lisp/textmodes/css-mode.el

   1 ;;; css-mode.el --- Major mode to edit CSS files -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 2006-2013 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
  41 (defun css-extract-keyword-list (res)
  42   (with-temp-buffer
  43     (url-insert-file-contents "http://www.w3.org/TR/REC-CSS2/css2.txt")
  44     (goto-char (point-max))
  45     (search-backward "Appendix H. Index")
  46     (forward-line)
  47     (delete-region (point-min) (point))
  48     (let ((result nil)
  49           keys)
  50       (dolist (re res)
  51         (goto-char (point-min))
  52         (setq keys nil)
  53         (while (re-search-forward (cdr re) nil t)
  54           (push (match-string 1) keys))
  55         (push (cons (car re) (sort keys 'string-lessp)) result))
  56       (nreverse result))))
  57
  58 (defun css-extract-parse-val-grammar (string env)
  59   (let ((start 0)
  60         (elems ())
  61         name)
  62     (while (string-match
  63             (concat "\\(?:"
  64                     (concat "<a [^>]+><span [^>]+>\\(?:"
  65                             "&lt;\\([^&]+\\)&gt;\\|'\\([^']+\\)'"
  66                             "\\)</span></a>")
  67                     "\\|" "\\(\\[\\)"
  68                     "\\|" "\\(]\\)"
  69                     "\\|" "\\(||\\)"
  70                     "\\|" "\\(|\\)"
  71                     "\\|" "\\([*+?]\\)"
  72                     "\\|" "\\({[^}]+}\\)"
  73                     "\\|" "\\(\\w+\\(?:-\\w+\\)*\\)"
  74                     "\\)[ \t\n]*")
  75             string start)
  76       ;; (assert (eq start (match-beginning 0)))
  77       (setq start (match-end 0))
  78       (cond
  79        ;; Reference to a type of value.
  80        ((setq name (match-string-no-properties 1 string))
  81         (push (intern name) elems))
  82        ;; Reference to another property's values.
  83        ((setq name (match-string-no-properties 2 string))
  84         (setq elems (delete-dups (append (cdr (assoc name env)) elems))))
  85        ;; A literal
  86        ((setq name (match-string-no-properties 9 string))
  87         (push name elems))
  88        ;; We just ignore the rest.  I.e. we ignore the structure because
  89        ;; it's too difficult to exploit anyway (it would allow us to only
  90        ;; complete top/center/bottom after one of left/center/right and
  91        ;; vice-versa).
  92        (t nil)))
  93     elems))
  94
  95
  96 (defun css-extract-props-and-vals ()
  97   (with-temp-buffer
  98     (url-insert-file-contents "http://www.w3.org/TR/CSS21/propidx.html")
  99     (goto-char (point-min))
 100     (let ((props ()))
 101       (while (re-search-forward "#propdef-\\([^\"]+\\)\"><span class=\"propinst-\\1 xref\">'\\1'</span></a>" nil t)
 102         (let ((prop (match-string-no-properties 1)))
 103           (save-excursion
 104             (goto-char (match-end 0))
 105             (search-forward "<td>")
 106             (let ((vals-string (buffer-substring (point)
 107                                                  (progn
 108                                                    (re-search-forward "[ \t\n]+|[ \t\n]+<a href=\"cascade.html#value-def-inherit\" class=\"noxref\"><span class=\"value-inst-inherit\">inherit</span></a>")
 109                                                    (match-beginning 0)))))
 110               ;;
 111               (push (cons prop (css-extract-parse-val-grammar vals-string props))
 112                     props)))))
 113       props)))
 114
 115 ;; Extraction was done with:
 116 ;; (css-extract-keyword-list
 117 ;;  '((pseudo . "^ +\\* :\\([^ \n,]+\\)")
 118 ;;    (at . "^ +\\* @\\([^ \n,]+\\)")
 119 ;;    (descriptor . "^ +\\* '\\([^ '\n]+\\)' (descriptor)")
 120 ;;    (media . "^ +\\* '\\([^ '\n]+\\)' media group")
 121 ;;    (property . "^ +\\* '\\([^ '\n]+\\)',")))
 122
 123 (defconst css-pseudo-ids
 124   '("active" "after" "before" "first" "first-child" "first-letter" "first-line"
 125     "focus" "hover" "lang" "left" "link" "right" "visited")
 126   "Identifiers for pseudo-elements and pseudo-classes.")
 127
 128 (defconst css-at-ids
 129   '("charset" "font-face" "import" "media" "page")
 130   "Identifiers that appear in the form @foo.")
