AndroMDA plugin help

hi,

I wanted to start coding a plugin for AndroMDA, I have been skimming
through the OpenAPI and the example plugins and I'm getting the feeling
that what I am trying to do is a little special:

I would like to support auto-completion for AndroMDA templates, these or
mainly Velocity templates, but never Java files.

The plugin should be aware of a few variables in the template, these
variables are instances of a specific andromda type, they often have a
lot of properties and it would be nice to be able to list them so that
the user would just have to select the one from the list.

I have no problem detecting the variables and their properties, my
problem is that I cannot find how to intercept the autocompletion (ie.
CTRL-SPACE) so that a popup can be shown.

Do I need to write the component for the popup myself ? I would like to
be able to reuse the existing one used in Java code.

How can I detect the auto-completion key-event in a non-java file ?

thanks in advance

-- Wouter