Re: ScrolledWindow::remove() problem

[Sebastián E.Peyrott <as7cf yahoo com>]

Sebasti�E. Peyrott <as7cf <at> yahoo.com> writes:

> 
> Murray Cumming <murrayc <at> murrayc.com> writes:
> 
> > 
> > On Sun, 2006-10-22 at 06:22 +0000, Sebasti�E.Peyrott wrote:
> > [snip]
> > > Whenever the app calls ScrolledWindow::remove() under 
> > > Windows (XP, gtk/gtkmm 2.8), it crashes. This behaviour is not seen
> > > under 
> > > Linux. The contained widgets are Gtk::Layouts, and none of them are
> > > managed. 
> > > The only difference between the Linux build and the Windows build are
> > > the 
> > > headers and libraries used to build the executable. For Linux I'm
> > > using 
> > > gtk/gtkmm-2.8, while for Windows, gtk/gtkmm-2.6
> > [snip]
> > 
> > There was a bug in gtkmm 2.6 that caused managed child widgets to be
> > destroyed when remove()ed from their parents. You could #ifdef for 2.6
> > and add the necessary extra child.reference() to work around that bug.
> > Just make sure that you don't do the extra reference with 2.8.
> > 
> > But it would be better to upgrade to gtkmm 2.8 or 2.10 for all
> > platforms.
> > 
> Thanks for the quick response =). Well, I thought it'd be possible there was 
a 
> bug in ScrolledWindow that caused the unexpected deletion of its children, 
but, 
> as I said before, none of the contained widgets are actually managed. In any 
> case, it does seem the child widget is getting destroyed (somehow, 
somewhere), 
> since whenever I try to access any of its member functions I get a segfault. 
As 
> a result, I cannot make a call to children->reference() before trying to 
remove 
> it from the ScrolledWindow. This behaviour is also very strange, since the 
> widgets are actually displayed in the ScrolledWindow and respond to user 
input 
> which would seem to imply they were not destroyed (??).
> I'll make them managed to see if there is any difference.
> 
> I'd like to upgrade to gtkmm-2.8 but I need to keep compatibility with 
Windows 
> 98, and, AFAIK you cannot use it there.
> 
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> 

OK, as a followup, I can confirm this also happens when building against 
gtkmm-2.8 for Windows, so it cannot be related to the aforementioned bug. I can 
also confirm it only happens when trying to remove() widgets from my derived 
classes (DeviceLayout : public Gtk::Layout), so I MUST be doing something 
wrong, I just cannot figure out what exactly. When removing standard widgets 
(Gtk::Layout) this doesn't happen. Is there any virtual function I should have 
overriden in my derived classes? (And even in that case, it should not fail, as 
ScrolledWindow keeps a reference to a Gtk::Widget?). I'm deriving widgets from 
Gtk::Layout.