[Fluxus] Fluxus Editor

[Jeff Rose]

Some thoughts on moving to a more scheme based editor...

As someone mentioned earlier, PLT scheme comes with a fancy editor 
framework, which could save us lots of time in creating a more full 
featured editor inside Fluxus.  Using an editor-canvas% that displays a 
text% object we can pretty quickly get support for pluggable commands 
that work with keymaps and a host of additional editor like 
functionality for understanding s-exps, search and replace, etc.

In order to use anything in scheme/gui though, where this stuff resides, 
we have to run the whole app under mred, the GUI enabled runtime, rather 
than mzscheme.  DrScheme itself is a mred application though, and the 
existing drflux.ss is already moving in the right direction.  It takes 
the input events from MrEd and forwards them to Fluxus, but it just uses 
the DrScheme editor and doesn't involve the GLEditor or Repl that are 
implemented in C++.

So, what I propose is that Fluxus itself move to becoming a mred 
application, rather than a Glut based application.  The big question is 
whether we want to re-implement the GLEditor and Repl classes in scheme, 
or instead morph the C++ editor into being an editor-canvas and export 
its interface to scheme.

For starters I was thinking of creating a standalone mred app that has a 
fluxus scratchpad window and a scheme editor window.  Once that is 
connected up so we can code in the editor and watch in the window, then 
we can implement an editor-canvas that uses GL right in the scratchpad 
and just plug it into the existing application.

Thoughts?

-Jeff