[sugar] Activity names vs. types (was: synapse/cerebro)

[Polychronis Ypodimatopoulos]

Hi Elliot,

You brought up an interesting issue. I really hope you won't mind me 
opening up the discussion to sugar ml.

Elliot Fairweather wrote:
> Mapping OLPC activity names (which take the form of well-known DBus 
> bus names) to a two byte activity type in Cerebro is problematic (as 
> well as creating a rather small upper bound for the number of possible 
> activity types.) Maybe the activity type could be a given as a string 
> or a longer byte array, maybe up to the maximum DBus bus name length 
> (256 bytes?)?

A valid argument. I remember discussing the idea behind this in the past 
with Michael, but I'm not sure if Sugar landed a decision on this. The 
activity type is supposed group different activities into a single type 
based on their capabilities and represent this group with a two-byte 
field. For example, I wrote an activity that does chat, file sharing and 
a bidding game. I _believe_ the activity should advertise its 
capabilities as 'xx' for chat, '\x00\x01' for file-sharing and '99' for 
the bidding game. The bytes chosen are clearly random, but the idea is 
that my activity would be able to engage in a chat session with a 
regular chat activity under the same activity type, or with previous 
version of itself lacking the file-sharing capability. Maybe this is 
simply an overkill.

At any rate, I will add (I filed a ticket) a sufficiently large (255 
chars?) name field for activities, although I would much prefer 
designing this mechanism properly (any suggestions by Sugar(ed) 
developers?).

> Something else I forgot in my earlier mail, is that it would be really 
> helpful if up-to-date documentation for the API was available. The 
> page to which I have been referring 
> (http://wiki.laptop.org/go/Cerebro) differs in quite a few places from 
> what d-feet tells me is there in reality :)

Right again. This may take some time though as I'm currently plagued by 
a thesis deadline :(

>
> Thanks again,
> Elliot

Pol

-- 
Polychronis Ypodimatopoulos
Graduate student
Viral Communications
MIT Media Lab
Tel: +1 (617) 459-6058
http://www.mit.edu/~ypod/