lisp/textmodes/css-mode.el

   1 ;;; css-mode.el --- Major mode to edit CSS files -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 2006-2012  Free Software Foundation, Inc.
   4
   5 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
   6 ;; Keywords: hypermedia
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;; Yet another CSS mode.
  26
  27 ;;; Todo:
  28
  29 ;; - electric ; and }
  30 ;; - filling code with auto-fill-mode
  31 ;; - completion
  32 ;; - fix font-lock errors with multi-line selectors
  33
  34 ;;; Code:
  35
  36 (defgroup css nil
  37   "Cascading Style Sheets (CSS) editing mode."
  38   :group 'languages)
  39
  40 (eval-when-compile (require 'cl))
  41
  42 (defun css-extract-keyword-list (res)
  43   (with-temp-buffer
  44     (url-insert-file-contents "http://www.w3.org/TR/REC-CSS2/css2.txt")
  45     (goto-char (point-max))
  46     (search-backward "Appendix H. Index")
  47     (forward-line)
  48     (delete-region (point-min) (point))
  49     (let ((result nil)
  50           keys)
  51       (dolist (re res)
  52         (goto-char (point-min))
  53         (setq keys nil)
  54         (while (re-search-forward (cdr re) nil t)
  55           (push (match-string 1) keys))
  56         (push (cons (car re) (sort keys 'string-lessp)) result))
  57       (nreverse result))))
  58
  59 (defun css-extract-parse-val-grammar (string env)
  60   (let ((start 0)
  61         (elems ())
  62         name)
  63     (while (string-match
  64             (concat "\\(?:"
  65                     (concat "<a [^>]+><span [^>]+>\\(?:"
  66                             "&lt;\\([^&]+\\)&gt;\\|'\\([^']+\\)'"
  67                             "\\)</span></a>")
  68                     "\\|" "\\(\\[\\)"
  69                     "\\|" "\\(]\\)"
  70                     "\\|" "\\(||\\)"
  71                     "\\|" "\\(|\\)"
  72                     "\\|" "\\([*+?]\\)"
  73                     "\\|" "\\({[^}]+}\\)"
  74                     "\\|" "\\(\\w+\\(?:-\\w+\\)*\\)"
  75                     "\\)[ \t\n]*")
  76             string start)
  77       ;; (assert (eq start (match-beginning 0)))
  78       (setq start (match-end 0))
  79       (cond
  80        ;; Reference to a type of value.
  81        ((setq name (match-string-no-properties 1 string))
  82         (push (intern name) elems))
  83        ;; Reference to another property's values.
  84        ((setq name (match-string-no-properties 2 string))
  85         (setq elems (delete-dups (append (cdr (assoc name env)) elems))))
  86        ;; A literal
  87        ((setq name (match-string-no-properties 9 string))
  88         (push name elems))
  89        ;; We just ignore the rest.  I.e. we ignore the structure because
  90        ;; it's too difficult to exploit anyway (it would allow us to only
  91        ;; complete top/center/bottom after one of left/center/right and
  92        ;; vice-versa).
  93        (t nil)))
  94     elems))
  95
  96
  97 (defun css-extract-props-and-vals ()
  98   (with-temp-buffer
  99     (url-insert-file-contents "http://www.w3.org/TR/CSS21/propidx.html")
 100     (goto-char (point-min))
 101     (let ((props ()))
 102       (while (re-search-forward "#propdef-\\([^\"]+\\)\"><span class=\"propinst-\\1 xref\">'\\1'</span></a>" nil t)
 103         (let ((prop (match-string-no-properties 1)))
 104           (save-excursion
 105             (goto-char (match-end 0))
 106             (search-forward "<td>")
 107             (let ((vals-string (buffer-substring (point)
 108                                                  (progn
 109                                                    (re-search-forward "[ \t\n]+|[ \t\n]+<a href=\"cascade.html#value-def-inherit\" class=\"noxref\"><span class=\"value-inst-inherit\">inherit</span></a>")
 110                                                    (match-beginning 0)))))
 111               ;;
 112               (push (cons prop (css-extract-parse-val-grammar vals-string props))
 113                     props)))))
 114       props)))
 115
 116 ;; Extraction was done with:
 117 ;; (css-extract-keyword-list
 118 ;;  '((pseudo . "^ +\\* :\\([^ \n,]+\\)")
 119 ;;    (at . "^ +\\* @\\([^ \n,]+\\)")
 120 ;;    (descriptor . "^ +\\* '\\([^ '\n]+\\)' (descriptor)")
 121 ;;    (media . "^ +\\* '\\([^ '\n]+\\)' media group")
 122 ;;    (property . "^ +\\* '\\([^ '\n]+\\)',")))
 123
 124 (defconst css-pseudo-ids
 125   '("active" "after" "before" "first" "first-child" "first-letter" "first-line"
 126     "focus" "hover" "lang" "left" "link" "right" "visited")
 127   "Identifiers for pseudo-elements and pseudo-classes.")
