Incorrect of a widget addition

Evgeny Siberia

Hi. Why this code is not correct?
I get the warning:
Warning: QLayout: Attempting to add QLayout "to QDialog "QDialog", which already has a layout

QWidget *w = new QWidget;
QDialog *dlg = new QDialog;
QVBoxLayout *lay = new QVBoxLayout;
dlg->setLayout(lay);
lay->addWidget(w);

Surely, I know QDialog has a layout. But when I tried to add into this layout widget, I get Segmentation Fault.

QWidget *w = new QWidget;
QDialog *dlg = new QDialog;
dlg->layout()->addWidget(w);

Christian Ehrlicher

@Evgeny-Siberia said in Incorrect of a widget addition:

_settingsForm

Shouldn't this be w ?

QDialog has no layout by default. You must be setting another one somewhere else.

J.Hilk

@Evgeny-Siberia

layout() pointer should be nullptr initialized, so check against it and do it appropriately.

QWidget *w = new QWidget;
QDialog *dlg = new QDialog;
if(dlg->layout()){
    dlg->layout()->addWidget(w);
}else{
   QVBoxLayout *lay = new QVBoxLayout;
   lay->addWidget(w);
   dlg->setLayout(lay);    
}