lisp/custom.el

   1 ;;; custom.el -- Tools for declaring and initializing options.
   2 ;;
   3 ;; Copyright (C) 1996, 1997, 1999, 2001 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
   6 ;; Maintainer: FSF
   7 ;; Keywords: help, faces
   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 2, or (at your option)
  14 ;; 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; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Commentary:
  27 ;;
  28 ;; This file only contain the code needed to declare and initialize
  29 ;; user options.  The code to customize options is autoloaded from
  30 ;; `cus-edit.el' and is documented in the Emacs Lisp Reference manual.
  31
  32 ;; The code implementing face declarations is in `cus-face.el'
  33
  34 ;;; Code:
  35
  36 (require 'widget)
  37
  38 (defvar custom-define-hook nil
  39   ;; Customize information for this option is in `cus-edit.el'.
  40   "Hook called after defining each customize option.")
  41
  42 ;;; The `defcustom' Macro.
  43
  44 (defun custom-initialize-default (symbol value)
  45   "Initialize SYMBOL with VALUE.
  46 This will do nothing if symbol already has a default binding.
  47 Otherwise, if symbol has a `saved-value' property, it will evaluate
  48 the car of that and used as the default binding for symbol.
  49 Otherwise, VALUE will be evaluated and used as the default binding for
  50 symbol."
  51   (unless (default-boundp symbol)
  52     ;; Use the saved value if it exists, otherwise the standard setting.
  53     (set-default symbol (if (get symbol 'saved-value)
  54                             (eval (car (get symbol 'saved-value)))
  55                           (eval value)))))
  56
  57 (defun custom-initialize-set (symbol value)
  58   "Initialize SYMBOL based on VALUE.
  59 If the symbol doesn't have a default binding already,
  60 then set it using its `:set' function (or `set-default' if it has none).
  61 The value is either the value in the symbol's `saved-value' property,
  62 if any, or VALUE."
  63   (unless (default-boundp symbol)
  64     (funcall (or (get symbol 'custom-set) 'set-default)
  65              symbol
  66              (if (get symbol 'saved-value)
  67                  (eval (car (get symbol 'saved-value)))
  68                (eval value)))))
  69
  70 (defun custom-initialize-reset (symbol value)
  71   "Initialize SYMBOL based on VALUE.
  72 Set the symbol, using its `:set' function (or `set-default' if it has none).
  73 The value is either the symbol's current value
  74  \(as obtained using the `:get' function), if any,
  75 or the value in the symbol's `saved-value' property if any,
  76 or (last of all) VALUE."
  77     (funcall (or (get symbol 'custom-set) 'set-default)
  78              symbol
  79              (cond ((default-boundp symbol)
  80                     (funcall (or (get symbol 'custom-get) 'default-value)
  81                              symbol))
  82                    ((get symbol 'saved-value)
  83                     (eval (car (get symbol 'saved-value))))
  84                    (t
  85                     (eval value)))))
  86
  87 (defun custom-initialize-changed (symbol value)
  88   "Initialize SYMBOL with VALUE.
  89 Like `custom-initialize-reset', but only use the `:set' function if
  90 not using the standard setting.
  91 For the standard setting, use `set-default'."
  92   (cond ((default-boundp symbol)
  93          (funcall (or (get symbol 'custom-set) 'set-default)
  94                   symbol
  95                   (funcall (or (get symbol 'custom-get) 'default-value)
  96                            symbol)))
  97         ((get symbol 'saved-value)
  98          (funcall (or (get symbol 'custom-set) 'set-default)
  99                   symbol
 100                   (eval (car (get symbol 'saved-value)))))
 101         (t
 102          (set-default symbol (eval value)))))
 103
 104 (defun custom-declare-variable (symbol default doc &rest args)
 105   "Like `defcustom', but SYMBOL and DEFAULT are evaluated as normal arguments.
 106 DEFAULT should be an expression to evaluate to compute the default value,
 107 not the default value itself."
 108   ;; Remember the standard setting.
 109   (put symbol 'standard-value (list default))
 110   ;; Maybe this option was rogue in an earlier version.  It no longer is.
