lisp/wid-edit.el

   1 ;;; wid-edit.el --- Functions for creating and using widgets.
   2 ;;
   3 ;; Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
   6 ;; Keywords: extensions
   7 ;; Version: 1.9942
   8 ;; X-URL: http://www.dina.kvl.dk/~abraham/custom/
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28 ;;
  29 ;; See `widget.el'.
  30
  31 ;;; Code:
  32
  33 (require 'widget)
  34 (eval-when-compile (require 'cl))
  35
  36 ;;; Compatibility.
  37
  38 (eval-and-compile
  39   (autoload 'pp-to-string "pp")
  40   (autoload 'Info-goto-node "info")
  41
  42   (when (string-match "XEmacs" emacs-version)
  43     (condition-case nil
  44         (require 'overlay)
  45       (error (load-library "x-overlay"))))
  46
  47   (if (string-match "XEmacs" emacs-version)
  48       (defun widget-event-point (event)
  49         "Character position of the end of event if that exists, or nil."
  50         (if (mouse-event-p event)
  51             (event-point event)
  52           nil))
  53     (defun widget-event-point (event)
  54       "Character position of the end of event if that exists, or nil."
  55       (posn-point (event-end event))))
  56
  57   (defalias 'widget-read-event (if (string-match "XEmacs" emacs-version)
  58                                    'next-event
  59                                  'read-event))
  60
  61   ;; The following should go away when bundled with Emacs.
  62   (condition-case ()
  63       (require 'custom)
  64     (error nil))
  65
  66   (unless (and (featurep 'custom) (fboundp 'custom-declare-variable))
  67     ;; We have the old custom-library, hack around it!
  68     (defmacro defgroup (&rest args) nil)
  69     (defmacro defcustom (var value doc &rest args)
  70       (` (defvar (, var) (, value) (, doc))))
  71     (defmacro defface (&rest args) nil)
  72     (define-widget-keywords :prefix :tag :load :link :options :type :group)
  73     (when (fboundp 'copy-face)
  74       (copy-face 'default 'widget-documentation-face)
  75       (copy-face 'bold 'widget-button-face)
  76       (copy-face 'italic 'widget-field-face)))
  77
  78   (unless (fboundp 'button-release-event-p)
  79     ;; XEmacs function missing from Emacs.
  80     (defun button-release-event-p (event)
  81       "Non-nil if EVENT is a mouse-button-release event object."
  82       (and (eventp event)
  83            (memq (event-basic-type event) '(mouse-1 mouse-2 mouse-3))
  84            (or (memq 'click (event-modifiers event))
  85                (memq  'drag (event-modifiers event))))))
  86
  87   (unless (fboundp 'functionp)
  88     ;; Missing from Emacs 19.34 and earlier.
  89     (defun functionp (object)
  90       "Non-nil of OBJECT is a type of object that can be called as a function."
  91       (or (subrp object) (byte-code-function-p object)
  92           (eq (car-safe object) 'lambda)
  93           (and (symbolp object) (fboundp object)))))
  94
  95   (unless (fboundp 'error-message-string)
  96     ;; Emacs function missing in XEmacs.
  97     (defun error-message-string (obj)
  98       "Convert an error value to an error message."
  99       (let ((buf (get-buffer-create " *error-message*")))
 100         (erase-buffer buf)
 101         (display-error obj buf)
 102         (buffer-string buf)))))
 103
 104 (when (let ((a "foo"))
 105         (put-text-property 1 2 'foo 1 a)
 106         (put-text-property 1 2 'bar 2 a)
 107         (set-text-properties 1 2 nil a)
 108         (text-properties-at 1 a))
 109   ;; XEmacs 20.2 and earlier had a buggy set-text-properties.
 110   (defun set-text-properties (start end props &optional buffer-or-string)
 111     "Completely replace properties of text from START to END.
 112 The third argument PROPS is the new property list.
 113 The optional fourth argument, BUFFER-OR-STRING,
 114 is the string or buffer containing the text."
 115     (map-extents #'(lambda (extent ignored)
 116                      (remove-text-properties
 117                       start end
 118                       (list (extent-property extent 'text-prop)
 119                             nil)
 120                       buffer-or-string)
 121                      nil)
 122                  buffer-or-string start end nil nil 'text-prop)
 123     (add-text-properties start end props buffer-or-string)))
 124
 125 ;;; Customization.
 126
 127 (defgroup widgets nil
 128   "Customization support for the Widget Library."
 129   :link '(custom-manual "(widget)Top")
 130   :link '(url-link :tag "Development Page"
 131                    "http://www.dina.kvl.dk/~abraham/custom/")
 132   :prefix "widget-"
 133   :group 'extensions
 134   :group 'hypermedia)
 135
 136 (defgroup widget-documentation nil
 137   "Options controling the display of documentation strings."
 138   :group 'widgets)
 139
 140 (defgroup widget-faces nil
 141   "Faces used by the widget library."
 142   :group 'widgets
 143   :group 'faces)
 144
 145 (defvar widget-documentation-face 'widget-documentation-face
 146   "Face used for documentation strings in widges.
 147 This exists as a variable so it can be set locally in certain buffers.")
 148
 149 (defface widget-documentation-face '((((class color)
 150                                        (background dark))
 151                                       (:foreground "lime green"))
 152                                      (((class color)
 153                                        (background light))
 154                                       (:foreground "dark green"))
 155                                      (t nil))
 156   "Face used for documentation text."
 157   :group 'widget-documentation
 158   :group 'widget-faces)
 159
 160 (defvar widget-button-face 'widget-button-face
 161   "Face used for buttons in widges.
 162 This exists as a variable so it can be set locally in certain buffers.")
 163
 164 (defface widget-button-face '((t (:bold t)))
 165   "Face used for widget buttons."
 166   :group 'widget-faces)
 167
 168 (defcustom widget-mouse-face 'highlight
 169   "Face used for widget buttons when the mouse is above them."
 170   :type 'face
 171   :group 'widget-faces)
 172
 173 (defface widget-field-face '((((class grayscale color)
 174                                (background light))
 175                               (:background "gray85"))
 176                              (((class grayscale color)
 177                                (background dark))
 178                               (:background "dim gray"))
 179                              (t
 180                               (:italic t)))
 181   "Face used for editable fields."
 182   :group 'widget-faces)
 183
 184 (defface widget-single-line-field-face '((((class grayscale color)
 185                                            (background light))
 186                                           (:background "gray85"))
 187                                          (((class grayscale color)
 188                                            (background dark))
 189                                           (:background "dim gray"))
 190                                          (t
 191                                           (:italic t)))
 192   "Face used for editable fields spanning only a single line."
 193   :group 'widget-faces)
 194
 195 (defvar widget-single-line-display-table
 196   (let ((table (make-display-table)))
 197     (aset table 9  "^I")
 198     (aset table 10 "^J")
 199     table)
 200   "Display table used for single-line editable fields.")
 201
 202 (when (fboundp 'set-face-display-table)
 203   (set-face-display-table 'widget-single-line-field-face
 204                           widget-single-line-display-table))
 205
 206 ;;; Utility functions.
 207 ;;
 208 ;; These are not really widget specific.
 209
 210 (defsubst widget-plist-member (plist prop)
 211   ;; Return non-nil if PLIST has the property PROP.
 212   ;; PLIST is a property list, which is a list of the form
 213   ;; (PROP1 VALUE1 PROP2 VALUE2 ...).  PROP is a symbol.
 214   ;; Unlike `plist-get', this allows you to distinguish between a missing
 215   ;; property and a property with the value nil.
 216   ;; The value is actually the tail of PLIST whose car is PROP.
 217   (while (and plist (not (eq (car plist) prop)))
 218     (setq plist (cdr (cdr plist))))
 219   plist)
 220
 221 (defun widget-princ-to-string (object)
 222   ;; Return string representation of OBJECT, any Lisp object.
 223   ;; No quoting characters are used; no delimiters are printed around
 224   ;; the contents of strings.
 225   (save-excursion
 226     (set-buffer (get-buffer-create " *widget-tmp*"))
 227     (erase-buffer)
 228     (let ((standard-output (current-buffer)))
 229       (princ object))
 230     (buffer-string)))
 231
 232 (defun widget-clear-undo ()
 233   "Clear all undo information."
 234   (buffer-disable-undo (current-buffer))
 235   (buffer-enable-undo))
 236
 237 (defcustom widget-menu-max-size 40
 238   "Largest number of items allowed in a popup-menu.
 239 Larger menus are read through the minibuffer."
 240   :group 'widgets
 241   :type 'integer)
 242
 243 (defcustom widget-menu-minibuffer-flag (string-match "XEmacs" emacs-version)
 244   "*Control how to ask for a choice from the keyboard.
 245 Non-nil means use the minibuffer;
 246 nil means read a single character."
 247   :group 'widgets
 248   :type 'boolean)
 249
 250 (defun widget-choose (title items &optional event)
 251   "Choose an item from a list.
 252
 253 First argument TITLE is the name of the list.
 254 Second argument ITEMS is an list whose members are either
 255  (NAME . VALUE), to indicate selectable items, or just strings to
 256  indicate unselectable items.
 257 Optional third argument EVENT is an input event.
 258
 259 The user is asked to choose between each NAME from the items alist,
 260 and the VALUE of the chosen element will be returned.  If EVENT is a
 261 mouse event, and the number of elements in items is less than
 262 `widget-menu-max-size', a popup menu will be used, otherwise the
 263 minibuffer."
 264   (cond ((and (< (length items) widget-menu-max-size)
 265               event (fboundp 'x-popup-menu) window-system)
 266          ;; We are in Emacs-19, pressed by the mouse
 267          (x-popup-menu event
 268                        (list title (cons "" items))))
 269         ((and (< (length items) widget-menu-max-size)
 270               event (fboundp 'popup-menu) window-system)
 271          ;; We are in XEmacs, pressed by the mouse
 272          (let ((val (get-popup-menu-response
 273                      (cons title
 274                            (mapcar
 275                             (function
 276                              (lambda (x)
 277                                (if (stringp x)
 278                                    (vector x nil nil)
 279                                  (vector (car x) (list (car x)) t))))
 280                             items)))))
 281            (setq val (and val
 282                           (listp (event-object val))
 283                           (stringp (car-safe (event-object val)))
 284                           (car (event-object val))))
 285            (cdr (assoc val items))))
 286         (widget-menu-minibuffer-flag
 287          ;; Read the choice of name from the minibuffer.
 288          (setq items (widget-remove-if 'stringp items))
 289          (let ((val (completing-read (concat title ": ") items nil t)))
 290            (if (stringp val)
 291                (let ((try (try-completion val items)))
 292                  (when (stringp try)
 293                    (setq val try))
 294                  (cdr (assoc val items)))
 295              nil)))
 296         (t
 297          ;; Construct a menu of the choices
 298          ;; and then use it for prompting for a single character.
 299          (let* ((overriding-terminal-local-map
 300                  (make-sparse-keymap))
 301                 map choice (next-digit ?0)
 302                 value)
 303            ;; Define SPC as a prefix char to get to this menu.
 304            (define-key overriding-terminal-local-map " "
 305              (setq map (make-sparse-keymap title)))
 306            (save-excursion
 307              (set-buffer (get-buffer-create " widget-choose"))
 308              (erase-buffer)
 309              (insert "Available choices:\n\n")
 310              (while items
 311                (setq choice (car items) items (cdr items))
 312                (if (consp choice)
 313                    (let* ((name (car choice))
 314                          (function (cdr choice)))
 315                      (insert (format "%c = %s\n" next-digit name))
 316                      (define-key map (vector next-digit) function)))
 317                ;; Allocate digits to disabled alternatives
 318                ;; so that the digit of a given alternative never varies.
 319                (setq next-digit (1+ next-digit)))
 320              (insert "\nC-g = Quit"))
 321            (define-key map [?\C-g] 'keyboard-quit)
 322            (define-key map [t] 'keyboard-quit)
 323            (setcdr map (nreverse (cdr map)))
 324            ;; Unread a SPC to lead to our new menu.
 325            (setq unread-command-events (cons ?\ unread-command-events))
 326            ;; Read a char with the menu, and return the result
 327            ;; that corresponds to it.
 328            (save-window-excursion
 329              (display-buffer (get-buffer " widget-choose"))
 330              (let ((cursor-in-echo-area t))
 331                (setq value
 332                      (lookup-key overriding-terminal-local-map
 333                                  (read-key-sequence title) t))))
 334            (when (eq value 'keyboard-quit)
 335              (error "Canceled"))
 336            value))))
 337
 338 (defun widget-remove-if (predictate list)
 339   (let (result (tail list))
 340     (while tail
 341       (or (funcall predictate (car tail))
 342           (setq result (cons (car tail) result)))
 343       (setq tail (cdr tail)))
 344     (nreverse result)))
 345
 346 ;;; Widget text specifications.
 347 ;;
 348 ;; These functions are for specifying text properties.
 349
 350 (defun widget-specify-none (from to)
 351   ;; Clear all text properties between FROM and TO.
 352   (set-text-properties from to nil))
 353
 354 (defun widget-specify-text (from to)
 355   ;; Default properties.
 356   (add-text-properties from to (list 'read-only t
 357                                      'front-sticky t
 358                                      'rear-nonsticky nil
 359                                      'start-open nil
 360                                      'end-open nil)))
 361
 362 (defcustom widget-field-add-space
 363   (or (< emacs-major-version 20)
 364       (and (eq emacs-major-version 20)
 365            (< emacs-minor-version 3))
 366       (not (string-match "XEmacs" emacs-version)))
 367   "Non-nil means add extra space at the end of editable text fields.
 368
 369 This is needed on all versions of Emacs, and on XEmacs before 20.3.
 370 If you don't add the space, it will become impossible to edit a zero
 371 size field."
