Re: gobject - A few questinons

[Tristan Van Berkom <tristan van berkom gmail com>]

On Mon, 20 Dec 2004 12:45:28 +0100, Stefan Kost
<kost imn htwk-leipzig de> wrote:
[...]
> > When I have parent objects created by myselfe, where do I set default
> > values for variables?  Is it ok to do that in my_object_instance_init
> > ()?
> instance_init should be okay. question to the gurus. Should one chain-up here
> like in dispose/finalize? - otherwise that would not be called?

Whether you derive from an object written by someone else or yourself,
you are only concerned with the initialization of MyObject members inside
my_object_init(). Rest assured that the members of MyParent have already
been taken care of in my_parent_init() during the life-cycle of g_object_new().

and "No" you should not chain up in the initialization function (class
or instance).

> > I have one parent which stores some simple information about my object.
> > The declaration for this is the struct for the parent instance.  When I
> > use that in a child object, do I have a copy of the parent there?  Or do
> > I have to cast with MY_PARENTOBJ (self) to get this variables, declared
> > there?
> The cast does it. The struct of the parent is embedded in the beginning of you
> child class. Anyway some developers prefer not to use public variables and
> access such data vie g_object_get(self,"property-name-1",&property_1,...,NULL);
> This methods automatically tries the parent classes up to G_OBJECT.

Essentially, (GTK_WIDGET (this) == G_OBJECT (this)) is always TRUE.

> > Can I use this variables more than one time?  Like:  child->data and
> > parent->data or are this variables equal, do they exist both or only
> > one?
> Huh?

If your parent instance has a member with the same name as your
child instance, this does not imply any relation between the two ;-)

Cheers,
                                                     -Tristan