lisp/textmodes/text-mode.el

   1 ;;; text-mode.el --- text mode, and its idiosyncratic commands
   2
   3 ;; Copyright (C) 1985, 1992, 1994 Free Software Foundation, Inc.
   4
   5 ;; Maintainer: FSF
   6
   7 ;; This file is part of GNU Emacs.
   8
   9 ;; GNU Emacs is free software; you can redistribute it and/or modify
  10 ;; it under the terms of the GNU General Public License as published by
  11 ;; the Free Software Foundation; either version 2, or (at your option)
  12 ;; any later version.
  13
  14 ;; GNU Emacs is distributed in the hope that it will be useful,
  15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 ;; GNU General Public License for more details.
  18
  19 ;; You should have received a copy of the GNU General Public License
  20 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  21 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  22 ;; Boston, MA 02111-1307, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; This package provides the fundamental text mode documented in the
  27 ;; Emacs user's manual.
  28
  29 ;;; Code:
  30
  31 (defcustom text-mode-hook nil
  32   "Normal hook run when entering Text mode and many related modes."
  33   :type 'hook
  34   :options '(turn-on-auto-fill flyspell-mode)
  35   :group 'data)
  36
  37 (defvar text-mode-variant nil
  38   "Non-nil if this buffer's major mode is a variant of Text mode.")
  39
  40 (defvar text-mode-syntax-table nil
  41   "Syntax table used while in text mode.")
  42
  43 (defvar text-mode-abbrev-table nil
  44   "Abbrev table used while in text mode.")
  45 (define-abbrev-table 'text-mode-abbrev-table ())
  46
  47 (if text-mode-syntax-table
  48     ()
  49   (setq text-mode-syntax-table (make-syntax-table))
  50   (modify-syntax-entry ?\" ".   " text-mode-syntax-table)
  51   (modify-syntax-entry ?\\ ".   " text-mode-syntax-table)
  52   (modify-syntax-entry ?' "w   " text-mode-syntax-table))
  53
  54 (defvar text-mode-map nil
  55   "Keymap for Text mode.
  56 Many other modes, such as Mail mode, Outline mode and Indented Text mode,
  57 inherit all the commands defined in this map.")
  58
  59 (if text-mode-map
  60     ()
  61   (setq text-mode-map (make-sparse-keymap))
  62   (define-key text-mode-map "\e\t" 'ispell-complete-word)
  63   (define-key text-mode-map "\t" 'indent-relative)
  64   (define-key text-mode-map "\es" 'center-line)
  65   (define-key text-mode-map "\eS" 'center-paragraph))
  66
  67 \f
  68 (defun text-mode ()
  69   "Major mode for editing text written for humans to read.
  70 In this mode, paragraphs are delimited only by blank or white lines.
  71 You can thus get the full benefit of adaptive filling
  72  (see the variable `adaptive-fill-mode').
  73 \\{text-mode-map}
  74 Turning on Text mode runs the normal hook `text-mode-hook'."
  75   (interactive)
  76   (kill-all-local-variables)
  77   (use-local-map text-mode-map)
  78   (setq local-abbrev-table text-mode-abbrev-table)
  79   (set-syntax-table text-mode-syntax-table)
  80   (make-local-variable 'paragraph-start)
  81   (setq paragraph-start (concat page-delimiter "\\|[ \t]*$"))
  82   (if (eq ?^ (aref paragraph-start 0))
  83       (setq paragraph-start (substring paragraph-start 1)))
  84   (make-local-variable 'paragraph-separate)
  85   (setq paragraph-separate paragraph-start)
  86   (make-local-variable 'indent-line-function)
  87   (setq indent-line-function 'indent-relative-maybe)
  88   (setq mode-name "Text")
  89   (setq major-mode 'text-mode)
  90   (run-hooks 'text-mode-hook))
  91
  92 (defun paragraph-indent-text-mode ()
  93   "Major mode for editing text, with leading spaces starting a paragraph.
  94 In this mode, you do not need blank lines between paragraphs
  95 when the first line of the following paragraph starts with whitespace.
  96 `paragraph-indent-minor-mode' provides a similar facility as a minor mode.
  97 Special commands:
  98 \\{text-mode-map}
  99 Turning on Paragraph-Indent Text mode runs the normal hooks
 100 `text-mode-hook' and `paragraph-indent-text-mode-hook'."
