reinbow

Reinbow

Reinbow is a Ruby gem for colorizing printed text on terminal.

It was original a fork of the great gem ku1ik/rainbow, but the old codebase took way too much efforts to overhaul, so instead this project was built from ground up.

That means this project has no relationship with the original rainbow beyond inspiration, does not contain codes from it, and is not compatible with it either.

require "reinbow"

using Reinbow

puts "Blue cat".blue + " " \
    + "jumps over".on_yellow + " " \
    + "big".bold + " " \
    + "lazy meatball".rgb( "#f9e02e" )

Installation

Using Gemfile:

gem 'reinbow'

Using gem CLI:

gem install reinbow

Usage

The intended way to use reinbow is by using refinement and calling coloring methods on String instances. But there's also a method for constructing the underlying Reinbow::Painter instances manually.

By default, coloring are enabled or disabled based on Standard for ANSI Colors in Terminals, but methods are provided to toggle it manually.

Refinement

Simply do:

# 1) import the gem
require "reinbow"

module DesiredModule
    # 2) "using" the Reinbow refinement in some module
    using Reinbow

    # 3) all string instances in this scope
    # will have coloring methods
    def colored = @message.blue
end

Such way reinbow doesn't pollute the precious method namespace.

API

Reinbow by default defines several methods to colorize or style strings, which have their names matching the SGR counterparts.

Full list of methods for applying terminal effects:

• #reset
• #bold
• #dim
• #italic
• #underline
• #blink a lot of terminals ignore this for accessability reasons
• #invert
• #hide
• #strike
• #double_underline
• #overline

Demo:

puts "strike bold and underline".strike.bold.underline

Full list of methods for coloring foreground and background, with the background ones having on_ prefix. Note that their bright variants are not yet supported.

• #black
• #red
• #green
• #yellow
• #blue
• #magenta
• #cyan
• #white
• #default
• #on_black
• #on_red
• #on_green
• #on_yellow
• #on_blue
• #on_magenta
• #on_cyan
• #on_white
• #on_default

Demo:

puts "red on white".red.on_white

The API also supports coloring with RGB values, and has a shorthand for using HEX string. Reinbow also comes with a full list of X11 Color Names. The detailed usage of both of them can be found in the Examples section below:

• #rgb( Reinbow::Rgb | String )
• #on_rgb( Reinbow::Rgb | String )

Demo:

puts "great readability" \
    .rgb( X11_COLORS[:lawngreen] ) \
    .on_rgb( "#faf0e6" )

All coloring methods return self so that all method calls are chainable.

puts "well, your terminal, your land" \
    .rgb( X11_COLORS[:coral] ).on_magenta \
    .strike.italic.underline.bold

There's also a method for turning reinbow functionality on and off. But note, unlike rainbow, there's no global switch for toggling it:

• #reinbow!( boolean )

And also a method for querying the on-off status:

• #reinbow?

Reinbow::Painter Class

T.B.D.

Examples

RGB Colors and X11 Color Names

Reinbow::Rgb is a Data class for holding RGB values. It has following class methods:

• ::new( red: 0..255, green: 0..255, blue: 0..255 )
• ::[]( 0..255, 0..255, 0..255 )
• ::hex( String )

Where ::[] is a shorthand for the keyword based constructor, and ::hex is for making Rgb instance from plain string HEX, which is case-insensitive and also supports 3-letter HEX.

Example:

Rgb.new( red: 1, green: 133, blue: 0 )
# or
Rgb[1, 133, 0]
# or
Rgb.hex( "#0b8500" )

# 3-letter HEX
Rgb.hex( "#abc" ) # => <... red=170, green=187, blue=204>

Reinbow::X11_COLORS is a predefined hash of X11 Colors Names to their corresponding RGB values. The X11 colors are not provided as coloring methods because there are whopping 130+ of them, which will pollute the instance methods.

Example:

X11 = Reinbow::X11_COLORS

puts "crimson line".rgb( X11[:crimson] ).underline

License

BSD-3-Clause