QThread and QTimer

[bibhukalyana]

Hi everyone,
I have one GUI class, one thread class, and one timer inside thread class.

mainwindow.h file:

class testClass : public QThread
{
    Q_OBJECT
public:
    testClass();
    void run();
public slots:
    void timerExpired();
    void startWork();
 
private:
    QTimer *timer;
};
 
class MainWindow : public QMainWindow
{
    Q_OBJECT
 
public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();
 
signals:
    void startSignal();
 
private slots:
    void on_pushButton_clicked();
 
private:
    Ui::MainWindow *ui;
};

class testClass : public QThread
{
    Q_OBJECT
public:
    testClass();
    void run();
public slots:
    void timerExpired();
    void startWork();

private:
    QTimer *timer;
};

class MainWindow : public QMainWindow
{
    Q_OBJECT

public:
    explicit MainWindow(QWidget *parent = 0);
    ~MainWindow();

signals:
    void startSignal();

private slots:
    void on_pushButton_clicked();

private:
    Ui::MainWindow *ui;
};

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mainwindow.c

void MainWindow::on_pushButton_clicked()
{
    emit startSignal();
}
 
 
testClass::testClass()
{}
 
void testClass::run()
{
    timer = new QTimer();
    QObject::connect(timer,SIGNAL(timeout()),this,SLOT(timerExpired()),Qt::DirectConnection);
    exec();
}
 
void testClass::startWork()
{
    timer->start(0);
}
 
void testClass::timerExpired()
{
    qDebug("Timer expired.");
}

void MainWindow::on_pushButton_clicked()
{
    emit startSignal();
}


testClass::testClass()
{}

void testClass::run()
{
    timer = new QTimer();
    QObject::connect(timer,SIGNAL(timeout()),this,SLOT(timerExpired()),Qt::DirectConnection);
    exec();
}

void testClass::startWork()
{
    timer->start(0);
}

void testClass::timerExpired()
{
    qDebug("Timer expired.");
}

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main.cpp

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    testClass tCls;
    QObject::connect(&w,SIGNAL(startSignal()),&tCls,SLOT(startWork()),Qt::QueuedConnection);
    w.show();
    tCls.start(QThread::NormalPriority);
 
    return a.exec();
}

int main(int argc, char *argv[])
{
    QApplication a(argc, argv);
    MainWindow w;
    testClass tCls;
    QObject::connect(&w,SIGNAL(startSignal()),&tCls,SLOT(startWork()),Qt::QueuedConnection);
    w.show();
    tCls.start(QThread::NormalPriority);

    return a.exec();
}

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In this case I am getting a run time error "QObject::startTimer: timers cannot be started from another thread".

What I understood :

timer is allocated inside run() so it belogs to testClass thread.But when i was trying to call the testClass::startWork() slot from mainwindow at that time testClass::startWork() belongs to mainwindow thread. So the timer is not able to start.
If I will take timer as static(from stack) then it will be fine because timer will be in main thread.

What i have mentioned here is it true ?
Is the member function of testClass belongs to testClass thread or not ?
I am using signal slot to communicate between two thread .But the current thread id of mainwindow and startWork() slot are same.
How i solve this ?

thanks.