code.delx.au - gnu-emacs/blob - lisp/whitespace.el

   1 ;;; whitespace.el --- Warn about and clean bogus whitespaces in the file.
   2
   3 ;; Copyright (C) 1999, 2000 Free Software Foundation, Inc.
   4
   5 ;; Author: Rajesh Vaidheeswarran <rv@gnu.org>
   6 ;; Keywords: convenience
   7
   8 ;; $Id: $
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Whitespace.el URL: http://www.dsmit.com/lisp/
  29
  30 ;; Exported functions:
  31
  32 ;; `whitespace-buffer' - To check the current buffer for whitespace problems.
  33 ;; `whitespace-cleanup' - To cleanup all whitespaces in the current buffer.
  34 ;; `whitespace-region' - To check between point and mark for whitespace
  35 ;;                       problems.
  36 ;; `whitespace-cleanup-region' - To cleanup all whitespaces between point
  37 ;;                               and mark in the current buffer.
  38 ;; `whitespace-describe' - A simple introduction to the library.
  39
  40 ;;; Code:
  41
  42 (defvar whitespace-version "3.0" "Version of the whitespace library.")
  43
  44 (defvar whitespace-all-buffer-files nil
  45   "An associated list of buffers and files checked for whitespace cleanliness.
  46
  47 This is to enable periodic checking of whitespace cleanliness in the files
  48 visited by the buffers.")
  49
  50 (defvar whitespace-rescan-timer nil
  51   "Timer object used to rescan the files in buffers that have been modified.")
  52
  53 ;; Tell Emacs about this new kind of minor mode
  54 (defvar whitespace-mode nil
  55   "Non-nil when Whitespace mode (a minor mode) is enabled.")
  56 (make-variable-buffer-local 'whitespace-mode)
  57 (put 'whitespace-mode 'permanent-local nil)
  58
  59 (defvar whitespace-mode-line nil
  60   "String to display in the mode line for Whitespace mode.")
  61 (make-variable-buffer-local 'whitespace-mode-line)
  62 (put 'whitespace-mode-line 'permanent-local nil)
  63
  64 (defvar whitespace-check-buffer-leading nil
  65   "Test leading whitespace for file in current buffer if t")
  66 (make-variable-buffer-local 'whitespace-check-buffer-leading)
  67 (put 'whitespace-check-buffer-leading 'permanent-local nil)
  68
  69 (defvar whitespace-check-buffer-trailing nil
  70   "Test trailing whitespace for file in current buffer if t")
  71 (make-variable-buffer-local 'whitespace-check-buffer-trailing)
  72 (put 'whitespace-check-buffer-trailing 'permanent-local nil)
  73
  74 (defvar whitespace-check-buffer-indent nil
  75   "Test indentation whitespace for file in current buffer if t")
  76 (make-variable-buffer-local 'whitespace-check-buffer-indent)
  77 (put 'whitespace-check-buffer-indent 'permanent-local nil)
  78
  79 (defvar whitespace-check-buffer-spacetab nil
  80   "Test Space-followed-by-TABS whitespace for file in current buffer if t")
  81 (make-variable-buffer-local 'whitespace-check-buffer-spacetab)
  82 (put 'whitespace-check-buffer-spacetab 'permanent-local nil)
  83
  84 (defvar whitespace-check-buffer-ateol nil
  85   "Test end-of-line whitespace for file in current buffer if t")
  86 (make-variable-buffer-local 'whitespace-check-buffer-ateol)
  87 (put 'whitespace-check-buffer-ateol 'permanent-local nil)
  88
  89 ;; For flavors of Emacs which don't define `defgroup' and `defcustom'.
  90 (eval-when-compile
  91   (if (not (fboundp 'defgroup))
  92       (defmacro defgroup (sym memb doc &rest args)
  93         "Null macro for defgroup in all versions of Emacs that don't define
  94 defgroup"
  95         t))
  96   (if (not (fboundp 'defcustom))
  97       (defmacro defcustom (sym val doc &rest args)
  98         "Macro to alias defcustom to defvar in all versions of Emacs that
  99 don't define defcustom"
 100         `(defvar ,sym ,val ,doc))))
 101
 102 (if (featurep 'xemacs)
 103 (defgroup whitespace nil
 104   "Check for and fix five different types of whitespaces in source code."