 111   (when (get symbol 'force-value)
 112     (put symbol 'force-value nil))
 113   (when doc
 114     (put symbol 'variable-documentation doc))
 115   (let ((initialize 'custom-initialize-reset)
 116         (requests nil))
 117     (while args
 118       (let ((arg (car args)))
 119         (setq args (cdr args))
 120         (unless (symbolp arg)
 121           (error "Junk in args %S" args))
 122         (let ((keyword arg)
 123               (value (car args)))
 124           (unless args
 125             (error "Keyword %s is missing an argument" keyword))
 126           (setq args (cdr args))
 127           (cond ((eq keyword :initialize)
 128                  (setq initialize value))
 129                 ((eq keyword :set)
 130                  (put symbol 'custom-set value))
 131                 ((eq keyword :get)
 132                  (put symbol 'custom-get value))
 133                 ((eq keyword :require)
 134                  (setq requests (cons value requests)))
 135                 ((eq keyword :type)
 136                  (put symbol 'custom-type (purecopy value)))
 137                 ((eq keyword :options)
 138                  (if (get symbol 'custom-options)
 139                      ;; Slow safe code to avoid duplicates.
 140                      (mapc (lambda (option)
 141                              (custom-add-option symbol option))
 142                              value)
 143                    ;; Fast code for the common case.
 144                    (put symbol 'custom-options (copy-sequence value))))
 145                 (t
 146                  (custom-handle-keyword symbol keyword value
 147                                         'custom-variable))))))
 148     (put symbol 'custom-requests requests)
 149     ;; Do the actual initialization.
 150     (funcall initialize symbol default))
 151   (setq current-load-list (cons symbol current-load-list))
 152   (run-hooks 'custom-define-hook)
 153   symbol)
 154
 155 (defmacro defcustom (symbol value doc &rest args)
 156   "Declare SYMBOL as a customizable variable that defaults to VALUE.
 157 DOC is the variable documentation.
 158
 159 Neither SYMBOL nor VALUE needs to be quoted.
 160 If SYMBOL is not already bound, initialize it to VALUE.
 161 The remaining arguments should have the form
 162
 163    [KEYWORD VALUE]...
 164
 165 The following keywords are meaningful:
 166
 167 :type   VALUE should be a widget type for editing the symbols value.
 168 :options VALUE should be a list of valid members of the widget type.
 169 :group  VALUE should be a customization group.
 170         Add SYMBOL to that group.
 171 :initialize
 172         VALUE should be a function used to initialize the
 173         variable.  It takes two arguments, the symbol and value
 174         given in the `defcustom' call.  The default is
 175         `custom-initialize-default'
 176 :set    VALUE should be a function to set the value of the symbol.
 177         It takes two arguments, the symbol to set and the value to
 178         give it.  The default choice of function is `custom-set-default'.
 179 :get    VALUE should be a function to extract the value of symbol.
 180         The function takes one argument, a symbol, and should return
 181         the current value for that symbol.  The default choice of function
 182         is `custom-default-value'.
 183 :require
 184         VALUE should be a feature symbol.  If you save a value
 185         for this option, then when your `.emacs' file loads the value,
 186         it does (require VALUE) first.
 187 :version
 188         VALUE should be a string specifying that the variable was
 189         first introduced, or its default value was changed, in Emacs
 190         version VERSION.
 191
 192 Read the section about customization in the Emacs Lisp manual for more
 193 information."
 194   ;; It is better not to use backquote in this file,
 195   ;; because that makes a bootstrapping problem
 196   ;; if you need to recompile all the Lisp files using interpreted code.
 197   (nconc (list 'custom-declare-variable
 198                (list 'quote symbol)
 199                (list 'quote value)
 200                doc)
 201          args))
 202
 203 ;;; The `defface' Macro.
 204
 205 (defmacro defface (face spec doc &rest args)
 206   "Declare FACE as a customizable face that defaults to SPEC.
 207 FACE does not need to be quoted.
 208
 209 Third argument DOC is the face documentation.
 210
 211 If FACE has been set with `custom-set-face', set the face attributes
 212 as specified by that function, otherwise set the face attributes
 213 according to SPEC.
