Re: Two warnings when creating a TreeStore

[José Alburquerque <jaalburquerque cox net>]

Murray Cumming wrote:
> On Wed, 2007-09-12 at 11:59 -0400, Jos�lburquerque wrote:
> [snip] 
>   
> > When you say a 
> > static instance, are you referring to one of my "Element" derived 
> > classes or are you referring to the TreeModelColumnRecord class I've 
> > defined (columns) which *is* static within my "DVDProject" class?  Would 
> > changing the "staticity" of this static member help?
> >     
>
> Yes, that's the problem.
>
>   
Thank you Paul, Murray and all who've replied to my questions.  You've 
all been really helpful.  I just wanted to say that thanks to all your 
replies I was able find that indeed the problem was the static member.  
I made it an instance and every warning disappeared.

In a way, Paul was right in that there was something going wrong because 
something global was being "instantiated" before the initialization of 
gtkmm and Murray put his finger right on the problem by pointing out 
that I had a static member that should be an instance.
> > On another note, can I pick your brain a bit more and ask you a little 
> > about how gtkmm handles inheritance?  As I had mentioned, all the 
> > objects I work with are derived from a base class (which I call 
> > "Element") with a virtual method called "getName()" designed to return a 
> > string naming the object I'm dealing with (so I can "render" the string 
> > in the TreeView).  I've overridden the method in various derived 
> > classes, but in a rendering method (which I set up with the 
> > TreeView::Column::set_cell_data_func()) when I call the object's 
> > "getName()" method, it's overridden method is not called, but instead 
> > the base class method is called.  Am I missing something?  If it helps 
> > the short TreeView initialization and the rendering method I use 
> > follows.  I'd really appreciate any insights.  Thanks for your comments.
> >     
> [snip]
>
> gtkmm doesn't change anything about how C++ does inheritance. 
>
> You should maybe check that your instance is really an instance of the
> class that you expect.
>
>   
As far as gtkmm and inheritance, I found that if I use something like 
TreeModelColumn<MyBaseClass> in a TreeModelColumnRecord, derived members 
of MyBaseClass only use the virtual methods of the base class (not the 
derived class!), but if I use something like 
TreeModelColumn<MyBaseClass*>, dereferencing the pointer to the derived 
class later, does use the virtual (overridden) method of the derived 
class.  Thanks again everyone for your help.

-Jose