 105   ;; Since XEmacs doesn't have a 'convenience group, use the next best group
 106   ;; which is 'editing?
 107   :group 'editing)
 108 (defgroup whitespace nil
 109   "Check for and fix five different types of whitespaces in source code."
 110   :version "21.1"
 111   :group 'convenience))
 112
 113 (defcustom whitespace-check-leading-whitespace t
 114   "Flag to check leading whitespace. This is the global for the system.
 115 It can be overriden by setting a buffer local variable
 116 `whitespace-check-buffer-leading'"
 117   :type 'boolean
 118   :group 'whitespace)
 119
 120 (defcustom whitespace-check-trailing-whitespace t
 121   "Flag to check trailing whitespace. This is the global for the system.
 122 It can be overriden by setting a buffer local variable
 123 `whitespace-check-buffer-trailing'"
 124   :type 'boolean
 125   :group 'whitespace)
 126
 127 (defcustom whitespace-check-spacetab-whitespace t
 128   "Flag to check space followed by a TAB. This is the global for the system.
 129 It can be overriden by setting a buffer local variable
 130 `whitespace-check-buffer-spacetab'"
 131   :type 'boolean
 132   :group 'whitespace)
 133
 134 (defcustom whitespace-spacetab-regexp " \t"
 135   "Regexp to match a space followed by a TAB."
 136   :type 'regexp
 137   :group 'whitespace)
 138
 139 (defcustom whitespace-check-indent-whitespace t
 140   "Flag to check indentation whitespace. This is the global for the system.
 141 It can be overriden by setting a buffer local variable
 142 `whitespace-check-buffer-indent'"
 143   :type 'boolean
 144   :group 'whitespace)
 145
 146 (defcustom whitespace-indent-regexp (concat "^\\(\t*\\)    " "    ")
 147   "Regexp to match (any TABS followed by) 8/more whitespaces at start of line."
 148   :type 'regexp
 149   :group 'whitespace)
 150
 151 (defcustom whitespace-check-ateol-whitespace t
 152   "Flag to check end-of-line whitespace. This is the global for the system.
 153 It can be overriden by setting a buffer local variable
 154 `whitespace-check-buffer-ateol'"
 155   :type 'boolean
 156   :group 'whitespace)
 157
 158 (defcustom whitespace-ateol-regexp "[ \t]$"
 159   "Regexp to match a TAB or a space at the EOL."
 160   :type 'regexp
 161   :group 'whitespace)
 162
 163 (defcustom whitespace-errbuf "*Whitespace Errors*"
 164   "The name of the buffer where whitespace related messages will be logged."
 165   :type 'string
 166   :group 'whitespace)
 167
 168 (defcustom whitespace-auto-cleanup nil
 169   "Cleanup a buffer automatically on finding it whitespace unclean."
 170   :type  'boolean
 171   :group 'whitespace)
 172
 173 (defcustom whitespace-silent nil
 174   "All whitespace errors will be shown only in the modeline when t.
 175
 176 Note that setting this may cause all whitespaces introduced in a file to go
 177 unnoticed when the buffer is killed, unless the user visits the `*Whitespace
 178 Errors*' buffer before opening (or closing) another file."
 179   :type 'boolean
 180   :group 'whitespace)
 181
 182 (defcustom whitespace-modes '(ada-mode asm-mode autoconf-mode awk-mode
 183                                        c-mode c++-mode cc-mode
 184                                        change-log-mode cperl-mode
 185                                        electric-nroff-mode emacs-lisp-mode
 186                                        f90-mode fortran-mode html-mode
 187                                        html3-mode java-mode jde-mode
 188                                        ksh-mode latex-mode LaTeX-mode
 189                                        lisp-mode m4-mode makefile-mode
 190                                        modula-2-mode nroff-mode objc-mode
 191                                        pascal-mode perl-mode prolog-mode
 192                                        python-mode scheme-mode sgml-mode
 193                                        sh-mode shell-script-mode simula-mode
 194                                        tcl-mode tex-mode texinfo-mode
 195                                        vrml-mode xml-mode)
 196
 197   "Major Modes in which we turn on whitespace checking.
