Porting from XEmacs to Emacs: event-glyph-extent

Porting from XEmacs to Emacs: event-glyph-extent

[Achim D. Brucker]

Hi,   
is there an howto about porting elisp-code from XEmacs to GNU Emacs?
      
At the moment I'm trying to port an (unmainted) XEmacs mode to GNU 
Emacs 21.3. With the help of lucid.el and looking into various (X)Emacs 
modes I got most of the stuff working, but now I'm getting stuck with the 
following routine:
       
(defun zeta-marker-activate (e)
  (interactive "e")
    (let ((m (event-glyph-extent e)) act)
        (if (and m (setq act (extent-property m 'zeta-marker-action)))
                (funcall act m)
         (mouse-set-point e))))
      
"event-glyph-extent" seems to be problematic, at least my attempts to
emulate this in GNU Emacs (with constructs like "overlays-at
(event-start e)")
failed. Is this non-trivial or do I just missing something obvious?
       
Achim  

Re: Porting from XEmacs to Emacs: event-glyph-extent

[Kai Grossjohann]

"Achim D. Brucker" <brucker@spamfence.net> writes:

> (defun zeta-marker-activate (e)
>   (interactive "e")
>     (let ((m (event-glyph-extent e)) act)
>         (if (and m (setq act (extent-property m 'zeta-marker-action)))
>                 (funcall act m)
>          (mouse-set-point e))))
>       
> "event-glyph-extent" seems to be problematic, at least my attempts to
> emulate this in GNU Emacs (with constructs like "overlays-at
> (event-start e)")
> failed. Is this non-trivial or do I just missing something obvious?

Perhaps it is better to use text properties?  Those will move with the
text.

The code snippet looks very interesting, btw.  What does the code do
that you are trying to port?

Kai

Re: Porting from XEmacs to Emacs: event-glyph-extent

[Stefan Monnier]

> > (defun zeta-marker-activate (e)
> >   (interactive "e")
> >   (let ((m (event-glyph-extent e)) act)
> >     (if (and m (setq act (extent-property m 'zeta-marker-action)))
> >         (funcall act m)
> >       (mouse-set-point e))))

> > "event-glyph-extent" seems to be problematic, at least my attempts to
> > emulate this in GNU Emacs (with constructs like "overlays-at
> > (event-start e)") failed.  Is this non-trivial or do I just missing
> > something obvious?

I think that using something like (overlays-at (posn-point (event-start e)))
should be workable.  It's probably easier to just put a `keymap'
property on the overlay, tho (same thing for XEmacs).


        Stefan