On Wed, 15 Oct 2014 19:08:31 +0800
James Harkins <jamshark70@qq.com> wrote:

> org-after-todo-statistics-hook allows you to do something to a node after its statistics cookie got updated. Unfortunately, it does this only for TODO subheadings and it doesn't work with checkboxes.
> (snip)
> Actually... after a little more poking around, the problem seems to be that org-update-checkbox-count refers to no hooks whatsoever. Should it go toward the end, here? (Untested.)
> 
>       (mapc (lambda (cookie)
> 	      (let* ((beg (car cookie))
> 		     (end (nth 1 cookie))
> 		     (percentp (nth 2 cookie))
> 		     (checked (car (nth 3 cookie)))
> 		     (total (cdr (nth 3 cookie)))
> 		     (new (if percentp
> 			      (format "[%d%%]" (/ (* 100 checked)
> 						  (max 1 total)))
> 			    (format "[%d/%d]" checked total))))
> 		(goto-char beg)
> 		(insert new)
> 		(delete-region (point) (+ (point) (- end beg)))
> 		(run-hook-with-args 'org-after-todo-statistics-hook
> 				    checked (- total checked))
> 		(when org-auto-align-tags (org-fix-tags-on-the-fly))))
> 	    cookies-list))))

After dinner, I tested the change that I had speculated about, and... it works exactly correctly.

* TODO Test A [0/2]
** TODO Test B [0/2]
   - [ ] 1
   - [ ] 2
** TODO Test C

C-c C-c on "1" (with my hook function[1]):

* TODO Test A [0/2]
** INPROG Test B [1/2]
   - [X] 1
   - [ ] 2
** TODO Test C

C-c C-c on "2":

* INPROG Test A [1/2]
** DONE Test B [2/2]
   - [X] 1
   - [X] 2
** TODO Test C

So I'm submitting this as a TINYCHANGE patch. Do with it as you will, although I will keep using it locally until something better comes along.

hjh

[1]
(defun hjh-org-summary-todo (n-done n-not-done)
  "Switch entry to DONE when all subentries are done, to TODO otherwise."
  (let (org-log-done org-log-states)   ; turn off logging
    (org-todo
     (if (= n-not-done 0)
	 "DONE"
         (if (= n-done 0) "TODO" "INPROG")))))

(add-hook 'org-after-todo-statistics-hook 'hjh-org-summary-todo)