 198
 199 These are mostly programming and documentation modes.  But you may add other
 200 modes that you want whitespaces checked in by adding something like the
 201 following to your `.emacs':
 202
 203 \(setq whitespace-modes (cons 'my-mode (cons 'my-other-mode
 204                                             whitespace-modes))\)
 205
 206 Or, alternately, you can use the Emacs `customize' command to set this."
 207   :type '(repeat symbol)
 208   :group 'whitespace)
 209
 210 (defcustom whitespace-rescan-timer-time 600
 211   "Period in seconds to rescan modified buffers for whitespace creep.
 212
 213 This is the period after which the timer will fire causing
 214 `whitespace-rescan-files-in-buffers' to check for whitespace creep in
 215 modified buffers.
 216
 217 To disable timer scans, set this to zero."
 218   :type 'integer
 219   :group 'whitespace)
 220
 221 (defcustom whitespace-display-in-modeline t
 222   "Display whitespace errors on the modeline."
 223   :type 'boolean
 224   :group 'whitespace)
 225
 226 (if (not (assoc 'whitespace-mode minor-mode-alist))
 227     (setq minor-mode-alist (cons '(whitespace-mode whitespace-mode-line)
 228                                  minor-mode-alist)))
 229
 230 (set-default 'whitespace-check-buffer-leading
 231              whitespace-check-leading-whitespace)
 232 (set-default 'whitespace-check-buffer-trailing
 233              whitespace-check-trailing-whitespace)
 234 (set-default 'whitespace-check-buffer-indent
 235              whitespace-check-indent-whitespace)
 236 (set-default 'whitespace-check-buffer-spacetab
 237              whitespace-check-spacetab-whitespace)
 238 (set-default 'whitespace-check-buffer-ateol
 239              whitespace-check-ateol-whitespace)
 240
 241 (defun whitespace-check-whitespace-mode (&optional arg)
 242   "Test and set the whitespace-mode in qualifying buffers."
 243   (if (null whitespace-mode)
 244       (setq whitespace-mode
 245             (if (or arg (member major-mode whitespace-modes))
 246                 t
 247               nil))))
 248
 249 ;;;###autoload
 250 (defun whitespace-toggle-leading-check ()
 251   "Toggle the check for leading space in the local buffer."
 252   (interactive)
 253   (let ((current-val whitespace-check-buffer-leading))
 254     (setq whitespace-check-buffer-leading (not current-val))
 255     (message "Will%s check for leading space in buffer."
 256              (if whitespace-check-buffer-leading "" " not"))
 257     (if whitespace-check-buffer-leading (whitespace-buffer-leading))))
 258
 259 ;;;###autoload
 260 (defun whitespace-toggle-trailing-check ()
 261   "Toggle the check for trailing space in the local buffer."
 262   (interactive)
 263   (let ((current-val whitespace-check-buffer-trailing))
 264     (setq whitespace-check-buffer-trailing (not current-val))
 265     (message "Will%s check for trailing space in buffer."
 266              (if whitespace-check-buffer-trailing "" " not"))
 267     (if whitespace-check-buffer-trailing (whitespace-buffer-trailing))))
 268
 269 ;;;###autoload
 270 (defun whitespace-toggle-indent-check ()
 271   "Toggle the check for indentation space in the local buffer."
 272   (interactive)
 273   (let ((current-val whitespace-check-buffer-indent))
 274     (setq whitespace-check-buffer-indent (not current-val))
 275     (message "Will%s check for indentation space in buffer."
 276              (if whitespace-check-buffer-indent "" " not"))
 277     (if whitespace-check-buffer-indent
 278         (whitespace-buffer-search whitespace-indent-regexp))))
 279
 280 ;;;###autoload
 281 (defun whitespace-toggle-spacetab-check ()
 282   "Toggle the check for space-followed-by-TABs in the local buffer."
 283   (interactive)
 284   (let ((current-val whitespace-check-buffer-spacetab))
 285     (setq whitespace-check-buffer-spacetab (not current-val))
 286     (message "Will%s check for space-followed-by-TABs in buffer."
 287              (if whitespace-check-buffer-spacetab "" " not"))
 288     (if whitespace-check-buffer-spacetab
 289         (whitespace-buffer-search whitespace-spacetab-regexp))))
 290
 291
 292 ;;;###autoload
 293 (defun whitespace-toggle-ateol-check ()
 294   "Toggle the check for end-of-line space in the local buffer."
