Re: Org-mode 'organized' visibility

[Carsten Dominik <dominik@science.uva.nl>]

Hi Caspar,

On Aug 23, 2006, at 15:13, Casper Gripenberg wrote:

> Hi..is it possible to not make S-TAB collapse
> empty spaces between items. If I have a long
> list of items I like to organize them into
> groups..and then when I collapse the whole
> tree I'd like my groupings it to be visible like this:
>
> * Tasks...
>
> * Something important...
> * Something related to above...
>
> * Something else not related...
> * Again related...
> * Related...
>
> * Not related...
>
> Instead of the current way:
>
> * Tasks...
> * Something important...
> * Something related to above...
> * Something else not related...
> * Again related...
> * Related...
> * Not related...
>
> ..which doesn't allow me to see the groupings
> between the tasks I have. I just think grouping provides
> much quicker visual feedback of the tasks/headlines and
> their relations to each other.
>
> To implement the groupings you might have a rule that
> more than two empty lines between two headings will
> then activate 'grouping'.
>
> So if I have:
>
> * Important
>
>   Blah blah
>
> * Related
>
>   Blah blah
>
>
> * Not related
>
> This would collapse into:
>
> * Important...
> * Related...
>
> * Not related...
>
> Or something along those lines..is that possible to
> do somehow?
>
> Thanks..
>
> Regards,
>   Casper

This is something outside the direct control of Org-mode, it is 
entirely done by outline-mode.  Looking at outline.el, I see two 
possibilities to address this:

1.  For this first one, you need a current version of Emacs (must be 
CVS, Emacs 21 does not have this).  Outline has an undocumented feature 
which makes it possible to relate an empty line before a heading to the 
heading.  So when the heading is shown, the empty line is shows along 
with it.  Similarly, a subtree is then defined to be before that empty 
line.  As I said, this is an undocumented feature in so far as the 
corresponding variable is not customizable.  However, you can still set 
it in the old way using

     (setq outline-blank-line t)

If you do it in this way, there will be no difference between a single 
or a double empty line.  An empty line before a heading will create an 
empty line in the CONTENT and CHILDREN views of org-cycle.

2. If we insist on your convention on using two line to mark a 
separation (we should, because it is the better convention), you would 
have to redefine a function in outline.  This is not clean, but who 
gives a s*** :-)  And I like this convention better, because I very 
often want to have an empty line above a headline without it meaning a 
separation.

The function to modify is outline-show-heading, and it must be modified 
after outline.el has been loaded.  If you are only using outline in 
connection with Org-mode, here is a way to do this:

(add-hook 'org-load-hook
	  (lambda ()
	    (defun outline-show-heading ()
	      "Show the current heading and move to its end."
	      (outline-flag-region
	       (- (point)
		  (cond
		   ((bobp) 0)
		   ((equal (buffer-substring
			    (max (point-min) (- (point) 3))  (point))
			   "\n\n\n")
		    2)
		   (t 1)))
	       (progn (outline-end-of-heading) (point))
	       nil))))

If you want this for other uses of outline as well, you could use 
`eval-after-load' or defadvice to achieve this change.

There is a small possibility that doing either of these things might 
break something else in org-mode.  I don't think so, but maybe I am not 
overseeing it fully.  If you see something strange, let me know.

Hope this helps.

- Carsten