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author | Simen Heggestøyl <simenheg@gmail.com> | 2017-12-16 09:49:54 +0100 |
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committer | Simen Heggestøyl <simenheg@gmail.com> | 2017-12-17 10:26:04 +0100 |
commit | bd9e8b31a1a38a2ffa5c2ff5e805a42ffccc36ec (patch) | |
tree | 441203fb603da9188c2b96171abafbbffe0c8bac /lisp/textmodes/css-mode.el | |
parent | ac0d6c06b805b8f05a854a69639531bf737fea3f (diff) | |
download | emacs-bd9e8b31a1a38a2ffa5c2ff5e805a42ffccc36ec.tar.gz |
Add command for cycling between CSS color formats
* lisp/textmodes/css-mode.el (css-mode-map): Add keybinding for
'css-cycle-color-format'.
(css--rgb-color): Add support for extracting alpha component.
(css--hex-alpha, css--color-to-4-dpc, css--named-color-to-hex)
(css--format-rgba-alpha, css--hex-to-rgb)
(css--rgb-to-named-color-or-hex): New functions.
(css-cycle-color-format): New command for cycling between color
formats.
* test/lisp/textmodes/css-mode-tests.el (css-test-color-to-4-dpc):
(css-test-named-color-to-hex, css-test-format-rgba-alpha)
(css-test-hex-to-rgb, css-test-rgb-to-named-color-or-hex)
(css-test-cycle-color-format, css-test-hex-alpha): New tests for the
changes mentioned above.
* etc/NEWS: Mention the new command.
Diffstat (limited to 'lisp/textmodes/css-mode.el')
-rw-r--r-- | lisp/textmodes/css-mode.el | 133 |
1 files changed, 127 insertions, 6 deletions
diff --git a/lisp/textmodes/css-mode.el b/lisp/textmodes/css-mode.el index b0e66d397f0..f0988827c31 100644 --- a/lisp/textmodes/css-mode.el +++ b/lisp/textmodes/css-mode.el @@ -32,12 +32,13 @@ ;;; Code: -(require 'eww) (require 'cl-lib) (require 'color) +(require 'eww) (require 'seq) (require 'sgml-mode) (require 'smie) +(require 'thingatpt) (eval-when-compile (require 'subr-x)) (defgroup css nil @@ -806,6 +807,7 @@ cannot be completed sensibly: `custom-ident', (defvar css-mode-map (let ((map (make-sparse-keymap))) (define-key map [remap info-lookup-symbol] 'css-lookup-symbol) + (define-key map "\C-c\C-f" 'css-cycle-color-format) map) "Keymap used in `css-mode'.") @@ -936,11 +938,13 @@ cannot be completed sensibly: `custom-ident', "Skip blanks and comments." (while (forward-comment 1))) -(cl-defun css--rgb-color () +(cl-defun css--rgb-color (&optional include-alpha) "Parse a CSS rgb() or rgba() color. Point should be just after the open paren. Returns a hex RGB color, or nil if the color could not be recognized. -This recognizes CSS-color-4 extensions." +This recognizes CSS-color-4 extensions. +When INCLUDE-ALPHA is non-nil, the alpha component is included in +the returned hex string." (let ((result '()) (iter 0)) (while (< iter 4) @@ -952,8 +956,8 @@ This recognizes CSS-color-4 extensions." (number (string-to-number str))) (when is-percent (setq number (* 255 (/ number 100.0)))) - ;; Don't push the alpha. - (when (< iter 3) + (if (and include-alpha (= iter 3)) + (push (round (* number 255)) result) (push (min (max 0 (truncate number)) 255) result)) (goto-char (match-end 0)) (css--color-skip-blanks) @@ -966,7 +970,11 @@ This recognizes CSS-color-4 extensions." (css--color-skip-blanks))) (when (looking-at ")") (forward-char) - (apply #'format "#%02x%02x%02x" (nreverse result))))) + (apply #'format + (if (and include-alpha (= (length result) 4)) + "#%02x%02x%02x%02x" + "#%02x%02x%02x") + (nreverse result))))) (cl-defun css--hsl-color () "Parse a CSS hsl() or hsla() color. @@ -1039,6 +1047,14 @@ This function simply drops any transparency." ;; Either #RGB or #RRGGBB, drop the "A" or "AA". (substring str 0 (if (> (length str) 5) 7 4))) +(defun css--hex-alpha (hex) + "Return the alpha component of CSS color HEX. +HEX can either be in the #RGBA or #RRGGBBAA format. Return nil +if the color doesn't have an alpha component." + (cl-case (length hex) + (5 (string (elt hex 4))) + (9 (substring hex 7 9)))) + (defun css--named-color (start-point str) "Check whether STR, seen at point, is CSS named color. Returns STR if it is a valid color. Special care is taken @@ -1381,6 +1397,111 @@ tags, classes and IDs." (progn (insert ": ;") (forward-char -1)))))))))) +(defun css--color-to-4-dpc (hex) + "Convert the CSS color HEX to four digits per component. +CSS colors use one or two digits per component for RGB hex +values. Convert the given color to four digits per component. + +Note that this function handles CSS colors specifically, and +should not be mixed with those in color.el." + (let ((six-digits (= (length hex) 7))) + (apply + #'concat + `("#" + ,@(seq-mapcat + (apply-partially #'make-list (if six-digits 2 4)) + (seq-partition (seq-drop hex 1) (if six-digits 2 1))))))) + +(defun css--named-color-to-hex () + "Convert named CSS color at point to hex format. +Return non-nil if a conversion was made. + +Note that this function handles CSS colors specifically, and +should not be mixed with those in color.el." + (save-excursion + (unless (or (looking-at css--colors-regexp) + (eq (char-before) ?#)) + (backward-word)) + (when (member (word-at-point) (mapcar #'car css--color-map)) + (looking-at css--colors-regexp) + (let ((color (css--compute-color (point) (match-string 0)))) + (replace-match color)) + t))) + +(defun css--format-rgba-alpha (alpha) + "Return ALPHA component formatted for use in rgba()." + (let ((a (string-to-number (format "%.2f" alpha)))) + (if (or (= a 0) + (= a 1)) + (format "%d" a) + (string-remove-suffix "0" (number-to-string a))))) + +(defun css--hex-to-rgb () + "Convert CSS hex color at point to RGB format. +Return non-nil if a conversion was made. + +Note that this function handles CSS colors specifically, and +should not be mixed with those in color.el." + (save-excursion + (unless (or (eq (char-after) ?#) + (eq (char-before) ?\()) + (backward-sexp)) + (when-let* ((hex (when (looking-at css--colors-regexp) + (and (eq (elt (match-string 0) 0) ?#) + (match-string 0)))) + (rgb (css--hex-color hex))) + (seq-let (r g b) + (mapcar (lambda (x) (round (* x 255))) + (color-name-to-rgb (css--color-to-4-dpc rgb))) + (replace-match + (if-let* ((alpha (css--hex-alpha hex)) + (a (css--format-rgba-alpha + (/ (string-to-number alpha 16) + (float (expt 16 (length alpha))))))) + (format "rgba(%d, %d, %d, %s)" r g b a) + (format "rgb(%d, %d, %d)" r g b)) + t)) + t))) + +(defun css--rgb-to-named-color-or-hex () + "Convert CSS RGB color at point to a named color or hex format. +Convert to a named color if the color at point has a name, else +convert to hex format. Return non-nil if a conversion was made. + +Note that this function handles CSS colors specifically, and +should not be mixed with those in color.el." + (save-excursion + (when-let* ((open-paren-pos (nth 1 (syntax-ppss)))) + (when (save-excursion + (goto-char open-paren-pos) + (looking-back "rgba?" (- (point) 4))) + (goto-char (nth 1 (syntax-ppss))))) + (when (eq (char-before) ?\)) + (backward-sexp)) + (skip-chars-backward "rgba") + (when (looking-at css--colors-regexp) + (let* ((start (match-end 0)) + (color (save-excursion + (goto-char start) + (css--rgb-color t)))) + (when color + (kill-sexp) + (kill-sexp) + (let ((named-color (seq-find (lambda (x) (equal (cdr x) color)) + css--color-map))) + (insert (if named-color (car named-color) color))) + t))))) + +(defun css-cycle-color-format () + "Cycle the color at point between different CSS color formats. +Supported formats are by name (if possible), hexadecimal, and +rgb()/rgba()." + (interactive) + (or (css--named-color-to-hex) + (css--hex-to-rgb) + (css--rgb-to-named-color-or-hex) + (message "It doesn't look like a color at point"))) + ;;;###autoload (define-derived-mode css-mode prog-mode "CSS" "Major mode to edit Cascading Style Sheets (CSS). |