problem painting

[eric_vi]

within an MDI I have subwindows as QScrollArea with a QWidget scrollAreaWidgetContents inside

childScrollArea::childScrollArea(QWidget *parent) :
    QScrollArea(parent),
    m_ui(new Ui::childScrollArea)
{
 
        scrollAreaWidgetContents = new QWidget();
        childScrollArea->setWidget(scrollAreaWidgetContents);
 
        scrollAreaWidgetContents->show();
 
}
 
 
void childScrollArea::paintEvent(QPaintEvent * /* event */)
{
    QPainter painter(this);
 
    painter.fillRect(QRect(0, 0, 300, 300), Qt::blue );
}

childScrollArea::childScrollArea(QWidget *parent) :
    QScrollArea(parent),
    m_ui(new Ui::childScrollArea)
{
 
        scrollAreaWidgetContents = new QWidget();
        childScrollArea->setWidget(scrollAreaWidgetContents);
 
        scrollAreaWidgetContents->show();

}
 
 
void childScrollArea::paintEvent(QPaintEvent * /* event */)
{
    QPainter painter(this);
 
    painter.fillRect(QRect(0, 0, 300, 300), Qt::blue );
}

To copy to clipboard, switch view to plain text mode 

unfortunately the paint event in this case does not do any painting in the window!

what do i do wrong?

Thanks for any hint

[wysota]

QScrollArea has a viewport, you should probably be painting on that, if at all.

[eric_vi]

ok the viewport did the display part, but i cannot get the scroll bar to show, whatever the size of my widget inside... so what else is missing?

[wysota]

It depends what the widget does. Does it have a layout?

[eric_vi]

i tried with a layout around the widget.. i don't get it to work..

also what is strange is that i do not have any event like mouse event within the minimum size of my scroll area, outside the minimum size i do have mouse event. i am sure it is related and i am missing something, i have no clue what

[wysota]

If it doesn't have a layout then its size is probably not constrained in any way. How do you set the size of this widget?