 128
 129 (defconst css-at-ids
 130   '("charset" "font-face" "import" "media" "page")
 131   "Identifiers that appear in the form @foo.")
 132
 133 (defconst css-descriptor-ids
 134   '("ascent" "baseline" "bbox" "cap-height" "centerline" "definition-src"
 135     "descent" "font-family" "font-size" "font-stretch" "font-style"
 136     "font-variant" "font-weight" "mathline" "panose-1" "slope" "src" "stemh"
 137     "stemv" "topline" "unicode-range" "units-per-em" "widths" "x-height")
 138   "Identifiers for font descriptors.")
 139
 140 (defconst css-media-ids
 141   '("all" "aural" "bitmap" "continuous" "grid" "paged" "static" "tactile"
 142     "visual")
 143   "Identifiers for types of media.")
 144
 145 (defconst css-property-ids
 146   '("azimuth" "background" "background-attachment" "background-color"
 147     "background-image" "background-position" "background-repeat" "block"
 148     "border" "border-bottom" "border-bottom-color" "border-bottom-style"
 149     "border-bottom-width" "border-collapse" "border-color" "border-left"
 150     "border-left-color" "border-left-style" "border-left-width" "border-right"
 151     "border-right-color" "border-right-style" "border-right-width"
 152     "border-spacing" "border-style" "border-top" "border-top-color"
 153     "border-top-style" "border-top-width" "border-width" "bottom"
 154     "caption-side" "clear" "clip" "color" "compact" "content"
 155     "counter-increment" "counter-reset" "cue" "cue-after" "cue-before"
 156     "cursor" "dashed" "direction" "display" "dotted" "double" "elevation"
 157     "empty-cells" "float" "font" "font-family" "font-size" "font-size-adjust"
 158     "font-stretch" "font-style" "font-variant" "font-weight" "groove" "height"
 159     "hidden" "inline" "inline-table" "inset" "left" "letter-spacing"
 160     "line-height" "list-item" "list-style" "list-style-image"
 161     "list-style-position" "list-style-type" "margin" "margin-bottom"
 162     "margin-left" "margin-right" "margin-top" "marker-offset" "marks"
 163     "max-height" "max-width" "min-height" "min-width" "orphans" "outline"
 164     "outline-color" "outline-style" "outline-width" "outset" "overflow"
 165     "padding" "padding-bottom" "padding-left" "padding-right" "padding-top"
 166     "page" "page-break-after" "page-break-before" "page-break-inside" "pause"
 167     "pause-after" "pause-before" "pitch" "pitch-range" "play-during" "position"
 168     "quotes" "richness" "ridge" "right" "run-in" "size" "solid" "speak"
 169     "speak-header" "speak-numeral" "speak-punctuation" "speech-rate" "stress"
 170     "table" "table-caption" "table-cell" "table-column" "table-column-group"
 171     "table-footer-group" "table-header-group" "table-layout" "table-row"
 172     "table-row-group" "text-align" "text-decoration" "text-indent"
 173     "text-shadow" "text-transform" "top" "unicode-bidi" "vertical-align"
 174     "visibility" "voice-family" "volume" "white-space" "widows" "width"
 175     "word-spacing" "z-index")
 176   "Identifiers for properties.")
 177
 178 (defcustom css-electric-keys '(?\} ?\;) ;; '()
 179   "Self inserting keys which should trigger re-indentation."
 180   :version "22.2"
 181   :type '(repeat character)
 182   :options '((?\} ?\;))
 183   :group 'css)
 184
 185 (defvar css-mode-syntax-table
 186   (let ((st (make-syntax-table)))
 187     ;; C-style comments.
 188     (modify-syntax-entry ?/ ". 14" st)
 189     (modify-syntax-entry ?* ". 23" st)
 190     ;; Strings.
 191     (modify-syntax-entry ?\" "\"" st)
 192     (modify-syntax-entry ?\' "\"" st)
 193     ;; Blocks.
 194     (modify-syntax-entry ?\{ "(}" st)
 195     (modify-syntax-entry ?\} "){" st)
 196     ;; Args in url(...) thingies and other "function calls".
