Re: include new package wconf.el in GNU ELPA

[Tassilo Horn <tsdh@gnu.org>]

Ingo Lohmar <i.lohmar@gmail.com> writes:

Hi Ingo,

> I have not thought about the point and window business yet, so there's
> no option.  Generally I am wary of dealing with window-config details
> (which I did in a much earlier version of the package), but this seems
> like a general and useful switch to have.. Maybe I will add that.  It
> would help me if you could add a github issue describing the option
> behavior, otherwise I'll try to keep a note myself.

I've thought about it, and I think such an option should be in emacs
itself so that you can have that behavior with winner, wconf, or
whatever else you use for window config business.

I had a look at the corresponding code in emacs, and actually the
restoration of point is not done in `set-window-configuration' but
instead it's done afterwards in `jump-to-register', in `winner-set', and
probably other places as well.

The best I could come up so far is this advice, which uses an ugly timer
to reclaim back the current points...

--8<---------------cut here---------------start------------->8---
(defun th/window-config-keep-points-and-selected-window (old config)
  (let ((bufpoints (mapcar
		    (lambda (buf)
		      (cons buf (with-selected-window (get-buffer-window buf)
				  (point))))
		    (cl-remove-if-not #'get-buffer-window
				      (buffer-list (selected-frame)))))
	(p (point)))
    (funcall old config)
    (when-let ((w (get-buffer-window)))
      (select-window w))
    ;; The setting of point is not performed by `set-window-configuration'
    ;; itself but by `jump-to-register' or the winner functions.
    (run-with-timer 0.139 nil
		    (lambda ()
		      (dolist (bp bufpoints)
			(let ((buf (car bp))
			      (p   (cdr bp)))
			  (when-let ((w (get-buffer-window buf)))
			    (with-selected-window
				(goto-char p)))))))))

(advice-add #'set-window-configuration :around
	    #'th/window-config-keep-points-and-selected-window)
--8<---------------cut here---------------end--------------->8---

Bye,
Tassilo