lisp/facemenu.el

   1 ;;; facemenu.el --- create a face menu for interactively adding fonts to text
   2
   3 ;; Copyright (C) 1994-1996, 2001-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Boris Goldowsky <boris@gnu.org>
   6 ;; Keywords: faces
   7 ;; Package: emacs
   8
   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 3 of the License, or
  14 ;; (at your option) 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.  If not, see <http://www.gnu.org/licenses/>.
  23
  24 ;;; Commentary:
  25
  26 ;; This file defines a menu of faces (bold, italic, etc) which allows you to
  27 ;; set the face used for a region of the buffer.  Some faces also have
  28 ;; keybindings, which are shown in the menu.
  29 ;;
  30 ;; The menu also contains submenus for indentation and justification-changing
  31 ;; commands.
  32
  33 ;;; Usage:
  34 ;; Selecting a face from the menu or typing the keyboard equivalent will
  35 ;; change the region to use that face.  If you use transient-mark-mode and the
  36 ;; region is not active, the face will be remembered and used for the next
  37 ;; insertion.  It will be forgotten if you move point or make other
  38 ;; modifications before inserting or typing anything.
  39 ;;
  40 ;; Faces can be selected from the keyboard as well.
  41 ;; The standard keybindings are M-o (or ESC o) + letter:
  42 ;; M-o i = "set italic",  M-o b = "set bold", etc.
  43
  44 ;;; Customization:
  45 ;; An alternative set of keybindings that may be easier to type can be set up
  46 ;; using "Alt" or "Hyper" keys.  This requires that you either have or create
  47 ;; an Alt or Hyper key on your keyboard.  On my keyboard, there is a key
  48 ;; labeled "Alt", but to make it act as an Alt key I have to put this command
  49 ;; into my .xinitrc:
  50 ;;    xmodmap -e "add Mod3 = Alt_L"
  51 ;; Or, I can make it into a Hyper key with this:
  52 ;;    xmodmap -e "keysym Alt_L = Hyper_L" -e "add Mod2 = Hyper_L"
  53 ;; Check with local X-perts for how to do it on your system.
  54 ;; Then you can define your keybindings with code like this in your .emacs:
  55 ;;   (setq facemenu-keybindings
  56 ;;    '((default     . [?\H-d])
  57 ;;      (bold        . [?\H-b])
  58 ;;      (italic      . [?\H-i])
  59 ;;      (bold-italic . [?\H-l])
  60 ;;      (underline   . [?\H-u])))
  61 ;;   (facemenu-update)
  62 ;;   (setq facemenu-keymap global-map)
  63 ;;   (define-key global-map [?\H-c] 'facemenu-set-foreground) ; set fg color
  64 ;;   (define-key global-map [?\H-C] 'facemenu-set-background) ; set bg color
  65 ;;
  66 ;; The order of the faces that appear in the menu and their keybindings can be
  67 ;; controlled by setting the variables `facemenu-keybindings' and
  68 ;; `facemenu-new-faces-at-end'.  List faces that you want to use in documents
  69 ;; in `facemenu-listed-faces'.
  70
  71 ;;; Known Problems:
  72 ;; Bold and Italic do not combine to create bold-italic if you select them
  73 ;; both, although most other combinations (eg bold + underline + some color)
  74 ;; do the intuitive thing.
  75 ;;
  76 ;; There is at present no way to display what the faces look like in
  77 ;; the menu itself.
  78 ;;
  79 ;; `list-faces-display' shows the faces in a different order than
  80 ;; this menu, which could be confusing.  I do /not/ sort the list
  81 ;; alphabetically, because I like the default order: it puts the most
  82 ;; basic, common fonts first.
  83 ;;
  84 ;; Please send me any other problems, comments or ideas.
  85
  86 ;;; Code:
  87
  88 (eval-when-compile
  89   (require 'help)
  90   (require 'button))
  91
  92 ;; Global bindings:
  93 (define-key global-map [C-down-mouse-2] 'facemenu-menu)
  94 (define-key global-map "\M-o" 'facemenu-keymap)
  95
  96 (defgroup facemenu nil
  97   "Create a face menu for interactively adding fonts to text."
  98   :group 'faces
  99   :prefix "facemenu-")
 100
 101 (defcustom facemenu-keybindings
 102   (mapcar 'purecopy
 103   '((default     . "d")
 104     (bold        . "b")
 105     (italic      . "i")
 106     (bold-italic . "l") ; {bold} intersect {italic} = {l}
 107     (underline   . "u")))
 108   "Alist of interesting faces and keybindings.
 109 Each element is itself a list: the car is the name of the face,
 110 the next element is the key to use as a keyboard equivalent of the menu item;
 111 the binding is made in `facemenu-keymap'.
 112
 113 The faces specifically mentioned in this list are put at the top of
 114 the menu, in the order specified.  All other faces which are defined
 115 in `facemenu-listed-faces' are listed after them, but get no
 116 keyboard equivalents.
 117
 118 If you change this variable after loading facemenu.el, you will need to call
 119 `facemenu-update' to make it take effect."
 120   :type '(repeat (cons face string))
 121   :group 'facemenu)
 122
 123 (defcustom facemenu-new-faces-at-end t
 124   "Where in the menu to insert newly-created faces.