 372   :type 'boolean
 373   :group 'widgets)
 374
 375 (defcustom widget-field-use-before-change
 376   (or (> emacs-minor-version 34)
 377       (> emacs-major-version 20)
 378       (string-match "XEmacs" emacs-version))
 379   "Non-nil means use `before-change-functions' to track editable fields.
 380 This enables the use of undo, but doesn'f work on Emacs 19.34 and earlier.
 381 Using before hooks also means that the :notify function can't know the
 382 new value."
 383   :type 'boolean
 384   :group 'widgets)
 385
 386 (defun widget-specify-field (widget from to)
 387   "Specify editable button for WIDGET between FROM and TO."
 388   (put-text-property from to 'read-only nil)
 389   ;; Terminating space is not part of the field, but necessary in
 390   ;; order for local-map to work.  Remove next sexp if local-map works
 391   ;; at the end of the overlay.
 392   (save-excursion
 393     (goto-char to)
 394     (when widget-field-add-space
 395       (insert-and-inherit " "))
 396     (setq to (point)))
 397   (if widget-field-add-space
 398       (add-text-properties (1- to) to
 399                            '(front-sticky nil start-open t read-only to))
 400     (add-text-properties to (1+ to)
 401                          '(front-sticky nil start-open t read-only to)))
 402   (add-text-properties (1- from) from
 403                        '(rear-nonsticky t end-open t read-only from))
 404   (let ((map (widget-get widget :keymap))
 405         (face (or (widget-get widget :value-face) 'widget-field-face))
 406         (help-echo (widget-get widget :help-echo))
 407         (overlay (make-overlay from to nil nil t)))
 408     (unless (or (stringp help-echo) (null help-echo))
 409       (setq help-echo 'widget-mouse-help))
 410     (widget-put widget :field-overlay overlay)
 411     (overlay-put overlay 'detachable nil)
 412     (overlay-put overlay 'field widget)
 413     (overlay-put overlay 'local-map map)
 414     (overlay-put overlay 'keymap map)
 415     (overlay-put overlay 'face face)
 416     (overlay-put overlay 'balloon-help help-echo)
 417     (overlay-put overlay 'help-echo help-echo)))
 418
 419 (defun widget-specify-button (widget from to)
 420   "Specify button for WIDGET between FROM and TO."
 421   (let ((face (widget-apply widget :button-face-get))
 422         (help-echo (widget-get widget :help-echo))
 423         (overlay (make-overlay from to nil t nil)))
 424     (widget-put widget :button-overlay overlay)
 425     (unless (or (null help-echo) (stringp help-echo))
 426       (setq help-echo 'widget-mouse-help))
 427     (overlay-put overlay 'button widget)
 428     (overlay-put overlay 'mouse-face widget-mouse-face)
 429     (overlay-put overlay 'balloon-help help-echo)
 430     (overlay-put overlay 'help-echo help-echo)
 431     (overlay-put overlay 'face face)))
 432
 433 (defun widget-mouse-help (extent)
 434   "Find mouse help string for button in extent."
 435   (let* ((widget (widget-at (extent-start-position extent)))
 436          (help-echo (and widget (widget-get widget :help-echo))))
 437     (cond ((stringp help-echo)
 438            help-echo)
 439           ((and (symbolp help-echo) (fboundp help-echo)
 440                 (stringp (setq help-echo (funcall help-echo widget))))
 441            help-echo)
 442           (t
 443            (format "(widget %S :help-echo %S)" widget help-echo)))))
 444
 445 (defun widget-specify-sample (widget from to)
 446   ;; Specify sample for WIDGET between FROM and TO.
 447   (let ((face (widget-apply widget :sample-face-get)))
 448     (when face
 449       (add-text-properties from to (list 'start-open t
 450                                          'end-open t
 451                                          'face face)))))
 452 (defun widget-specify-doc (widget from to)
 453   ;; Specify documentation for WIDGET between FROM and TO.
 454   (add-text-properties from to (list 'widget-doc widget
 455                                      'face widget-documentation-face)))
 456
 457 (defmacro widget-specify-insert (&rest form)
 458   ;; Execute FORM without inheriting any text properties.
 459   (`
 460    (save-restriction
 461      (let ((inhibit-read-only t)
 462            result
 463            before-change-functions
 464            after-change-functions)
 465        (insert "<>")
 466        (narrow-to-region (- (point) 2) (point))
 467        (widget-specify-none (point-min) (point-max))
 468        (goto-char (1+ (point-min)))
 469        (setq result (progn (,@ form)))
 470        (delete-region (point-min) (1+ (point-min)))
 471        (delete-region (1- (point-max)) (point-max))
 472        (goto-char (point-max))
 473        result))))
 474
 475 (defface widget-inactive-face '((((class grayscale color)
 476                                   (background dark))
 477                                  (:foreground "light gray"))
 478                                 (((class grayscale color)
 479                                   (background light))
 480                                  (:foreground "dim gray"))
 481                                 (t
 482                                  (:italic t)))
 483   "Face used for inactive widgets."
 484   :group 'widget-faces)
 485
 486 (defun widget-specify-inactive (widget from to)
 487   "Make WIDGET inactive for user modifications."
 488   (unless (widget-get widget :inactive)
 489     (let ((overlay (make-overlay from to nil t nil)))
 490       (overlay-put overlay 'face 'widget-inactive-face)
 491       ;; This is disabled, as it makes the mouse cursor change shape.
 492       ;; (overlay-put overlay 'mouse-face 'widget-inactive-face)
 493       (overlay-put overlay 'evaporate t)
 494       (overlay-put overlay 'priority 100)
 495       (overlay-put overlay (if (string-match "XEmacs" emacs-version)
 496                                'read-only
 497                              'modification-hooks) '(widget-overlay-inactive))
 498       (widget-put widget :inactive overlay))))
 499
 500 (defun widget-overlay-inactive (&rest junk)
 501   "Ignoring the arguments, signal an error."
 502   (unless inhibit-read-only
 503     (error "Attempt to modify inactive widget")))
 504
 505
 506 (defun widget-specify-active (widget)
 507   "Make WIDGET active for user modifications."
 508   (let ((inactive (widget-get widget :inactive)))
 509     (when inactive
 510       (delete-overlay inactive)
 511       (widget-put widget :inactive nil))))
 512
 513 ;;; Widget Properties.
 514
 515 (defsubst widget-type (widget)
 516   "Return the type of WIDGET, a symbol."
 517   (car widget))
 518
 519 (defun widget-put (widget property value)
 520   "In WIDGET set PROPERTY to VALUE.
 521 The value can later be retrived with `widget-get'."
 522   (setcdr widget (plist-put (cdr widget) property value)))
 523
 524 (defun widget-get (widget property)
 525   "In WIDGET, get the value of PROPERTY.
 526 The value could either be specified when the widget was created, or
 527 later with `widget-put'."
 528   (let ((missing t)
 529         value tmp)
 530     (while missing
 531       (cond ((setq tmp (widget-plist-member (cdr widget) property))
 532              (setq value (car (cdr tmp))
 533                    missing nil))
 534             ((setq tmp (car widget))
 535              (setq widget (get tmp 'widget-type)))
 536             (t
 537              (setq missing nil))))
 538     value))
 539
 540 (defun widget-get-indirect (widget property)
 541   "In WIDGET, get the value of PROPERTY.
 542 If the value is a symbol, return its binding.
 543 Otherwise, just return the value."
 544   (let ((value (widget-get widget property)))
 545     (if (symbolp value)
 546         (symbol-value value)
 547       value)))
 548
 549 (defun widget-member (widget property)
 550   "Non-nil iff there is a definition in WIDGET for PROPERTY."
 551   (cond ((widget-plist-member (cdr widget) property)
 552          t)
 553         ((car widget)
 554          (widget-member (get (car widget) 'widget-type) property))
 555         (t nil)))
 556
 557 ;;;###autoload
 558 (defun widget-apply (widget property &rest args)
 559   "Apply the value of WIDGET's PROPERTY to the widget itself.
 560 ARGS are passed as extra arguments to the function."
 561   (apply (widget-get widget property) widget args))
 562
 563 (defun widget-value (widget)
 564   "Extract the current value of WIDGET."
 565   (widget-apply widget
 566                 :value-to-external (widget-apply widget :value-get)))
 567
 568 (defun widget-value-set (widget value)
 569   "Set the current value of WIDGET to VALUE."
 570   (widget-apply widget
 571                 :value-set (widget-apply widget
 572                                          :value-to-internal value)))
 573
 574 (defun widget-match-inline (widget vals)
 575   ;; In WIDGET, match the start of VALS.
 576   (cond ((widget-get widget :inline)
 577          (widget-apply widget :match-inline vals))
 578         ((and vals
 579               (widget-apply widget :match (car vals)))
 580          (cons (list (car vals)) (cdr vals)))
 581         (t nil)))
 582
 583 (defun widget-apply-action (widget &optional event)
 584   "Apply :action in WIDGET in response to EVENT."
 585   (if (widget-apply widget :active)
 586       (widget-apply widget :action event)
 587     (error "Attempt to perform action on inactive widget")))
 588
 589 ;;; Helper functions.
 590 ;;
 591 ;; These are widget specific.
 592
 593 ;;;###autoload
 594 (defun widget-prompt-value (widget prompt &optional value unbound)
 595   "Prompt for a value matching WIDGET, using PROMPT.
 596 The current value is assumed to be VALUE, unless UNBOUND is non-nil."
 597   (unless (listp widget)
 598     (setq widget (list widget)))
 599   (setq prompt (format "[%s] %s" (widget-type widget) prompt))
 600   (setq widget (widget-convert widget))
 601   (let ((answer (widget-apply widget :prompt-value prompt value unbound)))
 602     (unless (widget-apply widget :match answer)
 603       (error "Value does not match %S type." (car widget)))
 604     answer))
 605
 606 (defun widget-get-sibling (widget)
 607   "Get the item WIDGET is assumed to toggle.
 608 This is only meaningful for radio buttons or checkboxes in a list."
 609   (let* ((parent (widget-get widget :parent))
 610          (children (widget-get parent :children))
 611          child)
 612     (catch 'child
 613       (while children
 614         (setq child (car children)
 615               children (cdr children))
 616         (when (eq (widget-get child :button) widget)
 617           (throw 'child child)))
 618       nil)))
 619
 620 (defun widget-map-buttons (function &optional buffer maparg)
 621   "Map FUNCTION over the buttons in BUFFER.
 622 FUNCTION is called with the arguments WIDGET and MAPARG.
 623
 624 If FUNCTION returns non-nil, the walk is cancelled.
 625
 626 The arguments MAPARG, and BUFFER default to nil and (current-buffer),
 627 respectively."
 628   (let ((cur (point-min))
 629         (widget nil)
 630         (parent nil)
 631         (overlays (if buffer
 632                       (save-excursion (set-buffer buffer) (overlay-lists))
 633                     (overlay-lists))))
 634     (setq overlays (append (car overlays) (cdr overlays)))
 635     (while (setq cur (pop overlays))
 636       (setq widget (overlay-get cur 'button))
 637       (if (and widget (funcall function widget maparg))
 638           (setq overlays nil)))))
 639
 640 ;;; Glyphs.
 641
 642 (defcustom widget-glyph-directory (concat data-directory "custom/")
 643   "Where widget glyphs are located.
 644 If this variable is nil, widget will try to locate the directory
 645 automatically."
 646   :group 'widgets
 647   :type 'directory)
 648
 649 (defcustom widget-glyph-enable t
 650   "If non nil, use glyphs in images when available."
 651   :group 'widgets
 652   :type 'boolean)
 653
 654 (defcustom widget-image-conversion
 655   '((xpm ".xpm") (gif ".gif") (png ".png") (jpeg ".jpg" ".jpeg")
 656     (xbm ".xbm"))
 657   "Conversion alist from image formats to file name suffixes."
 658   :group 'widgets
 659   :type '(repeat (cons :format "%v"
 660                        (symbol :tag "Image Format" unknown)
 661                        (repeat :tag "Suffixes"
 662                                (string :format "%v")))))
 663
 664 (defun widget-glyph-find (image tag)
 665   "Create a glyph corresponding to IMAGE with string TAG as fallback.
 666 IMAGE should either already be a glyph, or be a file name sans
 667 extension (xpm, xbm, gif, jpg, or png) located in
 668 `widget-glyph-directory'."
 669   (cond ((not (and image
 670                    (string-match "XEmacs" emacs-version)
 671                    widget-glyph-enable
 672                    (fboundp 'make-glyph)
 673                    (fboundp 'locate-file)
 674                    image))
 675          ;; We don't want or can't use glyphs.
 676          nil)
 677         ((and (fboundp 'glyphp)
 678               (glyphp image))
 679          ;; Already a glyph.  Use it.
 680          image)
 681         ((stringp image)
 682          ;; A string.  Look it up in relevant directories.
 683          (let* ((dirlist (list (or widget-glyph-directory
 684                                    (concat data-directory
 685                                            "custom/"))
 686                                data-directory))
 687                 (formats widget-image-conversion)
 688                 file)
 689            (while (and formats (not file))
 690              (when (valid-image-instantiator-format-p (car (car formats)))
 691                (setq file (locate-file image dirlist
 692                                        (mapconcat 'identity
 693                                                   (cdr (car formats))
 694                                                   ":"))))
 695              (unless file
 696                (setq formats (cdr formats))))
 697            (and file
 698                 ;; We create a glyph with the file as the default image
 699                 ;; instantiator, and the TAG fallback
 700                 (make-glyph (list (vector (car (car formats)) ':file file)
 701                                   (vector 'string ':data tag))))))
 702         ((valid-instantiator-p image 'image)
 703          ;; A valid image instantiator (e.g. [gif :file "somefile"] etc.)
 704          (make-glyph (list image
 705                            (vector 'string ':data tag))))
 706         ((consp image)
 707          ;; This could be virtually anything.  Let `make-glyph' sort it out.
 708          (make-glyph image))
 709         (t
 710          ;; Oh well.