 131
 132 (defconst css-descriptor-ids
 133   '("ascent" "baseline" "bbox" "cap-height" "centerline" "definition-src"
 134     "descent" "font-family" "font-size" "font-stretch" "font-style"
 135     "font-variant" "font-weight" "mathline" "panose-1" "slope" "src" "stemh"
 136     "stemv" "topline" "unicode-range" "units-per-em" "widths" "x-height")
 137   "Identifiers for font descriptors.")
 138
 139 (defconst css-media-ids
 140   '("all" "aural" "bitmap" "continuous" "grid" "paged" "static" "tactile"
 141     "visual")
 142   "Identifiers for types of media.")
 143
 144 (defconst css-property-ids
 145   '("azimuth" "background" "background-attachment" "background-color"
 146     "background-image" "background-position" "background-repeat" "block"
 147     "border" "border-bottom" "border-bottom-color" "border-bottom-style"
 148     "border-bottom-width" "border-collapse" "border-color" "border-left"
 149     "border-left-color" "border-left-style" "border-left-width" "border-right"
 150     "border-right-color" "border-right-style" "border-right-width"
 151     "border-spacing" "border-style" "border-top" "border-top-color"
 152     "border-top-style" "border-top-width" "border-width" "bottom"
 153     "caption-side" "clear" "clip" "color" "compact" "content"
 154     "counter-increment" "counter-reset" "cue" "cue-after" "cue-before"
 155     "cursor" "dashed" "direction" "display" "dotted" "double" "elevation"
 156     "empty-cells" "float" "font" "font-family" "font-size" "font-size-adjust"
 157     "font-stretch" "font-style" "font-variant" "font-weight" "groove" "height"
 158     "hidden" "inline" "inline-table" "inset" "left" "letter-spacing"
 159     "line-height" "list-item" "list-style" "list-style-image"
 160     "list-style-position" "list-style-type" "margin" "margin-bottom"
 161     "margin-left" "margin-right" "margin-top" "marker-offset" "marks"
 162     "max-height" "max-width" "min-height" "min-width" "orphans" "outline"
 163     "outline-color" "outline-style" "outline-width" "outset" "overflow"
 164     "padding" "padding-bottom" "padding-left" "padding-right" "padding-top"
 165     "page" "page-break-after" "page-break-before" "page-break-inside" "pause"
 166     "pause-after" "pause-before" "pitch" "pitch-range" "play-during" "position"
 167     "quotes" "richness" "ridge" "right" "run-in" "size" "solid" "speak"
 168     "speak-header" "speak-numeral" "speak-punctuation" "speech-rate" "stress"
 169     "table" "table-caption" "table-cell" "table-column" "table-column-group"
 170     "table-footer-group" "table-header-group" "table-layout" "table-row"
 171     "table-row-group" "text-align" "text-decoration" "text-indent"
 172     "text-shadow" "text-transform" "top" "unicode-bidi" "vertical-align"
 173     "visibility" "voice-family" "volume" "white-space" "widows" "width"
 174     "word-spacing" "z-index")
 175   "Identifiers for properties.")
 176
 177 (defcustom css-electric-keys '(?\} ?\;) ;; '()
 178   "Self inserting keys which should trigger re-indentation."
 179   :version "22.2"
 180   :type '(repeat character)
 181   :options '((?\} ?\;))
 182   :group 'css)
 183
 184 (defvar css-mode-syntax-table
 185   (let ((st (make-syntax-table)))
 186     ;; C-style comments.
 187     (modify-syntax-entry ?/ ". 14" st)
 188     (modify-syntax-entry ?* ". 23" st)
 189     ;; Strings.
 190     (modify-syntax-entry ?\" "\"" st)
 191     (modify-syntax-entry ?\' "\"" st)
 192     ;; Blocks.
 193     (modify-syntax-entry ?\{ "(}" st)
 194     (modify-syntax-entry ?\} "){" st)
 195     ;; Args in url(...) thingies and other "function calls".
 196     (modify-syntax-entry ?\( "()" st)
 197     (modify-syntax-entry ?\) ")(" st)
 198     ;; To match attributes in selectors.
 199     (modify-syntax-entry ?\[ "(]" st)
 200     (modify-syntax-entry ?\] ")[" st)
 201     ;; Special chars that sometimes come at the beginning of words.
 202     (modify-syntax-entry ?@ "'" st)
 203     ;; (modify-syntax-entry ?: "'" st)
 204     (modify-syntax-entry ?# "'" st)
 205     ;; Distinction between words and symbols.