 125 This should be nil to put them at the top of the menu, or t to put them
 126 just before \"Other\" at the end."
 127   :type 'boolean
 128   :group 'facemenu)
 129
 130 (defcustom facemenu-listed-faces nil
 131   "List of faces to include in the Face menu.
 132 Each element should be a symbol, the name of a face.
 133 The \"basic \" faces in `facemenu-keybindings' are automatically
 134 added to the Face menu, and need not be in this list.
 135
 136 This value takes effect when you load facemenu.el.  If the
 137 list includes symbols which are not defined as faces, they
 138 are ignored; however, subsequently defining or creating
 139 those faces adds them to the menu then.  You can call
 140 `facemenu-update' to recalculate the menu contents, such as
 141 if you change the value of this variable,
 142
 143 If this variable is t, all faces that you apply to text
 144 using the face menu commands (even by name), and all faces
 145 that you define or create, are added to the menu.  You may
 146 find it useful to set this variable to t temporarily while
 147 you define some faces, so that they will be added.  However,
 148 if the value is no longer t and you call `facemenu-update',
 149 it will remove any faces not explicitly in the list."
 150   :type '(choice (const :tag "List all faces" t)
 151                  (const :tag "None" nil)
 152                  (repeat symbol))
 153   :group 'facemenu
 154   :version "22.1")
 155
 156 (defvar facemenu-face-menu
 157   (let ((map (make-sparse-keymap "Face")))
 158     (define-key map "o" (cons (purecopy "Other...") 'facemenu-set-face))
 159     map)
 160   "Menu keymap for faces.")
 161 (defalias 'facemenu-face-menu facemenu-face-menu)
 162 (put 'facemenu-face-menu 'menu-enable '(facemenu-enable-faces-p))
 163
 164 (defvar facemenu-foreground-menu
 165   (let ((map (make-sparse-keymap "Foreground Color")))
 166     (define-key map "o" (cons (purecopy "Other...") 'facemenu-set-foreground))
 167     map)
 168   "Menu keymap for foreground colors.")
 169 (defalias 'facemenu-foreground-menu facemenu-foreground-menu)
 170 (put 'facemenu-foreground-menu 'menu-enable '(facemenu-enable-faces-p))
 171
 172 (defvar facemenu-background-menu
 173   (let ((map (make-sparse-keymap "Background Color")))
 174     (define-key map "o" (cons (purecopy "Other...") 'facemenu-set-background))
 175     map)
 176   "Menu keymap for background colors.")
 177 (defalias 'facemenu-background-menu facemenu-background-menu)
 178 (put 'facemenu-background-menu 'menu-enable '(facemenu-enable-faces-p))
 179
 180 ;;; Condition for enabling menu items that set faces.
 181 (defun facemenu-enable-faces-p ()
 182   ;; Enable the facemenu if facemenu-add-face-function is defined
 183   ;; (e.g. in Tex-mode and SGML mode), or if font-lock is off.
 184   (or (not (and font-lock-mode font-lock-defaults))
 185       facemenu-add-face-function))
 186
 187 (defvar facemenu-special-menu
 188   (let ((map (make-sparse-keymap "Special")))
 189     (define-key map [?s] (cons (purecopy "Remove Special")
 190                                'facemenu-remove-special))
 191     (define-key map [?t] (cons (purecopy "Intangible")
 192                                'facemenu-set-intangible))
 193     (define-key map [?v] (cons (purecopy "Invisible")
 194                                'facemenu-set-invisible))
 195     (define-key map [?r] (cons (purecopy "Read-Only")
 196                                'facemenu-set-read-only))
 197     map)
 198   "Menu keymap for non-face text-properties.")
 199 (defalias 'facemenu-special-menu facemenu-special-menu)
 200
 201 (defvar facemenu-justification-menu
 202   (let ((map (make-sparse-keymap "Justification")))
 203     (define-key map [?c] (cons (purecopy "Center") 'set-justification-center))
 204     (define-key map [?b] (cons (purecopy "Full") 'set-justification-full))
 205     (define-key map [?r] (cons (purecopy "Right") 'set-justification-right))
 206     (define-key map [?l] (cons (purecopy "Left") 'set-justification-left))
 207     (define-key map [?u] (cons (purecopy "Unfilled") 'set-justification-none))
 208     map)
 209   "Submenu for text justification commands.")
 210 (defalias 'facemenu-justification-menu facemenu-justification-menu)
 211
 212 (defvar facemenu-indentation-menu
 213   (let ((map (make-sparse-keymap "Indentation")))
 214     (define-key map [decrease-right-margin]
 215       (cons (purecopy "Indent Right Less") 'decrease-right-margin))
 216     (define-key map [increase-right-margin]
 217       (cons (purecopy "Indent Right More") 'increase-right-margin))
 218     (define-key map [decrease-left-margin]
 219       (cons (purecopy "Indent Less") 'decrease-left-margin))
 220     (define-key map [increase-left-margin]
 221       (cons (purecopy "Indent More") 'increase-left-margin))
 222     map)
 223   "Submenu for indentation commands.")