 711          nil)))
 712
 713 (defun widget-glyph-insert (widget tag image &optional down inactive)
 714   "In WIDGET, insert the text TAG or, if supported, IMAGE.
 715 IMAGE should either be a glyph, an image instantiator, or an image file
 716 name sans extension (xpm, xbm, gif, jpg, or png) located in
 717 `widget-glyph-directory'.
 718
 719 Optional arguments DOWN and INACTIVE is used instead of IMAGE when the
 720 glyph is pressed or inactive, respectively.
 721
 722 WARNING: If you call this with a glyph, and you want the user to be
 723 able to invoke the glyph, make sure it is unique.  If you use the
 724 same glyph for multiple widgets, invoking any of the glyphs will
 725 cause the last created widget to be invoked.
 726
 727 Instead of an instantiator, you can also use a list of instantiators,
 728 or whatever `make-glyph' will accept.  However, in that case you must
 729 provide the fallback TAG as a part of the instantiator yourself."
 730   (let ((glyph (widget-glyph-find image tag)))
 731     (if glyph
 732         (widget-glyph-insert-glyph widget
 733                                    glyph
 734                                    (widget-glyph-find down tag)
 735                                    (widget-glyph-find inactive tag))
 736       (insert tag))))
 737
 738 (defun widget-glyph-insert-glyph (widget glyph &optional down inactive)
 739   "In WIDGET, insert GLYPH.
 740 If optional arguments DOWN and INACTIVE are given, they should be
 741 glyphs used when the widget is pushed and inactive, respectively."
 742   (when widget
 743     (set-glyph-property glyph 'widget widget)
 744     (when down
 745       (set-glyph-property down 'widget widget))
 746     (when inactive
 747       (set-glyph-property inactive 'widget widget)))
 748   (insert "*")
 749   (let ((ext (make-extent (point) (1- (point))))
 750         (help-echo (and widget (widget-get widget :help-echo))))
 751     (set-extent-property ext 'invisible t)
 752     (set-extent-property ext 'start-open t)
 753     (set-extent-property ext 'end-open t)
 754     (set-extent-end-glyph ext glyph)
 755     (when help-echo
 756       (set-extent-property ext 'balloon-help help-echo)
 757       (set-extent-property ext 'help-echo help-echo)))
 758   (when widget
 759     (widget-put widget :glyph-up glyph)
 760     (when down (widget-put widget :glyph-down down))
 761     (when inactive (widget-put widget :glyph-inactive inactive))))
 762
 763 ;;; Buttons.
 764
 765 (defgroup widget-button nil
 766   "The look of various kinds of buttons."
 767   :group 'widgets)
 768
 769 (defcustom widget-button-prefix ""
 770   "String used as prefix for buttons."
 771   :type 'string
 772   :group 'widget-button)
 773
 774 (defcustom widget-button-suffix ""
 775   "String used as suffix for buttons."
 776   :type 'string
 777   :group 'widget-button)
 778
 779 ;;; Creating Widgets.
 780
 781 ;;;###autoload
 782 (defun widget-create (type &rest args)
 783   "Create widget of TYPE.
 784 The optional ARGS are additional keyword arguments."
 785   (let ((widget (apply 'widget-convert type args)))
 786     (widget-apply widget :create)
 787     widget))
 788
 789 (defun widget-create-child-and-convert (parent type &rest args)
 790   "As part of the widget PARENT, create a child widget TYPE.
 791 The child is converted, using the keyword arguments ARGS."
 792   (let ((widget (apply 'widget-convert type args)))
 793     (widget-put widget :parent parent)
 794     (unless (widget-get widget :indent)
 795       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 796                                     (or (widget-get widget :extra-offset) 0)
 797                                     (widget-get parent :offset))))
 798     (widget-apply widget :create)
 799     widget))
 800
 801 (defun widget-create-child (parent type)
 802   "Create widget of TYPE."
 803   (let ((widget (copy-sequence type)))
 804     (widget-put widget :parent parent)
 805     (unless (widget-get widget :indent)
 806       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 807                                     (or (widget-get widget :extra-offset) 0)
 808                                     (widget-get parent :offset))))
 809     (widget-apply widget :create)
 810     widget))
 811
 812 (defun widget-create-child-value (parent type value)
 813   "Create widget of TYPE with value VALUE."
 814   (let ((widget (copy-sequence type)))
 815     (widget-put widget :value (widget-apply widget :value-to-internal value))
 816     (widget-put widget :parent parent)
 817     (unless (widget-get widget :indent)
 818       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 819                                     (or (widget-get widget :extra-offset) 0)
 820                                     (widget-get parent :offset))))
 821     (widget-apply widget :create)
 822     widget))
 823
 824 ;;;###autoload
 825 (defun widget-delete (widget)
 826   "Delete WIDGET."
 827   (widget-apply widget :delete))
 828
 829 (defun widget-convert (type &rest args)
 830   "Convert TYPE to a widget without inserting it in the buffer.
 831 The optional ARGS are additional keyword arguments."
 832   ;; Don't touch the type.
 833   (let* ((widget (if (symbolp type)
 834                      (list type)
 835                    (copy-sequence type)))
 836          (current widget)
 837          (keys args))
 838     ;; First set the :args keyword.
 839     (while (cdr current)                ;Look in the type.
 840       (let ((next (car (cdr current))))
 841         (if (and (symbolp next) (eq (aref (symbol-name next) 0) ?:))
 842             (setq current (cdr (cdr current)))
 843           (setcdr current (list :args (cdr current)))
 844           (setq current nil))))
 845     (while args                         ;Look in the args.
 846       (let ((next (nth 0 args)))
 847         (if (and (symbolp next) (eq (aref (symbol-name next) 0) ?:))
 848             (setq args (nthcdr 2 args))
 849           (widget-put widget :args args)
 850           (setq args nil))))
 851     ;; Then Convert the widget.
 852     (setq type widget)
 853     (while type
 854       (let ((convert-widget (plist-get (cdr type) :convert-widget)))
 855         (if convert-widget
 856             (setq widget (funcall convert-widget widget))))
 857       (setq type (get (car type) 'widget-type)))
 858     ;; Finally set the keyword args.
 859     (while keys
 860       (let ((next (nth 0 keys)))
 861         (if (and (symbolp next) (eq (aref (symbol-name next) 0) ?:))
 862             (progn
 863               (widget-put widget next (nth 1 keys))
 864               (setq keys (nthcdr 2 keys)))
 865           (setq keys nil))))
 866     ;; Convert the :value to internal format.
 867     (if (widget-member widget :value)
 868         (let ((value (widget-get widget :value)))
 869           (widget-put widget
 870                       :value (widget-apply widget :value-to-internal value))))
 871     ;; Return the newly create widget.
 872     widget))
 873
 874 (defun widget-insert (&rest args)
 875   "Call `insert' with ARGS and make the text read only."
 876   (let ((inhibit-read-only t)
 877         before-change-functions
 878         after-change-functions
 879         (from (point)))
 880     (apply 'insert args)
 881     (widget-specify-text from (point))))
 882
 883 (defun widget-convert-text (type from to
 884                                  &optional button-from button-to
 885                                  &rest args)
 886   "Return a widget of type TYPE with endpoint FROM TO.
 887 Optional ARGS are extra keyword arguments for TYPE.
 888 and TO will be used as the widgets end points. If optional arguments
 889 BUTTON-FROM and BUTTON-TO are given, these will be used as the widgets
 890 button end points.
 891 Optional ARGS are extra keyword arguments for TYPE."
 892   (let ((widget (apply 'widget-convert type :delete 'widget-leave-text args))
 893         (from (copy-marker from))
 894         (to (copy-marker to)))
 895     (widget-specify-text from to)
 896     (set-marker-insertion-type from t)
 897     (set-marker-insertion-type to nil)
 898     (widget-put widget :from from)
 899     (widget-put widget :to to)
 900     (when button-from
 901       (widget-specify-button widget button-from button-to))
 902     widget))
 903
 904 (defun widget-convert-button (type from to &rest args)
 905   "Return a widget of type TYPE with endpoint FROM TO.
 906 Optional ARGS are extra keyword arguments for TYPE.
 907 No text will be inserted to the buffer, instead the text between FROM
 908 and TO will be used as the widgets end points, as well as the widgets
 909 button end points."
 910   (apply 'widget-convert-text type from to from to args))
 911
 912 (defun widget-leave-text (widget)
 913   "Remove markers and overlays from WIDGET and its children."
 914   (let ((from (widget-get widget :from))
 915         (to (widget-get widget :to))
 916         (button (widget-get widget :button-overlay))
 917         (field (widget-get widget :field-overlay))
 918         (children (widget-get widget :children)))
 919     (set-marker from nil)
 920     (set-marker to nil)
 921     (when button
 922       (delete-overlay button))
 923     (when field
 924       (delete-overlay field))
 925     (mapcar 'widget-leave-text children)))
 926
 927 ;;; Keymap and Commands.
 928
 929 (defvar widget-keymap nil
 930   "Keymap containing useful binding for buffers containing widgets.
 931 Recommended as a parent keymap for modes using widgets.")
 932
 933 (unless widget-keymap
 934   (setq widget-keymap (make-sparse-keymap))
 935   (define-key widget-keymap "\t" 'widget-forward)
 936   (define-key widget-keymap [(shift tab)] 'widget-backward)
 937   (define-key widget-keymap [backtab] 'widget-backward)
 938   (if (string-match "XEmacs" emacs-version)
 939       (progn
 940         ;;Glyph support.
 941         (define-key widget-keymap [button1] 'widget-button1-click)
 942         (define-key widget-keymap [button2] 'widget-button-click))
 943     (define-key widget-keymap [down-mouse-2] 'widget-button-click))
 944   (define-key widget-keymap "\C-m" 'widget-button-press))
 945
 946 (defvar widget-global-map global-map
 947   "Keymap used for events the widget does not handle themselves.")
 948 (make-variable-buffer-local 'widget-global-map)
 949
 950 (defvar widget-field-keymap nil
 951   "Keymap used inside an editable field.")
 952
 953 (unless widget-field-keymap
 954   (setq widget-field-keymap (copy-keymap widget-keymap))
 955   (unless (string-match "XEmacs" (emacs-version))
 956     (define-key widget-field-keymap [menu-bar] 'nil))
 957   (define-key widget-field-keymap "\C-k" 'widget-kill-line)
 958   (define-key widget-field-keymap "\M-\t" 'widget-complete)
 959   (define-key widget-field-keymap "\C-m" 'widget-field-activate)
 960   (define-key widget-field-keymap "\C-a" 'widget-beginning-of-line)
 961   (define-key widget-field-keymap "\C-e" 'widget-end-of-line)
 962   (set-keymap-parent widget-field-keymap global-map))
 963
 964 (defvar widget-text-keymap nil
 965   "Keymap used inside a text field.")
 966
 967 (unless widget-text-keymap
 968   (setq widget-text-keymap (copy-keymap widget-keymap))
 969   (unless (string-match "XEmacs" (emacs-version))
 970     (define-key widget-text-keymap [menu-bar] 'nil))
 971   (define-key widget-text-keymap "\C-a" 'widget-beginning-of-line)
 972   (define-key widget-text-keymap "\C-e" 'widget-end-of-line)
 973   (set-keymap-parent widget-text-keymap global-map))
 974
 975 (defun widget-field-activate (pos &optional event)
 976   "Invoke the ediable field at point."
 977   (interactive "@d")
 978   (let ((field (get-char-property pos 'field)))
 979     (if field
 980         (widget-apply-action field event)
 981       (call-interactively
 982        (lookup-key widget-global-map (this-command-keys))))))
 983
 984 (defface widget-button-pressed-face
 985   '((((class color))
 986      (:foreground "red"))
 987     (t
 988      (:bold t :underline t)))
 989   "Face used for pressed buttons."
 990   :group 'widget-faces)
 991
 992 (defun widget-button-click (event)
 993   "Invoke button below mouse pointer."
 994   (interactive "@e")
 995   (cond ((and (fboundp 'event-glyph)
 996               (event-glyph event))
 997          (widget-glyph-click event))
 998         ((widget-event-point event)
 999          (let* ((pos (widget-event-point event))
1000                 (button (get-char-property pos 'button)))
1001            (if button
1002                (let* ((overlay (widget-get button :button-overlay))
1003                       (face (overlay-get overlay 'face))
1004                       (mouse-face (overlay-get overlay 'mouse-face)))
1005                  (unwind-protect
1006                      (let ((track-mouse t))
1007                        (overlay-put overlay
1008                                     'face 'widget-button-pressed-face)
1009                        (overlay-put overlay
1010                                     'mouse-face 'widget-button-pressed-face)
1011                        (unless (widget-apply button :mouse-down-action event)
1012                          (while (not (button-release-event-p event))
1013                            (setq event (widget-read-event)
1014                                  pos (widget-event-point event))
1015                            (if (and pos
1016                                     (eq (get-char-property pos 'button)
1017                                         button))
1018                                (progn
1019                                  (overlay-put overlay
1020                                               'face
1021                                               'widget-button-pressed-face)
1022                                  (overlay-put overlay
1023                                               'mouse-face
1024                                               'widget-button-pressed-face))
1025                              (overlay-put overlay 'face face)
1026                              (overlay-put overlay 'mouse-face mouse-face))))
1027                        (when (and pos
1028                                   (eq (get-char-property pos 'button) button))
1029                          (widget-apply-action button event)))
1030                    (overlay-put overlay 'face face)
1031                    (overlay-put overlay 'mouse-face mouse-face)))
1032              (let ((up t)
1033                    command)
1034                ;; Find the global command to run, and check whether it
1035                ;; is bound to an up event.
1036                (cond ((setq command     ;down event
1037                             (lookup-key widget-global-map [ button2 ]))
1038                       (setq up nil))
1039                      ((setq command     ;down event
1040                             (lookup-key widget-global-map [ down-mouse-2 ]))
1041                       (setq up nil))
1042                      ((setq command     ;up event
1043                             (lookup-key widget-global-map [ button2up ])))
1044                      ((setq command     ;up event
1045                             (lookup-key widget-global-map [ mouse-2]))))
1046                (when up
1047                  ;; Don't execute up events twice.
