lisp/facemenu.el

   1 ;;; facemenu.el --- create a face menu for interactively adding fonts to text
   2
   3 ;; Copyright (c) 1994, 1995, 1996, 2001, 2002 Free Software Foundation, Inc.
   4
   5 ;; Author: Boris Goldowsky <boris@gnu.org>
   6 ;; Keywords: faces
   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 2, or (at your option)
  13 ;; 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; see the file COPYING.  If not, write to the
  22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  23 ;; Boston, MA 02111-1307, USA.
  24
  25 ;;; Commentary:
  26
  27 ;; This file defines a menu of faces (bold, italic, etc) which allows you to
  28 ;; set the face used for a region of the buffer.  Some faces also have
  29 ;; keybindings, which are shown in the menu.
  30 ;;
  31 ;; The menu also contains submenus for indentation and justification-changing
  32 ;; commands.
  33
  34 ;;; Usage:
  35 ;; Selecting a face from the menu or typing the keyboard equivalent will
  36 ;; change the region to use that face.  If you use transient-mark-mode and the
  37 ;; region is not active, the face will be remembered and used for the next
  38 ;; insertion.  It will be forgotten if you move point or make other
  39 ;; modifications before inserting or typing anything.
  40 ;;
  41 ;; Faces can be selected from the keyboard as well.
  42 ;; The standard keybindings are M-g (or ESC g) + letter:
  43 ;; M-g i = "set italic",  M-g b = "set bold", etc.
  44
  45 ;;; Customization:
  46 ;; An alternative set of keybindings that may be easier to type can be set up
  47 ;; using "Alt" or "Hyper" keys.  This requires that you either have or create
  48 ;; an Alt or Hyper key on your keyboard.  On my keyboard, there is a key
  49 ;; labeled "Alt", but to make it act as an Alt key I have to put this command
  50 ;; into my .xinitrc:
  51 ;;    xmodmap -e "add Mod3 = Alt_L"
  52 ;; Or, I can make it into a Hyper key with this:
  53 ;;    xmodmap -e "keysym Alt_L = Hyper_L" -e "add Mod2 = Hyper_L"
  54 ;; Check with local X-perts for how to do it on your system.
  55 ;; Then you can define your keybindings with code like this in your .emacs:
  56 ;;   (setq facemenu-keybindings
  57 ;;    '((default     . [?\H-d])
  58 ;;      (bold        . [?\H-b])
  59 ;;      (italic      . [?\H-i])
  60 ;;      (bold-italic . [?\H-l])
  61 ;;      (underline   . [?\H-u])))
  62 ;;   (facemenu-update)
  63 ;;   (setq facemenu-keymap global-map)
  64 ;;   (define-key global-map [?\H-c] 'facemenu-set-foreground) ; set fg color
  65 ;;   (define-key global-map [?\H-C] 'facemenu-set-background) ; set bg color
  66 ;;
  67 ;; The order of the faces that appear in the menu and their keybindings can be
  68 ;; controlled by setting the variables `facemenu-keybindings' and
  69 ;; `facemenu-new-faces-at-end'.  List faces that you don't use in documents
  70 ;; (eg, `region') in `facemenu-unlisted-faces'.
  71
  72 ;;; Known Problems:
  73 ;; Bold and Italic do not combine to create bold-italic if you select them
  74 ;; both, although most other combinations (eg bold + underline + some color)
  75 ;; do the intuitive thing.
  76 ;;
  77 ;; There is at present no way to display what the faces look like in
  78 ;; the menu itself.
  79 ;;
  80 ;; `list-faces-display' shows the faces in a different order than
  81 ;; this menu, which could be confusing.  I do /not/ sort the list
  82 ;; alphabetically, because I like the default order: it puts the most
  83 ;; basic, common fonts first.
  84 ;;
  85 ;; Please send me any other problems, comments or ideas.
  86
  87 ;;; Code:
  88
  89 (provide 'facemenu)
  90
  91 (eval-when-compile
  92   (require 'help)
  93   (require 'button))
  94
  95 ;;; Provide some binding for startup:
  96 ;;;###autoload (define-key global-map "\M-g" 'facemenu-keymap)
  97 ;;;###autoload (autoload 'facemenu-keymap "facemenu" "Keymap for face-changing commands." t 'keymap)
  98
  99 ;; Global bindings:
 100 (define-key global-map [C-down-mouse-2] 'facemenu-menu)
 101 (define-key global-map "\M-g" 'facemenu-keymap)
 102
 103 (defgroup facemenu nil
 104   "Create a face menu for interactively adding fonts to text"
 105   :group 'faces
 106   :prefix "facemenu-")
 107
 108 (defcustom facemenu-keybindings
 109   '((default     . "d")
 110     (bold        . "b")
 111     (italic      . "i")
 112     (bold-italic . "l") ; {bold} intersect {italic} = {l}
 113     (underline   . "u"))
 114   "Alist of interesting faces and keybindings.
 115 Each element is itself a list: the car is the name of the face,
 116 the next element is the key to use as a keyboard equivalent of the menu item;
 117 the binding is made in `facemenu-keymap'.
 118
 119 The faces specifically mentioned in this list are put at the top of
 120 the menu, in the order specified.  All other faces which are defined,
 121 except for those in `facemenu-unlisted-faces', are listed after them,
 122 but get no keyboard equivalents.
 123
 124 If you change this variable after loading facemenu.el, you will need to call
 125 `facemenu-update' to make it take effect."
 126   :type '(repeat (cons face string))
 127   :group 'facemenu)
 128
 129 (defcustom facemenu-new-faces-at-end t
 130   "*Where in the menu to insert newly-created faces.
 131 This should be nil to put them at the top of the menu, or t to put them
 132 just before \"Other\" at the end."
 133   :type 'boolean
 134   :group 'facemenu)
 135
 136 (defcustom facemenu-unlisted-faces
 137   `(modeline region secondary-selection highlight scratch-face
 138     ,(purecopy "^font-lock-") ,(purecopy "^gnus-") ,(purecopy "^message-")
 139     ,(purecopy "^ediff-") ,(purecopy "^term-") ,(purecopy "^vc-")
 140     ,(purecopy "^widget-") ,(purecopy "^custom-") ,(purecopy "^vm-"))
 141   "*List of faces not to include in the Face menu.
 142 Each element may be either a symbol, which is the name of a face, or a string,
 143 which is a regular expression to be matched against face names.  Matching
 144 faces will not be added to the menu.
 145
 146 You can set this list before loading facemenu.el, or add a face to it before
 147 creating that face if you do not want it to be listed.  If you change the
 148 variable so as to eliminate faces that have already been added to the menu,
 149 call `facemenu-update' to recalculate the menu contents.
 150
 151 If this variable is t, no faces will be added to the menu.  This is useful for
 152 temporarily turning off the feature that automatically adds faces to the menu
 153 when they are created."
 154   :type '(choice (const :tag "Don't add faces" t)
 155                  (const :tag "None (do add any face)" nil)
 156                  (repeat (choice symbol regexp)))
 157   :group 'facemenu)
 158
 159 ;;;###autoload
 160 (defvar facemenu-face-menu
 161   (let ((map (make-sparse-keymap "Face")))
 162     (define-key map "o" (cons "Other..." 'facemenu-set-face))
 163     map)
 164   "Menu keymap for faces.")
 165 ;;;###autoload
 166 (defalias 'facemenu-face-menu facemenu-face-menu)
 167
 168 ;;;###autoload
 169 (defvar facemenu-foreground-menu
 170   (let ((map (make-sparse-keymap "Foreground Color")))
 171     (define-key map "o" (cons "Other..." 'facemenu-set-foreground))
 172     map)
 173   "Menu keymap for foreground colors.")
 174 ;;;###autoload
 175 (defalias 'facemenu-foreground-menu facemenu-foreground-menu)
 176
 177 ;;;###autoload
 178 (defvar facemenu-background-menu
 179   (let ((map (make-sparse-keymap "Background Color")))
 180     (define-key map "o" (cons "Other..." 'facemenu-set-background))
 181     map)
 182   "Menu keymap for background colors.")
 183 ;;;###autoload
 184 (defalias 'facemenu-background-menu facemenu-background-menu)
 185
 186 ;;;###autoload
 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 ;;;###autoload
 200 (defalias 'facemenu-special-menu facemenu-special-menu)
 201
 202 ;;;###autoload
 203 (defvar facemenu-justification-menu
 204   (let ((map (make-sparse-keymap "Justification")))
 205     (define-key map [?c] (cons (purecopy "Center") 'set-justification-center))
 206     (define-key map [?b] (cons (purecopy "Full") 'set-justification-full))
 207     (define-key map [?r] (cons (purecopy "Right") 'set-justification-right))
 208     (define-key map [?l] (cons (purecopy "Left") 'set-justification-left))
 209     (define-key map [?u] (cons (purecopy "Unfilled") 'set-justification-none))
 210     map)
 211   "Submenu for text justification commands.")
 212 ;;;###autoload
 213 (defalias 'facemenu-justification-menu facemenu-justification-menu)
 214
 215 ;;;###autoload
 216 (defvar facemenu-indentation-menu
 217   (let ((map (make-sparse-keymap "Indentation")))
 218     (define-key map [decrease-right-margin]
 219       (cons (purecopy "Indent Right Less") 'decrease-right-margin))
 220     (define-key map [increase-right-margin]
 221       (cons (purecopy "Indent Right More") 'increase-right-margin))
 222     (define-key map [decrease-left-margin]
 223       (cons (purecopy "Indent Less") 'decrease-left-margin))
 224     (define-key map [increase-left-margin]
 225       (cons (purecopy "Indent More") 'increase-left-margin))
 226     map)
 227   "Submenu for indentation commands.")