 224 (defalias 'facemenu-indentation-menu facemenu-indentation-menu)
 225
 226 ;; This is split up to avoid an overlong line in loaddefs.el.
 227 (defvar facemenu-menu nil
 228   "Facemenu top-level menu keymap.")
 229 (setq facemenu-menu (make-sparse-keymap "Text Properties"))
 230 (let ((map facemenu-menu))
 231   (define-key map [dc] (cons (purecopy "Display Colors") 'list-colors-display))
 232   (define-key map [df] (cons (purecopy "Display Faces") 'list-faces-display))
 233   (define-key map [dp] (cons (purecopy "Describe Properties")
 234                              'describe-text-properties))
 235   (define-key map [ra] (list 'menu-item (purecopy "Remove Text Properties")
 236                              'facemenu-remove-all
 237                              :enable 'mark-active))
 238   (define-key map [rm] (list 'menu-item (purecopy "Remove Face Properties")
 239                              'facemenu-remove-face-props
 240                              :enable 'mark-active))
 241   (define-key map [s1] (list (purecopy "--"))))
 242 (let ((map facemenu-menu))
 243   (define-key map [in] (cons (purecopy "Indentation")
 244                              'facemenu-indentation-menu))
 245   (define-key map [ju] (cons (purecopy "Justification")
 246                              'facemenu-justification-menu))
 247   (define-key map [s2] (list (purecopy "--")))
 248   (define-key map [sp] (cons (purecopy "Special Properties")
 249                              'facemenu-special-menu))
 250   (define-key map [bg] (cons (purecopy "Background Color")
 251                              'facemenu-background-menu))
 252   (define-key map [fg] (cons (purecopy "Foreground Color")
 253                              'facemenu-foreground-menu))
 254   (define-key map [fc] (cons (purecopy "Face")
 255                              'facemenu-face-menu)))
 256 (defalias 'facemenu-menu facemenu-menu)
 257
 258 (defvar facemenu-keymap
 259   (let ((map (make-sparse-keymap "Set face")))
 260     (define-key map "o" (cons (purecopy "Other...") 'facemenu-set-face))
 261     (define-key map "\M-o" 'font-lock-fontify-block)
 262     map)
 263   "Keymap for face-changing commands.
 264 `Facemenu-update' fills in the keymap according to the bindings
 265 requested in `facemenu-keybindings'.")
 266 (defalias 'facemenu-keymap facemenu-keymap)
 267
 268
 269 (defcustom facemenu-add-face-function nil
 270   "Function called at beginning of text to change or nil.
 271 This function is passed the FACE to set and END of text to change, and must
 272 return a string which is inserted.  It may set `facemenu-end-add-face'."
 273   :type '(choice (const :tag "None" nil)
 274                  function)
 275   :group 'facemenu)
 276
 277 (defcustom facemenu-end-add-face nil
 278   "String to insert or function called at end of text to change or nil.
 279 This function is passed the FACE to set, and must return a string which is
 280 inserted."
 281   :type '(choice (const :tag "None" nil)
 282                  string
 283                  function)
 284   :group 'facemenu)
 285
 286 (defcustom facemenu-remove-face-function nil
 287   "When non-nil, this is a function called to remove faces.
 288 This function is passed the START and END of text to change.
 289 May also be t meaning to use `facemenu-add-face-function'."
 290   :type '(choice (const :tag "None" nil)
 291                  (const :tag "Use add-face" t)
 292                  function)
 293   :group 'facemenu)
 294
 295 ;;; Internal Variables
 296
 297 (defvar facemenu-color-alist nil
 298   "Alist of colors, used for completion.
 299 If this is nil, then the value of (defined-colors) is used.")
 300
 301 (defun facemenu-update ()
 302   "Add or update the \"Face\" menu in the menu bar.
 303 You can call this to update things if you change any of the menu configuration
 304 variables."
 305   (interactive)
 306
 307   ;; Add each defined face to the menu.
 308   (facemenu-iterate 'facemenu-add-new-face
 309                     (facemenu-complete-face-list facemenu-keybindings)))
 310
 311 (defun facemenu-set-face (face &optional start end)
 312   "Apply FACE to the region or next character typed.
 313
 314 If the region is active (normally true except in Transient
 315 Mark mode) and nonempty, and there is no prefix argument,
 316 this command applies FACE to the region.  Otherwise, it applies FACE
 317 to the faces to use for the next character
 318 inserted.  (Moving point or switching buffers before typing
 319 a character to insert cancels the specification.)
 320
 321 If FACE is `default', to \"apply\" it means clearing
 322 the list of faces to be used.  For any other value of FACE,
 323 to \"apply\" it means putting FACE at the front of the list
 324 of faces to be used, and removing any faces further
 325 along in the list that would be completely overridden by
 326 preceding faces (including FACE).
 327
 328 This command can also add FACE to the menu of faces,
 329 if `facemenu-listed-faces' says to do that."
