Re: How to determine if a GObject is "contained"?

[Tristan Van Berkom <tvb gnome org>]

Hans Oesterholt-Dijkema wrote:
> L.S.,
>
> I'm writing a language binding for mzscheme to Gtk. I recently
> derived a method to do memory mangement for GtkObject and
> GObjects. An artikle about it can be read here:
>
> http://www.elemental-programming.org/mzgtk2-mzgtk2-memory-management.html
>
> There is however one case, where I'm in trouble. See /"The containment 
> assumption falsified"/
> in this artikle. Now I have one burning question:
>
> Is there a decision procedure to determine if some GtkObject or
> GObject contains an other GObject? E.g., a GtkImage object will
> contain a GdkPixmap. When asked for, with gtk_image_get_pixmap,
> the reference count of the returned GdkPixmap will be 1. If my typemapper
> can decide somehow (e.g. by questioning the GdkPixmap GObject) that
> it is contained withing another object (the GtkImage GObject), my 
> typemapper
> can increase the reference count by 1.

    I'm not exactly clear as to why you must absolutely keep an
eye on every GObject created, note that a GtkImage which uses a
GdkPixbuf delagate is not really a "parent child" relationship.

The straight forward answer to your question is "no", you can
not find out what code segment is responsable for a given object,
GtkWidgets have a logical "heirarchy" which can be navigated
with the GtkWidget/GtkContainer APIs; if a GtkImage is finalized,
it is safe to say that it has released any references for any
external resources used.

Cheers,
                          -Tristan