 214
 215 The remaining arguments should have the form
 216
 217    [KEYWORD VALUE]...
 218
 219 The following KEYWORDs are defined:
 220
 221 :group  VALUE should be a customization group.
 222         Add FACE to that group.
 223
 224 SPEC should be an alist of the form ((DISPLAY ATTS)...).
 225
 226 The first element of SPEC where the DISPLAY matches the frame
 227 is the one that takes effect in that frame.  The ATTRs in this
 228 element take effect; the other elements are ignored, on that frame.
 229
 230 ATTS is a list of face attributes followed by their values:
 231   (ATTR VALUE ATTR VALUE...)
 232
 233 The possible attributes are `:family', `:width', `:height', `:weight',
 234 `:slant', `:underline', `:overline', `:strike-through', `:box',
 235 `:foreground', `:background', `:stipple', and `:inverse-video'.
 236
 237 DISPLAY can either be the symbol t, which will match all frames, or an
 238 alist of the form \((REQ ITEM...)...).  For the DISPLAY to match a
 239 FRAME, the REQ property of the frame must match one of the ITEM.  The
 240 following REQ are defined:
 241
 242 `type' (the value of `window-system')
 243   Under X, in addition to the values `window-system' can take,
 244   `motif', `lucid' and `x-toolkit' are allowed, and match when
 245   the Motif toolkit, Lucid toolkit, or any X toolkit is in use.
 246
 247 `class' (the frame's color support)
 248   Should be one of `color', `grayscale', or `mono'.
 249
 250 `background' (what color is used for the background text)
 251   Should be one of `light' or `dark'.
 252
 253 Read the section about customization in the Emacs Lisp manual for more
 254 information."
 255   ;; It is better not to use backquote in this file,
 256   ;; because that makes a bootstrapping problem
 257   ;; if you need to recompile all the Lisp files using interpreted code.
 258   (nconc (list 'custom-declare-face (list 'quote face) spec doc) args))
 259
 260 ;;; The `defgroup' Macro.
 261
 262 (defun custom-declare-group (symbol members doc &rest args)
 263   "Like `defgroup', but SYMBOL is evaluated as a normal argument."
 264   (while members
 265     (apply 'custom-add-to-group symbol (car members))
 266     (setq members (cdr members)))
 267   (put symbol 'custom-group (nconc members (get symbol 'custom-group)))
 268   (when doc
 269     ;; This text doesn't get into DOC.
 270     (put symbol 'group-documentation (purecopy doc)))
 271   (while args
 272     (let ((arg (car args)))
 273       (setq args (cdr args))
 274       (unless (symbolp arg)
 275         (error "Junk in args %S" args))
 276       (let ((keyword arg)
 277             (value (car args)))
 278         (unless args
 279           (error "Keyword %s is missing an argument" keyword))
 280         (setq args (cdr args))
 281         (cond ((eq keyword :prefix)
 282                (put symbol 'custom-prefix value))
 283               (t
 284                (custom-handle-keyword symbol keyword value
 285                                       'custom-group))))))
 286   (run-hooks 'custom-define-hook)
 287   symbol)
 288
 289 (defmacro defgroup (symbol members doc &rest args)
 290   "Declare SYMBOL as a customization group containing MEMBERS.
 291 SYMBOL does not need to be quoted.
 292
 293 Third arg DOC is the group documentation.
 294
 295 MEMBERS should be an alist of the form ((NAME WIDGET)...) where
 296 NAME is a symbol and WIDGET is a widget for editing that symbol.
 297 Useful widgets are `custom-variable' for editing variables,
 298 `custom-face' for edit faces, and `custom-group' for editing groups.
 299
 300 The remaining arguments should have the form
 301
 302    [KEYWORD VALUE]...
 303
 304 The following KEYWORDs are defined:
 305
 306 :group   VALUE should be a customization group.
 307          Add SYMBOL to that group.
 308
 309 :version VALUE should be a string specifying that the group was introduced
 310          in Emacs version VERSION.
 311
 312 Read the section about customization in the Emacs Lisp manual for more
 313 information."
