How to avoid QMdiArea.subWindowActivate.window.widget() crash?

sonichy

connect(ui->mdiArea,SIGNAL(subWindowActivated(QMdiSubWindow*)),this,SLOT(subWindowActivate(QMdiSubWindow*)));

void MainWindow::subWindowActivate(QMdiSubWindow *window)
{
    qDebug() << window;
    // minimized crash, close last subwindow crash
    MdiChild *child = (MdiChild*)(window->widget());
    label1->setText(child->path);
    label3->setText(child->scodec);
}

VRonin

do not call methods on null or dangling/invalid pointers.
C style downcast is always a bad idea.

void MainWindow::subWindowActivate(QMdiSubWindow *window)
{
    if(window){
    MdiChild *child = qobject_cast<MdiChild*>(window->widget());
    if(child){
    label1->setText(child->path);
    label3->setText(child->scodec);
}
}
}