From: Zach Dennis <zdennis@...>
Date: 2004-11-13T07:44:26+09:00
Subject: Re: Another design question...

Joe Van Dyk wrote:

>
>How would the AirplanePopupMenu object know what Airplane object's method to
>use when the user selects an item from the popup menu?
>
>  
>
You could couple Airplane and AirplanePopupMenu. This would allow 
AirplanePopupMenu to know about the methods on the Airplane class. If 
there are going to be more then one Airplane object at a time, then 
allow for the AirplaneMenu to be passed an instance of Airplane. For 
example:

class Airplane
    def  current_speed
       return 290 #speed in mph?
    end
end

class AirplanePopupMenu
    AP_SPEED = 11
   
    def get_menu( airplane, *args )
       args.each{ |arg|
           case arg
             when AP_SPEED
                  #process the code to add a MenuItem for speed here to 
your menu
                   menu_item = Menuitem.new
                   menu_item.set_label( airplane.speed )
                   @mymenu.add_menu_item( menu_item )
             else
          end
       return @mymenu
    end
end

I do not use GTK and I haven't used Ruby/Tk in a long while so I won't 
even attempt to have the code make sense like that. I'll leave the 
transitioning of code up to you.

Zach