 314   ;; It is better not to use backquote in this file,
 315   ;; because that makes a bootstrapping problem
 316   ;; if you need to recompile all the Lisp files using interpreted code.
 317   (nconc (list 'custom-declare-group (list 'quote symbol) members doc) args))
 318
 319 (defun custom-add-to-group (group option widget)
 320   "To existing GROUP add a new OPTION of type WIDGET.
 321 If there already is an entry for OPTION and WIDGET, nothing is done."
 322   (let ((members (get group 'custom-group))
 323         (entry (list option widget)))
 324     (unless (member entry members)
 325       (put group 'custom-group (nconc members (list entry))))))
 326
 327 ;;; Properties.
 328
 329 (defun custom-handle-all-keywords (symbol args type)
 330   "For customization option SYMBOL, handle keyword arguments ARGS.
 331 Third argument TYPE is the custom option type."
 332   (while args
 333     (let ((arg (car args)))
 334       (setq args (cdr args))
 335       (unless (symbolp arg)
 336         (error "Junk in args %S" args))
 337       (let ((keyword arg)
 338             (value (car args)))
 339         (unless args
 340           (error "Keyword %s is missing an argument" keyword))
 341         (setq args (cdr args))
 342         (custom-handle-keyword symbol keyword value type)))))
 343
 344 (defun custom-handle-keyword (symbol keyword value type)
 345   "For customization option SYMBOL, handle KEYWORD with VALUE.
 346 Fourth argument TYPE is the custom option type."
 347   (if purify-flag
 348       (setq value (purecopy value)))
 349   (cond ((eq keyword :group)
 350          (custom-add-to-group value symbol type))
 351         ((eq keyword :version)
 352          (custom-add-version symbol value))
 353         ((eq keyword :link)
 354          (custom-add-link symbol value))
 355         ((eq keyword :load)
 356          (custom-add-load symbol value))
 357         ((eq keyword :tag)
 358          (put symbol 'custom-tag value))
 359         ((eq keyword :set-after)
 360          (custom-add-dependencies symbol value))
 361         (t
 362          (error "Unknown keyword %s" keyword))))
 363
 364 (defun custom-add-dependencies (symbol value)
 365   "To the custom option SYMBOL, add dependencies specified by VALUE.
 366 VALUE should be a list of symbols.  For each symbol in that list,
 367 this specifies that SYMBOL should be set after the specified symbol, if
 368 both appear in constructs like `custom-set-variables'."
 369   (unless (listp value)
 370     (error "Invalid custom dependency `%s'" value))
 371   (let* ((deps (get symbol 'custom-dependencies))
 372          (new-deps deps))
 373     (while value
 374       (let ((dep (car value)))
 375         (unless (symbolp dep)
 376           (error "Invalid custom dependency `%s'" dep))
 377         (unless (memq dep new-deps)
 378           (setq new-deps (cons dep new-deps)))
 379         (setq value (cdr value))))
 380     (unless (eq deps new-deps)
 381       (put symbol 'custom-dependencies new-deps))))
 382
 383 (defun custom-add-option (symbol option)
 384   "To the variable SYMBOL add OPTION.
 385
 386 If SYMBOL is a hook variable, OPTION should be a hook member.
 387 For other types variables, the effect is undefined."
 388   (let ((options (get symbol 'custom-options)))
 389     (unless (member option options)
 390       (put symbol 'custom-options (cons option options)))))
 391
 392 (defun custom-add-link (symbol widget)
 393   "To the custom option SYMBOL add the link WIDGET."
 394   (let ((links (get symbol 'custom-links)))
 395     (unless (member widget links)
 396       (put symbol 'custom-links (cons (purecopy widget) links)))))
 397
 398 (defun custom-add-version (symbol version)
 399   "To the custom option SYMBOL add the version VERSION."
 400   (put symbol 'custom-version (purecopy version)))
 401
 402 (defun custom-add-load (symbol load)
 403   "To the custom option SYMBOL add the dependency LOAD.