 295   (interactive)
 296   (let ((current-val whitespace-check-buffer-ateol))
 297     (setq whitespace-check-buffer-ateol (not current-val))
 298     (message "Will%s check for end-of-line space in buffer."
 299              (if whitespace-check-buffer-ateol "" " not"))
 300     (if whitespace-check-buffer-ateol
 301         (whitespace-buffer-search whitespace-ateol-regexp))))
 302
 303
 304 ;;;###autoload
 305 (defun whitespace-buffer (&optional quiet)
 306   "Find five different types of white spaces in buffer.
 307 These are:
 308 1. Leading space \(empty lines at the top of a file\).
 309 2. Trailing space \(empty lines at the end of a file\).
 310 3. Indentation space \(8 or more spaces, that should be replaced with TABS\).
 311 4. Spaces followed by a TAB. \(Almost always, we never want that\).
 312 5. Spaces or TABS at the end of a line.
 313
 314 Check for whitespace only if this buffer really contains a non-empty file
 315 and:
 316 1. the major mode is one of the whitespace-modes, or
 317 2. `whitespace-buffer' was explicitly called with a prefix argument."
 318   (interactive)
 319   (let ((whitespace-error nil))
 320     (whitespace-check-whitespace-mode current-prefix-arg)
 321     (if (and buffer-file-name (> (buffer-size) 0) whitespace-mode)
 322         (progn
 323           (whitespace-check-buffer-list (buffer-name) buffer-file-name)
 324           (whitespace-tickle-timer)
 325           (if whitespace-auto-cleanup
 326               (if buffer-read-only
 327                   (if (not quiet)
 328                       (message "Can't cleanup: %s is read-only" (buffer-name)))
 329                 (whitespace-cleanup))
 330             (let ((whitespace-leading (if whitespace-check-buffer-leading
 331                                           (whitespace-buffer-leading)
 332                                         nil))
 333                   (whitespace-trailing (if whitespace-check-buffer-trailing
 334                                            (whitespace-buffer-trailing)
 335                                          nil))
 336                   (whitespace-indent (if whitespace-check-buffer-indent
 337                                          (whitespace-buffer-search
 338                                           whitespace-indent-regexp)
 339                                        nil))
 340                   (whitespace-spacetab (if whitespace-check-buffer-spacetab
 341                                            (whitespace-buffer-search
 342                                             whitespace-spacetab-regexp)
 343                                          nil))
 344                   (whitespace-ateol (if whitespace-check-buffer-ateol
 345                                         (whitespace-buffer-search
 346                                          whitespace-ateol-regexp)
 347                                       nil))
 348                   (whitespace-errmsg nil)
 349                   (whitespace-filename buffer-file-name)
 350                   (whitespace-this-modeline ""))
 351
 352               ;; Now let's complain if we found any of the above.
 353               (setq whitespace-error (or whitespace-leading whitespace-indent
 354                                          whitespace-spacetab whitespace-ateol
 355                                          whitespace-trailing))
 356
 357               (if whitespace-error
 358                   (progn
 359                     (setq whitespace-errmsg
 360                           (concat whitespace-filename " contains:\n"
 361                                   (if whitespace-leading
 362                                       "Leading whitespace\n")
 363                                   (if whitespace-indent
 364                                       (concat "Indentation whitespace"
 365                                               whitespace-indent "\n"))
 366                                   (if whitespace-spacetab
 367                                       (concat "Space followed by Tab"
 368                                               whitespace-spacetab "\n"))
 369                                   (if whitespace-ateol
 370                                       (concat "End-of-line whitespace"
 371                                               whitespace-ateol "\n"))
 372                                   (if whitespace-trailing
 373                                       "Trailing whitespace\n")
 374                                   "\ntype `M-x whitespace-cleanup' to "
 375                                   "cleanup the file."))
