example code of how to do an "on_click" method for a JButton

easy_way.rb

 require 'java'
 include_class 'javax.swing.JButton'
 include_class 'javax.swing.JFrame'
 include_class 'javax.swing.JLabel'
 include_class 'java.awt.event.ActionListener'

 
 class ClickAction
  include ActionListener

  def initialize &block
    @block = block
    raise unless block_given?
  end
  
  def actionPerformed(event)
    @block.call
  end
 end

 class JButton
   def on_clicked &block
     # maybe it can only have one on click handler for now?
     handler = ClickAction.new &block
     add_action_listener handler
   end
 end


 class MainWindow < JFrame
   def initialize
     super "JRuby/Swing Demo"
     button = JButton.new( "Click me!")
     button.on_clicked {
       p 'clicked good'
     }
     add button
     pack
   end
  
 end

MainWindow.new.show

even_easier_way.rb

 require 'java'
 include_class 'javax.swing.JButton'
 include_class 'javax.swing.JFrame'
 include_class 'javax.swing.JLabel'
 include_class 'java.awt.event.ActionListener'


 class JButton
   def on_clicked &block
     # maybe it can only have one on click handler for now?
     add_action_listener do |e|
       block.call
     end
   end
 end


 class MainWindow < JFrame
   def initialize
     super "JRuby/Swing Demo"
     button = JButton.new( "Click me!")
     button.on_clicked {
       p 'clicked good'
     }
     add button
     pack
   end
  
 end

MainWindow.new.show

"even easier way" gleaned from http://www.ruby-forum.com/topic/479162#962470