sugar-toolkit-gtk3/sugar/presence/Group.py

import Service

import sugar.util

def is_group_service_type(stype):
	"""Return True if the service type matches a group
	service type, or False if it does not."""
	if stype.endswith("_group_olpc._tcp") or stype.endswith("_group_olpc._udp"):
		return True
	return False

__GROUP_NAME_TAG = "Name"
__GROUP_RESOURCE_TAG = "Resource"

def new_group_service(group_name, resource):
	"""Create a new service suitable for defining a new group."""
	if type(group_name) != type("") or not len(group_name):
		raise ValueError("group name must be a valid string.")
	if type(resource) != type("") or not len(resource):
		raise ValueError("group resource must be a valid string.")

	# Create a randomized service type
	data = "%s%s" % (group_name, resource)
	stype = "_%s_group_olpc._udp" % sugar.util.unique_id(data)

	properties = {__GROUP_NAME_TAG: group_name, __GROUP_RESOURCE_TAG: resource }
	owner_nick = ""
	port = random.randint(5000, 65000)
	# Use random currently unassigned multicast address
	address = "232.%d.%d.%d" % (random.randint(0, 254), random.randint(1, 254),
			random.randint(1, 254))
	service = Service.Service(owner_nick, stype, "local", address=address,
			port=port, properties=properties)
	return service


class Group(object):
	"""Represents a collection of buddies all interested in the same resource."""
	def __init__(self, service):
		if not isinstance(service, Service.Service):
			raise ValueError("service argument was not a Service object.")
		if not service.is_group_service():
			raise ValueError("provided serivce was not a group service.")
		name = service.get_one_property(__GROUP_NAME_TAG)
		if name == None:
			raise ValueError("provided service did not provide a group name.")
		self._name = name
		resource = service.get_one_property(__GROUP_RESOURCE_TAG)
		if resource == None:
			raise ValueError("provided service did not provide a group resource.")
		self._resource = resource
		self._service = service

	def get_name(self):
		return self._name

	def get_service(self):
		return self._service

	def get_resource(self):
		return self._resource