架構師訓練營 week3 作業

# eager load
class IdGenerator
  @instance = IdGenerator.new
  @@id = 0
  private_class_method :new
  def self.instance
    @instance
  end
  def get_id
    @@id += 1
  end
  def initialize
    @@id = 0
  end
end

# lazy load
class IdGenerator
  @instance_mutex = Mutex.new
  private_class_method :new
  def self.instance
    return @instance if @instance
    @instance_mutex.synchronize do
      @instance ||= new
    end
    @instance
  end
  def get_id
    @@id += 1
  end
  def initialize
    @@id = 0
  end
end

# base_component.rb
class BaseComponent
  attr_reader :name
  def initialize(type, name)
    @type = type
    @name = name
  end
  def add
    raise NotImplementedError, "#{self.class} has not implemented method '#{__method__}'"
  end
  def remove
    raise NotImplementedError, "#{self.class} has not implemented method '#{__method__}'"
  end
  def print
    raise NotImplementedError, "#{self.class} has not implemented method '#{__method__}'"
  end
end

# window_component.rb
class WindowComponent < BaseComponent
  def initialize(name, type)
    @name = name
    @type = type
    @sub_nodes = []
  end
  def add(component)
    return unless component
    @sub_nodes << component
  end
  def remove(component)
    return unless component
    @sub_nodes.delete(component)
    @sub_nodes
  end
  def print
    puts "#{@type} #{@name}\n"
    @sub_nodes.each do |sub_node|
      sub_node.print
    end
  end
end

# demo.rb
require './base_component.rb'
require './window_component.rb'
window_form = WindowComponent.new('window_form', 'window')
logo = WindowComponent.new('picture', 'logo')
login_button = WindowComponent.new('button', 'login')
register_button = WindowComponent.new('button', 'register')
frame = WindowComponent.new('frame', 'frame1')
user_name_label = WindowComponent.new('label', 'user_name')
user_name_box = WindowComponent.new('text_box', 'user_name_box')
password_label = WindowComponent.new('label', 'password')
password_box = WindowComponent.new('password_box', 'password_box')
remember_user_check_box = WindowComponent.new('check_box', 'remember_user_check_box')
remember_user_label = WindowComponent.new('label', 'remember_user')
forgot_password_link = WindowComponent.new('link_lable', 'forgot_password_link')
frame.add(user_name_label)
frame.add(user_name_box)
frame.add(password_label)
frame.add(password_box)
frame.add(remember_user_check_box)
frame.add(remember_user_label)
frame.add(forgot_password_link)
window_form.add(logo)
window_form.add(frame)
window_form.add(login_button)
window_form.add(register_button)
window.print