Ruby Paint

Paint manages terminal colors and effects for you. It combines the strengths of term-ansicolor, rainbow and other similar projects into a simple to use, however still flexible terminal colorization gem with no core extensions by default.

Features

  • No string extensions (suitable for library development)

  • Supports setting 256 colors (for capable terminals)

  • Supports setting any effects (although most terminals won't support it)

  • Simple to use

  • Custom shortcuts can be defined and flexibly mixed in

  • Fall-back modes for non-256-color terminals (Paint.mode), supported modes:

    • 256 colors

    • 16 colors (only ansi colors, combined with bright effect)

    • 8 colors (only ansi colors)

    • 0 colors (deactivate)

Setup

Install with:

gem install paint

Or add to Gemfile:

gem 'paint'

and run `bundle install`

In Ruby do:

require 'paint'

Usage

The only method you need to know to get started is: Paint.[]

The first argument given to Paint.[] is the string to colorize (if the object is not a string, to_s will be called on it). The other arguments describe how to modify/colorize the string. Let's learn by example:

Paint['Ruby', :red]           # sets ansi color red
Paint['Ruby', :red, :bright]  # also applies bright/bold effect
Paint['Ruby', :bright, :red]  # does the same as above
Paint['Ruby', :red, :bright, :underline] # effects can often be combined
Paint['Ruby', :red, :blue]    # the second color you define is for background
Paint['Ruby', nil, :blue]     # pass a nil before a color to ignore foreground and only set background color
Paint['Ruby', [100, 255, 5]]  # you can define rgb colors that map to one of 256 colors. Only supported on 256-color terminals, of course
Paint['Ruby', "gold", "snow"] # Paint supports rgb.txt color names, note that the arguments are strings (:yellow != "yellow")!
Paint['Ruby', "#123456"]      # html like definitions are possible.
Paint['Ruby', "fff"]          # another html hex definition
Paint['Ruby', :random]        # pass :random to get one of eight random ansi foreground colors
Paint['Ruby', :inverse]       # swaps fore- and background
Paint['Ruby', :italic, :encircle, :rapid_blink, :overline] # probably not supported effects
Paint['Ruby']                 # don't pass any argument and the string will not be changed

When you pass multiple colors, the first one is taken as foreground color and the second one defines the background color, every other will be ignored. To only change the background color, you have to pass a nil first. Effects can be passed in any order.

You can find more examples in the specs.

Windows Support

For ANSI support in Windows OS, you can use ansicon or ConEmu.

More details about terminal colors and effects

Terminal colors/effects are set by ansi escape sequences. These are strings that look like this: \e[X;X;X;X;X]m where X are integers with some meaning. For example, 0 means reset, 31 means red foreground and 41 red background. When you tell Paint to use one of the eight ansi base colors as foreground color, it just inserts a number between 30 and 37 in the sequence. The following colors are available:

:black, :red, :green, :yellow, :blue, :magenta, :cyan, :white, (:default)

When combined with the :bright (= :bold) effect, the color in the terminal emulator often differs a little bit.

Through special sequences it's also possible to set 256-colors, instead of 8, which is also supported by many - but not all - terminals. Paint automatically translates given rgb colors to a suitable color of the 256 available colors.

When using the Paint.[] method, Paint wraps the given string between the calculated escape sequence and an reset sequence ("\e[0m"). You can get the raw escape sequence by using the Paint.color method.

Effects

Also see en.wikipedia.org/wiki/ANSI_escape_code:

Often supported

0) :reset, :nothing
1) :bright, :bold
4) :underline
7) :inverse, :negative
8) :conceal, :hide
22) :clean
24) :underline_off
26) :inverse_off, :positive
27) :conceal_off, :show, :reveal

Not widely supported

2) :faint
3) :italic
5) :blink, :slow_blink
6) :rapid_blink
9) :crossed, :crossed_out
10) :default_font, :font0
11-19) :font1, :font2, :font3, :font4, :font5, :font6, :font7, :font8, :font9
20) :fraktur
21) :bright_off, :bold_off, :double_underline
23) :italic_off, :fraktur_off
25) :blink_off
29) :crossed_off, :crossed_out_off
51) :frame
52) :encircle
53) :overline
54) :frame_off, :encircle_off
55) :overline_off

Paint.mode

You can choose between four ways to use Paint.[] by setting Paint.mode to one of the following:

  • 256: full support

  • 16: don't use 256 colors, but the ansi eight ones (combined with bright effect)

  • 8: don't use 256 colors, but the ansi eight ones

  • 0: don't colorize at all

Paint tries to automatically detect the proper value, please open an issue if Paint.detect_mode yields a wrong value for you.

Advanced Usage: Shortcuts

Now for the fancy part: You can create color shortcuts for your gems and scripts! Note: You don't have to use this feature (and only stick to Paint.[] instead) ;)

It's easy: Just setup a hash of symbol keys and escape string values at: Paint::SHORTCUTS[:your_namespace]. They are stored directly as escape sequences for performance reasons (this also means, you need different namespaces for different Paint.modes). Example:

Paint::SHORTCUTS[:example] = {
  :white => Paint.color(:black),
  :red => Paint.color(:red, :bright),
  :title => Paint.color(:underline),
}

The methods become “rubymagically” available in a Paint child model:

Paint::Example.red 'Ruby' # => "\e[31;1mRuby\e[0m"
Paint::Example.white      # => "\e[37m"

As you can see, the helper methods look useful and can take either one (wrap string) or none (only color) arguments …but they aren't really short yet.

Fortunately, you can include them:

include Paint::Example
red # => "\e[31;1m"
white 'Ruby' # => "\e[30m"

All shortcuts, defined in your shortcut namespace at this time, are now (privately) available in your current namespace (without using a method_missing implementation).

Furthermore, there are two variations of this approach:

include Paint::Example::String
"Ruby".title # => "\e[4mRuby\e[0m"
5.red # => "\e[31;1m5\e[0m"

In this case, self will be converted to a string and wrapped with the specific color code. Note, that the helper methods doesn't take any arguments when using this inclusion method.

The third way allows you to get a single color helper method to avoid cluttering namespaces:

include Paint::Example::Prefix::ExampleName
"Ruby".example_name(:red) # => "\e[31;1mRuby\e[0m"

Utilities

There are some supporting methods available. You can get a p like alternative for calling puts Paint.[]:

require 'paint/pa'
pa "Ruby", :red, :underline  # same as puts Paint["Ruby", :red, :underline]

Another helper method is Paint.unpaint, which removes any ansi colors:

Paint.unpaint( Paint['Ruby', :red, :bright] ).should == 'Ruby'

J-_-L

Copyright © 2011-2014 Jan Lelis <janlelis.com>, released under the MIT license.

Mainly influenced by rainbow and term-ansicolor. Contributors: