Re: [sigc] conditions in libsigc

[Chris Vine <chris cvine freeserve co uk>]

On Thursday 06 July 2006 21:44, Chris Vine wrote:
>
> Glib::RefPtr is designed to reference objects derived from GObject (sorry,
> I can't remember their glibmm class designation, probably Glib::Object) but
> not from GtkObject (Gtk::Object).  Classes derived from Gtk::Object are
> owned by the container in which they are placed, if you provide they are to
> be managed (as you did).  If you assign them to a Glib::RefPtr you will
> need to increment the reference count when doing so in order to pass
> ownership to the Glib::RefPtr smart pointer.  If you don't have them as
> managed objects, you don't need to increment the reference count (but you
> may have to call gtk_object_sink() on them to eliminate the floating
> reference - I am not sure whether you need to do this in gtkmm because I
> either use the raw C objects or, with gtkmm, have them managed by the
> container).

Actually I am not sure if I am right about the last sentence - it is true with 
GTK+ (with C objects) but I am not sure about gtkmm - you probably need to 
call delete on the gtkmm object at some stage if it is not managed by the 
container, since bringing the reference count to 0 will cause the underlying 
C object to be destroyed but not the C++ superstructure on top.  The best 
rule is never to use Glib::RefPtr with objects derived from Gtk::Object.

Chris