summaryrefslogtreecommitdiff
path: root/lisp/textmodes/text-mode.el
blob: 731c2d2d85d173758781b0e2c3f040205e7dc32c (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
;;; text-mode.el --- text mode, and its idiosyncratic commands

;; Copyright (C) 1985, 1992, 1994, 2001-2016 Free Software Foundation,
;; Inc.

;; Maintainer: emacs-devel@gnu.org
;; Keywords: wp
;; Package: emacs

;; 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 <http://www.gnu.org/licenses/>.

;;; Commentary:

;; This package provides the fundamental text mode documented in the
;; Emacs user's manual.

;;; Code:

;; Normally non-nil defaults for hooks are bad, but since this file is
;; preloaded it's ok/better, and avoids this showing up in customize-rogue.
(defcustom text-mode-hook '(text-mode-hook-identify)
  "Normal hook run when entering Text mode and many related modes."
  :type 'hook
  :options '(turn-on-auto-fill turn-on-flyspell)
  :group 'wp)

(defvar text-mode-variant nil
  "Non-nil if this buffer's major mode is a variant of Text mode.
Use (derived-mode-p \\='text-mode) instead.")

(defvar text-mode-syntax-table
  (let ((st (make-syntax-table)))
    (modify-syntax-entry ?\" ".   " st)
    (modify-syntax-entry ?\\ ".   " st)
    ;; We add `p' so that M-c on 'hello' leads to 'Hello' rather than 'hello'.
    (modify-syntax-entry ?' "w p" st)
    ;; UAX #29 says HEBREW PUNCTUATION GERESH behaves like a letter
    ;; for the purposes of finding word boundaries.
    (modify-syntax-entry #x5f3 "w   ") ; GERESH
    ;; UAX #29 says HEBREW PUNCTUATION GERSHAYIM should not be a word
    ;; boundary when surrounded by letters.  Our infrastructure for
    ;; finding a word boundary doesn't support 3-character
    ;; definitions, so for now simply make this a word-constituent
    ;; character.  This leaves a problem of having GERSHAYIM at the
    ;; beginning or end of a word, where it should be a boundary;
    ;; FIXME.
    (modify-syntax-entry #x5f4 "w   ") ; GERSHAYIM
    ;; These all should not be a word boundary when between letters,
    ;; according to UAX #29, so they again are prone to the same
    ;; problem as GERSHAYIM; FIXME.
    (modify-syntax-entry #xb7 "w   ")	; MIDDLE DOT
    (modify-syntax-entry #x2027 "w   ")	; HYPHENATION POINT
    (modify-syntax-entry #xff1a "w   ")	; FULLWIDTH COLON
    st)
  "Syntax table used while in `text-mode'.")

(defvar text-mode-map
  (let ((map (make-sparse-keymap)))
    (define-key map "\e\t" 'ispell-complete-word)
    (define-key map [menu-bar text]
      (cons "Text" (make-sparse-keymap "Text")))
    (bindings--define-key map [menu-bar text toggle-text-mode-auto-fill]
      '(menu-item "Auto Fill" toggle-text-mode-auto-fill
                  :button (:toggle . (memq 'turn-on-auto-fill text-mode-hook))
                  :help "Automatically fill text while typing in text modes (Auto Fill mode)"))
    (bindings--define-key map [menu-bar text paragraph-indent-minor-mode]
      '(menu-item "Paragraph Indent" paragraph-indent-minor-mode
                  :button (:toggle . (bound-and-true-p paragraph-indent-minor-mode))
                  :help "Toggle paragraph indent minor mode"))
    (bindings--define-key map [menu-bar text sep] menu-bar-separator)
    (bindings--define-key map [menu-bar text center-region]
      '(menu-item "Center Region" center-region
                  :help "Center the marked region"
                  :enable (region-active-p)))
    (bindings--define-key map [menu-bar text center-paragraph]
      '(menu-item "Center Paragraph" center-paragraph
                  :help "Center the current paragraph"))
    (bindings--define-key map [menu-bar text center-line]
      '(menu-item "Center Line" center-line
                  :help "Center the current line"))
    map)
  "Keymap for `text-mode'.
Many other modes, such as `mail-mode', `outline-mode' and `indented-text-mode',
inherit all the commands defined in this map.")