 101   (interactive)
 102   (kill-all-local-variables)
 103   (use-local-map text-mode-map)
 104   (setq mode-name "Parindent")
 105   (setq major-mode 'paragraph-indent-text-mode)
 106   (setq local-abbrev-table text-mode-abbrev-table)
 107   (set-syntax-table text-mode-syntax-table)
 108   (run-hooks 'text-mode-hook 'paragraph-indent-text-mode-hook))
 109
 110 (defun paragraph-indent-minor-mode ()
 111   "Minor mode for editing text, with leading spaces starting a paragraph.
 112 In this mode, you do not need blank lines between paragraphs when the
 113 first line of the following paragraph starts with whitespace, as with
 114 `paragraph-indent-mode'.
 115 Turning on Paragraph-Indent minor mode runs the normal hook
 116 `paragraph-indent-text-mode-hook'."
 117   (interactive)
 118   (set (make-local-variable 'paragraph-start)
 119        (default-value 'paragraph-start))
 120   (set (make-local-variable 'paragraph-separate) paragraph-start)
 121   (run-hooks 'paragraph-indent-text-mode-hook))
 122
 123 (defalias 'indented-text-mode 'text-mode)
 124
 125 (defun text-mode-hook-identify ()
 126   "Mark that this mode has run `text-mode-hook'.
 127 This is how `toggle-text-mode-auto-fill' knows which buffers to operate on."
 128   (make-local-variable 'text-mode-variant)
 129   (setq text-mode-variant t))
 130
 131 (add-hook 'text-mode-hook 'text-mode-hook-identify)
 132
 133 (defun toggle-text-mode-auto-fill ()
 134   "Toggle whether to use Auto Fill in Text mode and related modes.
 135 This command affects all buffers that use modes related to Text mode,
 136 both existing buffers and buffers that you subsequently create."
 137   (interactive)
 138   (let ((enable-mode (not (memq 'turn-on-auto-fill text-mode-hook)))
 139         (buffers (buffer-list)))
 140     (if enable-mode
 141         (add-hook 'text-mode-hook 'turn-on-auto-fill)
 142       (remove-hook 'text-mode-hook 'turn-on-auto-fill))
 143     (while buffers
 144       (with-current-buffer (car buffers)
 145         (if text-mode-variant
 146             (auto-fill-mode (if enable-mode 1 0))))
 147       (setq buffers (cdr buffers)))
 148     (message "Auto Fill %s in Text modes"
 149              (if enable-mode "enabled" "disabled"))))
 150 \f
 151 (defun center-paragraph ()
 152   "Center each nonblank line in the paragraph at or after point.
 153 See `center-line' for more info."
 154   (interactive)
 155   (save-excursion
 156     (forward-paragraph)
 157     (or (bolp) (newline 1))
 158     (let ((end (point)))
 159       (backward-paragraph)
 160       (center-region (point) end))))
 161
 162 (defun center-region (from to)
 163   "Center each nonblank line starting in the region.
 164 See `center-line' for more info."
 165   (interactive "r")
 166   (if (> from to)
 167       (let ((tem to))
 168         (setq to from from tem)))
 169   (save-excursion
 170     (save-restriction
 171       (narrow-to-region from to)
 172       (goto-char from)
 173       (while (not (eobp))
 174         (or (save-excursion (skip-chars-forward " \t") (eolp))
 175             (center-line))
 176         (forward-line 1)))))
 177
 178 (defun center-line (&optional nlines)
 179   "Center the line point is on, within the width specified by `fill-column'.
 180 This means adjusting the indentation so that it equals
 181 the distance between the end of the text and `fill-column'.
 182 The argument NLINES says how many lines to center."
 183   (interactive "P")
 184   (if nlines (setq nlines (prefix-numeric-value nlines)))
 185   (while (not (eq nlines 0))
 186     (save-excursion
 187       (let ((lm (current-left-margin))
 188             line-length)
 189         (beginning-of-line)
 190         (delete-horizontal-space)
 191         (end-of-line)
 192         (delete-horizontal-space)
 193         (setq line-length (current-column))
 194         (if (> (- fill-column lm line-length) 0)
 195             (indent-line-to
 196              (+ lm (/ (- fill-column lm line-length) 2))))))
 197     (cond ((null nlines)
 198            (setq nlines 0))
 199           ((> nlines 0)
 200            (setq nlines (1- nlines))
 201            (forward-line 1))
 202           ((< nlines 0)
 203            (setq nlines (1+ nlines))
 204            (forward-line -1)))))
 205
 206 ;;; text-mode.el ends here