Re: glib ref counting problem

[Stefan Kost <kost imn htwk-leipzig de>]

Hi Tristan,

at first thans for listening and suggesting!

I think I follow path a) plus using weak_pointers. Anyway, as destoying the song
will cause destruction of the childs (setup, pattern) this is just a matter of
safety (to aid debugging).

version b.) is not so appropriate here as e.g. only the song might know what
needs to be passed to construct the child objects.

oh yes, oo-design can be tricky :-)

Stefan

PS.: anyway, the code is in the CVS of http://www.buzztard.org
PS.: I need a fulltext search for gnome sources ;-)
Tristan Van Berkom wrote:
> Stefan Kost wrote:
> [...]
>
> > unfortunately there are no explicit docs for the behaviour, but in
> > set_property
> > method receiving a pointer needs to be secured. I will now try to
> > switch to
> > add_weak_pointer(). One thing I dont get about this function is why I
> > have to
> > pass the object and then the pointer to my weak pointer. In practice
> > it will
> > look like:
> > myobject=object;
> > g_object_add_weak_pointer(myobject,&myobject);
> > Btw.: the docs should say, that the method does not initialize the passed
> > pointer to point to object.
> >
> > same for
> >  g_object_remove_weak_pointer();
> >
> > ... I am drifting away ;-)
> > Anyway, I hope that this is the recommended way of doing these things,
> > as I will
> > update the GObject tutorial soon.
>
>
> I think I understand your quandry now.
>
>     You want the delagate object (BtPattern/BtSetup) to have the
> parenting/owning object (BtSong) as a "property". If you want my
> "recommendation", IMO this is backwards in principal. You would avoid
> alot of trouble if either:
>
>    a.) BtSong is created with a sufficient amount of args/properties
>        to create and own a delagate object where that object doesn't
>        need to reference BtSong directly.
>
>    b.) The delagate object (BtPattern/BtSetup) are created first
>        and then used to construct a BtSong (i.e. BtPattern/BtSetup
>        are properties of BtSong). Much in the same way that:
>
>        adjustment = g_object_new(GTK_TYPE_ADJUSTMENT, ...);
>        vscale = g_object_new(GTK_TYPE_VSCALE,
>                              "adjustment", adjustment, ...);
>
> Is that a little closer to the mark ?
>
> Cheers,
>                                        -Tristan

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