Re: Problem: Moving rows in a table changes vsum start and end

[Torsten Wagner <torsten.wagner@gmail.com>]

Hi Bastien,

ok,  I think it should be in org-table.el

and the function in question might be org-table-fix-formulas

I added

(defface org-table-formular-change-face
   '((t (:background "red")))
   "Used parts of tabe formulars which change by row and column moving
operations.")

to define a new face for changes in the formular.

Then I looked around how to do the face changing. By that I noticed,
org-mode uses its own set of functions (org-table-highlight-rectangle,
org-table-remove-rectangle-highlight).
Searching more around I figured out that emacs already comes with a
function for highlighting.

http://www.gnu.org/software/emacs/manual/html_node/emacs/Highlight-Interactively.html#Highlight-Interactively

Which makes me wonder why org-mode don't use that (maybe historical
reasons, the above function is not that old).
From this there are mainly two functions of interest

highlight-regexp
unhighlight-regexp (btw. a not very emacs conform naming)

they take a regular expression as input and optional the face to be set.
It works great in interactive mode.

So I was looking how to modify the function org-table-fix-formulas
using the above commands

I ended up with a very small change

(defun org-table-fix-formulas (key replace &optional limit delta remove)
  "Modify the equations after the table structure has been edited.
KEY is \"@\" or \"$\".  REPLACE is an alist of numbers to replace.
For all numbers larger than LIMIT, shift them by DELTA."
  (save-excursion
    (goto-char (org-table-end))
    (when (let ((case-fold-search t)) (looking-at "[ \t]*#\\+tblfm:"))
      (let ((re (concat key "\\([0-9]+\\)"))
	    (re2
	     (when remove
	       (if (or (equal key "$") (equal key "$LR"))
		   (format "\\(@[0-9]+\\)?%s%d=.*?\\(::\\|$\\)"
			   (regexp-quote key) remove)
		 (format "@%d\\$[0-9]+=.*?\\(::\\|$\\)" remove))))
	    s n a)
	(when remove
	  (while (re-search-forward re2 (point-at-eol) t)
	    (unless (save-match-data (org-in-regexp "remote([^)]+?)"))
	      (if (equal (char-before (match-beginning 0)) ?.)
		  (error "Change makes TBLFM term %s invalid.  Use undo to recover."
			 (match-string 0))
		(replace-match "")))))
	(while (re-search-forward re (point-at-eol) t)
	  (unless (save-match-data (org-in-regexp "remote([^)]+?)"))
	    (setq s (match-string 1) n (string-to-number s))
	    (cond
	     ((setq a (assoc s replace))
	      (replace-match (concat key (cdr a)) t t))
	     ((and limit (> n limit))
	      (replace-match (concat key (int-to-string (+ n delta)))
	      t t)))

;Added the single line below
	    (highlight-regexp re 'org-table-formular-change-face)
; really only the above line

	    ))))))


However, it  does not work.
Defining the face and using the above line works correct in the scratch buffer,
However, calling the function within org-mode (moving rows in a table)
I do not get an error message and do not get a highlight...
I made sure my modified version but no luck yet.

I greatly lack elisp knowledge, would be glad if you could give me
some advice why it doesn't work.

Furthermore, you might like to check about the highlight functions.
You might be able to simplify some of the org-table.el code by
relying on those functions instead of defining own functions. If we
get this started, I dream of
slightly different face different parts of org-tables:
* cells base on a formula and not been updated, despite changes were
made in the table,
* cells base on a formula but good overwritten by the user (this is
another dangerous situation I found myself in)
* highlight the formulas for the cell in which the pointer is located
(kind of reveres of the current fomular  editor highlighting)
* highlight changes after recalculation of an table

As for the last point. I also found the minor mode "highlight-changes-mode"
This is a great mode and calling it before starting to manipulate a
org-table, already ticks some of the above points. Please try if you
are not aware of it (create a table with some forms, call
highlight-changes-mode, do some operations on the table).

Greetings

Torsten





On 28 September 2012 22:53, Bastien <bzg@altern.org> wrote:
> Hi Torsten,
>
> Torsten Wagner <torsten.wagner@gmail.com> writes:
>
>> everytime you do this, I feel more embarrassed about my poor elisp knowledge. ;)
>> I might start very very simple and hope you are wiling enough to help
>> me to translate whatever mess I send you into some reasonable patch ;)
>
> Sure!  Actually I was not point at *you* in particular, "patch welcome"
> just means "if someone wants to put a stab, please feel free..."
>
> But thanks in advance if _you_ help with this!
>
> --
>  Bastien