From: Gennady Bystritsky <Gennady.Bystritsky@...>
Date: 2009-04-27T13:09:55+09:00
Subject: Re: JRuby constructor issue or just me?

In Ruby, "super()" is different from just "super". The former will invoke a superclass' constructor with no parameters, while the latter will call it with the same number of parameters as was in "new" call.

Gennady.

> -----Original Message-----
> From: Andrew S. Townley [mailto:ast@atownley.org]
> Sent: Sunday, April 26, 2009 2:50 PM
> To: ruby-talk ML
> Subject: JRuby constructor issue or just me?
> 
> Hi,
> 
> I can't figure out why this doesn't work.  I need to do this because
> I'm
> initializing the button elements separately within the constructor, but
> I want to ensure that the button is actually created first.  I do this
> all the time with GTK+ & Ruby/GNOME2 on MRI, but it doesn't seem to
> want
> to go with JRuby.
> 
> Is this problem something to do with the overloaded JButton
> constructors?  How can I force a particular one to be called?  I've
> read
> several Google results, but since I'm trying to call the JButton()
> constructor with no arguments, I can't figure out what to do.
> 
> Any help would be appreciated.
> 
> Cheers,
> 
> ast
> 
> $ cat $HOME/jbutton.rb
> require 'java'
> 
> include_class 'javax.swing.JButton'
> 
> class Foo < JButton
>   def initialize(count)
>     super()
>     self.text = "Foo"
>     @count = count
>   end
> end
> 
> foo = Foo.new
> 
> $ cat $HOME/output.txt
> nene$ c:/devel/src/jruby/bin/jruby -v
> jruby 1.3.0 (ruby 1.8.6p287) (2009-04-26 r6586) (Java HotSpot(TM)
> Client VM 1.6.0_13) [x86-java]
> nene$ c:/devel/src/jruby/bin/jruby jbutton.rb
> jbutton.rb:13: wrong # of arguments(0 for 1) (ArgumentError)
> 
> The above example is contrived to produce a suitable testcase, but
> based
> on the actual code that I'm trying to run.
> --
> Andrew S. Townley <ast@atownley.org>
> http://atownley.org
>