Re: Ctrl-x Ctrl-x (exchange-point-and-mark)

[Uday S Reddy <u.s.reddy@cs.bham.ac.uk>]

On 5/10/2010 8:42 PM, Harry Putnam wrote:
> I see there are no customizing option matching
> `exchange-point-and-mark' (Ctrl-x Ctrl-x)
>
> I wondered if I can do anyghing about the current behavior where when
> the exchange is made, the area in between is selected and highlighted.

If you put the following advice in your .emacs file, normal C-x C-x will have the effect of C-u C-x C-x and vice versa.

(defadvice exchange-point-and-mark (before toggled-mark activate)
   "Toggle activation of mark for exchange-point-and-mark."
   (interactive "P")
   (ad-set-arg 0 (null (ad-get-arg 0))))

This doesn't quite do what I would have liked myself.  Ideally, C-x C-x should keep the mark active if it is already active and refrain from activating it afresh.  This advice ends up deactivating the mark.  Can anybody beef up the advice more to get the better behavior?

Cheers,
Uday