Re: [Fxruby-users] Message Identifiers, Types, etc again.

[Lyle J. <jl...@cf...>]

Hugh Sasse Staff Elec Eng wrote:

> So, either I am right about this, and the api docs need fixing, or I
> am wrong about this, and http://www.fox-toolkit.org/messages.html
> needs fixing because  it says:
> <quote>
>  The approach taken by FOX is a Target/Message System. Each Widget
>  sends its message to a certain object called the target. As there
>  may be multiple Widgets sending messages to one specific target, a
>  message id is used to tell them apart.
> 
>  Moreover, a single Widget may be able to send several kinds of
>  messages; this problem is solved by typing the messages by a
>  message type. Using the message type and message id, the source and
>  type of a GUI event or action can be uniquely identified.
> </quote>
> 
> Or, is there in fact a third way to understand this, and reconcile
> both these documents?

I agree that the documentation on the FOX web site doesn't tell the 
whole story about how message identifiers are used, and instead focuses 
on one particular use. Obviously, if the *only* purpose of the message 
identifier were to distinguish between senders, you could arguably just 
hang on to a reference to the sender object(s) and compare them when you 
get a message:

     @button1 = FXButton.new(...)
     @button2 = FXButton.new(...)

     ...

     def onMessageReceived(sender, sel, ptr)
       if sender == @button1
         # do something
       elif sender == @button2
         # do something else
       end
       return 1
     end

But as I (hopefully) explained in my previous response, that in fact 
isn't the whole story when it comes to message identifiers ;)

Hope this helps,

Lyle