1048                  (while (not (button-release-event-p event))
1049                    (setq event (widget-read-event))))
1050                (when command
1051                  (call-interactively command))))))
1052         (t
1053          (message "You clicked somewhere weird."))))
1054
1055 (defun widget-button1-click (event)
1056   "Invoke glyph below mouse pointer."
1057   (interactive "@e")
1058   (if (and (fboundp 'event-glyph)
1059            (event-glyph event))
1060       (widget-glyph-click event)
1061     (call-interactively (lookup-key widget-global-map (this-command-keys)))))
1062
1063 (defun widget-glyph-click (event)
1064   "Handle click on a glyph."
1065   (let* ((glyph (event-glyph event))
1066          (widget (glyph-property glyph 'widget))
1067          (extent (event-glyph-extent event))
1068          (down-glyph (or (and widget (widget-get widget :glyph-down)) glyph))
1069          (up-glyph (or (and widget (widget-get widget :glyph-up)) glyph))
1070          (last event))
1071     ;; Wait for the release.
1072     (while (not (button-release-event-p last))
1073       (if (eq extent (event-glyph-extent last))
1074           (set-extent-property extent 'end-glyph down-glyph)
1075         (set-extent-property extent 'end-glyph up-glyph))
1076       (setq last (next-event event)))
1077     ;; Release glyph.
1078     (when down-glyph
1079       (set-extent-property extent 'end-glyph up-glyph))
1080     ;; Apply widget action.
1081     (when (eq extent (event-glyph-extent last))
1082       (let ((widget (glyph-property (event-glyph event) 'widget)))
1083         (cond ((null widget)
1084                (message "You clicked on a glyph."))
1085               ((not (widget-apply widget :active))
1086                (message "This glyph is inactive."))
1087               (t
1088                (widget-apply-action widget event)))))))
1089
1090 (defun widget-button-press (pos &optional event)
1091   "Invoke button at POS."
1092   (interactive "@d")
1093   (let ((button (get-char-property pos 'button)))
1094     (if button
1095         (widget-apply-action button event)
1096       (let ((command (lookup-key widget-global-map (this-command-keys))))
1097         (when (commandp command)
1098           (call-interactively command))))))
1099
1100 (defun widget-tabable-at (&optional pos)
1101   "Return the tabable widget at POS, or nil.
1102 POS defaults to the value of (point)."
1103   (unless pos
1104     (setq pos (point)))
1105   (let ((widget (or (get-char-property (point) 'button)
1106                     (get-char-property (point) 'field))))
1107     (if widget
1108         (let ((order (widget-get widget :tab-order)))
1109           (if order
1110               (if (>= order 0)
1111                   widget
1112                 nil)
1113             widget))
1114       nil)))
1115
1116 (defun widget-move (arg)
1117   "Move point to the ARG next field or button.
1118 ARG may be negative to move backward."
1119   (or (bobp) (> arg 0) (backward-char))
1120   (let ((pos (point))
1121         (number arg)
1122         (old (widget-tabable-at))
1123         new)
1124     ;; Forward.
1125     (while (> arg 0)
1126       (if (eobp)
1127           (goto-char (point-min))
1128         (forward-char 1))
1129       (and (eq pos (point))
1130            (eq arg number)
1131            (error "No buttons or fields found"))
1132       (let ((new (widget-tabable-at)))
1133         (when new
1134           (unless (eq new old)
1135             (setq arg (1- arg))
1136             (setq old new)))))
1137     ;; Backward.
1138     (while (< arg 0)
1139       (if (bobp)
1140           (goto-char (point-max))
1141         (backward-char 1))
1142       (and (eq pos (point))
1143            (eq arg number)
1144            (error "No buttons or fields found"))
1145       (let ((new (widget-tabable-at)))
1146         (when new
1147           (unless (eq new old)
1148             (setq arg (1+ arg))))))
1149     (let ((new (widget-tabable-at)))
1150       (while (eq (widget-tabable-at) new)
1151         (backward-char)))
1152     (forward-char))
1153   (widget-echo-help (point))
1154   (run-hooks 'widget-move-hook))
1155
1156 (defun widget-forward (arg)
1157   "Move point to the next field or button.
1158 With optional ARG, move across that many fields."
1159   (interactive "p")
1160   (run-hooks 'widget-forward-hook)
1161   (widget-move arg))
1162
1163 (defun widget-backward (arg)
1164   "Move point to the previous field or button.
1165 With optional ARG, move across that many fields."
1166   (interactive "p")
1167   (run-hooks 'widget-backward-hook)
1168   (widget-move (- arg)))
1169
1170 (defun widget-beginning-of-line ()
1171   "Go to beginning of field or beginning of line, whichever is first."
1172   (interactive)
1173   (let* ((field (widget-field-find (point)))
1174          (start (and field (widget-field-start field))))
1175     (if (and start (not (eq start (point))))
1176         (goto-char start)
1177       (call-interactively 'beginning-of-line))))
1178
1179 (defun widget-end-of-line ()
1180   "Go to end of field or end of line, whichever is first."
1181   (interactive)
1182   (let* ((field (widget-field-find (point)))
1183          (end (and field (widget-field-end field))))
1184     (if (and end (not (eq end (point))))
1185         (goto-char end)
1186       (call-interactively 'end-of-line))))
1187
1188 (defun widget-kill-line ()
1189   "Kill to end of field or end of line, whichever is first."
1190   (interactive)
1191   (let* ((field (widget-field-find (point)))
1192          (newline (save-excursion (forward-line 1) (point)))
1193          (end (and field (widget-field-end field))))
1194     (if (and field (> newline end))
1195         (kill-region (point) end)
1196       (call-interactively 'kill-line))))
1197
1198 (defcustom widget-complete-field (lookup-key global-map "\M-\t")
1199   "Default function to call for completion inside fields."
1200   :options '(ispell-complete-word complete-tag lisp-complete-symbol)
1201   :type 'function
1202   :group 'widgets)
1203
1204 (defun widget-complete ()
1205   "Complete content of editable field from point.
1206 When not inside a field, move to the previous button or field."
1207   (interactive)
1208   (let ((field (widget-field-find (point))))
1209     (if field
1210         (widget-apply field :complete)
1211       (error "Not in an editable field"))))
1212
1213 ;;; Setting up the buffer.
1214
1215 (defvar widget-field-new nil)
1216 ;; List of all newly created editable fields in the buffer.
1217 (make-variable-buffer-local 'widget-field-new)
1218
1219 (defvar widget-field-list nil)
1220 ;; List of all editable fields in the buffer.
1221 (make-variable-buffer-local 'widget-field-list)
1222
1223 (defun widget-setup ()
1224   "Setup current buffer so editing string widgets works."
1225   (let ((inhibit-read-only t)
1226         (after-change-functions nil)
1227         before-change-functions
1228         field)
1229     (while widget-field-new
1230       (setq field (car widget-field-new)
1231             widget-field-new (cdr widget-field-new)
1232             widget-field-list (cons field widget-field-list))
1233       (let ((from (car (widget-get field :field-overlay)))
1234             (to (cdr (widget-get field :field-overlay))))
1235         (widget-specify-field field
1236                               (marker-position from) (marker-position to))
1237         (set-marker from nil)
1238         (set-marker to nil))))
1239   (widget-clear-undo)
1240   ;; We need to maintain text properties and size of the editing fields.
1241   (make-local-variable 'after-change-functions)
1242   (setq after-change-functions
1243         (if widget-field-list '(widget-after-change) nil))
1244   (when widget-field-use-before-change
1245     (make-local-variable 'before-change-functions)
1246     (setq before-change-functions
1247           (if widget-field-list '(widget-before-change) nil))))
1248
1249 (defvar widget-field-last nil)
1250 ;; Last field containing point.
1251 (make-variable-buffer-local 'widget-field-last)
1252
1253 (defvar widget-field-was nil)
1254 ;; The widget data before the change.
1255 (make-variable-buffer-local 'widget-field-was)
1256
1257 (defun widget-field-buffer (widget)
1258   "Return the start of WIDGET's editing field."
1259   (let ((overlay (widget-get widget :field-overlay)))
1260     (and overlay (overlay-buffer overlay))))
1261
1262 (defun widget-field-start (widget)
1263   "Return the start of WIDGET's editing field."
1264   (let ((overlay (widget-get widget :field-overlay)))
1265     (and overlay (overlay-start overlay))))
1266
1267 (defun widget-field-end (widget)
1268   "Return the end of WIDGET's editing field."
1269   (let ((overlay (widget-get widget :field-overlay)))
1270     ;; Don't subtract one if local-map works at the end of the overlay.
1271     (and overlay (if widget-field-add-space
1272                      (1- (overlay-end overlay))
1273                    (overlay-end overlay)))))
1274
1275 (defun widget-field-find (pos)
1276   "Return the field at POS.
1277 Unlike (get-char-property POS 'field) this, works with empty fields too."
1278   (let ((fields widget-field-list)
1279         field found)
1280     (while fields
1281       (setq field (car fields)
1282             fields (cdr fields))
1283       (let ((start (widget-field-start field))
1284             (end (widget-field-end field)))
1285         (when (and (<= start pos) (<= pos end))
1286           (when found
1287             (debug "Overlapping fields"))
1288           (setq found field))))
1289     found))
1290
1291 (defun widget-before-change (from &rest ignore)
1292   ;; This is how, for example, a variable changes its state to `modified'.
1293   ;; when it is being edited.
1294   (condition-case nil
1295       (let ((field (widget-field-find from)))
1296         (widget-apply field :notify field))
1297     (error (debug "Before Change"))))
1298
1299 (defun widget-after-change (from to old)
1300   ;; Adjust field size and text properties.
1301   (condition-case nil
1302       (let ((field (widget-field-find from))
1303             (other (widget-field-find to)))
1304         (when field
1305           (unless (eq field other)
1306             (debug "Change in different fields"))
1307           (let ((size (widget-get field :size))
1308                 (secret (widget-get field :secret)))
1309             (when size
1310               (let ((begin (widget-field-start field))
1311                     (end (widget-field-end field)))
1312                 (cond ((< (- end begin) size)
1313                        ;; Field too small.
1314                        (save-excursion
1315                          (goto-char end)
1316                          (insert-char ?\  (- (+ begin size) end))))
1317                       ((> (- end begin) size)
1318                        ;; Field too large and
1319                        (if (or (< (point) (+ begin size))
1320                                (> (point) end))
1321                            ;; Point is outside extra space.
1322                            (setq begin (+ begin size))
1323                          ;; Point is within the extra space.
1324                          (setq begin (point)))
1325                        (save-excursion
1326                          (goto-char end)
1327                          (while (and (eq (preceding-char) ?\ )
1328                                      (> (point) begin))
1329                            (delete-backward-char 1)))))))
1330             (when secret
1331               (let ((begin (widget-field-start field))
1332                     (end (widget-field-end field)))
1333                 (when size
1334                   (while (and (> end begin)
1335                               (eq (char-after (1- end)) ?\ ))
1336                     (setq end (1- end))))
1337                 (while (< begin end)
1338                   (let ((old (char-after begin)))
1339                     (unless (eq old secret)
1340                       (subst-char-in-region begin (1+ begin) old secret)
1341                       (put-text-property begin (1+ begin) 'secret old))
1342                     (setq begin (1+ begin)))))))
1343           (widget-apply field :notify field)))
1344     (error (debug "After Change"))))
1345
1346 ;;; Widget Functions
1347 ;;
1348 ;; These functions are used in the definition of multiple widgets.
1349
1350 (defun widget-parent-action (widget &optional event)
1351   "Tell :parent of WIDGET to handle the :action.
1352 Optional EVENT is the event that triggered the action."
1353   (widget-apply (widget-get widget :parent) :action event))
1354
1355 (defun widget-children-value-delete (widget)
1356   "Delete all :children and :buttons in WIDGET."
1357   (mapcar 'widget-delete (widget-get widget :children))
1358   (widget-put widget :children nil)
1359   (mapcar 'widget-delete (widget-get widget :buttons))
1360   (widget-put widget :buttons nil))
1361
1362 (defun widget-children-validate (widget)
1363   "All the :children must be valid."
1364   (let ((children (widget-get widget :children))
1365         child found)
1366     (while (and children (not found))
1367       (setq child (car children)
1368             children (cdr children)
1369             found (widget-apply child :validate)))
1370     found))
1371
1372 (defun widget-types-convert-widget (widget)
1373   "Convert :args as widget types in WIDGET."
1374   (widget-put widget :args (mapcar 'widget-convert (widget-get widget :args)))
1375   widget)
1376
1377 (defun widget-value-convert-widget (widget)
1378   "Initialize :value from :args in WIDGET."
1379   (let ((args (widget-get widget :args)))
1380     (when args
1381       (widget-put widget :value (car args))
1382       ;; Don't convert :value here, as this is done in `widget-convert'.
1383       ;; (widget-put widget :value (widget-apply widget
1384       ;;                                      :value-to-internal (car args)))
1385       (widget-put widget :args nil)))
1386   widget)
1387
1388 (defun widget-value-value-get (widget)
1389   "Return the :value property of WIDGET."
1390   (widget-get widget :value))
1391
1392 ;;; The `default' Widget.
1393
1394 (define-widget 'default nil
1395   "Basic widget other widgets are derived from."