 228 ;;;###autoload
 229 (defalias 'facemenu-indentation-menu facemenu-indentation-menu)
 230
 231 ;; This is split up to avoid an overlong line in loaddefs.el.
 232 ;;;###autoload
 233 (defvar facemenu-menu nil
 234   "Facemenu top-level menu keymap.")
 235 ;;;###autoload
 236 (setq facemenu-menu (make-sparse-keymap "Text Properties"))
 237 ;;;###autoload
 238 (let ((map facemenu-menu))
 239   (define-key map [dc] (cons (purecopy "Display Colors") 'list-colors-display))
 240   (define-key map [df] (cons (purecopy "Display Faces") 'list-faces-display))
 241   (define-key map [dp] (cons (purecopy "Describe Text")
 242                              'describe-text-at))
 243   (define-key map [ra] (cons (purecopy "Remove Text Properties")
 244                              'facemenu-remove-all))
 245   (define-key map [rm] (cons (purecopy "Remove Face Properties")
 246                              'facemenu-remove-face-props))
 247   (define-key map [s1] (list (purecopy "--"))))
 248 ;;;###autoload
 249 (let ((map facemenu-menu))
 250   (define-key map [in] (cons (purecopy "Indentation")
 251                              'facemenu-indentation-menu))
 252   (define-key map [ju] (cons (purecopy "Justification")
 253                              'facemenu-justification-menu))
 254   (define-key map [s2] (list (purecopy "--")))
 255   (define-key map [sp] (cons (purecopy "Special Properties")
 256                              'facemenu-special-menu))
 257   (define-key map [bg] (cons (purecopy "Background Color")
 258                              'facemenu-background-menu))
 259   (define-key map [fg] (cons (purecopy "Foreground Color")
 260                              'facemenu-foreground-menu))
 261   (define-key map [fc] (cons (purecopy "Face")
 262                              'facemenu-face-menu)))
 263 ;;;###autoload
 264 (defalias 'facemenu-menu facemenu-menu)
 265
 266 (defvar facemenu-keymap
 267   (let ((map (make-sparse-keymap "Set face")))
 268     (define-key map "o" (cons (purecopy "Other...") 'facemenu-set-face))
 269     map)
 270   "Keymap for face-changing commands.
 271 `Facemenu-update' fills in the keymap according to the bindings
 272 requested in `facemenu-keybindings'.")
 273 (defalias 'facemenu-keymap facemenu-keymap)
 274
 275
 276 (defcustom facemenu-add-face-function nil
 277   "Function called at beginning of text to change or nil.
 278 This function is passed the FACE to set and END of text to change, and must
 279 return a string which is inserted.  It may set `facemenu-end-add-face'."
 280   :type '(choice (const :tag "None" nil)
 281                  function)
 282   :group 'facemenu)
 283
 284 (defcustom facemenu-end-add-face nil
 285   "String to insert or function called at end of text to change or nil.
 286 This function is passed the FACE to set, and must return a string which is
 287 inserted."
 288   :type '(choice (const :tag "None" nil)
 289                  string
 290                  function)
 291   :group 'facemenu)
 292
 293 (defcustom facemenu-remove-face-function nil
 294   "When non-nil, this is a function called to remove faces.
 295 This function is passed the START and END of text to change.
 296 May also be t meaning to use `facemenu-add-face-function'."
 297   :type '(choice (const :tag "None" nil)
 298                  (const :tag "Use add-face" t)
 299                  function)
 300   :group 'facemenu)
 301
 302 ;;; Internal Variables
 303
 304 (defvar facemenu-color-alist nil
 305   ;; Don't initialize here; that doesn't work if preloaded.
 306   "Alist of colors, used for completion.
 307 If null, `facemenu-read-color' will set it.")
 308
 309 (defun facemenu-update ()
 310   "Add or update the \"Face\" menu in the menu bar.
 311 You can call this to update things if you change any of the menu configuration
 312 variables."
 313   (interactive)
 314
 315   ;; Add each defined face to the menu.
 316   (facemenu-iterate 'facemenu-add-new-face
 317                     (facemenu-complete-face-list facemenu-keybindings)))
 318
 319 ;;;###autoload
 320 (defun facemenu-set-face (face &optional start end)
 321   "Add FACE to the region or next character typed.
 322 This adds FACE to the top of the face list; any faces lower on the list that
 323 will not show through at all will be removed.
 324
 325 Interactively, reads the face name with the minibuffer.
 326
 327 If the region is active (normally true except in Transient Mark mode)
 328 and there is no prefix argument, this command sets the region to the
 329 requested face.
