在静态函数中发出信号

Question

I've got aa static function : static void lancerServeur(std::atomic<bool>& boolServer) , this function is force to be static because I launch it in a thread, but due to this, I can't emit a signal in this function. Here's what I try to do :

void MainWindow::lancerServeur(std::atomic<bool>& boolServer){
    serveur s;
    StructureSupervision::T_StructureSupervision* bufferStructureRecu;
    while(boolServer){
        bufferStructureRecu = s.receiveDataUDP();
        if(bufferStructureRecu->SystemData._statutGroundFlight != 0){
            emit this->signal_TrameRecu(bufferStructureRecu);//IMPOSSIBLE TO DO
        }
    }
}

Is there a way to emit my signal ?

Thanks.

Answer 1

You can keep a static pointer to the instance of MainWindow in the MainWindow class and initialise it in the constructor. Then you can use that pointer to call the emit from the static function.

class MainWindow : public QMainWindow
{
    ...
    private:
        static MainWindow* m_psMainWindow;

        void emit_signal_TrameRecu(StructureSupervision::T_StructureSupervision* ptr)
        {
            emit signal_TrameRecup(ptr);
        }
};

// Implementation

// init static ptr
MainWindow* MainWindow::m_psMainWindow = nullptr; // C++ 11 nullptr

MainWindow::MainWindow(QWidget* parent)
    : QMainWindow(parent)
{
    m_psMainWindow = this;
}


void MainWindow::lancerServeur(std::atomic<bool>& boolServer)
{
    StructureSupervision::T_StructureSupervision* bufferStructureRecu;

    ...

    if(m_psMainWindow)
        m_psMainWindow->emit_signal_TrameRecu( bufferStructureRecu );
}

Answer 2

Pass the pointer to the class as a parameter to lancerServeur, or you can use a slot on a worker class and move it to a thread.

See this example http://qt-project.org/doc/qt-4.8/qthread.html on how to use a slot to do the work on a separate thread.