I found solution: Maybe someone will need this someday in problems with restore from minimizing using frameless window
void MainWindow::changeEvent( QEvent* e )
{
if( e->type() == QEvent::WindowStateChange)
{
if(this->windowState() & Qt::WindowMinimized )
{
//do something after minimize
}
else
{
setWindowFlags(Qt::Window); //show normal window
setWindowFlags(Qt::Window | Qt::FramelessWindowHint | Qt::WindowMinimizeButtonHint);
//and again frameless. somethign like refreshing frameless windows after minimize
this->showNormal();
}
}
}