From: Lyle Johnson <ljohnson@...>
Date: 2001-06-28T23:24:00+09:00
Subject: [ruby-talk:17009] Re: FOX subclassing FXTextField and messages

> I want to subclass FXTextField in order to map certain keys, eg Ctrl-Left,
> but don't know how to do this. onKeyPress doesn't get called.
>
> class MyTextField < FXTextField
>   def onKeyPress(sender, sel, ptr)
>     p "onKeyPress"
>     super(sender, sel, ptr)
>   end
> end
>
> I'm missing something important here but what?

Message handlers (like your "onKeyPress" method) need to be registered with
FOX so that it knows to call them.

    class MyTextField < FXTextField
      def initialize(p, ncols, tgt, sel, opts)
        # Be sure to call the base class constructor!
        super(p, ncols, tgt, sel, opts)

        # Map the SEL_KEYPRESS message to the onKeyPress instance method
        FXMAPFUNC(SEL_KEYPRESS, 0, "onKeyPress")
      end

      def onKeyPress(sender, sel, ptr)
        ... whatever ...
      end
    end

For some more information about FOX's message and target system, see:

    http://www.fox-toolkit.org/messages.html

Hope this helps,

Lyle