Re: [gnu.emacs.help] display margins

[Dave Love]

>>>>> Oliver Scholz writes:

 > Gerd Möllmann suggested in off-list mail to me that the "natural"
 > way to put text on the margin would be to use an overlay with a
 > before-string that has the according 'display property, analogous
 > to what is done for images with put-image.

Strange he didn't say so before...  This is an old issue and I know he
wrote code for XEmacs to which the Emacs approach was some reaction.
I didn't think that sort of thing was even supposed to work, but I'm
happy it does.  Thanks.  It isn't natural to me as an early user of
the new redisplay, and certainly needs documenting if that's the right
technique.

 > Anyway: this is the code I tried, that did not work but that
 > *should* work IMHO.

Yes, if that's how marginal hacks are supposed to be done.  (I think
Gerd's XEmacs-specific noweb mode used mouse-sensitive marginal
annotations, or whatever XEmacs calls them.)

As far as I remember, there is or was a similar problem with the
properties you might put on overlays to allow users to un-elide
regions with the mouse in outline-mode, for instance.  (Essentially
just activating the ellipsis, with help-echo, of course.)