http://www.aosabook.org/en/telepathy.html
1 communications as a service
2 D-Bus messaging
a. an asynchronous message bus for interprocess communication that forms the backbone of most GNU/Linux systems inkling the GNOME and KDE desktop environments.
b. transmit a targeted message or broadcast a signal through the bus
c. every application have a bus address and can claim a number of well-known names
d. D-bus daemon handles message passing and name registration
e. D-bus protocol libraries are lib dubs, GDBus, QtBus, and python-dbus.
3 Components
a. Connection manager : provides the interfere between Telepathy and the communication services ( XMPP, SIP, IRC etc)
b. Account manager: store accounts and establish a connection to each account
c. The Channel Dispatcher: listening for incoming channels signalled by each connection manager; provide outgoing service
d. Client : handle or observe communications channels.
e. Account manager and channel dispatcher are provided in a single process called Mission Control
f. components are talking with each other through use's session bus.
4 D-bus in telepathy
Each service publishes objects which a strictly namespaced object path.
Each object implements a number of interfaces.
Each interface provides methods, signals and properties that you call, listen to, or request
Mission control --- connection manager and channel dispatcher
Client --- a client object that can be accessed by channel dispatcher
connection manager -- a service object that can be used by the Account Manager to request new connections, an object per open connection, and an object per open channel.
ofd means org.freedesktop.Dbus
Connection object : ofdT.Connection.Interface,Avatars, ContactList, Location
Channel : ofdT.Channel.Type.Text, Call, FileTransfer, Messages, Group
Concept:
Handles : represent identifiers ( e.g. contacts and room names)
Connection -- Channel( an IM conversion, voice or video call) --- Clients
Clients have three types : observers, approvers, handlers
high-level bindings are Glib and Qt4 bindings
low-level bindings are Python and lib telepathy C bindings
D-Bus integrates well with Glib main loop used by the GTK+ and Qt toolkits.