Re: glist manipulation and reference count
- From: walty <walty8 gmail com>
- To: gtk-devel-list gnome org
- Subject: Re: glist manipulation and reference count
- Date: Thu, 14 May 2009 21:17:26 -0700 (PDT)
Thanks for the reply.
I think I had some confusion here, I thought GObject is part of GLib, and
apparently that's not true.
The scenario is that I need to temporary update the screen, and store the
old widgets on the list. So if I did not explicitly add the ref count, the
objects would be destroyed once they are removed from parent (even if I
stored the object reference in g_list).
I think I would use a general helper function for list insert & remove then.
Just want to make sure I did not miss something obvious.
And I would move my future questions to gtk-app-devel-list :P
Brian J. Tarricone wrote:
> [Note that your question is probably more appropriate for
> gtk-app-devel-list or gtk-list; this list is for the development *of*
> glib/gtk itself, not about developing apps that *use* glib/gtk.]
> On 05/14/2009 08:47 PM, walty wrote:
>> However, one thing that surprised me is that, when I do "g_list_append"
>> "g_list_prepend", it does not automatically add the reference count of
>> stored GObject (unlike objective-C).
> GList is a generic container that you can put any kind of pointer into.
> It doesn't know about GObjects or reference counting. In fact libglib
> (where GList is implemented) doesn't even link to libgobject.
>> So do I need to explicitly add the reference count each time the GObject
>> inserted? and reduce the reference count when the object is removed? That
>> seems quite cumbersome to me.
> That depends on how you want to use it. If you can be sure no one else
> will destroy the object while you're using it in the list, then no, you
> I've used both glib/gobject and NSArray/NSDictionary/etc., and
> personally I don't find either approach to be better or worse. I rarely
> need to increase refcnts on GObjects when I store them in lists, but
> perhaps others have different use cases that do require this.
>> Or can I add some function pointer to generalize this? Is there some kind
>> best practice on this?
> If you add the objects in one shot, you can do something like this after
> you've added all objects:
> g_list_foreach(list, (GFunc)g_object_ref, NULL);
> Of course that iterates over the entire list, so it would be a bit slow
> on a large list. You can always ref the objects as you insert them, e.g.:
> list = g_list_append(list, g_object_ref(obj));
> Of course you have to do something similar with _unref() when you remove
> items from the list or destroy the list.
> gtk-devel-list mailing list
> gtk-devel-list gnome org
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