;;; emacs-news-mode.el --- major mode to edit and view the NEWS file -*- lexical-binding: t; -*-
;; Copyright (C) 2022-2024 Free Software Foundation, Inc.
;; Keywords: tools
;; This file is part of GNU Emacs.
;; GNU Emacs 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.
;; GNU Emacs 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 GNU Emacs. If not, see <https://www.gnu.org/licenses/>.
;;; Commentary:
;;; Code:
(eval-when-compile (require 'cl-lib))
(require 'outline)
(require 'subr-x) ; `emacs-etc--hide-local-variables'
(defgroup emacs-news-mode nil
"Major mode for editing and viewing the Emacs NEWS file."
:group 'lisp)
(defface emacs-news-is-documented
'((t :inherit font-lock-type-face))
"Face used for displaying the \"is documented\" tag."
:version "29.1")
(defface emacs-news-does-not-need-documentation
'((t :inherit font-lock-preprocessor-face))
"Face used for displaying the \"does not need documentation\" tag."
:version "29.1")
(defvar-keymap emacs-news-common-map
;; Navigation like `org-mode'/`outline-minor-mode'.
"C-c C-f" #'outline-forward-same-level
"C-c C-b" #'outline-backward-same-level
"C-c C-n" #'outline-next-visible-heading
"C-c C-p" #'outline-previous-visible-heading
"C-c C-u" #'outline-up-heading)
(defvar-keymap emacs-news-mode-map
:parent emacs-news-common-map
"C-c C-s" #'emacs-news-next-untagged-entry
"C-c C-r" #'emacs-news-previous-untagged-entry
"C-c C-t" #'emacs-news-cycle-tag
"C-c C-d" #'emacs-news-delete-temporary-markers
"C-c C-g" #'emacs-news-goto-section
"C-c C-j" #'emacs-news-find-heading
"C-c C-e" #'emacs-news-count-untagged-entries
"C-x C-q" #'emacs-news-view-mode
"<remap> <open-line>" #'emacs-news-open-line)
(easy-menu-define emacs-news-mode-menu emacs-news-mode-map
"Menu for `emacs-news-mode'."
'("News"
["Next Untagged" emacs-news-next-untagged-entry :help "Go to next untagged entry"]
["Previous Untagged" emacs-news-previous-untagged-entry :help "Go to previous untagged entry"]
["Count Untagged" emacs-news-count-untagged-entries :help "Count the number of untagged entries"]
["Cycle Tag" emacs-news-cycle-tag :help "Cycle documentation tag of current entry"]
["Delete Tags" emacs-news-delete-temporary-markers :help "Delete all documentation tags in buffer"]
"--"
["Goto Section" emacs-news-goto-section :help "Prompt for section and go to it"]
["Goto Heading" emacs-news-find-heading :help "Prompt for heading and go to it"]
"--"
["Enter View Mode" emacs-news-view-mode :help "Enter view-only mode"]))
(defvar emacs-news-view-mode-map
;; This is defined this way instead of inheriting because we're
;; deriving the mode from `special-mode' and want the keys from there.
(let ((map (copy-keymap emacs-news-common-map)))
(keymap-set map "C-x C-q" #'emacs-news-mode)
map))
(defvar emacs-news-mode-font-lock-keywords
`(("^---$" 0 'emacs-news-does-not-need-documentation)
("^\\+\\+\\+$" 0 'emacs-news-is-documented)))
(defun emacs-news--mode-common ()
(setq-local font-lock-defaults '(emacs-news-mode-font-lock-keywords t))
(setq-local outline-minor-mode-cycle t
outline-minor-mode-highlight 'append
outline-minor-mode-use-buttons 'in-margins)
(outline-minor-mode)
(setq-local imenu-generic-expression outline-imenu-generic-expression)
(emacs-etc--hide-local-variables))
;;;###autoload
(define-derived-mode emacs-news-mode text-mode "NEWS"
"Major mode for editing the Emacs NEWS file."
;; Disable buttons.
(button-mode nil)
;; And make the buffer writable. This is used when toggling
;; emacs-news-mode.
(setq buffer-read-only nil)
(setq-local fill-paragraph-function #'emacs-news--fill-paragraph)
(emacs-news--mode-common))
;;;###autoload
(define-derived-mode emacs-news-view-mode special-mode "NEWS"
"Major mode for viewing the Emacs NEWS file."
(setq buffer-read-only t)
(emacs-news--buttonize)
(button-mode)
(emacs-news--mode-common))
(defun emacs-news--fill-paragraph (&optional justify)
(cond
;; We're in a heading -- do nothing.
((save-excursion
(beginning-of-line)
(looking-at "\\*+ "))
)
;; We're in a news item -- exclude the heading before filling.
((and (save-excursion
(re-search-backward (concat "^\\(?:" paragraph-start "\\|\\*+ \\)")
nil t))
(= (char-after (match-beginning 0)) ?*))
(save-restriction
(narrow-to-region (save-excursion
(goto-char (match-beginning 0))
(forward-line 1)
(point))
(point-max))
(fill-paragraph justify)))
;; Fill normally.
(t
(fill-paragraph justify))))
(defun emacs-news-next-untagged-entry (&optional reverse)
"Go to the next untagged NEWS entry.
If REVERSE (interactively, the prefix), go to the previous
untagged NEWS entry."
(interactive "P" emacs-news-mode)
(let ((start (point))
(found nil))
;; Don't consider the current line, because that would stop
;; progress if calling this command repeatedly.