 376                     (setq whitespace-this-modeline
 377                           (concat (if whitespace-ateol "e")
 378                                   (if whitespace-indent "i")
 379                                   (if whitespace-leading "l")
 380                                   (if whitespace-spacetab "s")
 381                                   (if whitespace-trailing "t")))))
 382               (whitespace-update-modeline whitespace-this-modeline)
 383               (save-excursion
 384                 (get-buffer-create whitespace-errbuf)
 385                 (kill-buffer whitespace-errbuf)
 386                 (get-buffer-create whitespace-errbuf)
 387                 (set-buffer whitespace-errbuf)
 388                 (if whitespace-errmsg
 389                     (progn
 390                       (insert whitespace-errmsg)
 391                       (if (not (or quiet whitespace-silent))
 392                           (display-buffer whitespace-errbuf t))
 393                       (if (not quiet)
 394                           (message "Whitespaces: [%s%s] in %s"
 395                                    whitespace-this-modeline
 396                                    (let ((whitespace-unchecked
 397                                           (whitespace-unchecked-whitespaces)))
 398                                      (if whitespace-unchecked
 399                                          (concat "!" whitespace-unchecked)
 400                                        ""))
 401                                    whitespace-filename)))
 402                   (if (not quiet)
 403                       (message "%s clean" whitespace-filename))))))))
 404     (if whitespace-error
 405         t
 406       nil)))
 407
 408 ;;;###autoload
 409 (defun whitespace-region (s e)
 410   "Check the region for whitespace errors."
 411   (interactive "r")
 412   (save-excursion
 413     (save-restriction
 414       (narrow-to-region s e)
 415       (whitespace-buffer))))
 416
 417 ;;;###autoload
 418 (defun whitespace-cleanup ()
 419   "Cleanup the five different kinds of whitespace problems.
 420
 421 Use \\[describe-function] whitespace-describe to read a summary of the
 422 whitespace problems."
 423   (interactive)
 424   ;; If this buffer really contains a file, then run, else quit.
 425   (whitespace-check-whitespace-mode current-prefix-arg)
 426   (if (and buffer-file-name whitespace-mode)
 427       (let ((whitespace-any nil)
 428             (whitespace-tabwith 8)
 429             (whitespace-tabwith-saved tab-width))
 430
 431         ;; since all printable TABS should be 8, irrespective of how
 432         ;; they are displayed.
 433         (setq tab-width whitespace-tabwith)
 434
 435         (if (and whitespace-check-buffer-leading
 436                  (whitespace-buffer-leading))
 437             (progn
 438               (whitespace-buffer-leading-cleanup)
 439               (setq whitespace-any t)))
 440
 441         (if (and whitespace-check-buffer-trailing
 442                  (whitespace-buffer-trailing))
 443             (progn
 444               (whitespace-buffer-trailing-cleanup)
 445               (setq whitespace-any t)))
 446
 447         (if (and whitespace-check-buffer-indent
 448                  (whitespace-buffer-search whitespace-indent-regexp))
 449             (progn
 450               (whitespace-indent-cleanup)
 451               (setq whitespace-any t)))
 452
 453         (if (and whitespace-check-buffer-spacetab
 454                  (whitespace-buffer-search whitespace-spacetab-regexp))
 455             (progn
 456               (whitespace-buffer-cleanup whitespace-spacetab-regexp "\t")
 457               (setq whitespace-any t)))
 458
 459         (if (and whitespace-check-buffer-ateol
 460                  (whitespace-buffer-search whitespace-ateol-regexp))
 461             (progn
 462               (whitespace-buffer-cleanup whitespace-ateol-regexp "")
 463               (setq whitespace-any t)))
 464
 465         ;; Call this recursively till everything is taken care of
 466         (if whitespace-any
 467             (whitespace-cleanup)
 468           (progn
 469             (message "%s clean" buffer-file-name)
 470             (whitespace-update-modeline)))
 471         (setq tab-width whitespace-tabwith-saved))))
 472
 473 ;;;###autoload
 474 (defun whitespace-cleanup-region (s e)
 475   "Whitespace cleanup on the region."
 476   (interactive "r")
 477   (save-excursion
 478     (save-restriction
 479       (narrow-to-region s e)
 480       (whitespace-cleanup))
 481     (whitespace-buffer t)))
 482
 483 (defun whitespace-buffer-leading ()
 484   "Check to see if there are any empty lines at the top of the file."