1396   :value-to-internal (lambda (widget value) value)
1397   :value-to-external (lambda (widget value) value)
1398   :button-prefix 'widget-button-prefix
1399   :button-suffix 'widget-button-suffix
1400   :complete 'widget-default-complete
1401   :create 'widget-default-create
1402   :indent nil
1403   :offset 0
1404   :format-handler 'widget-default-format-handler
1405   :button-face-get 'widget-default-button-face-get
1406   :sample-face-get 'widget-default-sample-face-get
1407   :delete 'widget-default-delete
1408   :value-set 'widget-default-value-set
1409   :value-inline 'widget-default-value-inline
1410   :menu-tag-get 'widget-default-menu-tag-get
1411   :validate (lambda (widget) nil)
1412   :active 'widget-default-active
1413   :activate 'widget-specify-active
1414   :deactivate 'widget-default-deactivate
1415   :mouse-down-action (lambda (widget event) nil)
1416   :action 'widget-default-action
1417   :notify 'widget-default-notify
1418   :prompt-value 'widget-default-prompt-value)
1419
1420 (defun widget-default-complete (widget)
1421   "Call the value of the :complete-function property of WIDGET.
1422 If that does not exists, call the value of `widget-complete-field'."
1423   (let ((fun (widget-get widget :complete-function)))
1424     (call-interactively (or fun widget-complete-field))))
1425
1426 (defun widget-default-create (widget)
1427   "Create WIDGET at point in the current buffer."
1428   (widget-specify-insert
1429    (let ((from (point))
1430          button-begin button-end
1431          sample-begin sample-end
1432          doc-begin doc-end
1433          value-pos)
1434      (insert (widget-get widget :format))
1435      (goto-char from)
1436      ;; Parse escapes in format.
1437      (while (re-search-forward "%\\(.\\)" nil t)
1438        (let ((escape (aref (match-string 1) 0)))
1439          (replace-match "" t t)
1440          (cond ((eq escape ?%)
1441                 (insert "%"))
1442                ((eq escape ?\[)
1443                 (setq button-begin (point))
1444                 (insert (widget-get-indirect widget :button-prefix)))
1445                ((eq escape ?\])
1446                 (insert (widget-get-indirect widget :button-suffix))
1447                 (setq button-end (point)))
1448                ((eq escape ?\{)
1449                 (setq sample-begin (point)))
1450                ((eq escape ?\})
1451                 (setq sample-end (point)))
1452                ((eq escape ?n)
1453                 (when (widget-get widget :indent)
1454                   (insert "\n")
1455                   (insert-char ?  (widget-get widget :indent))))
1456                ((eq escape ?t)
1457                 (let ((glyph (widget-get widget :tag-glyph))
1458                       (tag (widget-get widget :tag)))
1459                   (cond (glyph
1460                          (widget-glyph-insert widget (or tag "image") glyph))
1461                         (tag
1462                          (insert tag))
1463                         (t
1464                          (let ((standard-output (current-buffer)))
1465                            (princ (widget-get widget :value)))))))
1466                ((eq escape ?d)
1467                 (let ((doc (widget-get widget :doc)))
1468                   (when doc
1469                     (setq doc-begin (point))
1470                     (insert doc)
1471                     (while (eq (preceding-char) ?\n)
1472                       (delete-backward-char 1))
1473                     (insert "\n")
1474                     (setq doc-end (point)))))
1475                ((eq escape ?v)
1476                 (if (and button-begin (not button-end))
1477                     (widget-apply widget :value-create)
1478                   (setq value-pos (point))))
1479                (t
1480                 (widget-apply widget :format-handler escape)))))
1481      ;; Specify button, sample, and doc, and insert value.
1482      (and button-begin button-end
1483           (widget-specify-button widget button-begin button-end))
1484      (and sample-begin sample-end
1485           (widget-specify-sample widget sample-begin sample-end))
1486      (and doc-begin doc-end
1487           (widget-specify-doc widget doc-begin doc-end))
1488      (when value-pos
1489        (goto-char value-pos)
1490        (widget-apply widget :value-create)))
1491    (let ((from (copy-marker (point-min)))
1492          (to (copy-marker (point-max))))
1493      (widget-specify-text from to)
1494      (set-marker-insertion-type from t)
1495      (set-marker-insertion-type to nil)
1496      (widget-put widget :from from)
1497      (widget-put widget :to to)))
1498   (widget-clear-undo))
1499
1500 (defun widget-default-format-handler (widget escape)
1501   ;; We recognize the %h escape by default.
1502   (let* ((buttons (widget-get widget :buttons)))
1503     (cond ((eq escape ?h)
1504            (let* ((doc-property (widget-get widget :documentation-property))
1505                   (doc-try (cond ((widget-get widget :doc))
1506                                  ((symbolp doc-property)
1507                                   (documentation-property
1508                                    (widget-get widget :value)
1509                                    doc-property))
1510                                  (t
1511                                   (funcall doc-property
1512                                            (widget-get widget :value)))))
1513                   (doc-text (and (stringp doc-try)
1514                                  (> (length doc-try) 1)
1515                                  doc-try))
1516                   (doc-indent (widget-get widget :documentation-indent)))
1517              (when doc-text
1518                (and (eq (preceding-char) ?\n)
1519                     (widget-get widget :indent)
1520                     (insert-char ?  (widget-get widget :indent)))
1521                ;; The `*' in the beginning is redundant.
1522                (when (eq (aref doc-text  0) ?*)
1523                  (setq doc-text (substring doc-text 1)))
1524                ;; Get rid of trailing newlines.
1525                (when (string-match "\n+\\'" doc-text)
1526                  (setq doc-text (substring doc-text 0 (match-beginning 0))))
1527                (push (widget-create-child-and-convert
1528                       widget 'documentation-string
1529                       :indent (cond ((numberp doc-indent )
1530                                      doc-indent)
1531                                     ((null doc-indent)
1532                                      nil)
1533                                     (t 0))
1534                       doc-text)
1535                      buttons))))
1536           (t
1537            (error "Unknown escape `%c'" escape)))
1538     (widget-put widget :buttons buttons)))
1539
1540 (defun widget-default-button-face-get (widget)
1541   ;; Use :button-face or widget-button-face
1542   (or (widget-get widget :button-face)
1543       (let ((parent (widget-get widget :parent)))
1544         (if parent
1545             (widget-apply parent :button-face-get)
1546           widget-button-face))))
1547
1548 (defun widget-default-sample-face-get (widget)
1549   ;; Use :sample-face.
1550   (widget-get widget :sample-face))
1551
1552 (defun widget-default-delete (widget)
1553   ;; Remove widget from the buffer.
1554   (let ((from (widget-get widget :from))
1555         (to (widget-get widget :to))
1556         (inactive-overlay (widget-get widget :inactive))
1557         (button-overlay (widget-get widget :button-overlay))
1558         before-change-functions
1559         after-change-functions
1560         (inhibit-read-only t))
1561     (widget-apply widget :value-delete)
1562     (when inactive-overlay
1563       (delete-overlay inactive-overlay))
1564     (when button-overlay
1565       (delete-overlay button-overlay))
1566     (when (< from to)
1567       ;; Kludge: this doesn't need to be true for empty formats.
1568       (delete-region from to))
1569     (set-marker from nil)
1570     (set-marker to nil))
1571   (widget-clear-undo))
1572
1573 (defun widget-default-value-set (widget value)
1574   ;; Recreate widget with new value.
1575   (let* ((old-pos (point))
1576          (from (copy-marker (widget-get widget :from)))
1577          (to (copy-marker (widget-get widget :to)))
1578          (offset (if (and (<= from old-pos) (<= old-pos to))
1579                      (if (>= old-pos (1- to))
1580                          (- old-pos to 1)
1581                        (- old-pos from)))))
1582     ;;??? Bug: this ought to insert the new value before deleting the old one,
1583     ;; so that markers on either side of the value automatically
1584     ;; stay on the same side.  -- rms.
1585     (save-excursion
1586       (goto-char (widget-get widget :from))
1587       (widget-apply widget :delete)
1588       (widget-put widget :value value)
1589       (widget-apply widget :create))
1590     (if offset
1591         (if (< offset 0)
1592             (goto-char (+ (widget-get widget :to) offset 1))
1593           (goto-char (min (+ from offset) (1- (widget-get widget :to))))))))
1594
1595 (defun widget-default-value-inline (widget)
1596   ;; Wrap value in a list unless it is inline.
1597   (if (widget-get widget :inline)
1598       (widget-value widget)
1599     (list (widget-value widget))))
1600
1601 (defun widget-default-menu-tag-get (widget)
1602   ;; Use tag or value for menus.
1603   (or (widget-get widget :menu-tag)
1604       (widget-get widget :tag)
1605       (widget-princ-to-string (widget-get widget :value))))
1606
1607 (defun widget-default-active (widget)
1608   "Return t iff this widget active (user modifiable)."
1609   (and (not (widget-get widget :inactive))
1610        (let ((parent (widget-get widget :parent)))
1611          (or (null parent)
1612              (widget-apply parent :active)))))
1613
1614 (defun widget-default-deactivate (widget)
1615   "Make WIDGET inactive for user modifications."
1616   (widget-specify-inactive widget
1617                            (widget-get widget :from)
1618                            (widget-get widget :to)))
1619
1620 (defun widget-default-action (widget &optional event)
1621   ;; Notify the parent when a widget change
1622   (let ((parent (widget-get widget :parent)))
1623     (when parent
1624       (widget-apply parent :notify widget event))))
1625
1626 (defun widget-default-notify (widget child &optional event)
1627   ;; Pass notification to parent.
1628   (widget-default-action widget event))
1629
1630 (defun widget-default-prompt-value (widget prompt value unbound)
1631   ;; Read an arbitrary value.  Stolen from `set-variable'.
1632 ;;  (let ((initial (if unbound
1633 ;;                   nil
1634 ;;                 ;; It would be nice if we could do a `(cons val 1)' here.
1635 ;;                 (prin1-to-string (custom-quote value))))))
1636   (eval-minibuffer prompt ))
1637
1638 ;;; The `item' Widget.
1639
1640 (define-widget 'item 'default
1641   "Constant items for inclusion in other widgets."
1642   :convert-widget 'widget-value-convert-widget
1643   :value-create 'widget-item-value-create
1644   :value-delete 'ignore
1645   :value-get 'widget-value-value-get
1646   :match 'widget-item-match
1647   :match-inline 'widget-item-match-inline
1648   :action 'widget-item-action
1649   :format "%t\n")
1650
1651 (defun widget-item-value-create (widget)
1652   ;; Insert the printed representation of the value.
1653   (let ((standard-output (current-buffer)))
1654     (princ (widget-get widget :value))))
1655
1656 (defun widget-item-match (widget value)
1657   ;; Match if the value is the same.
1658   (equal (widget-get widget :value) value))
1659
1660 (defun widget-item-match-inline (widget values)
1661   ;; Match if the value is the same.
1662   (let ((value (widget-get widget :value)))
1663     (and (listp value)
1664          (<= (length value) (length values))
1665          (let ((head (widget-sublist values 0 (length value))))
1666            (and (equal head value)
1667                 (cons head (widget-sublist values (length value))))))))
1668
1669 (defun widget-sublist (list start &optional end)
1670   "Return the sublist of LIST from START to END.
1671 If END is omitted, it defaults to the length of LIST."
1672   (if (> start 0) (setq list (nthcdr start list)))
1673   (if end
1674       (if (<= end start)
1675           nil
1676         (setq list (copy-sequence list))
1677         (setcdr (nthcdr (- end start 1) list) nil)
1678         list)
1679     (copy-sequence list)))
1680
1681 (defun widget-item-action (widget &optional event)
1682   ;; Just notify itself.
1683   (widget-apply widget :notify widget event))
1684
1685 ;;; The `push-button' Widget.
1686
1687 (defcustom widget-push-button-gui t
1688   "If non nil, use GUI push buttons when available."
1689   :group 'widgets
1690   :type 'boolean)
1691
1692 ;; Cache already created GUI objects.
1693 (defvar widget-push-button-cache nil)
1694
1695 (defcustom widget-push-button-prefix "["
1696   "String used as prefix for buttons."
1697   :type 'string
1698   :group 'widget-button)
1699
1700 (defcustom widget-push-button-suffix "]"
1701   "String used as suffix for buttons."
1702   :type 'string
1703   :group 'widget-button)
1704
1705 (define-widget 'push-button 'item
1706   "A pushable button."
1707   :button-prefix ""
1708   :button-suffix ""
1709   :value-create 'widget-push-button-value-create
1710   :format "%[%v%]")
1711
1712 (defun widget-push-button-value-create (widget)
1713   ;; Insert text representing the `on' and `off' states.
1714   (let* ((tag (or (widget-get widget :tag)
1715                   (widget-get widget :value)))
1716          (tag-glyph (widget-get widget :tag-glyph))
1717          (text (concat widget-push-button-prefix
1718                        tag widget-push-button-suffix))
1719          (gui (cdr (assoc tag widget-push-button-cache))))
1720     (cond (tag-glyph
1721            (widget-glyph-insert widget text tag-glyph))
1722           ((and (fboundp 'make-gui-button)
1723              (fboundp 'make-glyph)
1724              widget-push-button-gui
1725              (fboundp 'device-on-window-system-p)
1726              (device-on-window-system-p)
1727              (string-match "XEmacs" emacs-version))
1728            (unless gui
1729              (setq gui (make-gui-button tag 'widget-gui-action widget))
1730              (push (cons tag gui) widget-push-button-cache))
1731            (widget-glyph-insert-glyph widget
1732                                       (make-glyph
1733                                        (list (nth 0 (aref gui 1))
1734                                              (vector 'string ':data text)))
1735                                       (make-glyph
1736                                        (list (nth 1 (aref gui 1))
1737                                              (vector 'string ':data text)))
1738                                       (make-glyph
1739                                        (list (nth 2 (aref gui 1))
1740                                              (vector 'string ':data text)))))
1741           (t
1742            (insert text)))))
1743
1744 (defun widget-gui-action (widget)
1745   "Apply :action for WIDGET."
1746   (widget-apply-action widget (this-command-keys)))
1747
1748 ;;; The `link' Widget.
1749
1750 (defcustom widget-link-prefix "["
1751   "String used as prefix for links."
