RE: component architecture

[<jheintz iconcomp com>]

I think that your plan sounds good, but I want to make sure I understand
exactly
what your saying.  (Yes, I'm that curious ;-)

First off, let me define my meaning of "component".  To me a component
is
a self contained, well defined thing - that may or may not have a gui.
A
JavaBean, a Corba service, and a Notepad editor are all "components" to
me.

The name "object" for me doesn't represent the compositional nature well
enough.  To me "object" represents both the "component" as a whole and
each
of the things that make it up.

My interpretation of what you suggest:
 - register an editor as a Corba service/component/object, 
 - register an event manager (that knows about the editor) as a Corba
event service,
 - and create something (like a file manager) to trigger events on the
event 
	manager to signal file editing.

Q1) Is the purpose of this prototype the editor, or the event manager?

I think both are valid things to prototype, but I would assume we want
to 
prototype the editor as a Corba service first, then add the additional
indirection
of the event manager. Right?

Q2) Does Midnight Commander map edit requests to different apps right
now?

I admit my ignorance, I haven't use MC.  It is the first Gnome file
manager right?
Anyway, how does it deal with this issue right now?  If it uses MIME,
can that be
adapted?

I thought that MIME was a way to get some file to the application that
matches
it?  Does MIME make any claim for editing vs. running vs. printing vs.
.....?
I guess I am questioning whether MIME is the right way to go.


PS - Despite using undefined terms and not being very clear with them at
that, 
what I was trying to ask about the Corba layer and independence from the
GUI is this:
	Will it be possible to disribute the Corba layer as a separate and 
	independent library from the rest of Gnome?

I think that a component model for *nix that is competitive to MS's COM
would be a very powerful tool that extends beyond Gnome.  I would like
to
see that layer be separately distributable with other parts of Gnome
built on top of it.

John


>-----Original Message-----
>From:	Tom Tromey [SMTP:tromey@creche.cygnus.com]
>Sent:	Wednesday, March 04, 1998 1:55 AM
>To:	John D. Heintz
>Cc:	;
>Subject:	Re: component architecture
>
>John> 2. Use CORBA to let apps talk to each other in a coarse-grained
>John> way.
>
>Once I finish my current mini project (argument parsing), I plan to
>start looking into this.
>
>My plan, roughly:
>
>- Write a simple event manager using the CORBA Event Service.
>  This event manager will basically be a bus through which
>  "interesting" desktop events are routed.
>
>- Define some simple editor interfaces (I'll just re-use the useful
>  bits from my old design).  These would be plugged into whatever
>  editors exist (perhaps a rewrite of Notepad into C/C++ is in order,
>  to make a proof of concept)
>
>- Figure out a good way to map edit requests onto CORBA objects.
>  My current thinking is that we should register editors with the
>  CORBA Naming Service; the editors would be registered according to
>  their MIME type.
>
>  E.g., a request to edit `text/plain' would first look for the
>  binding `GnomeEditor'/`text'/`plain', then `GnomeEditor'/`text'/`*',
>  etc.
>
>  More thought is required here.  The basic problem is that you want
>  the name of the object to express all the constraints you care about
>  at edit time.  Is the MIME type enough?  Maybe some editors can't
>  handle (certain) URLs, and you want a way to express that.  Or maybe
>  MIME isn't expressive enough?
>
>Comments on this would be greatly appreciated.
>
>
>John> PS - Is the CORBA/component model stuff planned on being
>John> completely independent from the desktop manager aspect of GNOME?
>John> A component architecture would be very useful for somethings
>John> without having any gui associated at all.
>
>I'm not sure I really understand.
>
>Or, rather, I think we're getting mixed up by our terminology.  I tend
>to think of "component" as being a CORBA object that exports a bit of
>user interface -- for instance, a panel applet.
>
>Non-GUI objects are just objects.
>
>To answer your question, I guess some objects will have a UI and some
>won't.  It just depends.  But yes, the CORBA layer is independent of
>the GUI-ness.  For instance, the event manager won't have a user
>interface.
>
>Tom
>
>
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