 330   (interactive (list (progn
 331                        (barf-if-buffer-read-only)
 332                        (read-face-name "Use face" (face-at-point t)))
 333                      (if (and mark-active (not current-prefix-arg))
 334                          (region-beginning))
 335                      (if (and mark-active (not current-prefix-arg))
 336                          (region-end))))
 337   (facemenu-add-new-face face)
 338   (facemenu-add-face face start end))
 339
 340 (defun facemenu-set-foreground (color &optional start end)
 341   "Set the foreground COLOR of the region or next character typed.
 342 This command reads the color in the minibuffer.
 343
 344 If the region is active (normally true except in Transient Mark mode)
 345 and there is no prefix argument, this command sets the region to the
 346 requested face.
 347
 348 Otherwise, this command specifies the face for the next character
 349 inserted.  Moving point or switching buffers before
 350 typing a character to insert cancels the specification."
 351   (interactive (list (progn
 352                        (barf-if-buffer-read-only)
 353                        (read-color "Foreground color: "))
 354                      (if (and mark-active (not current-prefix-arg))
 355                          (region-beginning))
 356                      (if (and mark-active (not current-prefix-arg))
 357                          (region-end))))
 358   (facemenu-set-face-from-menu
 359    (facemenu-add-new-color color 'facemenu-foreground-menu)
 360    start end))
 361
 362 (defun facemenu-set-background (color &optional start end)
 363   "Set the background COLOR of the region or next character typed.
 364 This command reads the color in the minibuffer.
 365
 366 If the region is active (normally true except in Transient Mark mode)
 367 and there is no prefix argument, this command sets the region to the
 368 requested face.
 369
 370 Otherwise, this command specifies the face for the next character
 371 inserted.  Moving point or switching buffers before
 372 typing a character to insert cancels the specification."
 373   (interactive (list (progn
 374                        (barf-if-buffer-read-only)
 375                        (read-color "Background color: "))
 376                      (if (and mark-active (not current-prefix-arg))
 377                          (region-beginning))
 378                      (if (and mark-active (not current-prefix-arg))
 379                          (region-end))))
 380   (facemenu-set-face-from-menu
 381    (facemenu-add-new-color color 'facemenu-background-menu)
 382    start end))
 383
 384 (defun facemenu-set-face-from-menu (face start end)
 385   "Set the FACE of the region or next character typed.
 386 This function is designed to be called from a menu; FACE is determined
 387 using the event type of the menu entry.  If FACE is a symbol whose
 388 name starts with \"fg:\" or \"bg:\", then this functions sets the
 389 foreground or background to the color specified by the rest of the
 390 symbol's name.  Any other symbol is considered the name of a face.
 391
 392 If the region is active (normally true except in Transient Mark mode)
 393 and there is no prefix argument, this command sets the region to the
 394 requested face.
 395
 396 Otherwise, this command specifies the face for the next character
 397 inserted.  Moving point or switching buffers before typing a character
 398 to insert cancels the specification."
 399   (interactive (list last-command-event
 400                      (if (and mark-active (not current-prefix-arg))
 401                          (region-beginning))
 402                      (if (and mark-active (not current-prefix-arg))
 403                          (region-end))))
 404   (barf-if-buffer-read-only)
 405   (facemenu-add-face
 406    (let ((fn (symbol-name face)))
 407      (if (string-match "\\`\\([fb]\\)g:\\(.+\\)" fn)
 408          (list (list (if (string= (match-string 1 fn) "f")
 409                          :foreground
 410                        :background)
 411                      (match-string 2 fn)))
 412        face))
 413    start end))
 414
 415 (defun facemenu-set-invisible (start end)
 416   "Make the region invisible.
 417 This sets the `invisible' text property; it can be undone with
 418 `facemenu-remove-special'."
 419   (interactive "r")
 420   (add-text-properties start end '(invisible t)))
 421
 422 (defun facemenu-set-intangible (start end)
 423   "Make the region intangible: disallow moving into it.
 424 This sets the `intangible' text property; it can be undone with
 425 `facemenu-remove-special'."
 426   (interactive "r")
 427   (add-text-properties start end '(intangible t)))
 428
 429 (defun facemenu-set-read-only (start end)
 430   "Make the region unmodifiable.
 431 This sets the `read-only' text property; it can be undone with
 432 `facemenu-remove-special'."
 433   (interactive "r")
 434   (add-text-properties start end '(read-only t)))
 435
 436 (defun facemenu-remove-face-props (start end)
 437   "Remove `face' and `mouse-face' text properties."
 438   (interactive "*r") ; error if buffer is read-only despite the next line.
 439   (let ((inhibit-read-only t))
 440     (remove-text-properties
 441      start end '(face nil mouse-face nil))))
 442
 443 (defun facemenu-remove-all (start end)
 444   "Remove all text properties from the region."
 445   (interactive "*r") ; error if buffer is read-only despite the next line.
 446   (let ((inhibit-read-only t))
 447     (set-text-properties start end nil)))
 448
 449 (defun facemenu-remove-special (start end)
 450   "Remove all the \"special\" text properties from the region.
 451 These special properties include `invisible', `intangible' and `read-only'."
 452   (interactive "*r") ; error if buffer is read-only despite the next line.
 453   (let ((inhibit-read-only t))
 454     (remove-text-properties
 455      start end '(invisible nil intangible nil read-only nil))))
 456 \f
 457 (defalias 'facemenu-read-color 'read-color)
 458
 459 (defcustom list-colors-sort nil
 460   "Color sort order for `list-colors-display'.
