Exploration Through Example

require ‘osx/cocoa‘
include OSX
require ‘growl‘

class GrowlController
  # The different kinds of messages you might send to Growl.
  PING_KIND = ‘stretch‘
  ACK_KIND = ‘ack‘

  # Tell the Growl Notifier class that we’ll be handling
  # callbacks from Growl.
  def initialize
    @growl = Growl::Notifier.alloc.initWithDelegate(self)
    @growl.start(:this_program, [PING_KIND, ACK_KIND])
  end

  # Send the initial message. The "context" argument 
  # tells Growl that we want a callback.
  def ping
    @growl.notify(kind = PING_KIND,
                  title = ‘Stretch!‘,
                  description = ‘You have thirty seconds.‘,
                  context = "new", sticky = true, priority = 0)
  end

  # This is the callback method for clicks.
  def growl_onClicked(sender, context)
    @growl.notify(kind = ACK_KIND,
                  title = ‘Bye!‘,
                  description = ‘Saw your click.‘,
                  context = nil, sticky = true, priority = 0)
    # I exit! instead of exit because the Cocoa framework catches
    # Ruby’s SystemExit exception.
    exit!
  end
end

if $0 == __FILE__ then
  growl_controller = GrowlController.new
  growl_controller.ping

  # Although it has no UI, this has to be an OS X application because
  # the run loop is needed to handle Growl callbacks.
  NSApplication.sharedApplication
  NSApp.run
end