scr_samples.rb

class Log
  def initialize(line = 0, col = 0, line_len = 10, size = 6)
    @line = line
    @col = col
    @buff = [''] * size
    @line_len = line_len
  end

  def push(str)
    str = str.chomp
    loop do
      @buff.shift
      @buff.push(str.slice!(0, @line_len).ljust(@line_len))
      break if str == ''
    end

    @buff.each_index do |i|
      print "\033[#{@line + i};#{@col}H#{@buff[i]}"
    end
  end
end

class Line
  def initialize(line = 0, col = 0)
    @line = line
    @col = col
    @size = 0
  end

  def push(str)
    print "\033[#{@line};#{@col}H#{str.ljust(@size)}"
    @size = str.size
  end
end

class List
  #attr_accessor :line, :col
  def initialize(line = 0, col = 0)
    @line = line
    @col = col
    @list = []
  end

  def push(obj)
    flag = false
    if obj.last == :delete
      @list.delete(obj.first.chomp.ljust(13))
      flag = true
    elsif obj.last == :add
      @list.push(obj.first.chomp.ljust(13))
    end
    refresh(flag)
  end

  def refresh(flag = false)
    i = 0
    @list.each do |u|
      print "\e[#{@line + i};#{@col}H#{u}"
      i += 1
    end
    print "\e[#{@line + i};#{@col}H#{' ' * 13}" if flag == true
  end
end

screen.rb

require 'io/console'
require_relative 'scr_samples'

# screen configuration
class Screen
  attr_reader :in
  def initialize(units_hash)
    @units_hash = units_hash
    @in = Queue.new
    @loop = Thread.new { loop { refresh } }
  end

  def refresh
    hsh, str = @in.deq
    @units_hash[hsh].push(str)
  end

  def stop
    @loop.kill
    print "\033[J"
  end
end

# input handlig
class Input
  def initialize(cmd_len: 30, cmd: :cmd, scr_queue: nil)
    @cmd_len = cmd_len
    @cmd = cmd
    @scr_queue = scr_queue
  end

  # check command
  def check_com(str)
    str != '/close'
  end

  def key_read
    buff = ''
    tr = true
    while tr
      in_key = $stdin.noecho(&:getch)
      if in_key == "\r"
        tr = check_com(buff)
        buff = ''
      elsif in_key == "\b"
        buff.chop!
      elsif buff.size < @cmd_len
        buff += in_key
      end
      @scr_queue << [@cmd, buff]
    end
  end
end

# TEST
# initializing
scr = Screen.new(cmd: Line.new(10, 0), clock: Line.new(0, 0))
in_keyboard = Input.new(scr_queue: scr.in)

# loops and input
Thread.new do # date and time
  loop do
    scr.in << [:clock, Time.new.to_s]
    sleep 1
  end
end
in_keyboard.key_read # could be run in thread