 485   (save-excursion
 486     (let ((pmin nil)
 487           (pmax nil))
 488       (goto-char (point-min))
 489       (beginning-of-line)
 490       (setq pmin (point))
 491       (end-of-line)
 492       (setq pmax (point))
 493       (if (equal pmin pmax)
 494           t
 495         nil))))
 496
 497 (defun whitespace-buffer-leading-cleanup ()
 498   "Remove any empty lines at the top of the file."
 499   (save-excursion
 500     (let ((pmin nil)
 501           (pmax nil))
 502       (goto-char (point-min))
 503       (beginning-of-line)
 504       (setq pmin (point))
 505       (end-of-line)
 506       (setq pmax (point))
 507       (if (equal pmin pmax)
 508           (progn
 509             (kill-line)
 510             (whitespace-buffer-leading-cleanup))))))
 511
 512 (defun whitespace-buffer-trailing ()
 513   "Check to see if are is more than one empty line at the bottom."
 514   (save-excursion
 515     (let ((pmin nil)
 516           (pmax nil))
 517       (goto-char (point-max))
 518       (beginning-of-line)
 519       (setq pmin (point))
 520       (end-of-line)
 521       (setq pmax (point))
 522       (if (equal pmin pmax)
 523           (progn
 524             (goto-char (- (point) 1))
 525             (beginning-of-line)
 526             (setq pmin (point))
 527             (end-of-line)
 528             (setq pmax (point))
 529             (if (equal pmin pmax)
 530                 t
 531               nil))
 532         nil))))
 533
 534 (defun whitespace-buffer-trailing-cleanup ()
 535   "Delete all the empty lines at the bottom."
 536   (save-excursion
 537     (let ((pmin nil)
 538           (pmax nil))
 539       (goto-char (point-max))
 540       (beginning-of-line)
 541       (setq pmin (point))
 542       (end-of-line)
 543       (setq pmax (point))
 544       (if (equal pmin pmax)
 545           (progn
 546             (goto-char (1- pmin))
 547             (beginning-of-line)
 548             (setq pmin (point))
 549             (end-of-line)
 550             (setq pmax (point))
 551             (if (equal pmin pmax)
 552                 (progn
 553                   (goto-char (1- (point-max)))
 554                   (beginning-of-line)
 555                   (kill-line)
 556                   (whitespace-buffer-trailing-cleanup))))))))
 557
 558 (defun whitespace-buffer-search (regexp)
 559   "Search for any given whitespace REGEXP."
 560   (let ((whitespace-retval ""))
 561     (save-excursion
 562       (goto-char (point-min))
 563       (while (re-search-forward regexp nil t)
 564         (setq whitespace-retval (format "%s %s " whitespace-retval
 565                                         (match-beginning 0))))
 566       (if (equal "" whitespace-retval)
 567           nil
 568         whitespace-retval))))
 569
 570 (defun whitespace-buffer-cleanup (regexp newregexp)
 571   "Search for any given whitespace REGEXP and replace it with the NEWREGEXP."
 572   (save-excursion
 573     (goto-char (point-min))
 574     (while (re-search-forward regexp nil t)
 575       (replace-match newregexp))))
 576
 577 (defun whitespace-indent-cleanup ()
 578   "Search for 8/more spaces at the start of a line and replace it with tabs."
 579   (save-excursion
 580     (goto-char (point-min))
 581     (while (re-search-forward whitespace-indent-regexp nil t)
 582       (let ((column (current-column))
 583             (indent-tabs-mode t))
 584         (delete-region (match-beginning 0) (point))
 585         (indent-to column)))))
 586
 587 (defun whitespace-unchecked-whitespaces ()
 588   "Return the list of whitespaces whose testing has been suppressed."
 589   (let ((unchecked-spaces
 590          (concat (if (not whitespace-check-buffer-ateol) "e")
 591                  (if (not whitespace-check-buffer-indent) "i")
 592                  (if (not whitespace-check-buffer-leading) "l")
 593                  (if (not whitespace-check-buffer-spacetab) "s")
 594                  (if (not whitespace-check-buffer-trailing) "t"))))
 595     (if (not (equal unchecked-spaces ""))
 596         unchecked-spaces
 597       nil)))
 598
 599 (defun whitespace-update-modeline (&optional whitespace-err)
 600   "Update modeline with whitespace errors.
