# File ../lib/roller/CWRP.rb, line 319
  def initialize(stream, show_progress)
    @show_progress = show_progress

    if @show_progress
      init_gui
    else
      @window = nil # But GUI might be inited later.
    end

    stream.binmode

    magic = stream.read 4
    case magic
    when ARMA_MAGIC
      @is_arma = true
      read_wrp(stream)
    when OFP_MAGIC
      @is_arma = false
      read_wrp(stream)
    else
      raise "Unrecognised magic code in input file (#{magic})"
    end
  end