NSDistributedNotifications in RubyCocoa

gistfile1.rbx

require 'osx/cocoa'
include OSX

class NotificationHandler < NSObject
  def initialize
    c = NSDistributedNotificationCenter.defaultCenter
    c.addObserver_selector_name_object(self, :notification, 'com.apple.iTunes.playerInfo', nil)
  end
  
  def notification(n)
    @data = n.userInfo # get a hash of the notification
    if @data['Player State'] == 'Playing'
      puts 'iTunes is playing!'
    end
  end
end

NotificationHandler.new
NSApplication.sharedApplication.run # run the Cocoa application loop