From: Hidetoshi NAGAI <nagai@...>
Date: 2005-01-11T00:49:31+09:00
Subject: Re: how do I add a C widget to Ruby/Tk?

Hi, 

From: Bill Paxton <paxton@kitp.ucsb.edu>
Subject: how do I add a C widget to Ruby/Tk?
Date: Mon, 10 Jan 2005 02:33:05 +0900
Message-ID: <BE06AACA.1C67%paxton@kitp.ucsb.edu>
> I have an existing Tcl/Tk widget written in C that I�d like to port to
> Ruby/Tk. 

Please use your widget as it is. 
Ruby/Tk (tcltklib) uses standard Tcl/Tk libraries. 
If your wish (which uses same Tcl/Tk libraries) can load your widget
library, Ruby/Tk can load the widget library. For exapmle, 

    <Ruby/Tk method call>                <call on Tcl/Tk>
 Tk.load_cmd_on_ip(tk_cmd)          -->  auto_load tk_cmd
 Tk.load_tclscript(file, enc=nil)   -->  source ?-encoding enc? file
 Tk.load_tcllibrary(file, pkg=None, -->  load file ?pkg? ?interp?
                    interp=None)

 Tk.tk_call(cmd, arg, ... )         -->  cmd arg ...
 Tk.ip_eval(script)                 -->  (eval "script" on Tcl/Tk ip)

Probably, you'll be able to load your widget library by
Tk.load_tcllibrary('your widget library').
After that, you can create and control your widgets by Tk.tk_call().

If you want create a class for your widget, 
it is better the class is a sub-class of TkWindow class. 
When the create command of your widget is "xxx path ??-opt val? ...?", 
minimum definition for your widget class is the following. 
----------------------------------------------------------
  class YOUR_WIDGET < TkWindow
    TkCommandNames = ['xxx'.freeze].freeze

    WidgetClassName = 'Xxx'                  # if needed
    WidgetClassNames[WidgetClassName] = self # if needed

    # define instance methods for your widget class

  end
----------------------------------------------------------
Then, you'll be able to create your widget by 
----------------------------------------------------------
  YOUR_WIDGET.new(parent, optkeys){ ... }
----------------------------------------------------------
like as other standard widgets. 
-- 
Hidetoshi NAGAI (nagai@ai.kyutech.ac.jp)