= Graphical Model Editor for ProMoT with SVG storage =

Since 1998 ProMoT has a graphical editor made in [http://java.sun.com Java], since 2000 
we are using [http://gef.tigris.org Graph Editing Framework (GEF)].
The graphical attributes are stored directly as attributes of the mathematical model,
Symbols for modeling entities are stored as GIF-Images (Raster-Format).

There are several inconvenient effects of the current architecture:

 * It is difficult to extend the graphical attributes, because for every new thing a
   new storage syntax has to be invented in the MDL. MDL and Lisp have nothing to do with 
   Graphics and these attributes just clutter the source code.
 * All graphics must be tied to modeling elements. This means additional graphics as 
   explanation, legend or label are not allowed.
 * GIF-icons are a old-fashioned solution. They are not scalable, they are distributed
   as separate files, leading to problems when sending a model to Coworkers. The
   VisualNavigator can't use them in the zooming interface.

As a new proposal it would be good to use SVG as storage for the graphics and just
couple the graph-like model of the mathematical system (modules, terminals and links) to
graphical elements of the diagram.
All information about the layout and the graphical attributes are created and edited in
the Java-GUI and stored to an SVG-fragment. This fragment is stored in a separate section
of the source-code and referenced by the `define-module` and `define-terminal` commands.

Icons for module-instances in other  model-classes are also created as SVG which can be by default a scaled version of the original view, but can also be reduced with a
SVG-graphics editor.