 206     (modify-syntax-entry ?- "_" st)
 207     st))
 208
 209 (defconst css-escapes-re
 210   "\\\\\\(?:[^\000-\037\177]\\|[0-9a-fA-F]+[ \n\t\r\f]?\\)")
 211 (defconst css-nmchar-re (concat "\\(?:[-[:alnum:]]\\|" css-escapes-re "\\)"))
 212 (defconst css-nmstart-re (concat "\\(?:[[:alpha:]]\\|" css-escapes-re "\\)"))
 213 (defconst css-ident-re (concat css-nmstart-re css-nmchar-re "*"))
 214 (defconst css-proprietary-nmstart-re ;; Vendor-specific properties.
 215   (concat "[-_]" (regexp-opt '("ms" "moz" "o" "khtml" "webkit")) "-"))
 216 (defconst css-name-re (concat css-nmchar-re "+"))
 217
 218 (defface css-selector '((t :inherit font-lock-function-name-face))
 219   "Face to use for selectors."
 220   :group 'css)
 221 (defface css-property '((t :inherit font-lock-variable-name-face))
 222   "Face to use for properties."
 223   :group 'css)
 224 (defface css-proprietary-property '((t :inherit (css-property italic)))
 225   "Face to use for vendor-specific properties.")
 226
 227 (defvar css-font-lock-keywords
 228   `(("!\\s-*important" . font-lock-builtin-face)
 229     ;; Atrules keywords.  IDs not in css-at-ids are valid (ignored).
 230     ;; In fact the regexp should probably be
 231     ;; (,(concat "\\(@" css-ident-re "\\)\\([ \t\n][^;{]*\\)[;{]")
 232     ;;  (1 font-lock-builtin-face))
 233     ;; Since "An at-rule consists of everything up to and including the next
 234     ;; semicolon (;) or the next block, whichever comes first."
 235     (,(concat "@" css-ident-re) . font-lock-builtin-face)
 236     ;; Selectors.
 237     ;; FIXME: attribute selectors don't work well because they may contain
 238     ;; strings which have already been highlighted as f-l-string-face and
 239     ;; thus prevent this highlighting from being applied (actually now that
 240     ;; I use `append' this should work better).  But really the part of hte
 241     ;; selector between [...] should simply not be highlighted.
 242     (,(concat "^\\([ \t]*[^@:{}\n][^:{}]+\\(?::" (regexp-opt css-pseudo-ids t)
 243               "\\(?:([^)]+)\\)?[^:{\n]*\\)*\\)\\(?:\n[ \t]*\\)*{")
 244      (1 'css-selector append))
 245     ;; In the above rule, we allow the open-brace to be on some subsequent
 246     ;; line.  This will only work if we properly mark the intervening text
 247     ;; as being part of a multiline element (and even then, this only
 248     ;; ensures proper refontification, but not proper discovery).
 249     ("^[ \t]*{" (0 (save-excursion
 250                      (goto-char (match-beginning 0))
 251                      (skip-chars-backward " \n\t")
 252                      (put-text-property (point) (match-end 0)
 253                                         'font-lock-multiline t)
 254                      ;; No face.
 255                      nil)))
 256     ;; Properties.  Again, we don't limit ourselves to css-property-ids.
 257     (,(concat "\\(?:[{;]\\|^\\)[ \t]*\\("
 258               "\\(?:\\(" css-proprietary-nmstart-re "\\)\\|"
 259               css-nmstart-re "\\)" css-nmchar-re "*"
 260               "\\)\\s-*:")
 261      (1 (if (match-end 2) 'css-proprietary-property 'css-property)))))
 262
 263 (defvar css-font-lock-defaults
 264   '(css-font-lock-keywords nil t))
 265
 266 ;;;###autoload
 267 (define-derived-mode css-mode fundamental-mode "CSS"
 268   "Major mode to edit Cascading Style Sheets."
