On 11/23/05, Otto Wyss <ott...@or...> wrote:
> Carl Godkin wrote:
>
> >When I create the control and populate it with more items than fit verti=
cally,
> >I don't get a scrollbar right away until I click on one of the items. T=
his
> >happens both on Windows and Linux so I presume it's intentional. Howeve=
r,
> >I'd like to always show the vertical scrollbar so that the user knows th=
ere are
> >more items below.
> >
> >
> >
> I've seen this as well lately and think it's something wrong within
> wxWidgets but I'm not sure. I haven't seen it in any of my old apps,
> only in the new TorMgr I write for the Tor GUI contest. So it might be a
> problem of 2.6.2, again I'm not sure.
>
> >Is there some way I can force this?
I looked into this and found the problem, I think.
The member function wxTreeListMainWindow::AdjustMyScrollbars()
calls GetSize() on the root item. However wxTreeListItem::GetSize()
doesn't think the root item is expanded, so all you get is the (hidden)
root item's size.
I worked around this by adding Expand(rootId) after I populate the tree
initially and now the vertical scrollbar appears as I think it should.
This even makes sense to me. I wondered if this problem would
happen in the generic tree control which was apparently the model
for the tree list control but found that there is a little code we might wa=
nt
to add to avoid this problem. Notice the difference here:
void wxTreeListMainWindow::SetWindowStyle (const long styles) {
// right now, just sets the styles. Eventually, we may
// want to update the inherited styles, but right now
// none of the parents has updatable styles
m_windowStyle =3D styles;
m_dirty =3D true;
}
void wxGenericTreeCtrl::SetWindowStyle(const long styles)
{
if (!HasFlag(wxTR_HIDE_ROOT) && (styles & wxTR_HIDE_ROOT))
{
// if we will hide the root, make sure children are visible
m_anchor->SetHasPlus();
m_anchor->Expand();
CalculatePositions();
}
// right now, just sets the styles. Eventually, we may
// want to update the inherited styles, but right now
// none of the parents has updatable styles
m_windowStyle =3D styles;
m_dirty =3D true;
}
(Note that m_anchor in the generic tree control is the same as m_rootItem
in the tree list control.)
Thanks,
carl
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