1752   :type 'string
1753   :group 'widget-button)
1754
1755 (defcustom widget-link-suffix "]"
1756   "String used as suffix for links."
1757   :type 'string
1758   :group 'widget-button)
1759
1760 (define-widget 'link 'item
1761   "An embedded link."
1762   :button-prefix 'widget-link-prefix
1763   :button-suffix 'widget-link-suffix
1764   :help-echo "Follow the link."
1765   :format "%[%t%]")
1766
1767 ;;; The `info-link' Widget.
1768
1769 (define-widget 'info-link 'link
1770   "A link to an info file."
1771   :action 'widget-info-link-action)
1772
1773 (defun widget-info-link-action (widget &optional event)
1774   "Open the info node specified by WIDGET."
1775   (Info-goto-node (widget-value widget)))
1776
1777 ;;; The `url-link' Widget.
1778
1779 (define-widget 'url-link 'link
1780   "A link to an www page."
1781   :action 'widget-url-link-action)
1782
1783 (defun widget-url-link-action (widget &optional event)
1784   "Open the url specified by WIDGET."
1785   (require 'browse-url)
1786   (funcall browse-url-browser-function (widget-value widget)))
1787
1788 ;;; The `editable-field' Widget.
1789
1790 (define-widget 'editable-field 'default
1791   "An editable text field."
1792   :convert-widget 'widget-value-convert-widget
1793   :keymap widget-field-keymap
1794   :format "%v"
1795   :value ""
1796   :prompt-internal 'widget-field-prompt-internal
1797   :prompt-history 'widget-field-history
1798   :prompt-value 'widget-field-prompt-value
1799   :action 'widget-field-action
1800   :validate 'widget-field-validate
1801   :valid-regexp ""
1802   :error "No match"
1803   :value-create 'widget-field-value-create
1804   :value-delete 'widget-field-value-delete
1805   :value-get 'widget-field-value-get
1806   :match 'widget-field-match)
1807
1808 (defvar widget-field-history nil
1809   "History of field minibuffer edits.")
1810
1811 (defun widget-field-prompt-internal (widget prompt initial history)
1812   ;; Read string for WIDGET promptinhg with PROMPT.
1813   ;; INITIAL is the initial input and HISTORY is a symbol containing
1814   ;; the earlier input.
1815   (read-string prompt initial history))
1816
1817 (defun widget-field-prompt-value (widget prompt value unbound)
1818   ;; Prompt for a string.
1819   (let ((initial (if unbound
1820                      nil
1821                    (cons (widget-apply widget :value-to-internal
1822                                        value) 0)))
1823         (history (widget-get widget :prompt-history)))
1824     (let ((answer (widget-apply widget
1825                                 :prompt-internal prompt initial history)))
1826       (widget-apply widget :value-to-external answer))))
1827
1828 (defvar widget-edit-functions nil)
1829
1830 (defun widget-field-action (widget &optional event)
1831   ;; Move to next field.
1832   (widget-forward 1)
1833   (run-hook-with-args 'widget-edit-functions widget))
1834
1835 (defun widget-field-validate (widget)
1836   ;; Valid if the content matches `:valid-regexp'.
1837   (save-excursion
1838     (let ((value (widget-apply widget :value-get))
1839           (regexp (widget-get widget :valid-regexp)))
1840       (if (string-match regexp value)
1841           nil
1842         widget))))
1843
1844 (defun widget-field-value-create (widget)
1845   ;; Create an editable text field.
1846   (let ((size (widget-get widget :size))
1847         (value (widget-get widget :value))
1848         (from (point))
1849         ;; This is changed to a real overlay in `widget-setup'.  We
1850         ;; need the end points to behave differently until
1851         ;; `widget-setup' is called.
1852         (overlay (cons (make-marker) (make-marker))))
1853     (widget-put widget :field-overlay overlay)
1854     (insert value)
1855     (and size
1856          (< (length value) size)
1857          (insert-char ?\  (- size (length value))))
1858     (unless (memq widget widget-field-list)
1859       (setq widget-field-new (cons widget widget-field-new)))
1860     (move-marker (cdr overlay) (point))
1861     (set-marker-insertion-type (cdr overlay) nil)
1862     (when (null size)
1863       (insert ?\n))
1864     (move-marker (car overlay) from)
1865     (set-marker-insertion-type (car overlay) t)))
1866
1867 (defun widget-field-value-delete (widget)
1868   ;; Remove the widget from the list of active editing fields.
1869   (setq widget-field-list (delq widget widget-field-list))
1870   ;; These are nil if the :format string doesn't contain `%v'.
1871   (let ((overlay (widget-get widget :field-overlay)))
1872     (when overlay
1873       (delete-overlay overlay))))
1874
1875 (defun widget-field-value-get (widget)
1876   ;; Return current text in editing field.
1877   (let ((from (widget-field-start widget))
1878         (to (widget-field-end widget))
1879         (buffer (widget-field-buffer widget))
1880         (size (widget-get widget :size))
1881         (secret (widget-get widget :secret))
1882         (old (current-buffer)))
1883     (if (and from to)
1884         (progn
1885           (set-buffer buffer)
1886           (while (and size
1887                       (not (zerop size))
1888                       (> to from)
1889                       (eq (char-after (1- to)) ?\ ))
1890             (setq to (1- to)))
1891           (let ((result (buffer-substring-no-properties from to)))
1892             (when secret
1893               (let ((index 0))
1894                 (while (< (+ from index) to)
1895                   (aset result index
1896                         (get-char-property (+ from index) 'secret))
1897                   (setq index (1+ index)))))
1898             (set-buffer old)
1899             result))
1900       (widget-get widget :value))))
1901
1902 (defun widget-field-match (widget value)
1903   ;; Match any string.
1904   (stringp value))
1905
1906 ;;; The `text' Widget.
1907
1908 (define-widget 'text 'editable-field
1909   :keymap widget-text-keymap
1910   "A multiline text area.")
1911
1912 ;;; The `menu-choice' Widget.
1913
1914 (define-widget 'menu-choice 'default
1915   "A menu of options."
1916   :convert-widget  'widget-types-convert-widget
1917   :format "%[%t%]: %v"
1918   :case-fold t
1919   :tag "choice"
1920   :void '(item :format "invalid (%t)\n")
1921   :value-create 'widget-choice-value-create
1922   :value-delete 'widget-children-value-delete
1923   :value-get 'widget-choice-value-get
1924   :value-inline 'widget-choice-value-inline
1925   :mouse-down-action 'widget-choice-mouse-down-action
1926   :action 'widget-choice-action
1927   :error "Make a choice"
1928   :validate 'widget-choice-validate
1929   :match 'widget-choice-match
1930   :match-inline 'widget-choice-match-inline)
1931
1932 (defun widget-choice-value-create (widget)
1933   ;; Insert the first choice that matches the value.
1934   (let ((value (widget-get widget :value))
1935         (args (widget-get widget :args))
1936         current)
1937     (while args
1938       (setq current (car args)
1939             args (cdr args))
1940       (when (widget-apply current :match value)
1941         (widget-put widget :children (list (widget-create-child-value
1942                                             widget current value)))
1943         (widget-put widget :choice current)
1944         (setq args nil
1945               current nil)))
1946     (when current
1947       (let ((void (widget-get widget :void)))
1948         (widget-put widget :children (list (widget-create-child-and-convert
1949                                             widget void :value value)))
1950         (widget-put widget :choice void)))))
1951
1952 (defun widget-choice-value-get (widget)
1953   ;; Get value of the child widget.
1954   (widget-value (car (widget-get widget :children))))
1955
1956 (defun widget-choice-value-inline (widget)
1957   ;; Get value of the child widget.
1958   (widget-apply (car (widget-get widget :children)) :value-inline))
1959
1960 (defcustom widget-choice-toggle nil
1961   "If non-nil, a binary choice will just toggle between the values.
1962 Otherwise, the user will explicitly have to choose between the values
1963 when he invoked the menu."
1964   :type 'boolean
1965   :group 'widgets)
1966
1967 (defun widget-choice-mouse-down-action (widget &optional event)
1968   ;; Return non-nil if we need a menu.
1969   (let ((args (widget-get widget :args))
1970         (old (widget-get widget :choice)))
1971     (cond ((not window-system)
1972            ;; No place to pop up a menu.
1973            nil)
1974           ((not (or (fboundp 'x-popup-menu) (fboundp 'popup-menu)))
1975            ;; No way to pop up a menu.
1976            nil)
1977           ((< (length args) 2)
1978            ;; Empty or singleton list, just return the value.
1979            nil)
1980           ((> (length args) widget-menu-max-size)
1981            ;; Too long, prompt.
1982            nil)
1983           ((> (length args) 2)
1984            ;; Reasonable sized list, use menu.
1985            t)
1986           ((and widget-choice-toggle (memq old args))
1987            ;; We toggle.
1988            nil)
1989           (t
1990            ;; Ask which of the two.
1991            t))))
1992
1993 (defun widget-choice-action (widget &optional event)
1994   ;; Make a choice.
1995   (let ((args (widget-get widget :args))
1996         (old (widget-get widget :choice))
1997         (tag (widget-apply widget :menu-tag-get))
1998         (completion-ignore-case (widget-get widget :case-fold))
1999         current choices)
2000     ;; Remember old value.
2001     (if (and old (not (widget-apply widget :validate)))
2002         (let* ((external (widget-value widget))
2003                (internal (widget-apply old :value-to-internal external)))
2004           (widget-put old :value internal)))
2005     ;; Find new choice.
2006     (setq current
2007           (cond ((= (length args) 0)
2008                  nil)
2009                 ((= (length args) 1)
2010                  (nth 0 args))
2011                 ((and widget-choice-toggle
2012                       (= (length args) 2)
2013                       (memq old args))
2014                  (if (eq old (nth 0 args))
2015                      (nth 1 args)
2016                    (nth 0 args)))
2017                 (t
2018                  (while args
2019                    (setq current (car args)
2020                          args (cdr args))
2021                    (setq choices
2022                          (cons (cons (widget-apply current :menu-tag-get)
2023                                      current)
2024                                choices)))
2025                  (widget-choose tag (reverse choices) event))))
2026     (when current
2027       (widget-value-set widget
2028                         (widget-apply current :value-to-external
2029                                       (widget-get current :value)))
2030       (widget-setup)
2031       (widget-apply widget :notify widget event)))
2032   (run-hook-with-args 'widget-edit-functions widget))
2033
2034 (defun widget-choice-validate (widget)
2035   ;; Valid if we have made a valid choice.
2036   (let ((void (widget-get widget :void))
2037         (choice (widget-get widget :choice))
2038         (child (car (widget-get widget :children))))
2039     (if (eq void choice)
2040         widget
2041       (widget-apply child :validate))))
2042
2043 (defun widget-choice-match (widget value)
2044   ;; Matches if one of the choices matches.
2045   (let ((args (widget-get widget :args))
2046         current found)
2047     (while (and args (not found))
2048       (setq current (car args)
2049             args (cdr args)
2050             found (widget-apply current :match value)))
2051     found))
2052
2053 (defun widget-choice-match-inline (widget values)
2054   ;; Matches if one of the choices matches.
2055   (let ((args (widget-get widget :args))
2056         current found)
2057     (while (and args (null found))
2058       (setq current (car args)
2059             args (cdr args)
2060             found (widget-match-inline current values)))
2061     found))
2062
2063 ;;; The `toggle' Widget.
2064
2065 (define-widget 'toggle 'item
2066   "Toggle between two states."
2067   :format "%[%v%]\n"
2068   :value-create 'widget-toggle-value-create
2069   :action 'widget-toggle-action
2070   :match (lambda (widget value) t)
2071   :on "on"
2072   :off "off")
2073
2074 (defun widget-toggle-value-create (widget)
2075   ;; Insert text representing the `on' and `off' states.
2076   (if (widget-value widget)
2077       (widget-glyph-insert widget
2078                            (widget-get widget :on)
2079                            (widget-get widget :on-glyph))
2080     (widget-glyph-insert widget
2081                          (widget-get widget :off)
2082                          (widget-get widget :off-glyph))))
2083
2084 (defun widget-toggle-action (widget &optional event)
2085   ;; Toggle value.
2086   (widget-value-set widget (not (widget-value widget)))
2087   (widget-apply widget :notify widget event)
2088   (run-hook-with-args 'widget-edit-functions widget))
2089
2090 ;;; The `checkbox' Widget.
2091
2092 (define-widget 'checkbox 'toggle
2093   "A checkbox toggle."
2094   :button-suffix ""
2095   :button-prefix ""
2096   :format "%[%v%]"
2097   :on "[X]"
2098   :on-glyph "check1"
2099   :off "[ ]"
2100   :off-glyph "check0"
2101   :action 'widget-checkbox-action)
2102
2103 (defun widget-checkbox-action (widget &optional event)
2104   "Toggle checkbox, notify parent, and set active state of sibling."
2105   (widget-toggle-action widget event)
2106   (let ((sibling (widget-get-sibling widget)))
2107     (when sibling
2108       (if (widget-value widget)
2109           (widget-apply sibling :activate)
2110         (widget-apply sibling :deactivate)))))
2111
2112 ;;; The `checklist' Widget.
2113
2114 (define-widget 'checklist 'default
2115   "A multiple choice widget."
2116   :convert-widget 'widget-types-convert-widget
2117   :format "%v"
2118   :offset 4
2119   :entry-format "%b %v"
2120   :menu-tag "checklist"
2121   :greedy nil
2122   :value-create 'widget-checklist-value-create
2123   :value-delete 'widget-children-value-delete
2124   :value-get 'widget-checklist-value-get
2125   :validate 'widget-checklist-validate
2126   :match 'widget-checklist-match
2127   :match-inline 'widget-checklist-match-inline)
2128
2129 (defun widget-checklist-value-create (widget)
2130   ;; Insert all values
2131   (let ((alist (widget-checklist-match-find widget (widget-get widget :value)))
2132         (args (widget-get widget :args)))
2133     (while args
2134       (widget-checklist-add-item widget (car args) (assq (car args) alist))
2135       (setq args (cdr args)))
2136     (widget-put widget :children (nreverse (widget-get widget :children)))))
2137
2138 (defun widget-checklist-add-item (widget type chosen)
2139   ;; Create checklist item in WIDGET of type TYPE.
