EdUarDo said:
> Hi all again :),
>
> How could I implement this model?
>
> Window <>--------------------- Button
>                                   ^
>                                   |
>                                   |
>                           -----------------
>                           |               |
>                        BigButton      LittleButton
>
>
> Being 'Button' an abstract class or an interface.
> I mean, how do I define an interface? Must I use modules?

If Button is a like a Java interface (i.e. no behavior), then you don't
need one in Ruby.  Just implement BigButton and LittleButton with
compatible methods.

If there is shared code in Button, then you can (1) create a class Button
and inherit from it in BigButton and LittleButton, or (2) Create a Button
module and include it in both Big and Little Buttons.

-- 
-- Jim Weirich     jim / weirichhouse.org    http://onestepback.org
-----------------------------------------------------------------
"Beware of bugs in the above code; I have only proved it correct,
not tried it." -- Donald Knuth (in a memo to Peter van Emde Boas)