 197     (modify-syntax-entry ?\( "()" st)
 198     (modify-syntax-entry ?\) ")(" st)
 199     ;; To match attributes in selectors.
 200     (modify-syntax-entry ?\[ "(]" st)
 201     (modify-syntax-entry ?\] ")[" st)
 202     ;; Special chars that sometimes come at the beginning of words.
 203     (modify-syntax-entry ?@ "'" st)
 204     ;; (modify-syntax-entry ?: "'" st)
 205     (modify-syntax-entry ?# "'" st)
 206     ;; Distinction between words and symbols.
 207     (modify-syntax-entry ?- "_" st)
 208     st))
 209
 210 (defconst css-escapes-re
 211   "\\\\\\(?:[^\000-\037\177]\\|[0-9a-fA-F]+[ \n\t\r\f]?\\)")
 212 (defconst css-nmchar-re (concat "\\(?:[-[:alnum:]]\\|" css-escapes-re "\\)"))
 213 (defconst css-nmstart-re (concat "\\(?:[[:alpha:]]\\|" css-escapes-re "\\)"))
 214 (defconst css-ident-re (concat css-nmstart-re css-nmchar-re "*"))
 215 (defconst css-proprietary-nmstart-re ;; Vendor-specific properties.
 216   (concat "[-_]" (regexp-opt '("ms" "moz" "o" "khtml" "webkit")) "-"))
 217 (defconst css-name-re (concat css-nmchar-re "+"))
 218
 219 (defface css-selector '((t :inherit font-lock-function-name-face))
 220   "Face to use for selectors."
 221   :group 'css)
 222 (defface css-property '((t :inherit font-lock-variable-name-face))
 223   "Face to use for properties."
 224   :group 'css)
 225 (defface css-proprietary-property '((t :inherit (css-property italic)))
 226   "Face to use for vendor-specific properties.")
 227
 228 (defvar css-font-lock-keywords
 229   `(("!\\s-*important" . font-lock-builtin-face)
 230     ;; Atrules keywords.  IDs not in css-at-ids are valid (ignored).
 231     ;; In fact the regexp should probably be
 232     ;; (,(concat "\\(@" css-ident-re "\\)\\([ \t\n][^;{]*\\)[;{]")
 233     ;;  (1 font-lock-builtin-face))
 234     ;; Since "An at-rule consists of everything up to and including the next
 235     ;; semicolon (;) or the next block, whichever comes first."
 236     (,(concat "@" css-ident-re) . font-lock-builtin-face)
 237     ;; Selectors.
 238     ;; FIXME: attribute selectors don't work well because they may contain
 239     ;; strings which have already been highlighted as f-l-string-face and
 240     ;; thus prevent this highlighting from being applied (actually now that
 241     ;; I use `append' this should work better).  But really the part of hte
 242     ;; selector between [...] should simply not be highlighted.
 243     (,(concat "^\\([ \t]*[^@:{}\n][^:{}]+\\(?::" (regexp-opt css-pseudo-ids t)
 244               "\\(?:([^)]+)\\)?[^:{\n]*\\)*\\)\\(?:\n[ \t]*\\)*{")
 245      (1 'css-selector append))
 246     ;; In the above rule, we allow the open-brace to be on some subsequent
 247     ;; line.  This will only work if we properly mark the intervening text
 248     ;; as being part of a multiline element (and even then, this only
 249     ;; ensures proper refontification, but not proper discovery).
 250     ("^[ \t]*{" (0 (save-excursion
 251                      (goto-char (match-beginning 0))
 252                      (skip-chars-backward " \n\t")
 253                      (put-text-property (point) (match-end 0)
 254                                         'font-lock-multiline t)
 255                      ;; No face.
 256                      nil)))
 257     ;; Properties.  Again, we don't limit ourselves to css-property-ids.
 258     (,(concat "\\(?:[{;]\\|^\\)[ \t]*\\("
 259               "\\(?:\\(" css-proprietary-nmstart-re "\\)\\|"
 260               css-nmstart-re "\\)" css-nmchar-re "*"
 261               "\\)\\s-*:")
 262      (1 (if (match-end 2) 'css-proprietary-property 'css-property)))))
 263
 264 (defvar css-font-lock-defaults
 265   '(css-font-lock-keywords nil t))
 266
 267 ;;;###autoload
 268 (define-derived-mode css-mode fundamental-mode "CSS"
 269   "Major mode to edit Cascading Style Sheets."
