Re: Narrow/widen in folding.el

[Leo Alekseyev <dnquark@gmail.com>]

On Tue, Dec 21, 2010 at 10:42 AM, Tassilo Horn <tassilo@member.fsf.org> wrote:
> --8<---------------cut here---------------start------------->8---
> (require 'outline)
>
> (defvar th-outline-minor-mode-font-lock-keywords
>  '((eval . (list (concat "^\\(?:" outline-regexp "\\).*")
>                  0 '(outline-font-lock-face) t t)))
>  "Additional expressions to highlight in Orgstruct Mode and Outline minor mode.
> The difference to `outline-font-lock-keywords' is that this will
> overwrite other highlighting.")
>
> (defun th-outline-regexp ()
>  "Calculate the outline regexp for the current mode."
>  (let ((comment-starter (replace-regexp-in-string
>                          "[[:space:]]+" "" comment-start)))
>    (when (string= comment-starter ";")
>      (setq comment-starter ";;"))
>    (concat comment-starter "[*]+ ")))
>
> (defun th-outline-minor-mode-init ()
>  (interactive)
>  (unless (eq major-mode 'latex-mode)
>    (setq outline-regexp (th-outline-regexp))
>    (font-lock-add-keywords
>     nil
>     th-outline-minor-mode-font-lock-keywords)))
>
> (add-hook 'outline-minor-mode-hook
>          'th-outline-minor-mode-init)
> --8<---------------cut here---------------end--------------->8---

Sincerest apologies for the spam, and please disregard the previous
two messages.  The problem with the above snippet still exists for me,
but only for certain modes.  In particular, for sql-mode, when
th-outline-minor-mode-init is invoked via a hook when loading a file,
as in Tassilo's code above, the font-lock-keywords variable does not
appear to be set correctly.  However, when th-outline-minor-mode-init
is called interactively (either via M-x th-outline-minor-mode-init, or
evaluating (outline-minor-mode t)), everything starts working.  In
other modes (e.g. shell and R), font-lock-keywords are set correctly,
it seems, but the font-lock for first level heading doesn't seem to
work.  In elisp mode, everything works :)

It's pretty hard to nail down the problem exactly, since it tends to
be (a) mode-specific and (b) depends on whether the code is being
called via a hook or interactively.  Still, if there's a quick obvious
fix, I'd like to know :)