QScrollArea - scrollbar for a widget with many childs

Question

So, I got some problems with QScrollArea .

I want to put a widget with many children in a QScrollArea , but I just dont get any scrollbars.

Heres the code:

QDialog *dialog = new QDialog();
QVBoxLayout *dialoglayout = new QVBoxLayout( dialog );

QScrollArea *area = new QScrollArea();

dialoglayout->setMargin( 0 );
dialoglayout->addWidget( area );

area->setAlignment( Qt::AlignCenter );
area->setAlignment( Qt::AlignTop );
area->setWidgetResizable( true );

// mainwidget has a lot of children
QWidget *mainwidget = randomclass.getWidget();
QVBoxLayout *mainwidgetlayout = new QVBoxLayout( mainwidget );

dialog->setWindowFlags( Qt::Window );

area->setWidget( mainwidget );

dialog->showMaximized();

if the mainwidget is bigger than the scrollarea, the content just overflows.

Can anyone help me? Thanks in advance.

Answer 1

Some widgets don't report the area to scroll and that causes the confusion with scroll area. For QScrollarea object to adjust to the content:

myWidget->setMinimumSize(myWidget->sizeHint());  // assume the min size 
scrollArea->setWidget( myWidget );               // use that widget in scroll area

Specific scrollers also might need to be enabled depending on the content:

scrollArea->setVerticalScrollBarPolicy(Qt::ScrollBarAsNeeded);
scrollArea->setHorizontalScrollBarPolicy(Qt::ScrollBarAsNeeded);