Hi,
sizeHint() is returning a valid sizeHint, regardless the scroll area's
visibility:
QSize QAbstractScrollArea::sizeHint() const
{
Q_D(const QAbstractScrollArea);
if (!d->sizeHint.isValid() || d->sizeAdjustPolicy ==
QAbstractScrollArea::AdjustToContents) {
const int f = 2 * d->frameWidth;
const QSize frame( f, f );
const QSize scrollbars( d->vbarpolicy == Qt::ScrollBarAlwaysOn ?
d->vbar->sizeHint().width() : 0,
d->hbarpolicy == Qt::ScrollBarAlwaysOn ?
d->hbar->sizeHint().height() : 0 );
d->sizeHint = frame + scrollbars + viewportSizeHint();
}
return d->sizeHint;
}
If it's not valid (or the other comparison is true) it's getting calculated and
saved. If the saved value is valid, it gets returned directly.
Christoph
12 jan 2012 kl. 16:11 skrev <jan-arve.saet...@nokia.com>:
> It's not quite right. sizeHint() should *always* (regardless of visibility)
> return a sensible value.
> For the interested, further details can be seen in my comment in the patch.
>
> regards,
> Jan-Arve
>
> From: ext Christoph Schleifenbaum [mailto:christoph.schleifenb...@kdab.com]
> Sent: 12. januar 2012 15:19
> To: Saether Jan-Arve (Nokia-MP/Oslo)
> Cc: development@qt-project.org
> Subject: Re: [Development] sizeHint for QAbstractScrollArea, especially item
> views
>
> Hi,
>
> ok, I added a adjustSizePolicy property. Please have a look:
>
> http://codereview.qt-project.org/12971
>
> Cheers,
> Christoph
>
> 11 jan 2012 kl. 12:09 skrev <jan-arve.saet...@nokia.com>
> <jan-arve.saet...@nokia.com>:
>
>
> Yes, if you think this is mostly an issue on initial show, (which I also
> think) then I think such a solution would acceptable.
> The default should then be AdjustToContentsOnFirstShow, as it is in QComboBox.
>
> regards,
> Jan-Arve
>
> From: ext Christoph Schleifenbaum [mailto:christoph.schleifenb...@kdab.com]
> Sent: 10. januar 2012 17:19
> To: Saether Jan-Arve (Nokia-MP/Oslo)
> Cc: development@qt-project.org
> Subject: Re: [Development] sizeHint for QAbstractScrollArea, especially item
> views
>
> Hi,
>
> thanks for your input. What do you think about adding some sizeHint policy to
> this? I'm thinking about as it is done for QComboBox, i.e. AdjustToContents
> vs. AdjustToContentsOnFirstShow. Translated to this use case would be to
> never return any different sizeHint (and especially never call
> updateGeometry()) after the scroll area is shown for the first time.
>
> 6 jan 2012 kl. 14:20 skrev <jan-arve.saet...@nokia.com>
> <jan-arve.saet...@nokia.com>:
>
>
>
> Hi,
> I agree that the current behavior is sometimes not optimal, but I'm not sure
> if this is such a good idea.
>
> With regards to behavior it has some advantages, but I believe it also has
> some disadvantages.
>
> And since in addition it might introduce a performance penalty I'm leaning
> towards that this is not a good idea.
>
> I've made a comment on the patch in gerrit:
> http://codereview.qt-project.org/#change,11763
>
>
> Jan-Arve
>
> From: development-bounces+jan-arve.saether=nokia....@qt-project.org
> [mailto:development-bounces+jan-arve.saether=nokia....@qt-project.org] On
> Behalf Of ext Christoph Schleifenbaum
> Sent: 22. desember 2011 18:07
> To: development@qt-project.org
> Subject: [Development] sizeHint for QAbstractScrollArea, especially item views
>
> Hi,
>
> currently, item views do return a rather random size hint. Some at KDAB,
> including me, would love to see a size hint actually being related to the
> scroll area's content. For this, we thought of a method viewportSizeHint
> which returns the size of the viewport as if there would be no scroll bars
> required.
>
> The most common use case for this is a list or a table of data in a window:
>
> a) The ui designer doesn't need to set a custom size for the view, the size
> hint will make sure all data are visible
>
> b) The amount of data might grow, in that case it might made sense to enlarge
> the view. Imagine three tree views below each other inside a scroll area. If
> the tree views would stay at their size, a scroll bar would appear in both
> the tree view and in the surrounding scroll area. This won't happen with a
> proper size hint combined with a size policy.
>
> I'v attached a patch to the current qtbase.git. It does the described
> behaviour for QScrollArea and QTableView. Try running the example at
> examples/itemviews/spreadsheet to see what happens if you e.g. resize the
> columns in the table view.
>
>
> Thoughts?
>
>
> Cheers,
> Christoph
>
>
>
> --
> Christoph Schleifenbaum | christoph.schleifenb...@kdab.com | Software Engineer
> Klarälvdalens Datakonsult AB, a KDAB Group company
> Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
> KDAB - Qt Experts - Platform-independent software solutions
>
> _______________________________________________
> Development mailing list
> Development@qt-project.org
> http://lists.qt-project.org/mailman/listinfo/development
>
> --
> Christoph Schleifenbaum | christoph.schleifenb...@kdab.com | Software Engineer
> Klarälvdalens Datakonsult AB, a KDAB Group company
> Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
> KDAB - Qt Experts - Platform-independent software solutions
>
>
> --
> Christoph Schleifenbaum | christoph.schleifenb...@kdab.com | Software Engineer
> Klarälvdalens Datakonsult AB, a KDAB Group company
> Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
> KDAB - Qt Experts - Platform-independent software solutions
>
--
Christoph Schleifenbaum | christoph.schleifenb...@kdab.com | Software Engineer
Klarälvdalens Datakonsult AB, a KDAB Group company
Tel. Sweden (HQ) +46-563-540090, USA +1-866-777-KDAB(5322)
KDAB - Qt Experts - Platform-independent software solutions
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