Re: [gtkmm] GTKMM classes handling local variables

[Ian Michell <ian michell hanzi co uk>]

Benoît Touron wrote:

> Ian,
>
> Your _label gets destroyed when you leave the constructor
> (MyClass::MyClass), because it's local.
> That's probably why it is not desplayed.
>
> You could either declare it in the class, or allocate it with new and 
> use Gtk::Manage on the pointer:
>
> This code should work:
>
> MyClass::MyClass()
> {
>     Label *_label = Gtk::Manage( new Label("Hello World"));
>     m_box.pack_start(*_label, PACK_SHRINK);
>     show_all_children();
> }
>
>
> Ben
>
> > Hi all,
> > Maybe someone can help me with this, I have only been developing with
> > GTKMM for a little while so I am a little bit of a newbie.
> >
> > Right here is a piece of example code:
> >
> > class MyClass : public Gtk::Window
> > {
> >     public:
> >         MyClass();
> >         virtual ~MyClass();
> >     private:
> >         VBox m_box;
> > };
> >
> > MyClass::MyClass()
> > {
> >     Label _label("Hello World");
> >     m_box.pack_start(_label, PACK_SHRINK);
> >     show_all_children);
> > }
> >
> > MyClass::~MyClass()
> > {
> > }
> >
> > Right what I cannot understand is why this program will compile but my
> > label will not be displayed? For some reason it will only work if I
> > declare my Label in the class definition... I don't see why it is not
> > working... :(
> >
> > Ian
> >
> > _______________________________________________
> > gtkmm-list mailing list
> > gtkmm-list gnome org
> > http://mail.gnome.org/mailman/listinfo/gtkmm-list
>
>
>
> _______________________________________________
> gtkmm-list mailing list
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Thanks for the advice, I think I will give GTK::Manage a try, I think it 
will take a little getting used to, usually 90% of my c++ code is based 
around pointers, even my old GTK stuff (I used to wrap GTK into C++ 
before I discovered GTKMM). I would have thought the GTKMM team would 
have catered for the use of local varibles in some way, hence my obvious 
mistake of just trying to use them, I do however love the way GTKMM does 
a lot of things better than QT, oh well, right thanks again for the 
advice, I should now be able to continue my projects (Gnome Easy CD -- 
website and source tree coming soonish, Groupmage - native linux client 
for Groupwise -- even though I use sun JDS, Fedora and Debian lol, -- 
GnomeEasyInstall and GnomeAutoCD) hmm :-D