 270   (set (make-local-variable 'font-lock-defaults) css-font-lock-defaults)
 271   (set (make-local-variable 'comment-start) "/*")
 272   (set (make-local-variable 'comment-start-skip) "/\\*+[ \t]*")
 273   (set (make-local-variable 'comment-end) "*/")
 274   (set (make-local-variable 'comment-end-skip) "[ \t]*\\*+/")
 275   (set (make-local-variable 'forward-sexp-function) 'css-forward-sexp)
 276   (set (make-local-variable 'parse-sexp-ignore-comments) t)
 277   (set (make-local-variable 'indent-line-function) 'css-indent-line)
 278   (set (make-local-variable 'fill-paragraph-function)
 279        'css-fill-paragraph)
 280   (when css-electric-keys
 281     (let ((fc (make-char-table 'auto-fill-chars)))
 282       (set-char-table-parent fc auto-fill-chars)
 283       (dolist (c css-electric-keys)
 284         (aset fc c 'indent-according-to-mode))
 285       (set (make-local-variable 'auto-fill-chars) fc))))
 286
 287 (defvar comment-continue)
 288
 289 (defun css-fill-paragraph (&optional justify)
 290   (save-excursion
 291     (let ((ppss (syntax-ppss))
 292           (eol (line-end-position)))
 293       (cond
 294        ((and (nth 4 ppss)
 295              (save-excursion
 296                (goto-char (nth 8 ppss))
 297                (forward-comment 1)
 298                (prog1 (not (bolp))
 299                  (setq eol (point)))))
 300         ;; Filling inside a comment whose comment-end marker is not \n.
 301         ;; This code is meant to be generic, so that it works not only for
 302         ;; css-mode but for all modes.
 303         (save-restriction
 304           (narrow-to-region (nth 8 ppss) eol)
 305           (comment-normalize-vars)      ;Will define comment-continue.
 306           (let ((fill-paragraph-function nil)
 307                 (paragraph-separate
 308                  (if (and comment-continue
 309                           (string-match "[^ \t]" comment-continue))
 310                      (concat "\\(?:[ \t]*" (regexp-quote comment-continue)
 311                              "\\)?\\(?:" paragraph-separate "\\)")
 312                    paragraph-separate))
 313                 (paragraph-start
 314                  (if (and comment-continue
 315                           (string-match "[^ \t]" comment-continue))
 316                      (concat "\\(?:[ \t]*" (regexp-quote comment-continue)
 317                              "\\)?\\(?:" paragraph-start "\\)")
 318                    paragraph-start)))
 319             (fill-paragraph justify)
 320             ;; Don't try filling again.
 321             t)))
 322
 323        ((and (null (nth 8 ppss))
 324              (or (nth 1 ppss)
 325                  (and (ignore-errors
 326                         (down-list 1)
 327                         (when (<= (point) eol)
 328                           (setq ppss (syntax-ppss)))))))
 329         (goto-char (nth 1 ppss))
 330         (let ((end (save-excursion
 331                      (ignore-errors (forward-sexp 1) (copy-marker (point) t)))))
 332           (when end
 333             (while (re-search-forward "[{;}]" end t)
 334               (cond
 335                ;; This is a false positive inside a string or comment.
 336                ((nth 8 (syntax-ppss)) nil)
 337                ((eq (char-before) ?\})
 338                 (save-excursion
 339                   (forward-char -1)
 340                   (skip-chars-backward " \t")
 341                   (unless (bolp) (newline))))
 342                (t
 343                 (while
 344                     (progn
 345                       (setq eol (line-end-position))
 346                       (and (forward-comment 1)
 347                            (> (point) eol)
 348                            ;; A multi-line comment should be on its own line.
 349                            (save-excursion (forward-comment -1)
 350                                            (when (< (point) eol)
 351                                              (newline)
 352                                              t)))))
 353                 (if (< (point) eol) (newline)))))
 354             (goto-char (nth 1 ppss))
 355             (indent-region (line-beginning-position 2) end)
 356             ;; Don't use the default filling code.
 357             t)))))))
 358
 359 ;;; Navigation and indentation.
 360
 361 (defconst css-navigation-syntax-table
 362   (let ((st (make-syntax-table css-mode-syntax-table)))
 363     (map-char-table (lambda (c v)
 364                       ;; Turn punctuation (code = 1) into symbol (code = 1).
