scrollable window ncurses ruby -

i created class trying make simulate richtextbox, sort of, on windows forms. means when add new data form/richtextbox added bottom of box/window , rest scrolled 1 line.

ive tried enable scrollok(), not seem want scroll. not sure if it's bugged or way of implementing wrong.

class textpad         attr_accessor :data, :name, :window         def initialize(name, height, width, startx, starty)                 @data   = []                 @name   = name                 @height = height                 @width  = width                 @startx = startx                 @starty = starty                 ncurses.refresh                 @window =  ncurses.newwin(height, width, starty, startx)                 @window.scrollok true                 @window.wrefresh         end          def add(packetid, username, message)                 @data.push [time.new.strftime('[%t]'), packetid, username, message]                 @data.shift if @data.length > 500         end         def draw                 ncurses.init_pair(1, ncurses::color_yellow, ncurses::color_black)                 ncurses.init_pair(2, ncurses::color_cyan, ncurses::color_black)                 ncurses.init_pair(3, ncurses::color_red, ncurses::color_black)                 ncurses.init_pair(4, ncurses::color_white, ncurses::color_black)                  @window.wclear                 position = 0                 @data.each |timestamp, packetid, username, message|                         case packetid                                 when '1005'                                         @window.mvwprintw(1*position, 1, "#{timestamp} «#{username}» #{message}")                                         @window.mvchgat(1*position, timestamp.length+2, 1, ncurses::a_normal, 3, nil)                                         @window.mvchgat(1*position, timestamp.length+3+username.length, 1, ncurses::a_normal, 3, nil) #colorize symboles around username                          end                         position += 1                 end                 @window.wrefresh         end end 

the problem inside draw method of textpad class. can fill data array textpad class hundreds of entries top of array gets written (until reaches bottom of window) no scrolling. manually have scroll screen or something? documentation says should automatically scroll when cursor reaches bottom , line added.

to quote man page:

the scrollok option controls happens when cursor of window moved off edge of window or scrolling region, either result of newline action on bottom line, or typing last character of last line. if disabled, (bf false), cursor left on bottom line. if enabled, (bf true), window scrolled 1 line...

what happening in code attempting print outside window error, error curses handles not printing anything.

you can either print new line when bottom of window or once reach bottom of window can call @window.scroll.

either way need keep printing on last line if explicitly setting position.