The tray displays activated signals on ubuntu, without Context and DoubleClick signals

connect(sysTray, SIGNAL(activated(QSystemTrayIcon::ActivationReason)), this, SLOT(system_tray_clicked(QSystemTrayIcon::ActivationReason)));

void MainWindow::system_tray_clicked(QSystemTrayIcon::ActivationReason reason)
{
    qDebug() << "reason = " << reason << endl;
    switch (reason)
    {
        case QSystemTrayIcon::Trigger:
        case QSystemTrayIcon::DoubleClick:
            if ( this->isHidden() || this->windowState() == Qt::WindowMinimized)
            {
                if (this->windowState() == Qt::WindowMinimized)
                    this->hide();
                this->showNormal();
            }
            else
            {
                this->hide();
            }
            break;
        default:
            break;
    }
}