2140   ;; If the item is checked, CHOSEN is a cons whose cdr is the value.
2141   (and (eq (preceding-char) ?\n)
2142        (widget-get widget :indent)
2143        (insert-char ?  (widget-get widget :indent)))
2144   (widget-specify-insert
2145    (let* ((children (widget-get widget :children))
2146           (buttons (widget-get widget :buttons))
2147           (button-args (or (widget-get type :sibling-args)
2148                            (widget-get widget :button-args)))
2149           (from (point))
2150           child button)
2151      (insert (widget-get widget :entry-format))
2152      (goto-char from)
2153      ;; Parse % escapes in format.
2154      (while (re-search-forward "%\\([bv%]\\)" nil t)
2155        (let ((escape (aref (match-string 1) 0)))
2156          (replace-match "" t t)
2157          (cond ((eq escape ?%)
2158                 (insert "%"))
2159                ((eq escape ?b)
2160                 (setq button (apply 'widget-create-child-and-convert
2161                                     widget 'checkbox
2162                                     :value (not (null chosen))
2163                                     button-args)))
2164                ((eq escape ?v)
2165                 (setq child
2166                       (cond ((not chosen)
2167                              (let ((child (widget-create-child widget type)))
2168                                (widget-apply child :deactivate)
2169                                child))
2170                             ((widget-get type :inline)
2171                              (widget-create-child-value
2172                               widget type (cdr chosen)))
2173                             (t
2174                              (widget-create-child-value
2175                               widget type (car (cdr chosen)))))))
2176                (t
2177                 (error "Unknown escape `%c'" escape)))))
2178      ;; Update properties.
2179      (and button child (widget-put child :button button))
2180      (and button (widget-put widget :buttons (cons button buttons)))
2181      (and child (widget-put widget :children (cons child children))))))
2182
2183 (defun widget-checklist-match (widget values)
2184   ;; All values must match a type in the checklist.
2185   (and (listp values)
2186        (null (cdr (widget-checklist-match-inline widget values)))))
2187
2188 (defun widget-checklist-match-inline (widget values)
2189   ;; Find the values which match a type in the checklist.
2190   (let ((greedy (widget-get widget :greedy))
2191         (args (copy-sequence (widget-get widget :args)))
2192         found rest)
2193     (while values
2194       (let ((answer (widget-checklist-match-up args values)))
2195         (cond (answer
2196                (let ((vals (widget-match-inline answer values)))
2197                  (setq found (append found (car vals))
2198                        values (cdr vals)
2199                        args (delq answer args))))
2200               (greedy
2201                (setq rest (append rest (list (car values)))
2202                      values (cdr values)))
2203               (t
2204                (setq rest (append rest values)
2205                      values nil)))))
2206     (cons found rest)))
2207
2208 (defun widget-checklist-match-find (widget vals)
2209   ;; Find the vals which match a type in the checklist.
2210   ;; Return an alist of (TYPE MATCH).
2211   (let ((greedy (widget-get widget :greedy))
2212         (args (copy-sequence (widget-get widget :args)))
2213         found)
2214     (while vals
2215       (let ((answer (widget-checklist-match-up args vals)))
2216         (cond (answer
2217                (let ((match (widget-match-inline answer vals)))
2218                  (setq found (cons (cons answer (car match)) found)
2219                        vals (cdr match)
2220                        args (delq answer args))))
2221               (greedy
2222                (setq vals (cdr vals)))
2223               (t
2224                (setq vals nil)))))
2225     found))
2226
2227 (defun widget-checklist-match-up (args vals)
2228   ;; Rerturn the first type from ARGS that matches VALS.
2229   (let (current found)
2230     (while (and args (null found))
2231       (setq current (car args)
2232             args (cdr args)
2233             found (widget-match-inline current vals)))
2234     (if found
2235         current
2236       nil)))
2237
2238 (defun widget-checklist-value-get (widget)
2239   ;; The values of all selected items.
2240   (let ((children (widget-get widget :children))
2241         child result)
2242     (while children
2243       (setq child (car children)
2244             children (cdr children))
2245       (if (widget-value (widget-get child :button))
2246           (setq result (append result (widget-apply child :value-inline)))))
2247     result))
2248
2249 (defun widget-checklist-validate (widget)
2250   ;; Ticked chilren must be valid.
2251   (let ((children (widget-get widget :children))
2252         child button found)
2253     (while (and children (not found))
2254       (setq child (car children)
2255             children (cdr children)
2256             button (widget-get child :button)
2257             found (and (widget-value button)
2258                        (widget-apply child :validate))))
2259     found))
2260
2261 ;;; The `option' Widget
2262
2263 (define-widget 'option 'checklist
2264   "An widget with an optional item."
2265   :inline t)
2266
2267 ;;; The `choice-item' Widget.
2268
2269 (define-widget 'choice-item 'item
2270   "Button items that delegate action events to their parents."
2271   :action 'widget-parent-action
2272   :format "%[%t%] \n")
2273
2274 ;;; The `radio-button' Widget.
2275
2276 (define-widget 'radio-button 'toggle
2277   "A radio button for use in the `radio' widget."
2278   :notify 'widget-radio-button-notify
2279   :format "%[%v%]"
2280   :button-suffix ""
2281   :button-prefix ""
2282   :on "(*)"
2283   :on-glyph "radio1"
2284   :off "( )"
2285   :off-glyph "radio0")
2286
2287 (defun widget-radio-button-notify (widget child &optional event)
2288   ;; Tell daddy.
2289   (widget-apply (widget-get widget :parent) :action widget event))
2290
2291 ;;; The `radio-button-choice' Widget.
2292
2293 (define-widget 'radio-button-choice 'default
2294   "Select one of multiple options."
2295   :convert-widget 'widget-types-convert-widget
2296   :offset 4
2297   :format "%v"
2298   :entry-format "%b %v"
2299   :menu-tag "radio"
2300   :value-create 'widget-radio-value-create
2301   :value-delete 'widget-children-value-delete
2302   :value-get 'widget-radio-value-get
2303   :value-inline 'widget-radio-value-inline
2304   :value-set 'widget-radio-value-set
2305   :error "You must push one of the buttons"
2306   :validate 'widget-radio-validate
2307   :match 'widget-choice-match
2308   :match-inline 'widget-choice-match-inline
2309   :action 'widget-radio-action)
2310
2311 (defun widget-radio-value-create (widget)
2312   ;; Insert all values
2313   (let ((args (widget-get widget :args))
2314         arg)
2315     (while args
2316       (setq arg (car args)
2317             args (cdr args))
2318       (widget-radio-add-item widget arg))))
2319
2320 (defun widget-radio-add-item (widget type)
2321   "Add to radio widget WIDGET a new radio button item of type TYPE."
2322   ;; (setq type (widget-convert type))
2323   (and (eq (preceding-char) ?\n)
2324        (widget-get widget :indent)
2325        (insert-char ?  (widget-get widget :indent)))
2326   (widget-specify-insert
2327    (let* ((value (widget-get widget :value))
2328           (children (widget-get widget :children))
2329           (buttons (widget-get widget :buttons))
2330           (button-args (or (widget-get type :sibling-args)
2331                            (widget-get widget :button-args)))
2332           (from (point))
2333           (chosen (and (null (widget-get widget :choice))
2334                        (widget-apply type :match value)))
2335           child button)
2336      (insert (widget-get widget :entry-format))
2337      (goto-char from)
2338      ;; Parse % escapes in format.
2339      (while (re-search-forward "%\\([bv%]\\)" nil t)
2340        (let ((escape (aref (match-string 1) 0)))
2341          (replace-match "" t t)
2342          (cond ((eq escape ?%)
2343                 (insert "%"))
2344                ((eq escape ?b)
2345                 (setq button (apply 'widget-create-child-and-convert
2346                                     widget 'radio-button
2347                                     :value (not (null chosen))
2348                                     button-args)))
2349                ((eq escape ?v)
2350                 (setq child (if chosen
2351                                 (widget-create-child-value
2352                                  widget type value)
2353                               (widget-create-child widget type)))
2354                 (unless chosen
2355                   (widget-apply child :deactivate)))
2356                (t
2357                 (error "Unknown escape `%c'" escape)))))
2358      ;; Update properties.
2359      (when chosen
2360        (widget-put widget :choice type))
2361      (when button
2362        (widget-put child :button button)
2363        (widget-put widget :buttons (nconc buttons (list button))))
2364      (when child
2365        (widget-put widget :children (nconc children (list child))))
2366      child)))
2367
2368 (defun widget-radio-value-get (widget)
2369   ;; Get value of the child widget.
2370   (let ((chosen (widget-radio-chosen widget)))
2371     (and chosen (widget-value chosen))))
2372
2373 (defun widget-radio-chosen (widget)
2374   "Return the widget representing the chosen radio button."
2375   (let ((children (widget-get widget :children))
2376         current found)
2377     (while children
2378       (setq current (car children)
2379             children (cdr children))
2380       (let* ((button (widget-get current :button))
2381              (value (widget-apply button :value-get)))
2382         (when value
2383           (setq found current
2384                 children nil))))
2385     found))
2386
2387 (defun widget-radio-value-inline (widget)
2388   ;; Get value of the child widget.
2389   (let ((children (widget-get widget :children))
2390         current found)
2391     (while children
2392       (setq current (car children)
2393             children (cdr children))
2394       (let* ((button (widget-get current :button))
2395              (value (widget-apply button :value-get)))
2396         (when value
2397           (setq found (widget-apply current :value-inline)
2398                 children nil))))
2399     found))
2400
2401 (defun widget-radio-value-set (widget value)
2402   ;; We can't just delete and recreate a radio widget, since children
2403   ;; can be added after the original creation and won't be recreated
2404   ;; by `:create'.
2405   (let ((children (widget-get widget :children))
2406         current found)
2407     (while children
2408       (setq current (car children)
2409             children (cdr children))
2410       (let* ((button (widget-get current :button))
2411              (match (and (not found)
2412                          (widget-apply current :match value))))
2413         (widget-value-set button match)
2414         (if match
2415             (progn
2416               (widget-value-set current value)
2417               (widget-apply current :activate))
2418           (widget-apply current :deactivate))
2419         (setq found (or found match))))))
2420
2421 (defun widget-radio-validate (widget)
2422   ;; Valid if we have made a valid choice.
2423   (let ((children (widget-get widget :children))
2424         current found button)
2425     (while (and children (not found))
2426       (setq current (car children)
2427             children (cdr children)
2428             button (widget-get current :button)
2429             found (widget-apply button :value-get)))
2430     (if found
2431         (widget-apply current :validate)
2432       widget)))
2433
2434 (defun widget-radio-action (widget child event)
2435   ;; Check if a radio button was pressed.
2436   (let ((children (widget-get widget :children))
2437         (buttons (widget-get widget :buttons))
2438         current)
2439     (when (memq child buttons)
2440       (while children
2441         (setq current (car children)
2442               children (cdr children))
2443         (let* ((button (widget-get current :button)))
2444           (cond ((eq child button)
2445                  (widget-value-set button t)
2446                  (widget-apply current :activate))
2447                 ((widget-value button)
2448                  (widget-value-set button nil)
2449                  (widget-apply current :deactivate)))))))
2450   ;; Pass notification to parent.
2451   (widget-apply widget :notify child event))
2452
2453 ;;; The `insert-button' Widget.
2454
2455 (define-widget 'insert-button 'push-button
2456   "An insert button for the `editable-list' widget."
2457   :tag "INS"
2458   :help-echo "Insert a new item into the list at this position."
2459   :action 'widget-insert-button-action)
2460
2461 (defun widget-insert-button-action (widget &optional event)
2462   ;; Ask the parent to insert a new item.
2463   (widget-apply (widget-get widget :parent)
2464                 :insert-before (widget-get widget :widget)))
2465
2466 ;;; The `delete-button' Widget.
2467
2468 (define-widget 'delete-button 'push-button
2469   "A delete button for the `editable-list' widget."
2470   :tag "DEL"
2471   :help-echo "Delete this item from the list."
2472   :action 'widget-delete-button-action)
2473
2474 (defun widget-delete-button-action (widget &optional event)
2475   ;; Ask the parent to insert a new item.
2476   (widget-apply (widget-get widget :parent)
2477                 :delete-at (widget-get widget :widget)))
2478
2479 ;;; The `editable-list' Widget.
2480
2481 (defcustom widget-editable-list-gui nil
2482   "If non nil, use GUI push-buttons in editable list when available."
2483   :type 'boolean
2484   :group 'widgets)
2485
2486 (define-widget 'editable-list 'default
2487   "A variable list of widgets of the same type."
2488   :convert-widget 'widget-types-convert-widget
2489   :offset 12
2490   :format "%v%i\n"
2491   :format-handler 'widget-editable-list-format-handler
2492   :entry-format "%i %d %v"
2493   :menu-tag "editable-list"
2494   :value-create 'widget-editable-list-value-create
2495   :value-delete 'widget-children-value-delete
2496   :value-get 'widget-editable-list-value-get
2497   :validate 'widget-children-validate
2498   :match 'widget-editable-list-match
2499   :match-inline 'widget-editable-list-match-inline
2500   :insert-before 'widget-editable-list-insert-before
2501   :delete-at 'widget-editable-list-delete-at)
2502
2503 (defun widget-editable-list-format-handler (widget escape)
2504   ;; We recognize the insert button.
