RubyのTkを用いてニコニコ動画みたいにツイートを左に流す

flowing_tweet.rb

#!/usr/bin/ruby
require 'tk'
require "twitter"
require "rubygems"

WIDTH = 1200
HEIGHT = 400
FONT_SIZE = 16

c = Tk::Canvas.new(nil, :width=>WIDTH, :height=>HEIGHT, :relief=>:sunken,
                   :borderwidth=>3).pack(:fill=>:both, :expand=>true)
f = TkFont.new('Helvetica -' + FONT_SIZE.to_s)

tag = TkcTag.new(c)
Thread.new do
    @client = Twitter::Streaming::Client.new do |config|
        config.consumer_key = #CONSUMER_KEY
        config.consumer_secret = #CONSUMER_SECRET
        config.access_token = #ACCESS_TOKEN
        config.access_token_secret = #ACCESS_TOKEN_SECRET
    end
    @client.user do |tweet|
        case tweet
        when Twitter::Tweet
            str = "@#{tweet.user.screen_name}: #{tweet.text}"
            Thread.new(str, rand(HEIGHT/30)+1) do
                |str, height|
                for i in 0..WIDTH+str.size*FONT_SIZE
                    t = TkcText.new(c, WIDTH-i*3+str.size*FONT_SIZE, height*30, :text=>str, :font=>f, :tags=>tag)
                    sleep 0.01
                    t.delete
                end
            end
        end
    end
end

Tk.mainloop