1;;; longlines.el --- automatically wrap long lines 2 3;; Copyright (C) 2000, 2001, 2004, 2005, 2006, 2007 Free Software Foundation, Inc. 4 5;; Authors: Kai Grossjohann <Kai.Grossjohann@CS.Uni-Dortmund.DE> 6;; Alex Schroeder <alex@gnu.org> 7;; Chong Yidong <cyd@stupidchicken.com> 8;; Maintainer: Chong Yidong <cyd@stupidchicken.com> 9;; Keywords: convenience, wp 10 11;; This file is part of GNU Emacs. 12 13;; GNU Emacs is free software; you can redistribute it and/or modify 14;; it under the terms of the GNU General Public License as published by 15;; the Free Software Foundation; either version 2, or (at your option) 16;; any later version. 17 18;; GNU Emacs is distributed in the hope that it will be useful, 19;; but WITHOUT ANY WARRANTY; without even the implied warranty of 20;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 21;; GNU General Public License for more details. 22 23;; You should have received a copy of the GNU General Public License 24;; along with GNU Emacs; see the file COPYING. If not, write to the 25;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 26;; Boston, MA 02110-1301, USA. 27 28;;; Commentary: 29 30;; Some text editors save text files with long lines, and they 31;; automatically break these lines at whitespace, without actually 32;; inserting any newline characters. When doing `M-q' in Emacs, you 33;; are inserting newline characters. Longlines mode provides a file 34;; format which wraps the long lines when reading a file and unwraps 35;; the lines when saving the file. It can also wrap and unwrap 36;; automatically as editing takes place. 37 38;; Special thanks to Rod Smith for many useful bug reports. 39 40;;; Code: 41 42(defgroup longlines nil 43 "Automatic wrapping of long lines when loading files." 44 :group 'fill) 45 46(defcustom longlines-auto-wrap t 47 "Non-nil means long lines are automatically wrapped after each command. 48Otherwise, you can perform filling using `fill-paragraph' or 49`auto-fill-mode'. In any case, the soft newlines will be removed 50when the file is saved to disk." 51 :group 'longlines 52 :type 'boolean) 53 54(defcustom longlines-wrap-follows-window-size nil 55 "Non-nil means wrapping and filling happen at the edge of the window. 56Otherwise, `fill-column' is used, regardless of the window size. This 57does not work well when the buffer is displayed in multiple windows 58with differing widths." 59 :group 'longlines 60 :type 'boolean) 61 62(defcustom longlines-show-hard-newlines nil 63 "Non-nil means each hard newline is marked on the screen. 64\(The variable `longlines-show-effect' controls what they look like.) 65You can also enable the display temporarily, using the command 66`longlines-show-hard-newlines'." 67 :group 'longlines 68 :type 'boolean) 69 70(defcustom longlines-show-effect (propertize "|\n" 'face 'escape-glyph) 71 "A string to display when showing hard newlines. 72This is used when `longlines-show-hard-newlines' is on." 73 :group 'longlines 74 :type 'string) 75 76;; Internal variables 77 78(defvar longlines-wrap-beg nil) 79(defvar longlines-wrap-end nil) 80(defvar longlines-wrap-point nil) 81(defvar longlines-showing nil) 82 83(make-variable-buffer-local 'longlines-wrap-beg) 84(make-variable-buffer-local 'longlines-wrap-end) 85(make-variable-buffer-local 'longlines-wrap-point) 86(make-variable-buffer-local 'longlines-showing) 87 88;; Mode 89 90;;;###autoload 91(define-minor-mode longlines-mode 92 "Toggle Long Lines mode. 93In Long Lines mode, long lines are wrapped if they extend beyond 94`fill-column'. The soft newlines used for line wrapping will not 95show up when the text is yanked or saved to disk. 96 97If the variable `longlines-auto-wrap' is non-nil, lines are automatically 98wrapped whenever the buffer is changed. You can always call 99`fill-paragraph' to fill individual paragraphs. 100 101If the variable `longlines-show-hard-newlines' is non-nil, hard newlines 102are indicated with a symbol." 