[I am trawling through my old e-mail, sorry for the late reply]
Jeff Mincy <jeff(a)delphioutpost.com> writes:
So, I've been using hide-ifdef-mode for C/C++ code.
[various nice feature suggestions deleted]
How would I go about making this change?
The problem with our hide-ifdef-mode is that is that is uses
'selective-display' which is absolutely ancient. Nowadays you would
do this using extents that are 'invisible'.
That way you can easily make them mousable, and as a bonus you can
make isearch automatically open the hidden areas. See 'outline.el' in
FSF Emacs 20.4 or later for an example.