Russian Qt Forum

class AnotherThread: public QThread
{
    Q_OBJECT

signals:
    void valueChanged(int);

public:
    AnotherThread(QObject *parent, int val)
        : QThread(parent),
        m_currentVal(val)
    {
    }

protected:
    virtual void run() {  
        for (int i = 0; i < m_currentVal; ++i)
            emit valueChanged(i); 
    }

private:
    int m_currentVal;
};

class MainWindow:public QMainWindow
{
    Q_OBJECT

public:
    MainWindow::MainWindow(QWidget *parent = 0) 
        : QMainWindow(parent)
    {
        QHBoxLayout *mainLayout = new QHBoxLayout();

        m_pbProgress = new QProgressBar();
        m_pbProgress->setMinimum(0);
        m_pbProgress->setMaximum(100);

        m_at = new AnotherThread(this, m_pbProgress->maximum());
        connect(m_at, SIGNAL(valueChanged(int)), m_pbProgress, SLOT(setValue(int)));

        QPushButton *pbRun = new QPushButton("Run");
        connect(pbRun, SIGNAL(clicked()), m_at, SLOT(start()));

        mainLayout->addWidget(m_pbProgress);
        mainLayout->addWidget(pbRun);

        QWidget *central = new QWidget();
        central->setLayout(mainLayout);
        setCentralWidget(central);
    }

private:
    QProgressBar *m_pbProgress;
    AnotherThread *m_at;
};

connect(m_at, SIGNAL(valueChanged(int)), m_pbProgress, SLOT(setValue(int)));

connect(m_at, SIGNAL(valueChanged(int)), m_pbProgress, SLOT(setValue(int)), Qt::QueuedConnection);

        if ((c->type == Qt::AutoConnection
             && (currentThreadData != sender->d_func()->threadData
                 || c->receiver->d_func()->threadData != sender->d_func()->threadData))
            || (c->type == Qt::QueuedConnection)) {