Re: Unhiding edited areas

[Samuel Wales <samologist@gmail.com>]

Hi Martin,

On 2009-07-30, Martin Pohlack <mp26@os.inf.tu-dresden.de> wrote:
>> '(defadvice undo (after org-undo-reveal activate)
>>  "Make point and context visible after an undo command in Org-mode."
>>  (and (org-mode-p) (org-reveal)))
>> ;;(ad-unadvise 'undo)
>
> Awesome, this is exactly what I was looking for!

Maybe we can improve on it with one or more of these:

  1) Check visibility before revealing.
  2) Speed.
  3) (emacs) /Include visibility in the undo stack/ so that
     visibility while undoing is always what it was when you
     did the editing.
  4) (emacs) Implement undo-redo so that manually revealing
     does not break the chain as it does with undo.

> The current undo system is very powerful as it doesn't lose history
> (unless you hit a quota limit).  With undo-redo systems you usually can
> lose history if you edit things in an old state.  Suddenly redo is not
> available anymore.  You can only access the most recent branch in the
> history tree.

Yes, unless you implement a tree.  But even with that
limitation, I prefer undo-redo.

The cognitive burden is not the only limitation
of undo-the-undo.  With undo-the-undo, you cannot
realistically copy text from different places in the undo
history.

Try to go back 50 edits, copy, go back a few more edits
(you're in trouble already :)), copy, go forward 10, copy,
go forward 15, copy, go back 15 more, copy, go back 15 more,
copy.  With undo-redo, I think that it would be faster.

>   http://e-texteditor.com/blog/2006/making-undo-usable

Yes, I agree that there are some good ideas there.

-- 
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