(define-derived-mode text-mode nil "Text"
  "Major mode for editing text written for humans to read.
In this mode, paragraphs are delimited only by blank or white lines.
You can thus get the full benefit of adaptive filling
 (see the variable `adaptive-fill-mode').
\\{text-mode-map}
Turning on Text mode runs the normal hook `text-mode-hook'."
  (set (make-local-variable 'text-mode-variant) t)
  (set (make-local-variable 'require-final-newline)
       mode-require-final-newline)
  (set (make-local-variable 'indent-line-function) 'indent-relative))

(define-derived-mode paragraph-indent-text-mode text-mode "Parindent"
  "Major mode for editing text, with leading spaces starting a paragraph.
In this mode, you do not need blank lines between paragraphs
when the first line of the following paragraph starts with whitespace.
`paragraph-indent-minor-mode' provides a similar facility as a minor mode.
Special commands:
\\{text-mode-map}
Turning on Paragraph-Indent Text mode runs the normal hooks
`text-mode-hook' and `paragraph-indent-text-mode-hook'."
  :abbrev-table nil :syntax-table nil
  (paragraph-indent-minor-mode))

(define-minor-mode paragraph-indent-minor-mode
  "Minor mode for editing text, with leading spaces starting a paragraph.
In this mode, you do not need blank lines between paragraphs when the
first line of the following paragraph starts with whitespace, as with
`paragraph-indent-text-mode'.
Turning on Paragraph-Indent minor mode runs the normal hook
`paragraph-indent-text-mode-hook'."
  :initial-value nil
  ;; Change the definition of a paragraph start.
  (let ((ps-re "[ \t\n\f]\\|"))
    (if (eq t (compare-strings ps-re nil nil
                               paragraph-start nil (length ps-re)))
        (if (not paragraph-indent-minor-mode)
            (set (make-local-variable 'paragraph-start)
                 (substring paragraph-start (length ps-re))))
      (if paragraph-indent-minor-mode
          (set (make-local-variable 'paragraph-start)
               (concat ps-re paragraph-start)))))
  ;; Change the indentation function.
  (if paragraph-indent-minor-mode
      (add-function :override (local 'indent-line-function)
                    #'indent-to-left-margin)
    (remove-function (local 'indent-line-function)
                     #'indent-to-left-margin)))

(defalias 'indented-text-mode 'text-mode)

;; This can be made a no-op once all modes that use text-mode-hook
;; are "derived" from text-mode.  (As of 2015/04, and probably well before,
;; the only one I can find that doesn't so derive is rmail-edit-mode.)
(defun text-mode-hook-identify ()
  "Mark that this mode has run `text-mode-hook'.
This is how `toggle-text-mode-auto-fill' knows which buffers to operate on."
  (set (make-local-variable 'text-mode-variant) t))

(defun toggle-text-mode-auto-fill ()
  "Toggle whether to use Auto Fill in Text mode and related modes.
This command affects all buffers that use modes related to Text mode,
both existing buffers and buffers that you subsequently create."
  (interactive)
  (let ((enable-mode (not (memq 'turn-on-auto-fill text-mode-hook))))
    (if enable-mode
	(add-hook 'text-mode-hook 'turn-on-auto-fill)
      (remove-hook 'text-mode-hook 'turn-on-auto-fill))
    (dolist (buffer (buffer-list))
      (with-current-buffer buffer
	(if (or (derived-mode-p 'text-mode) text-mode-variant)
	    (auto-fill-mode (if enable-mode 1 0)))))
    (message "Auto Fill %s in Text modes"
	     (if enable-mode "enabled" "disabled"))))


(define-key facemenu-keymap "\eS" 'center-paragraph)

(defun center-paragraph ()
  "Center each nonblank line in the paragraph at or after point.
See `center-line' for more info."
  (interactive)
  (save-excursion
    (forward-paragraph)
    (or (bolp) (newline 1))
    (let ((end (point)))
      (backward-paragraph)
      (center-region (point) end))))

(defun center-region (from to)
  "Center each nonblank line starting in the region.
See `center-line' for more info."
  (interactive "r")
  (if (> from to)
      (let ((tem to))
	(setq to from from tem)))
  (save-excursion
    (save-restriction
      (narrow-to-region from to)
      (goto-char from)
      (while (not (eobp))
	(or (save-excursion (skip-chars-forward " \t") (eolp))
	    (center-line))
	(forward-line 1)))))

(define-key facemenu-keymap "\es" 'center-line)

(defun center-line (&optional nlines)
  "Center the line point is on, within the width specified by `fill-column'.
This means adjusting the indentation so that it equals
the distance between the end of the text and `fill-column'.
The argument NLINES says how many lines to center."
  (interactive "P")
  (if nlines (setq nlines (prefix-numeric-value nlines)))
  (while (not (eq nlines 0))
    (save-excursion
      (let ((lm (current-left-margin))
	    line-length)
	(beginning-of-line)
	(delete-horizontal-space)
	(end-of-line)
	(delete-horizontal-space)
	(setq line-length (current-column))
	(if (> (- fill-column lm line-length) 0)
	    (indent-line-to
	     (+ lm (/ (- fill-column lm line-length) 2))))))
    (cond ((null nlines)
	   (setq nlines 0))
	  ((> nlines 0)
	   (setq nlines (1- nlines))
	   (forward-line 1))
	  ((< nlines 0)
	   (setq nlines (1+ nlines))
	   (forward-line -1)))))

;;; text-mode.el ends here