 330
 331 Otherwise, this command specifies the face for the next character
 332 inserted.  Moving point or switching buffers before
 333 typing a character to insert cancels the specification."
 334   (interactive (list (progn
 335                        (barf-if-buffer-read-only)
 336                        (read-face-name "Use face"))
 337                      (if (and mark-active (not current-prefix-arg))
 338                          (region-beginning))
 339                      (if (and mark-active (not current-prefix-arg))
 340                          (region-end))))
 341   (facemenu-add-new-face face)
 342   (facemenu-add-face face start end))
 343
 344 ;;;###autoload
 345 (defun facemenu-set-foreground (color &optional start end)
 346   "Set the foreground COLOR of the region or next character typed.
 347 This command reads the color in the minibuffer.
 348
 349 If the region is active (normally true except in Transient Mark mode)
 350 and there is no prefix argument, this command sets the region to the
 351 requested face.
 352
 353 Otherwise, this command specifies the face for the next character
 354 inserted.  Moving point or switching buffers before
 355 typing a character to insert cancels the specification."
 356   (interactive (list (progn
 357                        (barf-if-buffer-read-only)
 358                        (facemenu-read-color "Foreground color: "))
 359                      (if (and mark-active (not current-prefix-arg))
 360                          (region-beginning))
 361                      (if (and mark-active (not current-prefix-arg))
 362                          (region-end))))
 363   (unless (color-defined-p color)
 364     (message "Color `%s' undefined" color))
 365   (facemenu-add-new-face color 'facemenu-foreground-menu)
 366   (facemenu-add-face (list (list :foreground color)) start end))
 367
 368 ;;;###autoload
 369 (defun facemenu-set-background (color &optional start end)
 370   "Set the background COLOR of the region or next character typed.
 371 This command reads the color in the minibuffer.
 372
 373 If the region is active (normally true except in Transient Mark mode)
 374 and there is no prefix argument, this command sets the region to the
 375 requested face.
 376
 377 Otherwise, this command specifies the face for the next character
 378 inserted.  Moving point or switching buffers before
 379 typing a character to insert cancels the specification."
 380   (interactive (list (progn
 381                        (barf-if-buffer-read-only)
 382                        (facemenu-read-color "Background color: "))
 383                      (if (and mark-active (not current-prefix-arg))
 384                          (region-beginning))
 385                      (if (and mark-active (not current-prefix-arg))
 386                          (region-end))))
 387   (unless (color-defined-p color)
 388     (message "Color `%s' undefined" color))
 389   (facemenu-add-new-face color 'facemenu-background-menu)
 390   (facemenu-add-face (list (list :background color)) start end))
 391
 392 ;;;###autoload
 393 (defun facemenu-set-face-from-menu (face start end)
 394   "Set the FACE of the region or next character typed.
 395 This function is designed to be called from a menu; the face to use
 396 is the menu item's name.
 397
 398 If the region is active (normally true except in Transient Mark mode)
 399 and there is no prefix argument, this command sets the region to the
 400 requested face.
 401
 402 Otherwise, this command specifies the face for the next character
 403 inserted.  Moving point or switching buffers before
 404 typing a character to insert cancels the specification."
 405   (interactive (list last-command-event
 406                      (if (and mark-active (not current-prefix-arg))
 407                          (region-beginning))
 408                      (if (and mark-active (not current-prefix-arg))
 409                          (region-end))))
 410   (barf-if-buffer-read-only)
 411   (facemenu-get-face face)
 412   (if start
 413       (facemenu-add-face face start end)
 414     (facemenu-add-face face)))
 415
 416 ;;;###autoload
 417 (defun facemenu-set-invisible (start end)
 418   "Make the region invisible.
 419 This sets the `invisible' text property; it can be undone with
 420 `facemenu-remove-special'."
 421   (interactive "r")
 422   (add-text-properties start end '(invisible t)))
 423
 424 ;;;###autoload
 425 (defun facemenu-set-intangible (start end)
 426   "Make the region intangible: disallow moving into it.
 427 This sets the `intangible' text property; it can be undone with
 428 `facemenu-remove-special'."
 429   (interactive "r")
 430   (add-text-properties start end '(intangible t)))
 431
 432 ;;;###autoload
 433 (defun facemenu-set-read-only (start end)
 434   "Make the region unmodifiable.
 435 This sets the `read-only' text property; it can be undone with
 436 `facemenu-remove-special'."
 437   (interactive "r")
 438   (add-text-properties start end '(read-only t)))
 439
 440 ;;;###autoload
 441 (defun facemenu-remove-face-props (start end)
 442   "Remove `face' and `mouse-face' text properties."
 443   (interactive "*r") ; error if buffer is read-only despite the next line.
