🚀 go-pugleaf

InterViews version: 2.6

I am trying to implement a hierarchical iconic (= element) drawing
editor. In my project, a drawing starts with an atomic icon. There are
8 kinds of icons representing 8 kinds of processes, the atomic icon
being one of these 8 and the other 7 being non-atomic.

One can do the following operations to any icon:
  1. Coerce it to become a different type of icon. 
     (This has been implemented.)
  2. Decompose (or "Open") any non-atomic icon into the appropriate
     number of atomic icons (decompose a non-atomic icon into its
     "children"). A non-atomic icon has an attribute which determines
     the number of children (or atomic icons) it may be decomposed
     into.

Thus, all non-atomic icons have children which are atoms at the
beginning but the user may coerce any of these (atomic) children into
non-atomic icons. The user may also "close" any child item; this
replaces the child and all of its siblings by their (single) parent.

As an example, you may start with an atomic icon and change it into a
non-atomic icon with 3 children (step 1). Now, you "open" this icon and
you see 3 atomic icons(step #2). You pick one of these 3 and change it
to a non-atomic icon of your choice. Thus, you may go down to an
indefinite depth.

Any comments on what would be the best methodology for implementing
step #2 ? Comments welcome from InterViews/Unidraw experts.

Thanks,
Jimmy
Internet: jimmy@cs.UAlberta.CA                 USING VERSION 2.6
uucp:     jimmy@alberta.uucp
uunet:    ...!uunet!alberta!jimmy