Add more options for startup folding levels

[gusbrs]

This is a feature request. Org itself has more options as to the initial folded state of a buffer, namely the option org-startup-folded can receive values overview, showall or content. Outshine only offers outshine-startup-folded-p (and, implicitly, to start in a showall state). It would be nice if the equivalent of content could be also made available in Outshine.

Outshine uses outshine-startup-folded-p in the following passage of outshine--minor-mode-activate:

(when outshine-startup-folded-p
  (condition-case error-data
      (outline-hide-sublevels 1)
    ('error (message "No outline structure detected"))))

Thus the initial folding is being dealt with with an outline-mode function. But outline-mode already offers, besides outline-hide-sublevels, outline-hide-body and, if needed, outline-show-all. Which means the necessary functions are readily available.

I know the recent refactoring is drawing most of the attention as of late, but if some time could eventually be devoted to this minor improvement, it would be appreciated. By the way, thank you for the nice work being done here.

[alphapapa]

Thanks.

[yuhan0]

Just as a heads up, I have this implemented on my local branch, but among other things it's waiting for #38 to be merged. The options are copied from the Org mode ones:

'(choice
  (const :tag "No folding" nil)
  (const :tag "No folding" 'nofold)
  (const :tag "Overview: show top level headlines" t)
  (const :tag "Content: show all headlines" 'content))

I don't think "content" is a particularly good word to describe showing all headlines but hiding body text, but it's probably better to follow Org conventions

[alphapapa]

@yuhan0 Great!

I don't think "content" is a particularly good word to describe showing all headlines but hiding body text, but it's probably better to follow Org conventions

I think we can both "lead the way" to better descriptions and follow convention at the same time. How about:

All headlines (aka "Content" in Org)

[yuhan0]

Thanks for merging! I wasn't referring to the description but the symbol 'content, which is the keyword used in the Org variable org-startup-folded and #+STARTUP tags.

[gusbrs]

@yuhan0 Sorry, I'm probably missing something here. But I can't seem to find this particular defcustom either in the pull request or in the new master branch. Could you please point me in the right direction?

[alphapapa]

Thanks for merging! I wasn't referring to the description but the symbol 'content, which is the keyword used in the Org variable org-startup-folded and #+STARTUP tags.

Sure, but I was referring to the description. :)

[yuhan0]

@gusburs it wasn't in that PR or on any branch on Github now, I was just referencing a change I made on my own local copy - sorry for any confusion.
I should be publishing it soon, still figuring out the best way of dealing with dealing with the point being within a folded headline (may be okay for Org buffers, but very annoying for code where you lose the point's position)

[gusbrs]

@yuhan0 Oh, I see. I'll be looking forward to see it published then, when it is possible. Thank you very much.

Indeed, the question of the point within a folded line deserves care. I've been playing with this (for the time being I simply added :hook ((outshine-mode . outline-hide-body) (emacs-lisp-mode . outshine-mode))). And using xref-find-definitions (M-.) to an elisp buffer (given I enabled outshine for them), or clicking on a reference in an rgrep buffer to an elisp buffer, leaves one in an unfavourable position.

[yuhan0]

Yeah, that turns out to be a problem for plenty of commands which jump around the buffer at arbitrary positions like imenu, magit-diff-visit-file, flycheck-jump-to-error, etc.

If you're interested to try it out in the meantime, here's the helper function -

;;;###autoload
(defun outshine-reveal-context (&optional arg)
  "Expands the folded headline around the current point, (similar to what happens
  during isearch.) Use this to advise functions which may jump to the interior of a
folded section."
  (interactive)
  (when (and outshine-mode
             (invisible-p (point)) ;; faster than checking for heading
             (not (outline-on-heading-p nil)))
    (dolist (ov (overlays-at (point)))
      (when (memq 'outline (overlay-properties ov))
        (delete-overlay ov)))
    ;; (ignore-errors (save-excursion
    ;;                  (outline-back-to-heading t)
    ;;                  (outline-show-entry)
    ;;                  (outline-show-children)))
    ))

I started by using it to advise a list of functions which behave in that manner, but after a while found it easier to simply add it to the post-command-hook.

(add-hook 'post-command-hook 'outshine-reveal-context)

[alphapapa]

@yuhan0 FYI that function doesn't need to be autoloaded, as it won't be called (or certainly shouldn't be) until after Outshine is already loaded.