 444   (let ((inhibit-read-only t))
 445     (remove-text-properties
 446      start end '(face nil mouse-face nil))))
 447
 448 ;;;###autoload
 449 (defun facemenu-remove-all (start end)
 450   "Remove all text properties from the region."
 451   (interactive "*r") ; error if buffer is read-only despite the next line.
 452   (let ((inhibit-read-only t))
 453     (set-text-properties start end nil)))
 454
 455 ;;;###autoload
 456 (defun facemenu-remove-special (start end)
 457   "Remove all the \"special\" text properties from the region.
 458 These special properties include `invisible', `intangible' and `read-only'."
 459   (interactive "*r") ; error if buffer is read-only despite the next line.
 460   (let ((inhibit-read-only t))
 461     (remove-text-properties
 462      start end '(invisible nil intangible nil read-only nil))))
 463
 464 ;;; Describe-Text Mode.
 465
 466 (defun describe-text-done ()
 467   "Delete the current window or bury the current buffer."
 468   (interactive)
 469   (if (> (count-windows) 1)
 470       (delete-window)
 471     (bury-buffer)))
 472
 473 (defvar describe-text-mode-map
 474   (let ((map (make-sparse-keymap)))
 475     (set-keymap-parent map widget-keymap)
 476     map)
 477   "Keymap for `describe-text-mode'.")
 478
 479 (defcustom describe-text-mode-hook nil
 480   "List of hook functions ran by `describe-text-mode'."
 481   :type 'hook)
 482
 483 (defun describe-text-mode ()
 484   "Major mode for buffers created by `describe-text-at'.
 485
 486 \\{describe-text-mode-map}
 487 Entry to this mode calls the value of `describe-text-mode-hook'
 488 if that value is non-nil."
 489   (kill-all-local-variables)
 490   (setq major-mode 'describe-text-mode
 491         mode-name "Describe-Text")
 492   (use-local-map describe-text-mode-map)
 493   (widget-setup)
 494   (run-hooks 'describe-text-mode-hook))
 495
 496 ;;; Describe-Text Utilities.
 497
 498 (defun describe-text-widget (widget)
 499   "Insert text to describe WIDGET in the current buffer."
 500   (widget-create 'link
 501                  :notify `(lambda (&rest ignore)
 502                             (widget-browse ',widget))
 503                  (format "%S" (if (symbolp widget)
 504                                   widget
 505                                 (car widget))))
 506   (widget-insert " ")
 507   (widget-create 'info-link :tag "widget" "(widget)Top"))
 508
 509 (defun describe-text-sexp (sexp)
 510   "Insert a short description of SEXP in the current buffer."
 511   (let ((pp (condition-case signal
 512                 (pp-to-string sexp)
 513               (error (prin1-to-string signal)))))
 514     (when (string-match "\n\\'" pp)
 515       (setq pp (substring pp 0 (1- (length pp)))))
 516     (if (cond ((string-match "\n" pp)
 517                nil)
 518               ((> (length pp) (- (window-width) (current-column)))
 519                nil)
 520               (t t))
 521         (widget-insert pp)
 522       (widget-create 'push-button
 523                      :tag "show"
 524                      :action (lambda (widget &optional event)
 525                                (with-output-to-temp-buffer
 526                                    "*Pp Eval Output*"
 527                                  (princ (widget-get widget :value))))
 528                      pp))))
 529
 530
 531 (defun describe-text-properties (properties)
 532   "Insert a description of PROPERTIES in the current buffer.
 533 PROPERTIES should be a list of overlay or text properties.
 534 The `category' property is made into a widget button that call
 535 `describe-text-category' when pushed."
 536   (while properties
 537     (widget-insert (format "  %-20s " (car properties)))
 538     (let ((key (nth 0 properties))
 539           (value (nth 1 properties)))
 540       (cond ((eq key 'category)
 541              (widget-create 'link
 542                             :notify `(lambda (&rest ignore)
 543                                        (describe-text-category ',value))
 544                             (format "%S" value)))
 545             ((widgetp value)
 546              (describe-text-widget value))
 547             (t
 548              (describe-text-sexp value))))
 549     (widget-insert "\n")
 550     (setq properties (cdr (cdr properties)))))
 551
 552 ;;; Describe-Text Commands.
 553
 554 (defun describe-text-category (category)
 555   "Describe a text property category."
 556   (interactive "S")
 557   (when (get-buffer "*Text Category*")
 558     (kill-buffer "*Text Category*"))
 559   (save-excursion
 560     (with-output-to-temp-buffer "*Text Category*"
 561       (set-buffer "*Text Category*")
 562       (widget-insert "Category " (format "%S" category) ":\n\n")
 563       (describe-text-properties (symbol-plist category))
 564       (describe-text-mode)
 565       (goto-char (point-min)))))
 566
 567 ;;;###autoload
 568 (defun describe-text-at (pos)
 569   "Describe widgets, buttons, overlays and text properties at POS."
