <QListWidgetItem>

class TabSelect : public QListWidgetItem
{
    Q_OBJECT
public:
    std::string tabName;
    int participants;
    std::string leadingClub;
    TabSelect(std::string tabName);
    void update();
};

#endif // TABSELECT_H

and tabselect.cpp:

#include "tabselect.h"
#include <string>

TabSelect::TabSelect(std::string tabName)
{
    this->tabName = tabName;
    this->participants = 0;
    this->leadingClub = "";
    this->update();
}


void TabSelect::update()
{
    std::string content;
    content = "<b>tabName</b>\n";
    content +="<i>Uczestnicy: " + std::to_string(participants) + "</i>";
    content += "\n<i>Klub prowadzący: " + leadingClub + "</i>";
    this->QListWidgetItem::setText(QString::fromStdString(content));
}

So my problem is, I can not do this line:

ui->tabsList->addItem(item);

because QListWidget expects QListWidgetItem, not my derived class. Is there a way to make it work as I would like?