refactor-styles.rb

#coding: utf-8

class HighLine
  module BuiltinStyles
    def self.included(base)
      base.extend ClassMethods
    end

    STYLES = {
      erase_line: "\e[K",
      erase_char: "\e[P",
      clear:      "\e[0m",
      reset:      "\e[0m",
      bold:       "\e[1m",
      dark:       "\e[2m",
      underline:  "\e[4m",
      underscore: "\e[4m",
      blink:      "\e[5m",
      reverse:    "\e[7m",
      concealed:  "\e[8m"
    }

    STYLES.each do |style_name, code|
     style = String(style_name).upcase
     
     const_set style, code
     const_set style + "_STYLE", Style.new(style_name: style_name, code: code, builtin: true)
    end

    # These RGB colors are approximate; see http://en.wikipedia.org/wiki/ANSI_escape_code
    BLACK_STYLE      = Style.new(:name=>:black,      :builtin=>true, :code=>"\e[30m", :rgb=>[  0,  0,  0])
    RED_STYLE        = Style.new(:name=>:red,        :builtin=>true, :code=>"\e[31m", :rgb=>[128,  0,  0])
    GREEN_STYLE      = Style.new(:name=>:green,      :builtin=>true, :code=>"\e[32m", :rgb=>[  0,128,  0])
    BLUE_STYLE       = Style.new(:name=>:blue,       :builtin=>true, :code=>"\e[34m", :rgb=>[  0,  0,128])
    YELLOW_STYLE     = Style.new(:name=>:yellow,     :builtin=>true, :code=>"\e[33m", :rgb=>[128,128,  0])
    MAGENTA_STYLE    = Style.new(:name=>:magenta,    :builtin=>true, :code=>"\e[35m", :rgb=>[128,  0,128])
    CYAN_STYLE       = Style.new(:name=>:cyan,       :builtin=>true, :code=>"\e[36m", :rgb=>[  0,128,128])
    # On Mac OSX Terminal, white is actually gray
    WHITE_STYLE      = Style.new(:name=>:white,      :builtin=>true, :code=>"\e[37m", :rgb=>[192,192,192])
    # Alias for WHITE, since WHITE is actually a light gray on Macs
    GRAY_STYLE       = Style.new(:name=>:gray,       :builtin=>true, :code=>"\e[37m", :rgb=>[192,192,192])
    GREY_STYLE       = Style.new(:name=>:grey,       :builtin=>true, :code=>"\e[37m", :rgb=>[192,192,192])
    # On Mac OSX Terminal, this is black foreground, or bright white background.
    # Also used as base for RGB colors, if available
    NONE_STYLE       = Style.new(:name=>:none,       :builtin=>true, :code=>"\e[38m", :rgb=>[  0,  0,  0])

    BASIC_COLORS = %w{BLACK RED GREEN YELLOW BLUE MAGENTA CYAN WHITE GRAY GREY NONE}

    colors = BASIC_COLORS.dup
    BASIC_COLORS.each do |color|
      bright_color = "BRIGHT_#{color}"
      colors << bright_color
      const_set bright_color + '_STYLE', const_get(color + '_STYLE').bright

      light_color = "LIGHT_#{color}"
      colors << light_color
      const_set light_color + '_STYLE', const_get(color + '_STYLE').light
    end
    COLORS = colors

    colors.each do |color|
      const_set color, const_get("#{color}_STYLE").code
      const_set "ON_#{color}_STYLE", const_get("#{color}_STYLE").on
      const_set "ON_#{color}", const_get("ON_#{color}_STYLE").code
    end
    ON_NONE_STYLE.rgb = [255,255,255] # Override; white background

    module ClassMethods
      RGB_COLOR = /^(ON_)?(RGB_)([A-F0-9]{6})(_STYLE)?$/
      # For RGB colors: - add example here -
      def const_missing(name)
        if name.to_s =~ RGB_COLOR
          on = $1
          suffix = $4
          
          if suffix
            code_name = $1.to_s + $2 + $3
          else
            code_name = name.to_s
          end
          
          style_name = code_name + '_STYLE'
          style = Style.rgb($3)
          style = style.on if on
          
          const_set(style_name, style)
          const_set(code_name, style.code)
          
          suffix ? style : style.code
        else
          raise NameError, "Bad color or uninitialized constant #{name}"
        end
      end
    end
  end
end