Re: refptr and this

[José Alburquerque <jaalburquerque cox net>]

Jonathon Jongsma wrote:
> I've run into an issue while playing around with goocanvasmm trying to
> implement custom items and I'm wondering if anybody has run into this
> before.  The issue is as follows:
> - To create a 'group' item, you need to implement the add_child virtual
> function
> - within the add_child virtual function, it appears that you are
> supposed to call set_parent on the new child and set its parent to
> yourself.  In other words, something like:
>
> add_child_vfunc(Glib::RefPtr<Item> child, int position) {
>  // add child to an array of items
>  child->set_parent(this);
> }
>
> The problem is, the set_parent() function takes a Glib::RefPtr<>, so I
> would need to do something like
>  child->set_parent(Glib::RefPtr<Item>(this));
> Except this seems to cause refcounting problems and the program crashes.
>
>   
I'm experiencing similar refcounting problems in gstreamermm and up 
until now, am still thinking about what a good solution would be (I even 
got into a bit of trouble by asking around in the gstreamer list :-(  
Murray had mentioned possibly using a boolean in RefPtr but I'm focusing 
on other things while the solution sort of "bakes".

-Jose