Add support for completion in `css-mode'

[gnu-emacs] / lisp / textmodes / css-mode.el

diff --git a/lisp/textmodes/css-mode.el b/lisp/textmodes/css-mode.el
index 44dc4dff3de2f81c79d4d4588338c52e603d69c3..555122b1b42091de3be2baada2632c1724454233 100644 (file)
--- a/lisp/textmodes/css-mode.el
+++ b/lisp/textmodes/css-mode.el
@@ -3,6 +3,7 @@
 ;; Copyright (C) 2006-2015 Free Software Foundation, Inc.
 
 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
+;; Maintainer: Simen Heggestøyl <simenheg@gmail.com>
 ;; Keywords: hypermedia
 
 ;; This file is part of GNU Emacs.
@@ -28,7 +29,7 @@
 
 ;; - electric ; and }
 ;; - filling code with auto-fill-mode
-;; - completion
+;; - attribute value completion
 ;; - fix font-lock errors with multi-line selectors
 
 ;;; Code:
@@ -120,10 +121,17 @@
 ;;    (media . "^ +\\* '\\([^ '\n]+\\)' media group")
 ;;    (property . "^ +\\* '\\([^ '\n]+\\)',")))
 
-(defconst css-pseudo-ids
-  '("active" "after" "before" "first" "first-child" "first-letter" "first-line"
-    "focus" "hover" "lang" "left" "link" "right" "visited")
-  "Identifiers for pseudo-elements and pseudo-classes.")
+(defconst css-pseudo-class-ids
+  '("active" "checked" "disabled" "empty" "enabled" "first"
+    "first-child" "first-of-type" "focus" "hover" "indeterminate" "lang"
+    "last-child" "last-of-type" "left" "link" "nth-child"
+    "nth-last-child" "nth-last-of-type" "nth-of-type" "only-child"
+    "only-of-type" "right" "root" "target" "visited")
+  "Identifiers for pseudo-classes.")
+
+(defconst css-pseudo-element-ids
+  '("after" "before" "first-letter" "first-line")
+  "Identifiers for pseudo-elements.")
 
 (defconst css-at-ids
   '("charset" "font-face" "import" "media" "page")
@@ -258,7 +266,11 @@
          (concat "\\(?:" scss--hash-re
                  "\\|[^@/:{} \t\n#]\\)"
                  "[^:{}#]*\\(?:" scss--hash-re "[^:{}#]*\\)*"))
-       "\\(?::" (regexp-opt css-pseudo-ids t)
+       ;; Even though pseudo-elements should be prefixed by ::, a
+       ;; single colon is accepted for backward compatibility.
+       "\\(?:\\(:" (regexp-opt (append css-pseudo-class-ids
+                                       css-pseudo-element-ids) t)
+       "\\|\\::" (regexp-opt css-pseudo-element-ids t) "\\)"
        "\\(?:([^\)]+)\\)?"
        (if (not sassy)
            "[^:{}\n]*"
@@ -334,6 +346,45 @@
     (`(:before . ,(or "{" "("))
      (if (smie-rule-hanging-p) (smie-rule-parent 0)))))
 
+;;; Completion
+
+(defun css--complete-property ()
+  "Complete property at point."
+  (save-excursion
+    (let ((pos (point)))
+      (skip-chars-backward "-[:alnum:]")
+      (let ((start (point)))
+        (skip-chars-backward " \t\r\n")
+        (when (memq (char-before) '(?\{ ?\;))
+          (list start pos css-property-ids))))))
+
+(defun css--complete-pseudo-element-or-class ()
+  "Complete pseudo-element or pseudo-class at point."
+  (save-excursion
+    (let ((pos (point)))
+      (skip-chars-backward "-[:alnum:]")
+      (when (eq (char-before) ?\:)
+        (list (point) pos
+              (if (eq (char-before (- (point) 1)) ?\:)
+                  css-pseudo-element-ids
+                css-pseudo-class-ids))))))
+
+(defun css--complete-at-rule ()
+  "Complete at-rule (statement beginning with `@') at point."
+  (save-excursion
+    (let ((pos (point)))
+      (skip-chars-backward "-[:alnum:]")
+      (when (eq (char-before) ?\@)
+        (list (point) pos css-at-ids)))))
+
+(defun css-completion-at-point ()
+  "Complete current symbol at point.
+Currently supports completion of CSS properties, pseudo-elements,
+pesudo-classes, and at-rules."
+  (or (css--complete-property)
+      (css--complete-pseudo-element-or-class)
+      (css--complete-at-rule)))
+
 ;;;###autoload
 (define-derived-mode css-mode fundamental-mode "CSS"
   "Major mode to edit Cascading Style Sheets."
@@ -349,7 +400,9 @@
               :forward-token #'css-smie--forward-token
               :backward-token #'css-smie--backward-token)
   (setq-local electric-indent-chars
-              (append css-electric-keys electric-indent-chars)))
+              (append css-electric-keys electric-indent-chars))
+  (add-hook 'completion-at-point-functions
+            #'css-completion-at-point nil 'local))
 
 (defvar comment-continue)