Saving Window Size State

class MainWindow : public QMainWindow
{
 Q_OBJECT
public:
 MainWindow(QWidget *parent = 0) : QMainWindow(parent) {
  QSettings settings;
  restoreGeometry(settings.value("mainWindowGeometry").toByteArray());
  // create docks, toolbars, etc…
  restoreState(settings.value("mainWindowState").toByteArray());
 }

 void closeEvent(QCloseEvent *event) {
  QSettings settings;
  settings.setValue("mainWindowGeometry", saveGeometry());
  settings.setValue("mainWindowState", saveState());
 }
};

int main(int argc, char *argv[])
{
 QApplication a(argc, argv);
 QCoreApplication::setOrganizationDomain("OrgDomain");
 QCoreApplication::setOrganizationName("OrgName");
 QCoreApplication::setApplicationName("AppName");
 QCoreApplication::setApplicationVersion("1.0.0");

 MainWindow w;
 w.show();
 
 return a.exec();
}