[Qt-interest] How do I get QScrollArea to let its widget expand?

[Girish Ramakrishnan]

Hi,

On Thu, Feb 24, 2011 at 9:23 PM, kent williams
<nkwmailinglists at gmail.com> wrote:
> Every time I have to do this, I have to try a bunch of different
> permutations to get it to work, and THEN what I end up doing doesn't
> WORK in the next context in which I try to do the SAME THING, so now
> I'm asking how do I get this to work properly?
>
> QScrollArea *scrollArea = new QScrollArea(parent);
>
> QWidget *widgetForScrolling = new QWidget(scrollArea);
>

This only makes widgetForScrolling a child of the scrollArea. A
QScrollArea does not show scrollbars based on it's children's
geometry, but based on the widget you set using
QScrollArea::setWidget(). So, what's missing is:

scrollArea->setWidget(widgetForScrolling);

The above call actually reparent the widgetForScrolling into
QScrollArea's internal viewport widget. So, passing the parent
argument can mislead you into thinking scrollArea is the parent of
widgetForScrolling.

Girish