Creating a menu with curses

Question

I'm trying to follow this tutorial: http://www.tldp.org/HOWTO/NCURSES-Programming-HOWTO/keys.html

But I'm afraid I'm not getting on well with it at all.

This isn't the best code in the world, but it illustrates what I want to do:

        require "curses"
        include Curses

        init_screen #initialize first screen
        start_color #
        noecho

    close = false


        t1 = Thread.new{
        four = Window.new(5,60,2,2)
        four.box('|', '-')


            t2 = Thread.new{

                menu = Window.new(7,40,7,2)
                menu.box('|', '-')
                menu.setpos 1,1
                menu.addstr "item_one"
                menu.setpos 2,1

                menu.attrset(A_STANDOUT)

                menu.addstr "item_two"
                menu.setpos 3,1

                menu.attrset(A_NORMAL)

                menu.addstr "item_three"
                menu.setpos 4,1
                menu.addstr "item_four"

                menu.getch
            }
            t2.join

        while close == false
            ch = four.getch
            case ch
                when 'w'
                    four.setpos 2,1
                    four.addstr 'move up'
                    four.refresh
                when 's'
                    four.setpos 2,1
                    four.addstr 'move down'
                    four.refresh
                when 'x'
                    close = true
            end
        end


        }
        t1.join

By pressing W and D keys, I want to move the highlight up and down the menu items in the menu window. Literally no idea how I can move that highlight. It would mean moving the attribute setter in the code. I really don't know. There's not many resources out there in way of Curses.

Answer 1

there is no need for threads in your example.

you can see how this can be done here: https://gist.github.com/phoet/6988038

require "curses"
include Curses

init_screen
start_color
noecho

def draw_menu(menu, active_index=nil)
  4.times do |i|
    menu.setpos(i + 1, 1)
    menu.attrset(i == active_index ? A_STANDOUT : A_NORMAL)
    menu.addstr "item_#{i}"
  end
end

def draw_info(menu, text)
  menu.setpos(1, 10)
  menu.attrset(A_NORMAL)
  menu.addstr text
end

position = 0

menu = Window.new(7,40,7,2)
menu.box('|', '-')
draw_menu(menu, position)
while ch = menu.getch
  case ch
  when 'w'
    draw_info menu, 'move up'
    position -= 1
  when 's'
    draw_info menu, 'move down'
    position += 1
  when 'x'
    exit
  end
  position = 3 if position < 0
  position = 0 if position > 3
  draw_menu(menu, position)
end