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rubycommand-line-interfacecurses

Curses array browsing with keyboard in Ruby

I'm trying to make a cli app in Ruby that takes a given array then then displays it as a list that I can browse with the arrow keys.

I feel like I've already seen a library in Ruby that does this already, but I can't remember the name of it.

I'm trying to reverse engineer the code from soundcloud2000 to do something similar, but his code is tightly-coupled to the use of the Soundcloud API.

I'm aware of the curses gem, I'm thinking with something with more abstraction.Ad

Has anyone seen a library that does it or some proof of concept Ruby code that could do this?

Solution

  • I don't know if this is what you are looking for but maybe you can use my idea.

    Since I don't have more information of what you are trying to accomplish, what is your input and so on, this example will be very simple.

    Let's say we have a class to work with called PlaylistDemo that will create a playlist with songs:

    class PlaylistDemo
  attr_accessor :position

  def initialize songs
    @playlist = Array.new
    songs.each { |song| @playlist << song }
    @position = 0
  end

  def show_playlist
    @playlist.each_with_index.map do |song, index|
      position == index ? "[#{song}]" : " #{song} "
    end
  end

end

    Prepare some songs:

    # From billboard.com
songs = [
  "Taylor Swift -  Blank Space",
  "Mark Ronson Featuring Bruno Mars -  Uptown Funk!",
  "Hozier -  Take Me To Church",
  "Meghan Trainor - Lips Are Movin",
  "Meghan Trainor -  All About That Bass"
]

    And go ahead and make an object:

    pd = PlaylistDemo.new(songs)

    Now my idea is to use dispel to manipulate position and see exactly where you are (and update the "UI" accordingly).

    For this I've prepared a function that will make the UI for your CLI application:

    def show_ui playlist_obj
  ["\n", playlist_obj.show_playlist, "\nCurrent position: #{playlist_obj.position + 1} "].join("\n")
end

    Final piece of code:

    Dispel::Screen.open do |screen|
  screen.draw show_ui(pd)

  Dispel::Keyboard.output do |key|
    case key
    when :up then pd.position -= 1
    when :down then pd.position += 1
    when "q" then break
    end

    screen.draw show_ui(pd)
  end
end

    You can also use colorize but for that you'll need puts somewhere.

    Please not that I didn't set a limit for position since this is only an example.

    See my example here:

    Full code: http://paste.debian.net/139651/