 601 Also with whitespaces whose testing has been turned off."
 602   (if whitespace-display-in-modeline
 603       (progn
 604         (setq whitespace-mode-line nil)
 605         ;; Whitespace errors
 606         (if (and whitespace-err (not (equal whitespace-err "")))
 607             (setq whitespace-mode-line whitespace-err))
 608         ;; Whitespace suppressed errors
 609         (let ((whitespace-unchecked (whitespace-unchecked-whitespaces)))
 610           (if whitespace-unchecked
 611               (setq whitespace-mode-line
 612                     (concat whitespace-mode-line "!" whitespace-unchecked))))
 613         ;; Add the whitespace modeline prefix
 614         (setq whitespace-mode-line (if whitespace-mode-line
 615                                        (concat " W:" whitespace-mode-line)
 616                                      nil))
 617         (whitespace-force-mode-line-update))))
 618
 619 ;; Force mode line updation for different Emacs versions
 620 (defun whitespace-force-mode-line-update ()
 621   "Force the mode line update for different flavors of Emacs."
 622   (if (fboundp 'redraw-modeline)
 623       (redraw-modeline)                 ; XEmacs
 624     (force-mode-line-update)))          ; Emacs
 625
 626 (defun whitespace-check-buffer-list (buf-name buf-file)
 627   "Add a buffer and its file to the whitespace monitor list.
 628
 629 The buffer named BUF-NAME and its associated file BUF-FILE are now monitored
 630 periodically for whitespace."
 631   (if (and whitespace-mode (not (member (list buf-file buf-name)
 632                                         whitespace-all-buffer-files)))
 633       (add-to-list 'whitespace-all-buffer-files (list buf-file buf-name))))
 634
 635 (defun whitespace-tickle-timer ()
 636   "Tickle timer to periodically to scan qualifying files for whitespace creep.
 637
 638 If timer is not set, then set it to scan the files in
 639 `whitespace-all-buffer-files' periodically (defined by
 640 `whitespace-rescan-timer-time') for whitespace creep."
 641   (if (and whitespace-rescan-timer-time (not whitespace-rescan-timer))
 642       (setq whitespace-rescan-timer
 643             (add-timeout whitespace-rescan-timer-time
 644                          'whitespace-rescan-files-in-buffers nil
 645                          whitespace-rescan-timer-time))))
 646
 647 (defun whitespace-rescan-files-in-buffers (&optional arg)
 648   "Check monitored files for whitespace creep since last scan."
 649   (let ((whitespace-all-my-files whitespace-all-buffer-files)
 650         buffile bufname thiselt buf)
 651     (if (not whitespace-all-my-files)
 652         (progn
 653           (disable-timeout whitespace-rescan-timer)
 654           (setq whitespace-rescan-timer nil))
 655       (while whitespace-all-my-files
 656         (setq thiselt (car whitespace-all-my-files))
 657         (setq whitespace-all-my-files (cdr whitespace-all-my-files))
 658         (setq buffile (car thiselt))
 659         (setq bufname (cadr thiselt))
 660         (setq buf (get-buffer bufname))
 661         (if (buffer-live-p buf)
 662             (save-excursion
 663               ;;(message "buffer %s live" bufname)
 664               (set-buffer bufname)
 665               (if whitespace-mode
 666                   (progn
 667                     ;;(message "checking for whitespace in %s" bufname)
 668                     (if whitespace-auto-cleanup
 669                         (progn
 670                           ;;(message "cleaning up whitespace in %s" bufname)
 671                           (whitespace-cleanup))
 672                       (progn
 673                         ;;(message "whitespace-buffer %s." (buffer-name))
 674                         (whitespace-buffer t))))
 675                 ;;(message "Removing %s from refresh list" bufname)
 676                 (whitespace-refresh-rescan-list buffile bufname)))
 677           ;;(message "Removing %s from refresh list" bufname)
 678           (whitespace-refresh-rescan-list buffile bufname))))))
 679
 680 (defun whitespace-refresh-rescan-list (buffile bufname)
 681   "Refresh the list of files to be rescaned for whitespace creep."
