Re: Widget destroy process

[John Cupitt <john cupitt ng-london org uk>]

Hi Stephane,

Stephane Demurget wrote:
> I've just written a top-level widget, but I've got some troubles with
> the destroy process. I've read the ref counting doc, so I know there's
> some extra work needed by a top-level widget to be done and that's why
> ref counting don't work for it. So I need to explicitly destroy it.

This took me ages to get right too :-( I'm sure some gtk-guru can give a better
answer, but the rules seem to be:

- make instances with _new(), destroy those instances with 
  gtk_object_destroy()

- if you're a container widget (ie. you contain other widgets), 
  when you are given a new child, you need to do:

	gtk_object_ref( obj );
	gtk_object_sink( obj );

- when you loose a child, you need to do:

	gtk_object_unref( obj );

- when you are destroyed, you need to remove all of your children
  (call your remove_child() thing repeatedly)

- some clean up can be delayed until _finalize() if that helps

If you subclass your container from GtkContainer (not always possible), it does
most of this stuff for you. 
  
John