Minor tweak, try to make long flavour text last longer, move the hurt self messages to unused messages group, so they don't get wiped by crate an instant later.
#include <QApplication>
#include "mainform.h"
int main(int argc, char *argv[])
{
QApplication app(argc, argv);
MyWindow *mainWin = new MyWindow;
mainWin->show();
return app.exec();
}