Curses Part 2-3: Subwindow

gistfile1.rb

#!/usr/local/bin/ruby
require "curses"

begin
  Curses.init_screen
  Curses.noecho

  win  = Curses::Window.new(Curses.lines-10, Curses.cols - 10, 5, 5)
  win.keypad(true)

  STEP_Y = 1
  STEP_X = 5
  SW_SIDE = 6

  subwin = win.subwin(5, 10, SW_SIDE, SW_SIDE)

  x, y = subwin.begx, subwin.begy

  loop do
    win.clear
    win.box("|", "-")
    win.refresh

    subwin.move(y, x)
    subwin.setpos(1,2)
    subwin.addstr("#{x} \n/ #{subwin.maxx} /\n #{win.maxx}")
    subwin.box(".", ".")
    subwin.refresh

    case win.getch
    when Curses::Key::UP then    y -= STEP_Y
    when Curses::Key::DOWN then  y += STEP_Y
    when Curses::Key::LEFT then  x -= STEP_X
    when Curses::Key::RIGHT then x += STEP_X
    when ?q then break
    end

    # Check bounds
    if y >= win.maxy
      y = win.maxy - 1#subwin.maxy - 1
    end
    y = SW_SIDE if y < SW_SIDE

    if x + SW_SIDE > win.maxx
      x = win.maxx  - SW_SIDE#(subwin.maxx / 2)
    end
    x = SW_SIDE if x < SW_SIDE
  end

  win.close
ensure
  Curses.close_screen
end