persistent-outline/persistent-outline.el

157 lines
5.1 KiB
EmacsLisp

;;; persistent-outline.el --- Save outline visibility
;; Copyright (C) 2013 Tom Willemse
;; Author: Tom Willemse <tom@ryuslash.org>
;; Keywords: convenience, outlines
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation, either version 3 of the License, or
;; (at your option) any later version.
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;; You should have received a copy of the GNU General Public License
;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;;; Commentary:
;; Save outline visibility between sessions.
;;; Code:
(require 'eieio)
(defgroup persistent-outline nil
"Customization settings for persistent-outline."
:group 'outlines)
(defcustom persistent-outline-storage 'perso-filesystem-storage
"How to store outlines."
:group 'persistent-outline
:type '(radio
(const :tag "In separate file" perso-filesystem-storage)
(const :tag "In a file-local variable" perso-file-local-storage)))
(defcustom persistent-outline-storage-directory
(concat user-emacs-directory "perso/")
"Directory where `perso-filesystem-storage' will save its files."
:group 'persistent-outline
:type 'directory)
(defclass perso-file-local-storage () ())
(defclass perso-filesystem-storage () ())
(defvar perso-outline)
(defun perso-outline-state ()
""
(when (outline-on-heading-p)
(let* ((current-level (outline-level))
(current-invisible (outline-invisible-p (line-end-position)))
(next-heading (save-excursion (outline-next-heading)))
(next-level (outline-level))
(next-invisible (outline-invisible-p next-heading)))
(cond
((and current-invisible next-invisible) 'subtree-hidden)
((and current-invisible (not next-invisible)
(> next-level current-level)) 'entry-hidden)
((and current-invisible (not next-invisible)
(<= next-level current-level)) 'subtree-hidden)
(t 'entry-visible)))))
(defun perso-record-outline ()
""
(save-excursion
(goto-char (point-min))
(let ((states (when (outline-on-heading-p)
(list (list (point) (perso-outline-state))))))
(while (> (point-max) (point))
(outline-next-visible-heading 1)
(when (outline-on-heading-p)
(setq states
(cons (list (point) (perso-outline-state)) states))))
(reverse states))))
(defun perso-apply-outline (outlines)
(mapc (lambda (outline)
(case (cadr outline)
(entry-visible nil)
(entry-hidden
(goto-char (car outline))
(hide-entry))
(subtree-hidden
(goto-char (car outline))
(hide-subtree))))
outlines))
(defun perso--get-filename (file)
(concat persistent-outline-storage-directory
(subst-char-in-string
?/ ?! (replace-regexp-in-string "!" "!!" buffer-file-name))))
(defun perso--ensure-directory (file)
(let ((directory (file-name-directory file)))
(unless (file-exists-p directory)
(make-directory directory :parents))))
(defmethod perso-save-to-storage ((storage perso-file-local-storage)
outline)
(let ((modifiedp (buffer-modified-p)))
(add-file-local-variable 'perso-outline outline)
(set (make-local-variable 'perso-outline) outline)))
(defmethod perso-save-to-storage ((storage perso-filesystem-storage)
outline)
(let ((filename (perso--get-filename buffer-file-name)))
(perso--ensure-directory filename)
(with-temp-buffer
(print outline (current-buffer))
(write-file filename))))
(defmethod perso-load-from-storage ((storage perso-file-local-storage))
(when (boundp (make-local-variable 'perso-outline))
(symbol-value 'perso-outline)))
(defmethod perso-load-from-storage ((storage perso-filesystem-storage))
(let ((filename (perso--get-filename buffer-file-name)))
(when (file-exists-p filename)
(with-temp-buffer
(insert-file-contents filename)
(read (current-buffer))))))
;;;###autoload
(put 'perso-outline 'safe-local-variable 'listp)
(defun persistent-outline-save ()
(interactive)
(save-excursion
(perso-save-to-storage (make-instance persistent-outline-storage)
(perso-record-outline))))
(defun persistent-outline-load ()
(interactive)
(save-excursion
(perso-apply-outline
(perso-load-from-storage
(make-instance persistent-outline-storage)))))
;;;###autoload
(define-minor-mode persistent-outline-mode
""
nil "P" nil
:group 'outlines
(if persistent-outline-mode
(progn
(persistent-outline-load)
(add-hook 'before-save-hook #'persistent-outline-save
nil :local))
(remove-hook 'before-save-hook #'persistent-outline-save :local)))
(provide 'persistent-outline)
;;; persistent-outline.el ends here