Re: Proposal and RFC: DAL, the Desktop Abstraction Layer

[Ikke <eikke eikke com>]

On Thu, 2005-01-13 at 16:03 +0000, Jamie McCracken wrote:
> Ikke wrote:
> > Hi Gnome desktop hackers,
> > 
> > This morning I sent an email[1] to the XDG list at freedesktop.org,
> > explaining some new idea I got and I'd like to hack on.
> > 
> > I'd like to hear your thoughts on this too, as it won't be very useful
> > to write something like this if nobody is going to use it.
> > 
> > Please express your opinion :-)
> 
> Excellent stuff - I too had been thinking along those lines though mine 
> was more influenced by application profiles like you get in bluetooth.
> 
> Profiles define a common api (set of methods and events) such that any 
> app implementing that profile can manipulate it without knowing anything 
> else about it (IE theres no need to introspect the methods/events).
> 
> Profiles come as both public (pre-defined) and private (for propriety 
> extensions). The idea is that any app can implement any number of 
> public or private profiles which are defined by some XML based spec. It 
> would be easy to implement this using DBus as you have suggested.
> 
> This is great for implementing things like interfacing with an email 
> app. Its currently not very nice to open an email client and prefill its 
> contents (with some clients you can pass it as command line parameters 
> others like Evolution require the use of some nasty corba etc). If there 
> was an email profile which email clients used then regardless of what 
> email client was installed I would be able to use it in the same way. 
> Now if what you are saying is DAL is pretty much the same thing as this 
> then yes that would be cool to implement.
> 
> 
> jamie.
> 
> > 
> > 
> > Kind regards,
> > 
> > Ikke                                            http://www.eikke.com
> > 
> > PS I hope this is the correct list to post an email regarding a topic
> > like this to. If not, please point me at the right direction.
> > 
> > [1] http://lists.freedesktop.org/archives/xdg/2005-January/005687.html

Currently, it looks like this would be best implemented like as you
said, bluetooth. We will create a standard way/interface to interact
certain information, and next to this create libraries that hide the
technology behind these messages (ie DBUS), so an app can just say
"announce I received an email", then the library will create a
DBusMessage following our interface, and send it on the session bus.
Then in every listening app (which also use our lib) a callback will be
called. Of course applications can listen on the session bus directly
too.
We will have to make several libs of course: a low-level one, one that
can be easily used by GTK/Glib based apps, one suitde for kdelibs/Qt,...
so there are no boundaries: if a user wants to use KMail instead of
Evolution in a Gnome environment (dont ask me why he'd ever do that, but
well ;)) he should have the same functionality as when using KDE and
KMail.


Regards, Ikke