 269   (setq-local font-lock-defaults css-font-lock-defaults)
 270   (setq-local comment-start "/*")
 271   (setq-local comment-start-skip "/\\*+[ \t]*")
 272   (setq-local comment-end "*/")
 273   (setq-local comment-end-skip "[ \t]*\\*+/")
 274   (setq-local forward-sexp-function 'css-forward-sexp)
 275   (setq-local parse-sexp-ignore-comments t)
 276   (setq-local indent-line-function 'css-indent-line)
 277   (setq-local fill-paragraph-function 'css-fill-paragraph)
 278   (setq-local add-log-current-defun-function #'css-current-defun-name)
 279   (when css-electric-keys
 280     (let ((fc (make-char-table 'auto-fill-chars)))
 281       (set-char-table-parent fc auto-fill-chars)
 282       (dolist (c css-electric-keys)
 283         (aset fc c 'indent-according-to-mode))
 284       (setq-local auto-fill-chars fc))))
 285
 286 (defvar comment-continue)
 287
 288 (defun css-fill-paragraph (&optional justify)
 289   (save-excursion
 290     (let ((ppss (syntax-ppss))
 291           (eol (line-end-position)))
 292       (cond
 293        ((and (nth 4 ppss)
 294              (save-excursion
 295                (goto-char (nth 8 ppss))
 296                (forward-comment 1)
 297                (prog1 (not (bolp))
 298                  (setq eol (point)))))
 299         ;; Filling inside a comment whose comment-end marker is not \n.
 300         ;; This code is meant to be generic, so that it works not only for
 301         ;; css-mode but for all modes.
 302         (save-restriction
 303           (narrow-to-region (nth 8 ppss) eol)
 304           (comment-normalize-vars)      ;Will define comment-continue.
 305           (let ((fill-paragraph-function nil)
 306                 (paragraph-separate
 307                  (if (and comment-continue
 308                           (string-match "[^ \t]" comment-continue))
 309                      (concat "\\(?:[ \t]*" (regexp-quote comment-continue)
 310                              "\\)?\\(?:" paragraph-separate "\\)")
 311                    paragraph-separate))
 312                 (paragraph-start
 313                  (if (and comment-continue
 314                           (string-match "[^ \t]" comment-continue))
 315                      (concat "\\(?:[ \t]*" (regexp-quote comment-continue)
 316                              "\\)?\\(?:" paragraph-start "\\)")
 317                    paragraph-start)))
 318             (fill-paragraph justify)
 319             ;; Don't try filling again.
 320             t)))
 321
 322        ((and (null (nth 8 ppss))
 323              (or (nth 1 ppss)
 324                  (and (ignore-errors
 325                         (down-list 1)
 326                         (when (<= (point) eol)
 327                           (setq ppss (syntax-ppss)))))))
 328         (goto-char (nth 1 ppss))
 329         (let ((end (save-excursion
 330                      (ignore-errors (forward-sexp 1) (copy-marker (point) t)))))
 331           (when end
 332             (while (re-search-forward "[{;}]" end t)
 333               (cond
 334                ;; This is a false positive inside a string or comment.
 335                ((nth 8 (syntax-ppss)) nil)
 336                ((eq (char-before) ?\})
 337                 (save-excursion
 338                   (forward-char -1)
 339                   (skip-chars-backward " \t")
 340                   (unless (bolp) (newline))))
 341                (t
 342                 (while
 343                     (progn
 344                       (setq eol (line-end-position))
 345                       (and (forward-comment 1)
 346                            (> (point) eol)
 347                            ;; A multi-line comment should be on its own line.
 348                            (save-excursion (forward-comment -1)
 349                                            (when (< (point) eol)
 350                                              (newline)
 351                                              t)))))
 352                 (if (< (point) eol) (newline)))))
 353             (goto-char (nth 1 ppss))
 354             (indent-region (line-beginning-position 2) end)
 355             ;; Don't use the default filling code.
 356             t)))))))
 357
 358 ;;; Navigation and indentation.
 359
 360 (defconst css-navigation-syntax-table
 361   (let ((st (make-syntax-table css-mode-syntax-table)))
 362     (map-char-table (lambda (c v)
 363                       ;; Turn punctuation (code = 1) into symbol (code = 1).
 364                       (if (eq (car-safe v) 1)
 365                           (set-char-table-range st c (cons 3 (cdr v)))))
 366                     st)
 367     st))
 368
 369 (defun css-backward-sexp (n)
 370   (let ((forward-sexp-function nil))
 371     (if (< n 0) (css-forward-sexp (- n))
 372       (while (> n 0)
 373         (setq n (1- n))
 374         (forward-comment (- (point-max)))
 375         (if (not (eq (char-before) ?\;))
 376             (backward-sexp 1)
 377           (while (progn (backward-sexp 1)
 378                         (save-excursion
 379                           (forward-comment (- (point-max)))
 380                           ;; FIXME: We should also skip punctuation.