 365                       (if (eq (car-safe v) 1)
 366                           (set-char-table-range st c (cons 3 (cdr v)))))
 367                     st)
 368     st))
 369
 370 (defun css-backward-sexp (n)
 371   (let ((forward-sexp-function nil))
 372     (if (< n 0) (css-forward-sexp (- n))
 373       (while (> n 0)
 374         (setq n (1- n))
 375         (forward-comment (- (point-max)))
 376         (if (not (eq (char-before) ?\;))
 377             (backward-sexp 1)
 378           (while (progn (backward-sexp 1)
 379                         (save-excursion
 380                           (forward-comment (- (point-max)))
 381                           ;; FIXME: We should also skip punctuation.
 382                           (not (or (bobp) (memq (char-before) '(?\; ?\{))))))))))))
 383
 384 (defun css-forward-sexp (n)
 385   (let ((forward-sexp-function nil))
 386     (if (< n 0) (css-backward-sexp (- n))
 387       (while (> n 0)
 388         (setq n (1- n))
 389         (forward-comment (point-max))
 390         (if (not (eq (char-after) ?\;))
 391             (forward-sexp 1)
 392           (while (progn (forward-sexp 1)
 393                         (save-excursion
 394                           (forward-comment (point-max))
 395                           ;; FIXME: We should also skip punctuation.
 396                           (not (memq (char-after) '(?\; ?\})))))))))))
 397
 398 (defun css-indent-calculate-virtual ()
 399   (if (or (save-excursion (skip-chars-backward " \t") (bolp))
 400           (if (looking-at "\\s(")
 401               (save-excursion
 402                 (forward-char 1) (skip-chars-forward " \t")
 403                 (not (or (eolp) (looking-at comment-start-skip))))))
 404       (current-column)
 405     (css-indent-calculate)))
 406
 407 (defcustom css-indent-offset 4
 408   "Basic size of one indentation step."
 409   :version "22.2"
 410   :type 'integer
 411   :group 'css)
 412
 413 (defun css-indent-calculate ()
 414   (let ((ppss (syntax-ppss))
 415         pos)
 416     (with-syntax-table css-navigation-syntax-table
 417       (save-excursion
 418         (cond
 419          ;; Inside a string.
 420          ((nth 3 ppss) 'noindent)
 421          ;; Inside a comment.
 422          ((nth 4 ppss)
 423           (setq pos (point))
 424           (forward-line -1)
 425           (skip-chars-forward " \t")
 426           (if (>= (nth 8 ppss) (point))
 427               (progn
 428                 (goto-char (nth 8 ppss))
 429                 (if (eq (char-after pos) ?*)
 430                     (forward-char 1)
 431                   (if (not (looking-at comment-start-skip))
 432                       (error "Internal css-mode error")
 433                     (goto-char (match-end 0))))
 434                 (current-column))
 435             (if (and (eq (char-after pos) ?*) (eq (char-after) ?*))
 436                 (current-column)
 437               ;; 'noindent
 438               (current-column)
 439               )))
 440          ;; In normal code.
 441          (t
 442           (or
 443            (when (looking-at "\\s)")
 444              (forward-char 1)
 445              (backward-sexp 1)
 446              (css-indent-calculate-virtual))
 447            (when (looking-at comment-start-skip)
 448              (forward-comment (point-max))
 449              (css-indent-calculate))
 450            (when (save-excursion (forward-comment (- (point-max)))
 451                                  (setq pos (point))
 452                                  (eq (char-syntax (preceding-char)) ?\())
 453              (goto-char (1- pos))
 454              (if (not (looking-at "\\s([ \t]*"))
 455                  (error "Internal css-mode error")
 456                (if (or (memq (char-after (match-end 0)) '(?\n nil))
 457                        (save-excursion (goto-char (match-end 0))
 458                                        (looking-at comment-start-skip)))
 459                    (+ (css-indent-calculate-virtual) css-indent-offset)
 460                  (progn (goto-char (match-end 0)) (current-column)))))
 461            (progn
 462              (css-backward-sexp 1)
 463              (if (looking-at "\\s(")
 464                  (css-indent-calculate)
 465                (css-indent-calculate-virtual))))))))))
 466
 467
 468 (defun css-indent-line ()
 469   "Indent current line according to CSS indentation rules."
 470   (interactive)
 471   (let* ((savep (point))
 472          (forward-sexp-function nil)
 473          (indent (condition-case nil
 474                      (save-excursion
 475                        (forward-line 0)
 476                        (skip-chars-forward " \t")
 477                        (if (>= (point) savep) (setq savep nil))
 478                        (css-indent-calculate))
 479                    (error nil))))
 480     (if (not (numberp indent)) 'noindent
 481       (if savep
 482           (save-excursion (indent-line-to indent))
 483         (indent-line-to indent)))))
 484
 485 (provide 'css-mode)
 486 ;;; css-mode.el ends here