 570   (interactive "d")
 571   (when (eq (current-buffer) (get-buffer "*Text Description*"))
 572     (error "Can't do self inspection"))
 573   (let* ((properties (text-properties-at pos))
 574          (overlays (overlays-at pos))
 575          overlay
 576          (wid-field (get-char-property pos 'field))
 577          (wid-button (get-char-property pos 'button))
 578          (wid-doc (get-char-property pos 'widget-doc))
 579          ;; If button.el is not loaded, we have no buttons in the text.
 580          (button (and (fboundp 'button-at) (button-at pos)))
 581          (button-type (and button (button-type button)))
 582          (button-label (and button (button-label button)))
 583          (widget (or wid-field wid-button wid-doc)))
 584     (if (not (or properties overlays))
 585         (message "This is plain text.")
 586       (when (get-buffer "*Text Description*")
 587         (kill-buffer "*Text Description*"))
 588       (save-excursion
 589         (with-output-to-temp-buffer "*Text Description*"
 590           (set-buffer "*Text Description*")
 591           (widget-insert "Text content at position " (format "%d" pos) ":\n\n")
 592           ;; Widgets
 593           (when (widgetp widget)
 594             (widget-insert (cond (wid-field "This is an editable text area")
 595                                  (wid-button "This is an active area")
 596                                  (wid-doc "This is documentation text")))
 597             (widget-insert " of a ")
 598             (describe-text-widget widget)
 599             (widget-insert ".\n\n"))
 600           ;; Buttons
 601           (when (and button (not (widgetp wid-button)))
 602             (widget-insert "Here is a " (format "%S" button-type)
 603                            " button labeled `" button-label "'.\n\n"))
 604           ;; Overlays
 605           (when overlays
 606             (if (eq (length overlays) 1)
 607                 (widget-insert "There is an overlay here:\n")
 608               (widget-insert "There are " (format "%d" (length overlays))
 609                              " overlays here:\n"))
 610             (dolist (overlay overlays)
 611               (widget-insert " From " (format "%d" (overlay-start overlay))
 612                              " to " (format "%d" (overlay-end overlay)) "\n")
 613               (describe-text-properties (overlay-properties overlay)))
 614             (widget-insert "\n"))
 615           ;; Text properties
 616           (when properties
 617             (widget-insert "There are text properties here:\n")
 618             (describe-text-properties properties))
 619           (describe-text-mode)
 620           (goto-char (point-min)))))))
 621
 622 ;;; List Text Properties
 623
 624 ;;;###autoload
 625 (defun list-text-properties-at (p)
 626   "Pop up a buffer listing text-properties at LOCATION."
 627   (interactive "d")
 628   (let ((props (text-properties-at p))
 629         category
 630         str)
 631     (if (null props)
 632         (message "None")
 633       (if (and (not (cdr (cdr props)))
 634                (not (eq (car props) 'category))
 635                (< (length (setq str (format "Text property at %d:  %s  %S"
 636                                             p (car props) (car (cdr props)))))
 637                   (frame-width)))
 638           (message "%s" str)
 639         (with-output-to-temp-buffer "*Text Properties*"
 640           (princ (format "Text properties at %d:\n\n" p))
 641           (setq help-xref-stack nil)
 642           (while props
 643             (if (eq (car props) 'category)
 644                 (setq category (car (cdr props))))
 645             (princ (format "%-20s %S\n"
 646                            (car props) (car (cdr props))))
 647             (setq props (cdr (cdr props))))
 648           (if category
 649               (progn
 650                 (setq props (symbol-plist category))
 651                 (princ (format "\nCategory %s:\n\n" category))
 652                 (while props
 653                   (princ (format "%-20s %S\n"
 654                                  (car props) (car (cdr props))))
 655                   (if (eq (car props) 'category)
 656                       (setq category (car (cdr props))))
 657                   (setq props (cdr (cdr props)))))))))))
 658
 659 ;;;###autoload
 660 (defun facemenu-read-color (&optional prompt)
 661   "Read a color using the minibuffer."
 662   (let ((col (completing-read (or prompt "Color: ")
 663                               (or facemenu-color-alist
 664                                   (mapcar 'list (defined-colors)))
 665                               nil t)))
 666     (if (equal "" col)
 667         nil
 668       col)))
 669
 670 ;;;###autoload
 671 (defun list-colors-display (&optional list)
 672   "Display names of defined colors, and show what they look like.
 673 If the optional argument LIST is non-nil, it should be a list of
 674 colors to display.  Otherwise, this command computes a list
 675 of colors that the current display can handle."
 676   (interactive)
 677   (when (and (null list) (> (display-color-cells) 0))
 678     (setq list (defined-colors))
 679     ;; Delete duplicate colors.