 461 nil means default implementation-dependent order (defined in `x-colors').
 462 `name' sorts by color name.
 463 `rgb' sorts by red, green, blue components.
 464 `(rgb-dist . COLOR)' sorts by the RGB distance to the specified color.
 465 `hsv' sorts by hue, saturation, value.
 466 `(hsv-dist . COLOR)' sorts by the HSV distance to the specified color
 467 and excludes grayscale colors.
 468 `luminance' sorts by relative luminance in the CIE XYZ color space."
 469   :type '(choice (const :tag "Unsorted" nil)
 470                  (const :tag "Color Name" name)
 471                  (const :tag "Red-Green-Blue" rgb)
 472                  (cons :tag "Distance on RGB cube"
 473                        (const :tag "Distance from Color" rgb-dist)
 474                        (color :tag "Source Color Name"))
 475                  (const :tag "Hue-Saturation-Value" hsv)
 476                  (cons :tag "Distance on HSV cylinder"
 477                        (const :tag "Distance from Color" hsv-dist)
 478                        (color :tag "Source Color Name"))
 479                  (const :tag "Luminance" luminance))
 480   :group 'facemenu
 481   :version "24.1")
 482
 483 (defun list-colors-sort-key (color)
 484   "Return a list of keys for sorting colors depending on `list-colors-sort'.
 485 COLOR is the name of the color.  When return value is nil,
 486 filter out the color from the output."
 487   (require 'color)
 488   (cond
 489    ((null list-colors-sort) color)
 490    ((eq list-colors-sort 'name)
 491     (downcase color))
 492    ((eq list-colors-sort 'rgb)
 493     (color-values color))
 494    ((eq (car-safe list-colors-sort) 'rgb-dist)
 495     (color-distance color (cdr list-colors-sort)))
 496    ((eq list-colors-sort 'hsv)
 497     (apply 'color-rgb-to-hsv (color-name-to-rgb color)))
 498    ((eq (car-safe list-colors-sort) 'hsv-dist)
 499     (let* ((c-rgb (color-name-to-rgb color))
 500            (c-hsv (apply 'color-rgb-to-hsv c-rgb))
 501            (o-hsv (apply 'color-rgb-to-hsv
 502                          (color-name-to-rgb (cdr list-colors-sort)))))
 503       (unless (and (eq (nth 0 c-rgb) (nth 1 c-rgb)) ; exclude grayscale
 504                    (eq (nth 1 c-rgb) (nth 2 c-rgb)))
 505         ;; 3D Euclidean distance (sqrt is not needed for sorting)
 506         (+ (expt (- 180 (abs (- 180 (abs (- (nth 0 c-hsv) ; wrap hue
 507                                             (nth 0 o-hsv)))))) 2)
 508            (expt (- (nth 1 c-hsv) (nth 1 o-hsv)) 2)
 509            (expt (- (nth 2 c-hsv) (nth 2 o-hsv)) 2)))))
 510    ((eq list-colors-sort 'luminance)
 511     (let ((c-rgb (color-name-to-rgb color)))
 512       (+ (* (nth 0 c-rgb) 0.21266729)
 513          (* (nth 1 c-rgb) 0.7151522)
 514          (* (nth 2 c-rgb) 0.0721750))))))
 515
 516 (defvar list-colors-callback nil
 517   "Value of CALLBACK arg passed to `list-colors-display'; internal use.")
 518
 519 (defun list-colors-redisplay (_ignore-auto _noconfirm)
 520   "Redisplay the colors using `list-colors-sort'.
 521
 522 This is installed as a `revert-buffer-function' in the *Colors* buffer."
 523   (list-colors-display nil (buffer-name) list-colors-callback))
 524
 525 (defun list-colors-display (&optional list buffer-name callback)
 526   "Display names of defined colors, and show what they look like.
 527 If the optional argument LIST is non-nil, it should be a list of
 528 colors to display.  Otherwise, this command computes a list of
 529 colors that the current display can handle.  Customize
 530 `list-colors-sort' to change the order in which colors are shown.
 531 Type `g' or \\[revert-buffer] after customizing `list-colors-sort'
 532 to redisplay colors in the new order.
 533
 534 If the optional argument BUFFER-NAME is nil, it defaults to *Colors*.
 535
 536 If the optional argument CALLBACK is non-nil, it should be a
 537 function to call each time the user types RET or clicks on a
 538 color.  The function should accept a single argument, the color name."
 539   (interactive)
 540   (when (and (null list) (> (display-color-cells) 0))
 541     (setq list (list-colors-duplicates (defined-colors)))
 542     (when list-colors-sort
 543       ;; Schwartzian transform with `(color key1 key2 key3 ...)'.
 544       (setq list (mapcar
 545                   'car
 546                   (sort (delq nil (mapcar
 547                                    (lambda (c)
 548                                      (let ((key (list-colors-sort-key
 549                                                  (car c))))
 550                                        (when key
 551                                          (cons c (if (consp key) key
 552                                                    (list key))))))
 553                                    list))
 554                         (lambda (a b)
 555                           (let* ((a-keys (cdr a))
 556                                  (b-keys (cdr b))
 557                                  (a-key (car a-keys))
 558                                  (b-key (car b-keys)))
 559                             ;; Skip common keys at the beginning of key lists.
