require 'gtk'
require 'find'

window = Gtk::Window.new(Gtk::WINDOW_TOPLEVEL)
window.border_width = 2
tree = Gtk::Tree.new
tree.set_usize 200, 200
top = ARGV.shift
dir = {}
dir[File.dirname(top)] = tree

Find.find(top) {|f|
  dirname = File.dirname(f)
  item = Gtk::TreeItem.new(File.basename f)
  item.show
  dir[dirname].append item
  if File.directory? f
    dir[f] = Gtk::Tree.new
    item.set_subtree dir[f]
  end
}

window.add tree
tree.show
window.show
Gtk.main