[sugar] Activity bundle tutorial

[Dan Williams]

On Fri, 2007-02-09 at 03:22 -0800, Don Hopkins wrote:
> Thanks a lot for writing the activity tutorial, and for answering 
> questions about them!
> 
> I have some questions about activities, and would appreciate anything 
> tips you can give me, please:
> 
> What's a good example of an activity that starts and manages another X11 
> process, like Squeak?

Not really, because people who write those activities usually don't take
the time to put in real D-Bus support, which makes it all a hack.  You
then need the shim layer, which might talk to the real activity over a
unix domain socket, but that's just silly.  It's quite a bit easier to
just add the D-Bus support.

> What are the issues surrounding activities that are implemented as 
> external processes, as opposed to activities implemented in Python?

You need D-Bus support.  There's nothing preventing you from writing an
activity in any of the languages/libraries that D-Bus has bindings for
(C, C++, C#, Python, Qt, GLib, and more).  It just happens that in
Python, it's _so_ easy to write D-Bus enabled apps.

> Is it possible to program activities in Python that run in the Sugar 
> "desktop manager" process (or whatever it's called), or do they run as 
> separate Python processes?

No, not at this time.

> I suppose that would make it possible to quickly start light weight 
> activities, but it would not firewall them from each other and restrict 
> their privileges... How's that intended to work?

It's not intended to work at this time.

> Can you make light weight (to use an ancient term) "desk accessory" 
> sub-activities that are built into the Sugar manager, that you can pop 
> up and use quickly while in other activities? (Kinda like the chat 
> window?) Are those considered activities, or are they called something 
> else?

There aren't currently plans for this, but it's something we've talked
about on and off for a while.  We haven't yet decided whether to support
these or not.

> I'm interested to know what ways there are to hook into the Sugar user 
> interface, and plug in various kinds of user interface thingamabobs.

There aren't any ways right now.  That's not to say there won't be a way
in the future, but I'd caution you that this breaks trust and security
models in a few ways.

In any case, what type of applets were you thinking about?  There may be
alternate ways of achieving the functionality that you'd like to have.

Cheers,
Dan