From: dejaspam@... (Bill Atkins)
Date: 2004-04-08T05:24:18+09:00
Subject: Assorted Ruby/Tk Questions/Comments

I'm looking into using Ruby/Tk for a major project.  Maybe I'm crazy,
but I find its interface cleaner than that of FOX.  I'm very
experienced with Perl/Tk, but I'm just getting started with the Ruby
port.  Here are some questions and observations:


1. There appears to be a bug in TkRoot.new (or possibly TkWindow.new).
 On my Win2K box, the following code:

require 'tk'

TkRoot.new do
    puts "test"
end

produces:
test
test

The block is being called twice.  This can be prevented with the
following code:

TkRoot.new do
    return if @here
    @here = true

    ...
end

This looks like a bug to me.

2.  Do I have to install Tcl on *NIX boxes to use Ruby/Tk?  I know I
can just redistribute the DLL's on Windows, but how does this work on
NIX?  Does Ruby/Tk come with everything it needs to run right out of
the box?

3.  How can I use TkTree?  It looks like it's in the tcltk-ext
package, but I'm not sure how to use this on Windows.  Or Linux for
that matter.  Does this also require Tcl to be installed?

4.  pack doesn't accept a block, even though Programming Ruby implies
that this is so.  I've written the following code to allow pack to
accept a block.  It's hackish, so maybe someone more familiar with the
Ruby/Tk internals can improve it:

class TkWindow
	class PackContext
		attr_reader	:args
		
		def initialize
			@args = {}
		end
		
		def method_missing(sym, *args)
			name = sym.id2name
			@args[name] = args[0]
		end
	end
	
	alias_method :old_pack, :pack

	def pack(*args, &b)
		if block_given?
			pc = PackContext.new
			pc.instance_eval(&b)
			params = pc.args
		else
			params = *args
		end
		old_pack(params)
	end
end

Then you can do things like

label.pack do
    expand 1
    fill "both"
end

which is kind of useful to me.

5.  Are there any special reasons not to use Tk?  I need a toolkit
with a clean interface and small footprint.

Thanks in advance for your help,
Bill Atkins