(unless reverse
(forward-line 1))
(while (and (not found)
(funcall (if reverse #'re-search-backward
#'re-search-forward)
"^\\(\\*+\\) " nil t))
(when (and (not (save-excursion
(forward-line -1)
(looking-at "---$\\|\\+\\+\\+$")))
;; We have an entry without a tag before it, but
;; check whether it's a heading (which we can
;; determine if the next entry has more asterisks).
(not (emacs-news--heading-p)))
;; It wasn't a sub-heading, so we've found one.
(setq found t)))
(if found
(progn
(push-mark start)
(message "Untagged entry")
(beginning-of-line)
t)
(message "No further untagged entries")
(goto-char start)
nil)))
(defun emacs-news--heading-p ()
(save-excursion
(beginning-of-line)
;; A heading starts with * characters, and then a blank line, and
;; then paragraphs with more * characters than in the heading.
(and (looking-at "\\(\\*+\\) ")
(let ((level (length (match-string 1))))
(forward-line 1)
(and (looking-at "$")
(re-search-forward "^\\(\\*+\\) " nil t)
(> (length (match-string 1)) level))))))
(defun emacs-news-previous-untagged-entry ()
"Go to the previous untagged NEWS entry."
(interactive nil emacs-news-mode)
(emacs-news-next-untagged-entry t))
(defun emacs-news-cycle-tag ()
"Cycle documentation tag of current headline in the Emacs NEWS file."
(interactive nil emacs-news-mode)
(save-excursion
(goto-char (line-beginning-position))
(cond ((or (looking-at (rx bol (or "---" "+++") eol)))
(forward-line 2))
((or (looking-at (rx bol "**"
(zero-or-more "*")
" ")))
(forward-line 1)))
(outline-previous-visible-heading 1)
(forward-line -1)
(cond ((not (looking-at (rx bol (or "---" "+++") eol)))
(insert "\n---"))
((looking-at (rx bol "---" eol))
(delete-char 3)
(insert "+++"))
((looking-at (rx bol "+++" eol))
(delete-char 4))
(t (user-error "Invalid headline tag; can't cycle")))))
(defun emacs-news-count-untagged-entries ()
"Say how many untagged entries there are in the current NEWS buffer."
(interactive nil emacs-news-mode)
(save-excursion
(goto-char (point-min))
(let ((i 0))
(while (emacs-news-next-untagged-entry)
(setq i (1+ i)))
(message (if (= i 1)
"There's 1 untagged entry"
(format "There are %s untagged entries" i))))))
(defun emacs-news--buttonize ()
"Make manual and symbol references into buttons."
(save-excursion
(with-silent-modifications
(let ((inhibit-read-only t))
;; Do functions and variables.
(goto-char (point-min))
(search-forward "\f" nil t)
(while (re-search-forward "'\\([^-][^ \t\n]+\\)'" nil t)
;; Filter out references to key sequences.
(let ((string (match-string 1)))
(when-let ((symbol (intern-soft string)))
(when (or (boundp symbol)
(fboundp symbol))
(buttonize-region (match-beginning 1) (match-end 1)
(lambda (symbol)
(describe-symbol symbol))
symbol)))))
;; Do manual references.
(goto-char (point-min))
(search-forward "\f" nil t)
(while (re-search-forward "\"\\(([a-z0-9-]+)[ \n][^\"]\\{1,80\\}\\)\""
nil t)
(buttonize-region (match-beginning 1) (match-end 1)
(lambda (node) (info node))
(match-string 1)))))))
(defun emacs-news--sections (regexp)
(let ((sections nil))
(save-excursion
(goto-char (point-min))
(while (re-search-forward (concat "^" regexp "\\(.*\\)") nil t)
(when (save-match-data (emacs-news--heading-p))
(push (buffer-substring-no-properties
(match-beginning 1) (match-end 1))
sections))))
(nreverse sections)))
(defun emacs-news-goto-section (section)
"Go to SECTION in the Emacs NEWS file."
(interactive (list
(completing-read "Goto section: " (emacs-news--sections "\\* ")
nil t))
emacs-news-mode)
(goto-char (point-min))
(when (search-forward (concat "\n* " section) nil t)
(beginning-of-line)))
(defun emacs-news-find-heading (heading)
"Go to HEADING in the Emacs NEWS file."
(interactive (list
(completing-read "Goto heading: "
(emacs-news--sections "\\*\\*\\*? ")
nil t))
emacs-news-mode)
(goto-char (point-min))
(when (re-search-forward (concat "^*+ " (regexp-quote heading)) nil t)
(beginning-of-line)))
(defun emacs-news-open-line (n)
"Open a new line in a NEWS file.
This is like `open-line', but skips any temporary NEWS-style
documentation marks on the previous line."
(interactive "*p" emacs-news-mode)
(when (save-excursion (forward-line -1)
(looking-at (rx bol (or "---" "+++") eol)))
(forward-line -1))
(open-line n))
(defun emacs-news-delete-temporary-markers ()
"Delete any temporary markers.
This is used when preparing a new release of Emacs."
(interactive nil emacs-news-mode)
(goto-char (point-min))
(re-search-forward "^Temporary note:$")
(forward-line -1)
(delete-region (point) (save-excursion (forward-paragraph) (point)))
(while (re-search-forward (rx bol (or "+++" "---") eol) nil t)
(delete-line)))
(provide 'emacs-news-mode)
;;; emacs-news-mode.el ends here