 560                             (while (and a-key b-key (equal a-key b-key))
 561                               (setq a-keys (cdr a-keys) a-key (car a-keys)
 562                                     b-keys (cdr b-keys) b-key (car b-keys)))
 563                             (cond
 564                              ((and (numberp a-key) (numberp b-key))
 565                               (< a-key b-key))
 566                              ((and (stringp a-key) (stringp b-key))
 567                               (string< a-key b-key)))))))))
 568     (when (memq (display-visual-class) '(gray-scale pseudo-color direct-color))
 569       ;; Don't show more than what the display can handle.
 570       (let ((lc (nthcdr (1- (display-color-cells)) list)))
 571         (if lc
 572             (setcdr lc nil)))))
 573   (unless buffer-name
 574     (setq buffer-name "*Colors*"))
 575   (with-help-window buffer-name
 576     (with-current-buffer standard-output
 577       (erase-buffer)
 578       (list-colors-print list callback)
 579       (set-buffer-modified-p nil)
 580       (setq truncate-lines t)
 581       (setq-local list-colors-callback callback)
 582       (setq revert-buffer-function 'list-colors-redisplay)))
 583   (when callback
 584     (pop-to-buffer buffer-name)
 585     (message "Click on a color to select it.")))
 586
 587 (defun list-colors-print (list &optional callback)
 588   (let ((callback-fn
 589          (if callback
 590              `(lambda (button)
 591                 (funcall ,callback (button-get button 'color-name))))))
 592     (dolist (color list)
 593       (if (consp color)
 594           (if (cdr color)
 595               (setq color (sort color (lambda (a b)
 596                                         (string< (downcase a)
 597                                                  (downcase b))))))
 598         (setq color (list color)))
 599       (let* ((opoint (point))
 600              (color-values (color-values (car color)))
 601              (light-p (>= (apply 'max color-values)
 602                           (* (car (color-values "white")) .5))))
 603         (insert (car color))
 604         (indent-to 22)
 605         (put-text-property opoint (point) 'face `(:background ,(car color)))
 606         (put-text-property
 607          (prog1 (point)
 608            (insert " ")
 609            ;; Insert all color names.
 610            (insert (mapconcat 'identity color ",")))
 611          (point)
 612          'face (list :foreground (car color)))
 613         (insert (propertize " " 'display '(space :align-to (- right 9))))
 614         (insert " ")
 615         (insert (propertize
 616                  (apply 'format "#%02x%02x%02x"
 617                         (mapcar (lambda (c) (lsh c -8))
 618                                 color-values))
 619                  'mouse-face 'highlight
 620                  'help-echo
 621                  (let ((hsv (apply 'color-rgb-to-hsv
 622                                    (color-name-to-rgb (car color)))))
 623                    (format "H:%.2f S:%.2f V:%.2f"
 624                            (nth 0 hsv) (nth 1 hsv) (nth 2 hsv)))))
 625         (when callback
 626           (make-text-button
 627            opoint (point)
 628            'follow-link t
 629            'mouse-face (list :background (car color)
 630                              :foreground (if light-p "black" "white"))
 631            'color-name (car color)
 632            'action callback-fn)))
 633       (insert "\n"))
 634     (goto-char (point-min))))
 635
 636
 637 (defun list-colors-duplicates (&optional list)
 638   "Return a list of colors with grouped duplicate colors.
 639 If a color has no duplicates, then the element of the returned list
 640 has the form (COLOR-NAME).  The element of the returned list with
 641 duplicate colors has the form (COLOR-NAME DUPLICATE-COLOR-NAME ...).
 642 This function uses the predicate `facemenu-color-equal' to compare
 643 color names.  If the optional argument LIST is non-nil, it should
 644 be a list of colors to display.  Otherwise, this function uses
 645 a list of colors that the current display can handle."
 646   (let* ((list (mapcar 'list (or list (defined-colors))))
 647          (l list))
 648     (while (cdr l)
 649       (if (and (facemenu-color-equal (car (car l)) (car (car (cdr l))))
 650                ;; On MS-Windows, there are logical colors that might have
 651                ;; the same value but different names and meanings.  For
 652                ;; example, `SystemMenuText' (the color w32 uses for the
 653                ;; text in menu entries) and `SystemWindowText' (the default
 654                ;; color w32 uses for the text in windows and dialogs) may
 655                ;; be the same display color and be adjacent in the list.
 656                ;; These system colors all have names prefixed with "System",
 657                ;; which is hardcoded in w32fns.c (SYSTEM_COLOR_PREFIX).
 658                ;; This makes them different to any other color.  Bug#9722
 659                (not (and (eq system-type 'windows-nt)
 660                          (string-match-p "^System" (car (car l))))))
 661           (progn
 662             (setcdr (car l) (cons (car (car (cdr l))) (cdr (car l))))
 663             (setcdr l (cdr (cdr l))))
 664         (setq l (cdr l))))
 665     list))
 666
 667 (defun facemenu-color-equal (a b)
 668   "Return t if colors A and B are the same color.
