handle grapics with Document/View design

[jswensen]

I went back and re-read jwe's email (and responses) concerning a Document/View
design and realize that it is a much better solution.  I don't think the work I
have done so far has been in vain, though, since it got me more familiar with
octave internals, etc.

I want to shoot some ideas by everyone before I start work on this one, to see
if I understand your concept of a Doc/View design, as well as how those who are
really maintainers view integration with octave.

----------------------           -------------------------
|  handle graphics   |           |  handle graphics view |
|        DOC         |<--------->|        VIEW           |
|                    |           | (gtkmm in my case)    |
----------------------           -------------------------
          ^
          |                      ----------------
          |                      |              |
          |--------------------->|    Octave    |
                                 |              |
                                 ----------------

I spent a little time last night toying around with an XML schema and believe
that the DOC can be an XML file (with an associated schema).  Thus, the DOC
will *be* an XML file and the communication between the DOC and VIEW will be a
validatable subset of the whole document.  The interface between Octave and the
DOC will be the standard get, set, gcf, etc.

At some point (once the DOC portion is fairly well developed), I think it will
make sense to have Octave push the values of certain items (e.g. diary state
and filename, echo state, etc <mostly root handle properties>) into the
document when they are set in the Octave environment.

Does this seem reasonable to everyone?  Did anyone see this working differently?
 Does anyone have issues with using XML as the 'Document' format?

John

----------------------------------------------------------------