 381                           (not (or (bobp) (memq (char-before) '(?\; ?\{))))))))))))
 382
 383 (defun css-forward-sexp (n)
 384   (let ((forward-sexp-function nil))
 385     (if (< n 0) (css-backward-sexp (- n))
 386       (while (> n 0)
 387         (setq n (1- n))
 388         (forward-comment (point-max))
 389         (if (not (eq (char-after) ?\;))
 390             (forward-sexp 1)
 391           (while (progn (forward-sexp 1)
 392                         (save-excursion
 393                           (forward-comment (point-max))
 394                           ;; FIXME: We should also skip punctuation.
 395                           (not (memq (char-after) '(?\; ?\})))))))))))
 396
 397 (defun css-indent-calculate-virtual ()
 398   (if (or (save-excursion (skip-chars-backward " \t") (bolp))
 399           (if (looking-at "\\s(")
 400               (save-excursion
 401                 (forward-char 1) (skip-chars-forward " \t")
 402                 (not (or (eolp) (looking-at comment-start-skip))))))
 403       (current-column)
 404     (css-indent-calculate)))
 405
 406 (defcustom css-indent-offset 4
 407   "Basic size of one indentation step."
 408   :version "22.2"
 409   :type 'integer
 410   :group 'css)
 411
 412 (defun css-indent-calculate ()
 413   (let ((ppss (syntax-ppss))
 414         pos)
 415     (with-syntax-table css-navigation-syntax-table
 416       (save-excursion
 417         (cond
 418          ;; Inside a string.
 419          ((nth 3 ppss) 'noindent)
 420          ;; Inside a comment.
 421          ((nth 4 ppss)
 422           (setq pos (point))
 423           (forward-line -1)
 424           (skip-chars-forward " \t")
 425           (if (>= (nth 8 ppss) (point))
 426               (progn
 427                 (goto-char (nth 8 ppss))
 428                 (if (eq (char-after pos) ?*)
 429                     (forward-char 1)
 430                   (if (not (looking-at comment-start-skip))
 431                       (error "Internal css-mode error")
 432                     (goto-char (match-end 0))))
 433                 (current-column))
 434             (if (and (eq (char-after pos) ?*) (eq (char-after) ?*))
 435                 (current-column)
 436               ;; 'noindent
 437               (current-column)
 438               )))
 439          ;; In normal code.
 440          (t
 441           (or
 442            (when (looking-at "\\s)")
 443              (forward-char 1)
 444              (backward-sexp 1)
 445              (css-indent-calculate-virtual))
 446            (when (looking-at comment-start-skip)
 447              (forward-comment (point-max))
 448              (css-indent-calculate))
 449            (when (save-excursion (forward-comment (- (point-max)))
 450                                  (setq pos (point))
 451                                  (eq (char-syntax (preceding-char)) ?\())
 452              (goto-char (1- pos))
 453              (if (not (looking-at "\\s([ \t]*"))
 454                  (error "Internal css-mode error")
 455                (if (or (memq (char-after (match-end 0)) '(?\n nil))
 456                        (save-excursion (goto-char (match-end 0))
 457                                        (looking-at comment-start-skip)))
 458                    (+ (css-indent-calculate-virtual) css-indent-offset)
 459                  (progn (goto-char (match-end 0)) (current-column)))))
 460            (progn
 461              (css-backward-sexp 1)
 462              (if (looking-at "\\s(")
 463                  (css-indent-calculate)
 464                (css-indent-calculate-virtual))))))))))
 465
 466
 467 (defun css-indent-line ()
 468   "Indent current line according to CSS indentation rules."
 469   (interactive)
 470   (let* ((savep (point))
 471          (forward-sexp-function nil)
 472          (indent (condition-case nil
 473                      (save-excursion
 474                        (forward-line 0)
 475                        (skip-chars-forward " \t")
 476                        (if (>= (point) savep) (setq savep nil))
 477                        (css-indent-calculate))
 478                    (error nil))))
 479     (if (not (numberp indent)) 'noindent
 480       (if savep
 481           (save-excursion (indent-line-to indent))
 482         (indent-line-to indent)))))
 483
 484 (defun css-current-defun-name ()
 485   "Return the name of the CSS section at point, or nil."
 486   (save-excursion
 487     (let ((max (max (point-min) (- (point) 1600))))  ; approx 20 lines back
 488       (when (search-backward "{" max t)
 489         (skip-chars-backward " \t\r\n")
 490         (beginning-of-line)
 491         (if (looking-at "^[ \t]*\\([^{\r\n]*[^ {\t\r\n]\\)")
 492             (match-string-no-properties 1))))))
 493
 494 (provide 'css-mode)
 495 ;;; css-mode.el ends here