Restore the GUI to previous state when System signal occurs

[arunvv]

Hi Here is the code,

static void WriteSettings(int sigNum);

void sighandler(int sig)
{
MainWindow h;
h.writeSettings(); // On calling this Function it has to writeSettings. But not updating settings or indexes
sig = 0;
printf("This is when signal emits \n"); // This is printing when SIGTERM is caught
return ;
}

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QFont f;
MainWindow h;
signal(SIGTERM, sighandler); // catching the Signal
h.resize(1024,768);
h.setWindowTitle("DENSO WAVE Demonstration Application V1.0.1");
f.setPixelSize(32);
QApplication::setFont(f);
h.show();
return app.exec();
}

void MainWindow::writeSettings()
{
QSettings settings("configWda.ini",QSettings::IniFormat);
settings.beginGroup("session");
settings.sync();
settings.setValue("WSMTxRate",WSMTxRate->currentIndex());
settings.sync();
settings.setValue("TxPriority",TxPriority->currentIndex());
settings.sync();
settings.setValue("DataRate",DataRate->currentIndex());
settings.sync();
settings.setValue("TxPower",TxPower->currentIndex());
settings.sync();
settings.setValue("ConfigTabWidget",Configtabwidge t->currentIndex());
settings.sync();
settings.setValue("IPTxRate",IPTxRate->currentIndex());
settings.sync();
settings.setValue("PSIDIndex",ProviderServiceID->currentIndex());
settings.sync();
settings.setValue("SPIndex",ServicePriority->currentIndex());
settings.sync();
settings.endGroup();
}

[wysota]

You don't need to sync() in this situation, because the object gets synced when it's deleted. Does the signal handler actually get called?

[jpn]

Also, looks like you create a new MainWindow object in sighandler(). It's not the original window you have shown but another object..

[arunvv]

It worked now, it was just the way I was calling the writeSettings function.

Here is the way I handled the signal for MainWindow.
signal(SIGTERM, MainWindow::writeSettings);

And declared static void writeSettings(int sigNum); in header file under public.
And thus this function has been called when SIGTERM signal is caught.

Thanks to all who supported me in correcting me from doing faults.