# Observerパターン
#
# Java言語で学ぶデザインパターンと同様の例題をRubyで記述した。
#
# coded by Takehiro Kaga
#

require "thread"
require "observer"

class RandomNumberGenerator
  include Observable
  def execute
    for i in 0..20
      @number = rand(50)
   
	changed
	notify_observers(@number)

      sleep(1)

    end
 
  end
end

class DigitObserver
  def initialize(randomNumberGenerator)
    @generator = randomNumberGenerator
    @generator.add_observer(self)
  end
  def update(number)
    puts "DigitObserver: " + number.to_s
  end
end

class GraphObserver
  def initialize(randomNumberGenerator)
    @generator = randomNumberGenerator
    @generator.add_observer(self)
  end
  def update(number)
    print "GraphObserver: "
    for i in 1..number
      print "*"
    end
    puts ""
  end
end


# ---- Main ---- #

randomNumberGenerator = RandomNumberGenerator.new
DigitObserver.new(randomNumberGenerator)
GraphObserver.new(randomNumberGenerator)

randomNumberGenerator.execute