class Middleman::CoreExtensions::FileWatcher

def initialize(app, config={}, &block)
  super
  # Setup source collection.
  @sources = ::Middleman::Sources.new(app,
                                      disable_watcher: app.config[:watcher_disable],
                                      force_polling: app.config[:force_polling],
                                      latency: app.config[:watcher_latency])
  # Add default ignores.
  IGNORES.each do |key, value|
    @sources.ignore key, :all, value
  end
  # Watch current source.
  start_watching(app.config[:source])
  # Expose API to app and config.
  app.add_to_instance(:files, &method(:sources))
  app.add_to_config_context(:files, &method(:sources))
end