 680     (let ((l list))
 681       (while (cdr l)
 682         (if (facemenu-color-equal (car l) (car (cdr l)))
 683             (setcdr l (cdr (cdr l)))
 684           (setq l (cdr l)))))
 685     ;; Don't show more than what the display can handle.
 686     (let ((lc (nthcdr (1- (display-color-cells)) list)))
 687       (if lc
 688           (setcdr lc nil))))
 689   (with-output-to-temp-buffer "*Colors*"
 690     (save-excursion
 691       (set-buffer standard-output)
 692       (let (s)
 693         (while list
 694           (setq s (point))
 695           (insert (car list))
 696           (indent-to 20)
 697           (put-text-property s (point) 'face
 698                              (cons 'background-color (car list)))
 699           (setq s (point))
 700           (insert "  " (car list) "\n")
 701           (put-text-property s (point) 'face
 702                              (cons 'foreground-color (car list)))
 703           (setq list (cdr list)))))))
 704
 705 (defun facemenu-color-equal (a b)
 706   "Return t if colors A and B are the same color.
 707 A and B should be strings naming colors.
 708 This function queries the display system to find out what the color
 709 names mean.  It returns nil if the colors differ or if it can't
 710 determine the correct answer."
 711   (cond ((equal a b) t)
 712         ((equal (color-values a) (color-values b)))))
 713
 714 (defun facemenu-add-face (face &optional start end)
 715   "Add FACE to text between START and END.
 716 If START is nil or START to END is empty, add FACE to next typed character
 717 instead.  For each section of that region that has a different face property,
 718 FACE will be consed onto it, and other faces that are completely hidden by
 719 that will be removed from the list.
 720 If `facemenu-add-face-function' and maybe `facemenu-end-add-face' are non-nil,
 721 they are used to set the face information.
 722
 723 As a special case, if FACE is `default', then the region is left with NO face
 724 text property.  Otherwise, selecting the default face would not have any
 725 effect.  See `facemenu-remove-face-function'."
 726   (interactive "*xFace: \nr")
 727   (if (and (eq face 'default)
 728            (not (eq facemenu-remove-face-function t)))
 729       (if facemenu-remove-face-function
 730           (funcall facemenu-remove-face-function start end)
 731         (if (and start (< start end))
 732             (remove-text-properties start end '(face default))
 733           (setq self-insert-face 'default
 734                 self-insert-face-command this-command)))
 735     (if facemenu-add-face-function
 736         (save-excursion
 737           (if end (goto-char end))
 738           (save-excursion
 739             (if start (goto-char start))
 740             (insert-before-markers
 741              (funcall facemenu-add-face-function face end)))
 742           (if facemenu-end-add-face
 743               (insert (if (stringp facemenu-end-add-face)
 744                           facemenu-end-add-face
 745                         (funcall facemenu-end-add-face face)))))
 746       (if (and start (< start end))
 747           (let ((part-start start) part-end)
 748             (while (not (= part-start end))
 749               (setq part-end (next-single-property-change part-start 'face
 750                                                           nil end))
 751               (let ((prev (get-text-property part-start 'face)))
 752                 (put-text-property part-start part-end 'face
 753                                    (if (null prev)
 754                                        face
 755                                      (facemenu-active-faces
 756                                       (cons face
 757                                             (if (listp prev)
 758                                                 prev
 759                                               (list prev)))))))
 760               (setq part-start part-end)))
 761         (setq self-insert-face (if (eq last-command self-insert-face-command)
 762                                    (cons face (if (listp self-insert-face)
 763                                                   self-insert-face
 764                                                 (list self-insert-face)))
 765                                  face)
 766               self-insert-face-command this-command)))))
 767
 768 (defun facemenu-active-faces (face-list &optional frame)
 769   "Return from FACE-LIST those faces that would be used for display.
 770 This means each face attribute is not specified in a face earlier in FACE-LIST
 771 and such a face is therefore active when used to display text.
 772 If the optional argument FRAME is given, use the faces in that frame; otherwise
 773 use the selected frame.  If t, then the global, non-frame faces are used."
 774   (let* ((mask-atts (copy-sequence
 775                      (if (consp (car face-list))
 776                          (face-attributes-as-vector (car face-list))
 777                        (or (internal-lisp-face-p (car face-list) frame)
 778                            (check-face (car face-list))))))
 779          (active-list (list (car face-list)))
 780          (face-list (cdr face-list))
 781          (mask-len (length mask-atts)))
 782     (while face-list
 783       (if (let ((face-atts
 784                  (if (consp (car face-list))
 785                      (face-attributes-as-vector (car face-list))
 786                    (or (internal-lisp-face-p (car face-list) frame)
 787                        (check-face (car face-list)))))
 788                 (i mask-len)
 789                 (useful nil))
 790             (while (> (setq i (1- i)) 1)
 791               (and (not (memq (aref face-atts i) '(nil unspecified)))
 792                    (memq (aref mask-atts i) '(nil unspecified))
 793                    (aset mask-atts i (setq useful t))))
 794             useful)
 795           (setq active-list (cons (car face-list) active-list)))
 796       (setq face-list (cdr face-list)))
 797     (nreverse active-list)))
 798
 799 (defun facemenu-get-face (symbol)
 800   "Make sure FACE exists.
