happyguy.rb

require 'curses'

def init_screen
  Curses.noecho # do not show typed keys
  Curses.init_screen
  Curses.start_color
  Curses.stdscr.keypad(true) # enable arrow keys
  Curses.curs_set(0)
  Curses.ESCDELAY = 0

  $color = Curses.has_colors?
  
  begin
    yield
  ensure
    Curses.close_screen
  end
end

def write(line, column, text)
  Curses.setpos(line, column)
  
  #Curses.attron(color) if $color
  Curses.addstr(text);
  #Curses.attroff(color) if $color 
end

class Player < Struct.new(:x, :y, :icon)
  
  def move(dx, dy)
    erase
    self.x = (self.x + dx) % Curses.cols
    self.y = (self.y + dy) % Curses.lines
    draw
  end

  def erase
    write(y, x, " " * icon.size)
  end

  def draw
    write(y, x, icon)
  end
  
end    


init_screen do

  p = Player.new(10, 10, ":D")
  p.draw
  
  loop do
    ch = Curses.getch
    case ch
      when Curses::Key::UP    then p.move( 0, -1)
      when Curses::Key::DOWN  then p.move( 0,  1)
      when Curses::Key::LEFT  then p.move(-1,  0)
      when Curses::Key::RIGHT then p.move( 1,  0)
      when 410 then 
        write(0,0,"Resized to: #{Curses.cols}x#{Curses.lines}")
        Curses.clrtoeol
      when 27, ?q then break
      else write(0,0,"Unknown char: #{ch}")
    end
  end
end