Re: [ruby-fltk-devel] Mapping C++ objects to Ruby objects

[Takaaki T. <tt...@ja...>]

At Thu, 16 Aug 2001 23:47:48 -0700,
> No, wait. I just remembered that we're thinking of creating our own wrapper
> class for each FLTK C++ class. We can add a local member variable there
> that contains the ruby object. No hash table needed, and simpler memory
> management.

I see. you think about making the class like:

class RBFl_Xxxx : Fl_Xxxx {
public:
  VALUE rb_object;
  ....
}

and making the structure for the Ruby class,

struct rb_fl_data {
  RBFl_Xxxxx *widget;
}

and we can create ruby objects using Data_Make_Struct macro like:

struct rb_fl_data *data;
VALUE rb_cFl_Xxxxx = rb_define_class("ClassName");
VALUE obj = Data_Make_Struct(rb_cFl_Xxxx, ...., data);
data->widget = new RBFl_Xxxxx(....);
data->widget->rb_object = obj;

now we can obtain the ruby object `obj'.
Is this right?

> We could also store callback data there. But as I mentioned, I think
> there's value in keeping the C++ code to a minimum, and doing as much as we
> can in ruby.

I think it is also possible. but I heard that it is not recommended
that VALUE data is owned by the structure like `rb_fl_data' and class
`RBFl_Xxxx'.
if we adopt such mechanism, we would carefully deal with the both of
the ruby object and C++ object.
I will ask some ruby developers this issues.
-- 
Takaaki Tateishi <tt...@ja...>