 682   (if whitespace-all-buffer-files
 683       (setq whitespace-all-buffer-files
 684             (delete (list buffile bufname) whitespace-all-buffer-files))
 685     (when whitespace-rescan-timer
 686       (disable-timeout whitespace-rescan-timer)
 687       (setq whitespace-rescan-timer nil))))
 688
 689 ;;;###autoload
 690 (defcustom whitespace-global-mode nil
 691   "Toggle global Whitespace mode.
 692
 693 Setting this variable directly does not take effect;
 694 use either \\[customize] or the function `whitespace-global-mode'
 695 \(which see)."
 696   :set (lambda (sym val)
 697          (whitespace-global-mode (or val 0)))
 698   :initialize 'custom-initialize-default
 699   :type 'boolean
 700   :group 'whitespace
 701   :require 'whitespace)
 702
 703 (defun whitespace-global-mode (&optional arg)
 704   "Toggle using Whitespace mode in new buffers.
 705 With ARG, turn the mode on if and only iff ARG is positive.
 706
 707 When this mode is active, `whitespace-buffer' is added to
 708 `find-file-hooks' and `kill-buffer-hook'."
 709   (interactive "P")
 710   (setq arg (if arg
 711                 (> (prefix-numeric-value arg) 0)
 712               (not whitespace-global-mode)))
 713   (if arg
 714       (progn
 715         (add-hook 'find-file-hooks 'whitespace-buffer)
 716         (add-hook 'kill-buffer-hook 'whitespace-buffer))
 717     (remove-hook 'find-file-hooks 'whitespace-buffer)
 718     (remove-hook 'kill-buffer-hook 'whitespace-buffer)))
 719
 720 ;;;###autoload
 721 (defun whitespace-describe ()
 722   "A summary of whitespaces and what this library can do about them.
 723
 724 The whitespace library is intended to find and help fix five different types
 725 of whitespace problems that commonly exist in source code.
 726
 727 1. Leading space (empty lines at the top of a file).
 728 2. Trailing space (empty lines at the end of a file).
 729 3. Indentation space (8 or more spaces at beginning of line, that should be
 730                       replaced with TABS).
 731 4. Spaces followed by a TAB.  (Almost always, we never want that).
 732 5. Spaces or TABS at the end of a line.
 733
 734 Whitespace errors are reported in a buffer, and on the modeline.
 735
 736 Modeline will show a W:<x>!<y> to denote a particular type of whitespace,
 737 where `x' and `y' can be one (or more) of:
 738
 739 e - End-of-Line whitespace.
 740 i - Indentation whitespace.
 741 l - Leading whitespace.
 742 s - Space followed by Tab.
 743 t - Trailing whitespace.
 744
 745 If any of the whitespace checks is turned off, the modeline will display a
 746 !<y>.
 747
 748     (since (3) is the most controversial one, here is the rationale: Most
 749     terminal drivers and printer drivers have TAB configured or even
 750     hardcoded to be 8 spaces.  (Some of them allow configuration, but almost
 751     always they default to 8.)
 752
 753     Changing `tab-width' to other than 8 and editing will cause your code to
 754     look different from within Emacs, and say, if you cat it or more it, or
 755     even print it.
 756
 757     Almost all the popular programming modes let you define an offset (like
 758     c-basic-offset or perl-indent-level) to configure the offset, so you
 759     should never have to set your `tab-width' to be other than 8 in all these
 760     modes.  In fact, with an indent level of say, 4, 2 TABS will cause Emacs
 761     to replace your 8 spaces with one \t (try it).  If vi users in your
 762     office complain, tell them to use vim, which distinguishes between
 763     tabstop and shiftwidth (vi equivalent of our offsets), and also ask them
 764     to set smarttab.)
 765
 766 All the above have caused (and will cause) unwanted codeline integration and
 767 merge problems.
 768
 769 whitespace.el will complain if it detects whitespaces on opening a file, and
 770 warn you on closing a file also (in case you had inserted any
 771 whitespaces during the process of your editing)."
 772   (interactive)
 773   (message "Use C-h f whitespace-describe to read about whitespace.el v%s."
 774            whitespace-version))
 775
 776 (defun whitespace-unload-hook ()
 777   (remove-hook 'find-file-hooks 'whitespace-buffer)
 778   (remove-hook 'kill-buffer-hook 'whitespace-buffer))
 779
 780 (provide 'whitespace)
 781
 782 ;;; whitespace.el ends here