 801 If not, create it and add it to the appropriate menu.  Return the SYMBOL."
 802   (let ((name (symbol-name symbol)))
 803     (cond ((facep symbol))
 804           (t (make-face symbol))))
 805   symbol)
 806
 807 (defun facemenu-add-new-face (face-or-color &optional menu)
 808   "Add FACE-OR-COLOR (a face or a color) to the appropriate Face menu.
 809 If MENU is nil, then FACE-OR-COLOR is a face to be added
 810 to `facemenu-face-menu'.  If MENU is `facemenu-foreground-menu'
 811 or `facemenu-background-menu', FACE-OR-COLOR is a color
 812 to be added to the specified menu.
 813
 814 This is called whenever you create a new face."
 815   (let* (name
 816          symbol
 817          docstring
 818          (key (cdr (assoc face-or-color facemenu-keybindings)))
 819          function menu-val)
 820     (if (symbolp face-or-color)
 821         (setq name (symbol-name face-or-color)
 822               symbol face-or-color)
 823       (setq name face-or-color
 824             symbol (intern name)))
 825     (cond ((eq menu 'facemenu-foreground-menu)
 826            (setq docstring
 827                  (format "Select foreground color %s for subsequent insertion."
 828                          name)))
 829           ((eq menu 'facemenu-background-menu)
 830            (setq docstring
 831                  (format "Select background color %s for subsequent insertion."
 832                          name)))
 833           (t
 834            (setq menu 'facemenu-face-menu)
 835            (setq docstring
 836                  (format "Select face `%s' for subsequent insertion."
 837                          name))))
 838     (cond ((eq t facemenu-unlisted-faces))
 839           ((memq symbol facemenu-unlisted-faces))
 840           ;; test against regexps in facemenu-unlisted-faces
 841           ((let ((unlisted facemenu-unlisted-faces)
 842                  (matched nil))
 843              (while (and unlisted (not matched))
 844                (if (and (stringp (car unlisted))
 845                         (string-match (car unlisted) name))
 846                    (setq matched t)
 847                  (setq unlisted (cdr unlisted))))
 848              matched))
 849           (key ; has a keyboard equivalent.  These go at the front.
 850            (setq function (intern (concat "facemenu-set-" name)))
 851            (fset function
 852                  `(lambda ()
 853                     ,docstring
 854                     (interactive)
 855                     (facemenu-set-face
 856                      (quote ,symbol)
 857                      (if (and mark-active (not current-prefix-arg))
 858                          (region-beginning))
 859                      (if (and mark-active (not current-prefix-arg))
 860                          (region-end)))))
 861            (define-key 'facemenu-keymap key (cons name function))
 862            (define-key menu key (cons name function)))
 863           ((facemenu-iterate ; check if equivalent face is already in the menu
 864             (lambda (m) (and (listp m)
 865                              (symbolp (car m))
 866                              (face-equal (car m) symbol)))
 867             (cdr (symbol-function menu))))
 868           (t   ; No keyboard equivalent.  Figure out where to put it:
 869            (setq key (vector symbol)
 870                  function 'facemenu-set-face-from-menu
 871                  menu-val (symbol-function menu))
 872            (if (and facemenu-new-faces-at-end
 873                    (> (length menu-val) 3))
 874                (define-key-after menu-val key (cons name function)
 875                  (car (nth (- (length menu-val) 3) menu-val)))
 876              (define-key menu key (cons name function))))))
 877   nil) ; Return nil for facemenu-iterate
 878
 879 (defun facemenu-complete-face-list (&optional oldlist)
 880   "Return list of all faces that look different.
 881 Starts with given ALIST of faces, and adds elements only if they display
 882 differently from any face already on the list.
 883 The faces on ALIST will end up at the end of the returned list, in reverse
 884 order."
 885   (let ((list (nreverse (mapcar 'car oldlist))))
 886     (facemenu-iterate
 887      (lambda (new-face)
 888        (if (not (memq new-face list))
 889            (setq list (cons new-face list)))
 890        nil)
 891      (nreverse (face-list)))
 892     list))
 893
 894 (defun facemenu-iterate (func list)
 895   "Apply FUNC to each element of LIST until one returns non-nil.
 896 Returns the non-nil value it found, or nil if all were nil."
 897   (while (and list (not (funcall func (car list))))
 898     (setq list (cdr list)))
 899   (car list))
 900
 901 (facemenu-update)
 902
 903 ;;; facemenu.el ends here