 669 A and B should be strings naming colors.
 670 This function queries the display system to find out what the color
 671 names mean.  It returns nil if the colors differ or if it can't
 672 determine the correct answer."
 673   (cond ((equal a b) t)
 674         ((equal (color-values a) (color-values b)))))
 675
 676
 677 (defvar facemenu-self-insert-data nil)
 678
 679 (defun facemenu-post-self-insert-function ()
 680   (when (and (car facemenu-self-insert-data)
 681              (eq last-command (cdr facemenu-self-insert-data)))
 682     (put-text-property (1- (point)) (point)
 683                        'face (car facemenu-self-insert-data))
 684     (setq facemenu-self-insert-data nil))
 685   (remove-hook 'post-self-insert-hook 'facemenu-post-self-insert-function))
 686
 687 (defun facemenu-set-self-insert-face (face)
 688   "Arrange for the next self-inserted char to have face `face'."
 689   (setq facemenu-self-insert-data (cons face this-command))
 690   (add-hook 'post-self-insert-hook 'facemenu-post-self-insert-function))
 691
 692 (defun facemenu-add-face (face &optional start end)
 693   "Add FACE to text between START and END.
 694 If START is nil or START to END is empty, add FACE to next typed character
 695 instead.  For each section of that region that has a different face property,
 696 FACE will be consed onto it, and other faces that are completely hidden by
 697 that will be removed from the list.
 698 If `facemenu-add-face-function' and maybe `facemenu-end-add-face' are non-nil,
 699 they are used to set the face information.
 700
 701 As a special case, if FACE is `default', then the region is left with NO face
 702 text property.  Otherwise, selecting the default face would not have any
 703 effect.  See `facemenu-remove-face-function'."
 704   (interactive "*xFace: \nr")
 705   (cond
 706    ((and (eq face 'default)
 707          (not (eq facemenu-remove-face-function t)))
 708     (if facemenu-remove-face-function
 709         (funcall facemenu-remove-face-function start end)
 710       (if (and start (< start end))
 711           (remove-text-properties start end '(face default))
 712         (facemenu-set-self-insert-face 'default))))
 713    (facemenu-add-face-function
 714     (save-excursion
 715       (if end (goto-char end))
 716       (save-excursion
 717         (if start (goto-char start))
 718         (insert-before-markers
 719          (funcall facemenu-add-face-function face end)))
 720       (if facemenu-end-add-face
 721           (insert (if (stringp facemenu-end-add-face)
 722                       facemenu-end-add-face
 723                     (funcall facemenu-end-add-face face))))))
 724    ((and start (< start end))
 725     (let ((part-start start) part-end)
 726       (while (not (= part-start end))
 727         (setq part-end (next-single-property-change part-start 'face
 728                                                     nil end))
 729         (let ((prev (get-text-property part-start 'face)))
 730           (put-text-property part-start part-end 'face
 731                              (if (null prev)
 732                                  face
 733                                (facemenu-active-faces
 734                                 (cons face
 735                                       (if (face-list-p prev)
 736                                           prev
 737                                         (list prev)))
 738                                 ;; Specify the selected frame
 739                                 ;; because nil would mean to use
 740                                 ;; the new-frame default settings,
 741                                 ;; and those are usually nil.
 742                                 (selected-frame)))))
 743         (setq part-start part-end))))
 744    (t
 745     (facemenu-set-self-insert-face
 746      (if (eq last-command (cdr facemenu-self-insert-data))
 747          (cons face (if (listp (car facemenu-self-insert-data))
 748                         (car facemenu-self-insert-data)
 749                       (list (car facemenu-self-insert-data))))
 750        face))))
 751   (unless (facemenu-enable-faces-p)
 752     (message "Font-lock mode will override any faces you set in this buffer")))
 753
 754 (defun facemenu-active-faces (face-list &optional frame)
 755   "Return from FACE-LIST those faces that would be used for display.
 756 This means each face attribute is not specified in a face earlier in FACE-LIST
 757 and such a face is therefore active when used to display text.
 758 If the optional argument FRAME is given, use the faces in that frame; otherwise
 759 use the selected frame.  If t, then the global, non-frame faces are used."
 760   (let* ((mask-atts (copy-sequence
 761                      (if (consp (car face-list))
 762                          (face-attributes-as-vector (car face-list))
 763                        (or (internal-lisp-face-p (car face-list) frame)
 764                            (check-face (car face-list))))))
 765          (active-list (list (car face-list)))
 766          (face-list (cdr face-list))
 767          (mask-len (length mask-atts)))
 768     (while face-list
 769       (if (let ((face-atts
 770                  (if (consp (car face-list))
 771                      (face-attributes-as-vector (car face-list))
 772                    (or (internal-lisp-face-p (car face-list) frame)
 773                        (check-face (car face-list)))))
 774                 (i mask-len)
 775                 (useful nil))
 776             (while (>= (setq i (1- i)) 0)
 777               (and (not (memq (aref face-atts i) '(nil unspecified)))
 778                    (memq (aref mask-atts i) '(nil unspecified))
 779                    (aset mask-atts i (setq useful t))))
 780             useful)
 781           (setq active-list (cons (car face-list) active-list)))
 782       (setq face-list (cdr face-list)))
 783     (nreverse active-list)))
 784
 785 (defun facemenu-add-new-face (face)
 786   "Add FACE (a face) to the Face menu if `facemenu-listed-faces' says so.
