glimmer_listbox.rb

class Person 
  attr_accessor :country, :country_options
  
  def initialize
    self.country_options=["", "Canada", "US", "Mexico"]
    self.country = "Canada"
  end
end

class HelloList
  include Glimmer
  def launch
    shell {
      list {
        selection bind(Person.new, :country)
      }
    }.open
  end
end

HelloList.new.launch