103 :group 'longlines :lighter " ll" 104 (if longlines-mode 105 ;; Turn on longlines mode 106 (progn 107 (use-hard-newlines 1 'never) 108 (set (make-local-variable 'require-final-newline) nil) 109 (add-to-list 'buffer-file-format 'longlines) 110 (add-hook 'change-major-mode-hook 'longlines-mode-off nil t) 111 (add-hook 'before-revert-hook 'longlines-before-revert-hook nil t) 112 (make-local-variable 'buffer-substring-filters) 113 (set (make-local-variable 'isearch-search-fun-function) 114 'longlines-search-function) 115 (add-to-list 'buffer-substring-filters 'longlines-encode-string) 116 (when longlines-wrap-follows-window-size 117 (set (make-local-variable 'fill-column) 118 (- (window-width) window-min-width)) 119 (add-hook 'window-configuration-change-hook 120 'longlines-window-change-function nil t)) 121 (let ((buffer-undo-list t) 122 (inhibit-read-only t) 123 (after-change-functions nil) 124 (mod (buffer-modified-p))) 125 ;; Turning off undo is OK since (spaces + newlines) is 126 ;; conserved, except for a corner case in 127 ;; longlines-wrap-lines that we'll never encounter from here 128 (save-restriction 129 (widen) 130 (longlines-decode-buffer) 131 (longlines-wrap-region (point-min) (point-max))) 132 (set-buffer-modified-p mod)) 133 (when (and longlines-show-hard-newlines 134 (not longlines-showing)) 135 (longlines-show-hard-newlines)) 136 137 ;; Hacks to make longlines play nice with various modes. 138 (cond ((eq major-mode 'mail-mode) 139 (add-hook 'mail-setup-hook 'longlines-decode-buffer nil t) 140 (or mail-citation-hook 141 (add-hook 'mail-citation-hook 'mail-indent-citation nil t)) 142 (add-hook 'mail-citation-hook 'longlines-decode-region nil t)) 143 ((eq major-mode 'message-mode) 144 (add-hook 'message-setup-hook 'longlines-decode-buffer nil t) 145 (make-local-variable 'message-indent-citation-function) 146 (if (not (listp message-indent-citation-function)) 147 (setq message-indent-citation-function 148 (list message-indent-citation-function))) 149 (add-to-list 'message-indent-citation-function 150 'longlines-decode-region t))) 151 152 (when longlines-auto-wrap 153 (auto-fill-mode 0) 154 (add-hook 'after-change-functions 155 'longlines-after-change-function nil t) 156 (add-hook 'post-command-hook 157 'longlines-post-command-function nil t))) 158 ;; Turn off longlines mode 159 (setq buffer-file-format (delete 'longlines buffer-file-format)) 160 (if longlines-showing 161 (longlines-unshow-hard-newlines)) 162 (let ((buffer-undo-list t) 163 (after-change-functions nil) 164 (inhibit-read-only t)) 165 (save-restriction 166 (widen) 167 (longlines-encode-region (point-min) (point-max)))) 168 (remove-hook 'change-major-mode-hook 'longlines-mode-off t) 169 (remove-hook 'after-change-functions 'longlines-after-change-function t) 170 (remove-hook 'post-command-hook 'longlines-post-command-function t) 171 (remove-hook 'before-revert-hook 'longlines-before-revert-hook t) 172 (remove-hook 'window-configuration-change-hook 173 'longlines-window-change-function t) 174 (when longlines-wrap-follows-window-size 175 (kill-local-variable 'fill-column)) 176 (kill-local-variable 'isearch-search-fun-function) 177 (kill-local-variable 'require-final-newline) 178 (kill-local-variable 'buffer-substring-filters) 179 (kill-local-variable 'use-hard-newlines))) 180 181(defun longlines-mode-off () 182 "Turn off longlines mode. 183This function exists to be called by `change-major-mode-hook' when the 184major mode changes." 185 (longlines-mode 0)) 186 187;; Showing the effect of hard newlines in the buffer 188 189(defun longlines-show-hard-newlines (&optional arg) 190 "Make hard newlines visible by adding a face. 191With optional argument ARG, make the hard newlines invisible again." 192 (interactive "P") 193 (let ((buffer-undo-list t) 194 (mod (buffer-modified-p))) 195 (if arg 196 (longlines-unshow-hard-newlines) 197 (setq longlines-showing t) 198 (longlines-show-region (point-min) (point-max))) 199 (set-buffer-modified-p mod))) 200 201(defun longlines-show-region (beg end) 202 "Make hard newlines between BEG and END visible." 203 (let* ((pmin (min beg end)) 204 (pmax (max beg end)) 205 (pos (text-property-not-all pmin pmax 'hard nil)) 206 (inhibit-read-only t)) 207 (while pos 208 (put-text-property pos (1+ pos) 'display 209 (copy-sequence longlines-show-effect)) 210 (setq pos (text-property-not-all (1+ pos) pmax 'hard nil))))) 211 212(defun longlines-unshow-hard-newlines () 213 "Make hard newlines invisible again." 214 (interactive) 215 (setq longlines-showing nil) 216 (let ((pos (text-property-not-all (point-min) (point-max) 'hard nil))) 217 (while pos 218 (remove-text-properties pos (1+ pos) '(display)) 219 (setq pos (text-property-not-all (1+ pos) (point-max) 'hard nil))))) 220 221;; Wrapping the paragraphs. 