 404 LOAD should be either a library file name, or a feature name."
 405   (let ((loads (get symbol 'custom-loads)))
 406     (unless (member load loads)
 407       (put symbol 'custom-loads (cons (purecopy load) loads)))))
 408
 409 ;;; Initializing.
 410
 411 (defvar custom-local-buffer nil
 412   "Non-nil, in a Customization buffer, means customize a specific buffer.
 413 If this variable is non-nil, it should be a buffer,
 414 and it means customize the local bindings of that buffer.
 415 This variable is a permanent local, and it normally has a local binding
 416 in every Customization buffer.")
 417 (put 'custom-local-buffer 'permanent-local t)
 418
 419 (defun custom-set-variables (&rest args)
 420   "Initialize variables according to user preferences.
 421
 422 The arguments should be a list where each entry has the form:
 423
 424   (SYMBOL VALUE [NOW [REQUEST [COMMENT]]])
 425
 426 The unevaluated VALUE is stored as the saved value for SYMBOL.
 427 If NOW is present and non-nil, VALUE is also evaluated and bound as
 428 the default value for the SYMBOL.
 429 REQUEST is a list of features we must require for SYMBOL.
 430 COMMENT is a comment string about SYMBOL."
 431   (setq args
 432         (sort args
 433               (lambda (a1 a2)
 434                 (let* ((sym1 (car a1))
 435                        (sym2 (car a2))
 436                        (1-then-2 (memq sym1 (get sym2 'custom-dependencies)))
 437                        (2-then-1 (memq sym2 (get sym1 'custom-dependencies))))
 438                   (cond ((and 1-then-2 2-then-1)
 439                          (error "Circular custom dependency between `%s' and `%s'"
 440                                 sym1 sym2))
 441                         (1-then-2 t)
 442                         (t nil))))))
 443   (while args
 444     (let ((entry (car args)))
 445       (if (listp entry)
 446           (let* ((symbol (nth 0 entry))
 447                  (value (nth 1 entry))
 448                  (now (nth 2 entry))
 449                  (requests (nth 3 entry))
 450                  (comment (nth 4 entry))
 451                  set)
 452             (when requests
 453               (put symbol 'custom-requests requests)
 454               (mapc 'require requests))
 455             (setq set (or (get symbol 'custom-set) 'custom-set-default))
 456             (put symbol 'saved-value (list value))
 457             (put symbol 'saved-variable-comment comment)
 458             ;; Allow for errors in the case where the setter has
 459             ;; changed between versions, say, but let the user know.
 460             (condition-case data
 461                 (cond (now
 462                        ;; Rogue variable, set it now.
 463                        (put symbol 'force-value t)
 464                        (funcall set symbol (eval value)))
 465                       ((default-boundp symbol)
 466                        ;; Something already set this, overwrite it.
 467                        (funcall set symbol (eval value))))
 468               (error
 469                (message "Error setting %s: %s" symbol data)))
 470             (setq args (cdr args))
 471             (and (or now (default-boundp symbol))
 472                  (put symbol 'variable-comment comment)))
 473         ;; Old format, a plist of SYMBOL VALUE pairs.
 474         (message "Warning: old format `custom-set-variables'")
 475         (ding)
 476         (sit-for 2)
 477         (let ((symbol (nth 0 args))
 478               (value (nth 1 args)))
 479           (put symbol 'saved-value (list value)))
 480         (setq args (cdr (cdr args)))))))
 481
 482 (defun custom-set-default (variable value)
 483   "Default :set function for a customizable variable.
 484 Normally, this sets the default value of VARIABLE to VALUE,
 485 but if `custom-local-buffer' is non-nil,
 486 this sets the local binding in that buffer instead."
 487   (if custom-local-buffer
 488       (with-current-buffer custom-local-buffer
 489         (set variable value))
 490     (set-default variable value)))
 491
 492 ;;; The End.
 493
 494 ;; Process the defcustoms for variables loaded before this file.
 495 (while custom-declare-variable-list
 496   (apply 'custom-declare-variable (car custom-declare-variable-list))
 497   (setq custom-declare-variable-list (cdr custom-declare-variable-list)))
 498
 499 (provide 'custom)
 500
 501 ;;; custom.el ends here