Nonsense values for selected_line

spoons.rb

#!/usr/bin/env ruby
# -*- coding: utf-8 -*-

require 'rubygems'
require 'plist'
require 'curses'
#require 'mplayer'

class Library
  def initialize()
    @itml = Plist::parse_xml('iTML.xml')
    @tracks = @itml['Tracks']
    @playlists = @itml['Playlists']
    @_tracks_by_album_name = {}
    @lines = []

    @line_begin = 0

    @selected_line = 10
    # sort by something sensible
    @tracks.each do |tid, track|
      label = sprintf("%s%04d", (track['Album'] ? track['Album'] : '').gsub(' ', '-'), track['Track Number'] ? track['Track Number'] : 0)
      unless @_tracks_by_album_name.has_key?(label)
        @_tracks_by_album_name[label] = []
      end
      @_tracks_by_album_name[label] << tid
    end

    @_tracks_by_album_name.sort.each do |uuid, tracks|
      tracks.each do |tid|
        track = @tracks[tid]
        return unless track != nil
        name = track['Name'][0..29]
        album = (track['Album'] ? track['Album'] : '')[0..19]
        artist = (track['Artist'] ? track['Artist'] : '')[0..19]
        d_m = ((track['Total Time'] ? track['Total Time'] : 0)/1000)/60
        d_s = ((track['Total Time'] ? track['Total Time'] : 0)/1000)%60
        
        @lines << sprintf("%30s | %20s | %20s | %02d:%02d", name, artist, album, d_m, d_s)
      end
    end
  end

  def display_at()
    @line = 6
    selected = false
    # XXX autocalculate number of displayable rows
    thisLine = 0

    @display_end = Curses.lines-1 - @line
    @display_endbound = @line_begin + @display_end

    Curses.setpos(0, 10)
    Curses.addstr("library position: at #{@selected_line}: #{@line_begin}..#{@display_endbound} (window: #{@display_end}l) #{@line_begin.class} #{@display_endbound.class}")

    @lines[@line_begin..@display_endbound].each do |row|
      if (@line_begin + thisLine) == @selected_line
        selected = true
      else
        selected = false
      end

      Curses.setpos(@line, 0)
      is_selected(selected) do
        Curses.addstr(row)
      end
      @line += 1
      thisLine += 1
    end

    Curses.refresh
  end

  def is_selected(selected)
    if selected
      Curses.attron(Curses::A_REVERSE)
    end
    yield
    if selected
      Curses.attroff(Curses::A_REVERSE)
    end
    return
  end

  def select_next()
    @display_end = Curses.lines-1 - @line
    @display_endbound = @line_begin + @display_end

    if @selected_line > @display_endbound
      @line_begin += 1
    end
    @selected_line += 1
    display_at()
  end

  def select_nextpg()
    @display_end = Curses.lines-1 - 6
    @display_endbound = @line_begin + @display_end

    @line_begin += @display_end
    @selected_line += @display_end

    display_at()
  end

  def select_prev()
    if @selected_line <= @line_begin
      @line_begin -= 1
    end
    @selected_line -= 1
    display_at()
  end

  def select_prevpg()
    @display_end = Curses.lines-1 - 6
    @display_endbound = @line_begin + @display_end

    @line_begin -= @display_end
    @selected_line -= @display_end

    display_at()
  end

  def search()
    Curses.setpos(5, 0)
    Curses.addstr("Enter search term: ")
    str = ""
    while (c = Curses.getch) != 10
      str += c
      Curses.addstr(c)
    end

    str
  end
end

class NowPlay
end

STATUS_LINE = 1
NOWPLAY_BEGIN = 2
LIBRARY_BEGIN = 6

def write(line, column, text)
  Curses.setpos(line, column)
  Curses.addstr(text)
end

def init_screen
  Curses.noecho # do not show typed keys
  Curses.init_screen
  Curses.stdscr.keypad(true) # enable arrow keys
  begin
    yield
  ensure 
    Curses.close_screen
  end
end

init_screen do
  write(STATUS_LINE, 0, "spoons - not playing")

  library = Library.new
#  nowplay = NowPlay.new
  library.display_at()
#  nowplay.display_at()

  Curses.refresh

  loop do
    case Curses.getch
    when Curses::Key::UP then library.select_prev
    when Curses::Key::DOWN then library.select_next
    when Curses::Key::PPAGE then library.select_prevpg
    when Curses::Key::NPAGE then library.select_nextpg
    when Curses::Key::RIGHT then nowplay.ff
    when Curses::Key::LEFT then nowplay.rev
    when ' ' then nowplay.playpause
    when 10 then nowplay.select(library.selected)
    when '/' then library.search
    end
  end
end