I guess soon we will have other requirements such as adding inner shapes
dynamically.
We already do this. :) (and of course it is draggable and resizable, both
the outer and inner elements :))
But since we have an extra layer on top of Roassal we can somewhat offset
this problem — each shape has a controller, where we define the necessary
behavior; however this is really an abuse of the controller as it has
different responsibilities. And if there is no best way or systematic
structure than it is always reimplemented manually (of course everywhere
differently), so it is a constantly increasing mess... but this will
definitely require more thinking and designing to get this whole problem
right.
Peter