RE: gtk_object_set_data_full

["Thomas Cameron" <tom ceisystems com>]

Ah yes,

The zen of programming shines through again.  :-)  I know that I do the
same thing many times, using certain calls because I've seen it done
before.  It really depends on which version of GTK+ you're using.  In
GTK+-2.0.x, this function has actually been depreciated and replaced by
"g_object_set_data_full().  From what I gather, the only purpose to
using this function is to be notified when the the object or its
associations are destroyed.  I would assume that this would be for
cleanup purposes, etc.

Good Luck,
Tom Cameron


-----Original Message-----
From: drl22 cornell edu [mailto:drl22 cornell edu] 
Sent: Thursday, September 05, 2002 1:44 AM
To: gtk-app-devel-list gnome org
Subject: Re: gtk_object_set_data_full


Two little changes, you need to cast the 4th argument, 
and gtk_object_ref returns void :-P.  Try this:

gtk_object_ref(GTK_OBJECT(tree_view));
gtk_object_set_data_full(
  GTK_OBJECT(main_window),
  "tree_view",
  GTK_OBJECT(tree_view),
  (GtkDestroyNotify)gtk_object_unref
);

That works nicely!

Anybody know why these ref/unrefs are necessary when 
you add a child widget pointer to the parent widget?  I 
know glade-generated code puts them in, so I do too, 
but I don't understand them.

The child widget will be destroyed when the parent 
widget is destroyed, so the parent's object data will 
be inaccessible, right?  Am I missing something?

-Dan

Quoting Collin Starkweather 
<collin starkweather collinstarkweather com>:

> I'm very new to Gtk and not so hot with C, so please
bear with me.
> I'm trying to set data using gtk_object_set_data_full
() to keep track of
> some child widgets of my main window.  I'm using the
Gnome 1.x
> libraries.
>
> To do so, I'm trying something like
>
>   gtk_object_set_data_full(
>     GTK_OBJECT(main_window),
>     "tree_view",
>     gtk_object_ref(GTK_OBJECT(tree_view)),
>     gtk_object_unref
>   );
>
> where tree_view is a GtkTree widget and which is
consistent with an
> example I saw in a mailing list somewhere.
>
> I'm getting an error:
>
>   passing arg 4 of `gtk_object_set_data_full' from
incompatible pointer
> type
>
> Unfortunately, I can't find any documentation for 
> gtk_object_set_data_full other than the prototype in
the generic API
> documentation such as
>
>   
http://developer.gnome.org/doc/API/2.0/gtk/gtkobject.htm
l
> which seems like it may be helpful if I had alot more
experience in Gtk
> and/or C.  A bit of a chicken-and-egg problem there.
>
> There's also no mention of it I can find in the book
I'm using, SAMS
> "Teach Yourself Gtk+ Programming in 21 Days."  (I
know, I know, it's
> probably not the most comprehensive manual out there,
but I'm just
> learning.)
>
> Any suggestions would be appreciated.
>
> -Collin
>
> --
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~
> Collin Starkweather              
http://www.collinstarkweather.com
>
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~~~~~~~~~~
> _______________________________________________
> gtk-app-devel-list mailing list
> gtk-app-devel-list gnome org
> http://mail.gnome.org/mailman/listinfo/gtk-app-devel-
list
>

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