222 223(defun longlines-wrap-region (beg end) 224 "Wrap each successive line, starting with the line before BEG. 225Stop when we reach lines after END that don't need wrapping, or the 226end of the buffer." 227 (setq longlines-wrap-point (point)) 228 (goto-char beg) 229 (forward-line -1) 230 ;; Two successful longlines-wrap-line's in a row mean successive 231 ;; lines don't need wrapping. 232 (while (null (and (longlines-wrap-line) 233 (or (eobp) 234 (and (>= (point) end) 235 (longlines-wrap-line)))))) 236 (goto-char longlines-wrap-point)) 237 238(defun longlines-wrap-line () 239 "If the current line needs to be wrapped, wrap it and return nil. 240If wrapping is performed, point remains on the line. If the line does 241not need to be wrapped, move point to the next line and return t." 242 (if (longlines-set-breakpoint) 243 (progn (insert-before-markers ?\n) 244 (backward-char 1) 245 (delete-char -1) 246 (forward-char 1) 247 nil) 248 (if (longlines-merge-lines-p) 249 (progn (end-of-line) 250 ;; After certain commands (e.g. kill-line), there may be two 251 ;; successive soft newlines in the buffer. In this case, we 252 ;; replace these two newlines by a single space. Unfortunately, 253 ;; this breaks the conservation of (spaces + newlines), so we 254 ;; have to fiddle with longlines-wrap-point. 255 (if (or (prog1 (bolp) (forward-char 1)) (eolp)) 256 (progn 257 (delete-char -1) 258 (if (> longlines-wrap-point (point)) 259 (setq longlines-wrap-point 260 (1- longlines-wrap-point)))) 261 (insert-before-markers-and-inherit ?\s) 262 (backward-char 1) 263 (delete-char -1) 264 (forward-char 1)) 265 nil) 266 (forward-line 1) 267 t))) 268 269(defun longlines-set-breakpoint () 270 "Place point where we should break the current line, and return t. 271If the line should not be broken, return nil; point remains on the 272line." 273 (move-to-column fill-column) 274 (if (and (re-search-forward "[^ ]" (line-end-position) 1) 275 (> (current-column) fill-column)) 276 ;; This line is too long. Can we break it? 277 (or (longlines-find-break-backward) 278 (progn (move-to-column fill-column) 279 (longlines-find-break-forward))))) 280 281(defun longlines-find-break-backward () 282 "Move point backward to the first available breakpoint and return t. 283If no breakpoint is found, return nil." 284 (and (search-backward " " (line-beginning-position) 1) 285 (save-excursion 286 (skip-chars-backward " " (line-beginning-position)) 287 (null (bolp))) 288 (progn (forward-char 1) 289 (if (and fill-nobreak-predicate 290 (run-hook-with-args-until-success 291 'fill-nobreak-predicate)) 292 (progn (skip-chars-backward " " (line-beginning-position)) 293 (longlines-find-break-backward)) 294 t)))) 295 296(defun longlines-find-break-forward () 297 "Move point forward to the first available breakpoint and return t. 298If no break point is found, return nil." 299 (and (search-forward " " (line-end-position) 1) 300 (progn (skip-chars-forward " " (line-end-position)) 301 (null (eolp))) 302 (if (and fill-nobreak-predicate 303 (run-hook-with-args-until-success 304 'fill-nobreak-predicate)) 305 (longlines-find-break-forward) 306 t))) 307 308(defun longlines-merge-lines-p () 309 "Return t if part of the next line can fit onto the current line. 310Otherwise, return nil. Text cannot be moved across hard newlines." 311 (save-excursion 312 (end-of-line) 313 (and (null (eobp)) 314 (null (get-text-property (point) 'hard)) 315 (let ((space (- fill-column (current-column)))) 316 (forward-line 1) 317 (if (eq (char-after) ? ) 318 t ; We can always merge some spaces 319 (<= (if (search-forward " " (line-end-position) 1) 320 (current-column) 321 (1+ (current-column))) 322 space)))))) 323 324(defun longlines-decode-region (&optional beg end) 325 "Turn all newlines between BEG and END into hard newlines. 326If BEG and END are nil, the point and mark are used." 327 (if (null beg) (setq beg (point))) 328 (if (null end) (setq end (mark t))) 329 (save-excursion 330 (let ((reg-max (max beg end))) 331 (goto-char (min beg end)) 332 (while (search-forward "\n" reg-max t) 333 (set-hard-newline-properties 334 (match-beginning 0) (match-end 0)))))) 335 336(defun longlines-decode-buffer () 337 "Turn all newlines in the buffer into hard newlines." 338 (longlines-decode-region (point-min) (point-max))) 339 340(defun longlines-encode-region (beg end &optional buffer) 341 "Replace each soft newline between BEG and END with exactly one space. 