 787 This is called whenever you create a new face, and at other times."
 788   (let* (name
 789          symbol
 790          menu docstring
 791          (key (cdr (assoc face facemenu-keybindings)))
 792          function menu-val)
 793     (if (symbolp face)
 794         (setq name (symbol-name face)
 795               symbol face)
 796       (setq name face
 797             symbol (intern name)))
 798     (setq menu 'facemenu-face-menu)
 799     (setq docstring
 800           (purecopy (format "Select face `%s' for subsequent insertion.
 801 If the mark is active and there is no prefix argument,
 802 apply face `%s' to the region instead.
 803 This command was defined by `facemenu-add-new-face'."
 804                   name name)))
 805     (cond ((facemenu-iterate ; check if equivalent face is already in the menu
 806             (lambda (m) (and (listp m)
 807                              (symbolp (car m))
 808                              ;; Avoid error in face-equal
 809                              ;; when a non-face is erroneously present.
 810                              (facep (car m))
 811                              (face-equal (car m) symbol)))
 812             (cdr (symbol-function menu))))
 813           ;; Faces with a keyboard equivalent.  These go at the front.
 814           (key
 815            (setq function (intern (concat "facemenu-set-" name)))
 816            (fset function
 817                  `(lambda ()
 818                     ,docstring
 819                     (interactive)
 820                     (facemenu-set-face
 821                      (quote ,symbol)
 822                      (if (and mark-active (not current-prefix-arg))
 823                          (region-beginning))
 824                      (if (and mark-active (not current-prefix-arg))
 825                          (region-end)))))
 826            (define-key 'facemenu-keymap key (cons name function))
 827            (define-key menu key (cons name function)))
 828           ;; Faces with no keyboard equivalent.  Figure out where to put it:
 829           ((or (eq t facemenu-listed-faces)
 830                (memq symbol facemenu-listed-faces))
 831            (setq key (vector symbol)
 832                  function 'facemenu-set-face-from-menu
 833                  menu-val (symbol-function menu))
 834            (if (and facemenu-new-faces-at-end
 835                     (> (length menu-val) 3))
 836                (define-key-after menu-val key (cons name function)
 837                  (car (nth (- (length menu-val) 3) menu-val)))
 838              (define-key menu key (cons name function))))))
 839   nil) ; Return nil for facemenu-iterate
 840
 841 (defun facemenu-add-new-color (color menu)
 842   "Add COLOR (a color name string) to the appropriate Face menu.
 843 MENU should be `facemenu-foreground-menu' or `facemenu-background-menu'.
 844 Return the event type (a symbol) of the added menu entry.
 845
 846 This is called whenever you use a new color."
 847   (let (symbol)
 848     (unless (color-defined-p color)
 849       (error "Color `%s' undefined" color))
 850     (cond ((eq menu 'facemenu-foreground-menu)
 851            (setq symbol (intern (concat "fg:" color))))
 852           ((eq menu 'facemenu-background-menu)
 853            (setq symbol (intern (concat "bg:" color))))
 854           (t (error "MENU should be `facemenu-foreground-menu' or `facemenu-background-menu'")))
 855     (unless (facemenu-iterate ; Check if color is already in the menu.
 856              (lambda (m) (and (listp m)
 857                               (eq (car m) symbol)))
 858              (cdr (symbol-function menu)))
 859       ;; Color is not in the menu.  Figure out where to put it.
 860       (let ((key (vector symbol))
 861             (function 'facemenu-set-face-from-menu)
 862             (menu-val (symbol-function menu)))
 863         (if (and facemenu-new-faces-at-end
 864                  (> (length menu-val) 3))
 865             (define-key-after menu-val key (cons color function)
 866               (car (nth (- (length menu-val) 3) menu-val)))
 867           (define-key menu key (cons color function)))))
 868     symbol))
 869
 870 (defun facemenu-complete-face-list (&optional oldlist)
 871   "Return list of all faces that look different.
 872 Starts with given ALIST of faces, and adds elements only if they display
 873 differently from any face already on the list.
 874 The faces on ALIST will end up at the end of the returned list, in reverse
 875 order."
 876   (let ((list (nreverse (mapcar 'car oldlist))))
 877     (facemenu-iterate
 878      (lambda (new-face)
 879        (if (not (memq new-face list))
 880            (setq list (cons new-face list)))
 881        nil)
 882      (nreverse (face-list)))
 883     list))
 884
 885 (defun facemenu-iterate (func list)
 886   "Apply FUNC to each element of LIST until one returns non-nil.
 887 Returns the non-nil value it found, or nil if all were nil."
 888   (while (and list (not (funcall func (car list))))
 889     (setq list (cdr list)))
 890   (car list))
 891
 892 (facemenu-update)
 893
 894 (provide 'facemenu)
 895
 896 ;;; facemenu.el ends here