342Hard newlines are left intact. The optional argument BUFFER exists for 343compatibility with `format-alist', and is ignored." 344 (save-excursion 345 (let ((reg-max (max beg end)) 346 (mod (buffer-modified-p))) 347 (goto-char (min beg end)) 348 (while (search-forward "\n" reg-max t) 349 (unless (get-text-property (match-beginning 0) 'hard) 350 (replace-match " "))) 351 (set-buffer-modified-p mod) 352 end))) 353 354(defun longlines-encode-string (string) 355 "Return a copy of STRING with each soft newline replaced by a space. 356Hard newlines are left intact." 357 (let* ((str (copy-sequence string)) 358 (pos (string-match "\n" str))) 359 (while pos 360 (if (null (get-text-property pos 'hard str)) 361 (aset str pos ? )) 362 (setq pos (string-match "\n" str (1+ pos)))) 363 str)) 364 365;; Auto wrap 366 367(defun longlines-auto-wrap (&optional arg) 368 "Turn on automatic line wrapping, and wrap the entire buffer. 369With optional argument ARG, turn off line wrapping." 370 (interactive "P") 371 (remove-hook 'after-change-functions 'longlines-after-change-function t) 372 (remove-hook 'post-command-hook 'longlines-post-command-function t) 373 (if arg 374 (progn (setq longlines-auto-wrap nil) 375 (message "Auto wrap disabled.")) 376 (setq longlines-auto-wrap t) 377 (add-hook 'after-change-functions 378 'longlines-after-change-function nil t) 379 (add-hook 'post-command-hook 380 'longlines-post-command-function nil t) 381 (let ((mod (buffer-modified-p))) 382 (longlines-wrap-region (point-min) (point-max)) 383 (set-buffer-modified-p mod)) 384 (message "Auto wrap enabled."))) 385 386(defun longlines-after-change-function (beg end len) 387 "Update `longlines-wrap-beg' and `longlines-wrap-end'. 388This is called by `after-change-functions' to keep track of the region 389that has changed." 390 (unless undo-in-progress 391 (setq longlines-wrap-beg 392 (if longlines-wrap-beg (min longlines-wrap-beg beg) beg)) 393 (setq longlines-wrap-end 394 (if longlines-wrap-end (max longlines-wrap-end end) end)))) 395 396(defun longlines-post-command-function () 397 "Perform line wrapping on the parts of the buffer that have changed. 398This is called by `post-command-hook' after each command." 399 (when longlines-wrap-beg 400 (if (or (eq this-command 'yank) 401 (eq this-command 'yank-pop)) 402 (longlines-decode-region (point) (mark t))) 403 (if longlines-showing 404 (longlines-show-region longlines-wrap-beg longlines-wrap-end)) 405 (unless (or (eq this-command 'fill-paragraph) 406 (eq this-command 'fill-region)) 407 (longlines-wrap-region longlines-wrap-beg longlines-wrap-end)) 408 (setq longlines-wrap-beg nil) 409 (setq longlines-wrap-end nil))) 410 411(defun longlines-window-change-function () 412 "Re-wrap the buffer if the window width has changed. 413This is called by `window-configuration-change-hook'." 414 (when (/= fill-column (- (window-width) window-min-width)) 415 (setq fill-column (- (window-width) window-min-width)) 416 (let ((mod (buffer-modified-p))) 417 (longlines-wrap-region (point-min) (point-max)) 418 (set-buffer-modified-p mod)))) 419 420;; Isearch 421 422(defun longlines-search-function () 423 (cond 424 (isearch-word 425 (if isearch-forward 'word-search-forward 'word-search-backward)) 426 (isearch-regexp 427 (if isearch-forward 're-search-forward 're-search-backward)) 428 (t 429 (if isearch-forward 430 'longlines-search-forward 431 'longlines-search-backward)))) 432 433(defun longlines-search-forward (string &optional bound noerror count) 434 (let ((search-spaces-regexp "[ \n]+")) 435 (re-search-forward (regexp-quote string) bound noerror count))) 436 437(defun longlines-search-backward (string &optional bound noerror count) 438 (let ((search-spaces-regexp "[ \n]+")) 439 (re-search-backward (regexp-quote string) bound noerror count))) 440 441;; Loading and saving 442 443(defun longlines-before-revert-hook () 444 (add-hook 'after-revert-hook 'longlines-after-revert-hook nil t) 445 (longlines-mode 0)) 446 447(defun longlines-after-revert-hook () 448 (remove-hook 'after-revert-hook 'longlines-after-revert-hook t) 449 (longlines-mode 1)) 450 451(add-to-list 452 'format-alist 453 (list 'longlines "Automatically wrap long lines." nil nil 454 'longlines-encode-region t nil)) 455 456(provide 'longlines) 457 458;; arch-tag: 3489d225-5506-47b9-8659-d8807b77c624 459;;; longlines.el ends here 460