2505   (let ((widget-push-button-gui widget-editable-list-gui))
2506     (cond ((eq escape ?i)
2507            (and (widget-get widget :indent)
2508                 (insert-char ?  (widget-get widget :indent)))
2509            (apply 'widget-create-child-and-convert
2510                   widget 'insert-button
2511                   (widget-get widget :append-button-args)))
2512           (t
2513            (widget-default-format-handler widget escape)))))
2514
2515 (defun widget-editable-list-value-create (widget)
2516   ;; Insert all values
2517   (let* ((value (widget-get widget :value))
2518          (type (nth 0 (widget-get widget :args)))
2519          (inlinep (widget-get type :inline))
2520          children)
2521     (widget-put widget :value-pos (copy-marker (point)))
2522     (set-marker-insertion-type (widget-get widget :value-pos) t)
2523     (while value
2524       (let ((answer (widget-match-inline type value)))
2525         (if answer
2526             (setq children (cons (widget-editable-list-entry-create
2527                                   widget
2528                                   (if inlinep
2529                                       (car answer)
2530                                     (car (car answer)))
2531                                   t)
2532                                  children)
2533                   value (cdr answer))
2534           (setq value nil))))
2535     (widget-put widget :children (nreverse children))))
2536
2537 (defun widget-editable-list-value-get (widget)
2538   ;; Get value of the child widget.
2539   (apply 'append (mapcar (lambda (child) (widget-apply child :value-inline))
2540                          (widget-get widget :children))))
2541
2542 (defun widget-editable-list-match (widget value)
2543   ;; Value must be a list and all the members must match the type.
2544   (and (listp value)
2545        (null (cdr (widget-editable-list-match-inline widget value)))))
2546
2547 (defun widget-editable-list-match-inline (widget value)
2548   (let ((type (nth 0 (widget-get widget :args)))
2549         (ok t)
2550         found)
2551     (while (and value ok)
2552       (let ((answer (widget-match-inline type value)))
2553         (if answer
2554             (setq found (append found (car answer))
2555                   value (cdr answer))
2556           (setq ok nil))))
2557     (cons found value)))
2558
2559 (defun widget-editable-list-insert-before (widget before)
2560   ;; Insert a new child in the list of children.
2561   (save-excursion
2562     (let ((children (widget-get widget :children))
2563           (inhibit-read-only t)
2564           before-change-functions
2565           after-change-functions)
2566       (cond (before
2567              (goto-char (widget-get before :entry-from)))
2568             (t
2569              (goto-char (widget-get widget :value-pos))))
2570       (let ((child (widget-editable-list-entry-create
2571                     widget nil nil)))
2572         (when (< (widget-get child :entry-from) (widget-get widget :from))
2573           (set-marker (widget-get widget :from)
2574                       (widget-get child :entry-from)))
2575         (widget-specify-text (widget-get child :entry-from)
2576                              (widget-get child :entry-to))
2577         (if (eq (car children) before)
2578             (widget-put widget :children (cons child children))
2579           (while (not (eq (car (cdr children)) before))
2580             (setq children (cdr children)))
2581           (setcdr children (cons child (cdr children)))))))
2582   (widget-setup)
2583   (widget-apply widget :notify widget))
2584
2585 (defun widget-editable-list-delete-at (widget child)
2586   ;; Delete child from list of children.
2587   (save-excursion
2588     (let ((buttons (copy-sequence (widget-get widget :buttons)))
2589           button
2590           (inhibit-read-only t)
2591           before-change-functions
2592           after-change-functions)
2593       (while buttons
2594         (setq button (car buttons)
2595               buttons (cdr buttons))
2596         (when (eq (widget-get button :widget) child)
2597           (widget-put widget
2598                       :buttons (delq button (widget-get widget :buttons)))
2599           (widget-delete button))))
2600     (let ((entry-from (widget-get child :entry-from))
2601           (entry-to (widget-get child :entry-to))
2602           (inhibit-read-only t)
2603           before-change-functions
2604           after-change-functions)
2605       (widget-delete child)
2606       (delete-region entry-from entry-to)
2607       (set-marker entry-from nil)
2608       (set-marker entry-to nil))
2609     (widget-put widget :children (delq child (widget-get widget :children))))
2610   (widget-setup)
2611   (widget-apply widget :notify widget))
2612
2613 (defun widget-editable-list-entry-create (widget value conv)
2614   ;; Create a new entry to the list.
2615   (let ((type (nth 0 (widget-get widget :args)))
2616         (widget-push-button-gui widget-editable-list-gui)
2617         child delete insert)
2618     (widget-specify-insert
2619      (save-excursion
2620        (and (widget-get widget :indent)
2621             (insert-char ?  (widget-get widget :indent)))
2622        (insert (widget-get widget :entry-format)))
2623      ;; Parse % escapes in format.
2624      (while (re-search-forward "%\\(.\\)" nil t)
2625        (let ((escape (aref (match-string 1) 0)))
2626          (replace-match "" t t)
2627          (cond ((eq escape ?%)
2628                 (insert "%"))
2629                ((eq escape ?i)
2630                 (setq insert (apply 'widget-create-child-and-convert
2631                                     widget 'insert-button
2632                                     (widget-get widget :insert-button-args))))
2633                ((eq escape ?d)
2634                 (setq delete (apply 'widget-create-child-and-convert
2635                                     widget 'delete-button
2636                                     (widget-get widget :delete-button-args))))
2637                ((eq escape ?v)
2638                 (if conv
2639                     (setq child (widget-create-child-value
2640                                  widget type value))
2641                   (setq child (widget-create-child widget type))))
2642                (t
2643                 (error "Unknown escape `%c'" escape)))))
2644      (widget-put widget
2645                  :buttons (cons delete
2646                                 (cons insert
2647                                       (widget-get widget :buttons))))
2648      (let ((entry-from (copy-marker (point-min)))
2649            (entry-to (copy-marker (point-max))))
2650        (widget-specify-text entry-from entry-to)
2651        (set-marker-insertion-type entry-from t)
2652        (set-marker-insertion-type entry-to nil)
2653        (widget-put child :entry-from entry-from)
2654        (widget-put child :entry-to entry-to)))
2655     (widget-put insert :widget child)
2656     (widget-put delete :widget child)
2657     child))
2658
2659 ;;; The `group' Widget.
2660
2661 (define-widget 'group 'default
2662   "A widget which group other widgets inside."
2663   :convert-widget 'widget-types-convert-widget
2664   :format "%v"
2665   :value-create 'widget-group-value-create
2666   :value-delete 'widget-children-value-delete
2667   :value-get 'widget-editable-list-value-get
2668   :validate 'widget-children-validate
2669   :match 'widget-group-match
2670   :match-inline 'widget-group-match-inline)
2671
2672 (defun widget-group-value-create (widget)
2673   ;; Create each component.
2674   (let ((args (widget-get widget :args))
2675         (value (widget-get widget :value))
2676         arg answer children)
2677     (while args
2678       (setq arg (car args)
2679             args (cdr args)
2680             answer (widget-match-inline arg value)
2681             value (cdr answer))
2682       (and (eq (preceding-char) ?\n)
2683            (widget-get widget :indent)
2684            (insert-char ?  (widget-get widget :indent)))
2685       (push (cond ((null answer)
2686                    (widget-create-child widget arg))
2687                   ((widget-get arg :inline)
2688                    (widget-create-child-value widget arg  (car answer)))
2689                   (t
2690                    (widget-create-child-value widget arg  (car (car answer)))))
2691             children))
2692     (widget-put widget :children (nreverse children))))
2693
2694 (defun widget-group-match (widget values)
2695   ;; Match if the components match.
2696   (and (listp values)
2697        (let ((match (widget-group-match-inline widget values)))
2698          (and match (null (cdr match))))))
2699
2700 (defun widget-group-match-inline (widget vals)
2701   ;; Match if the components match.
2702   (let ((args (widget-get widget :args))
2703         argument answer found)
2704     (while args
2705       (setq argument (car args)
2706             args (cdr args)
2707             answer (widget-match-inline argument vals))
2708       (if answer
2709           (setq vals (cdr answer)
2710                 found (append found (car answer)))
2711         (setq vals nil
2712               args nil)))
2713     (if answer
2714         (cons found vals)
2715       nil)))
2716
2717 ;;; The `visibility' Widget.
2718
2719 (define-widget 'visibility 'item
2720   "An indicator and manipulator for hidden items."
2721   :format "%[%v%]"
2722   :button-prefix ""
2723   :button-suffix ""
2724   :on "Hide"
2725   :off "Show"
2726   :value-create 'widget-visibility-value-create
2727   :action 'widget-toggle-action
2728   :match (lambda (widget value) t))
2729
2730 (defun widget-visibility-value-create (widget)
2731   ;; Insert text representing the `on' and `off' states.
2732   (let ((on (widget-get widget :on))
2733         (off (widget-get widget :off)))
2734     (if on
2735         (setq on (concat widget-push-button-prefix
2736                          on
2737                          widget-push-button-suffix))
2738       (setq on ""))
2739     (if off
2740         (setq off (concat widget-push-button-prefix
2741                           off
2742                           widget-push-button-suffix))
2743       (setq off ""))
2744     (if (widget-value widget)
2745         (widget-glyph-insert widget on "down" "down-pushed")
2746       (widget-glyph-insert widget off "right" "right-pushed"))))
2747
2748 ;;; The `documentation-link' Widget.
2749 ;;
2750 ;; This is a helper widget for `documentation-string'.
2751
2752 (define-widget 'documentation-link 'link
2753   "Link type used in documentation strings."
2754   :tab-order -1
2755   :help-echo 'widget-documentation-link-echo-help
2756   :action 'widget-documentation-link-action)
2757
2758 (defun widget-documentation-link-echo-help (widget)
2759   "Tell what this link will describe."
2760   (concat "Describe the `" (widget-get widget :value) "' symbol."))
2761
2762 (defun widget-documentation-link-action (widget &optional event)
2763   "Display documentation for WIDGET's value.  Ignore optional argument EVENT."
2764   (let* ((string (widget-get widget :value))
2765          (symbol (intern string)))
2766     (if (and (fboundp symbol) (boundp symbol))
2767         ;; If there are two doc strings, give the user a way to pick one.
2768         (apropos (concat "\\`" (regexp-quote string) "\\'"))
2769       (if (fboundp symbol)
2770           (describe-function symbol)
2771         (describe-variable symbol)))))
2772
2773 (defcustom widget-documentation-links t
2774   "Add hyperlinks to documentation strings when non-nil."
2775   :type 'boolean
2776   :group 'widget-documentation)
2777
2778 (defcustom widget-documentation-link-regexp "`\\([^\n`' ]+\\)'"
2779   "Regexp for matching potential links in documentation strings.
2780 The first group should be the link itself."
2781   :type 'regexp
2782   :group 'widget-documentation)
2783
2784 (defcustom widget-documentation-link-p 'intern-soft
2785   "Predicate used to test if a string is useful as a link.
2786 The value should be a function.  The function will be called one
2787 argument, a string, and should return non-nil if there should be a
2788 link for that string."
2789   :type 'function
2790   :options '(widget-documentation-link-p)
2791   :group 'widget-documentation)
2792
2793 (defcustom widget-documentation-link-type 'documentation-link
2794   "Widget type used for links in documentation strings."
2795   :type 'symbol
2796   :group 'widget-documentation)
2797
2798 (defun widget-documentation-link-add (widget from to)
2799   (widget-specify-doc widget from to)
2800   (when widget-documentation-links
2801     (let ((regexp widget-documentation-link-regexp)
2802           (predicate widget-documentation-link-p)
2803           (type widget-documentation-link-type)
2804           (buttons (widget-get widget :buttons)))
2805       (save-excursion
2806         (goto-char from)
2807         (while (re-search-forward regexp to t)
2808           (let ((name (match-string 1))
2809                 (begin (match-beginning 1))
2810                 (end (match-end 1)))
2811             (when (funcall predicate name)
2812               (push (widget-convert-button type begin end :value name)
2813                     buttons)))))
2814       (widget-put widget :buttons buttons)))
2815   (let ((indent (widget-get widget :indent)))
2816     (when (and indent (not (zerop indent)))
2817       (save-excursion
2818         (save-restriction
2819           (narrow-to-region from to)
2820           (goto-char (point-min))
2821           (while (search-forward "\n" nil t)
2822             (insert-char ?\  indent)))))))
2823
2824 ;;; The `documentation-string' Widget.
2825
2826 (define-widget 'documentation-string 'item
2827   "A documentation string."
2828   :format "%v"
2829   :action 'widget-documentation-string-action
2830   :value-delete 'widget-children-value-delete
2831   :value-create 'widget-documentation-string-value-create)
2832
2833 (defun widget-documentation-string-value-create (widget)
2834   ;; Insert documentation string.
2835   (let ((doc (widget-value widget))
2836         (indent (widget-get widget :indent))
2837         (shown (widget-get (widget-get widget :parent) :documentation-shown))
2838         (start (point)))
2839     (if (string-match "\n" doc)
2840         (let ((before (substring doc 0 (match-beginning 0)))
2841               (after (substring doc (match-beginning 0)))
2842               buttons)
2843           (insert before " ")
2844           (widget-documentation-link-add widget start (point))
2845           (push (widget-create-child-and-convert
2846                  widget 'visibility
2847                  :help-echo "Show or hide rest of the documentation."
2848                  :off "More"
2849                  :action 'widget-parent-action
2850                  shown)
2851                 buttons)
2852           (when shown
2853             (setq start (point))
2854             (when (and indent (not (zerop indent)))
2855               (insert-char ?\  indent))
2856             (insert after)
2857             (widget-documentation-link-add widget start (point)))
2858           (widget-put widget :buttons buttons))
2859       (insert doc)
2860       (widget-documentation-link-add widget start (point))))
2861   (insert "\n"))
2862
2863 (defun widget-documentation-string-action (widget &rest ignore)
2864   ;; Toggle documentation.
2865   (let ((parent (widget-get widget :parent)))
2866     (widget-put parent :documentation-shown
2867                 (not (widget-get parent :documentation-shown))))
2868   ;; Redraw.
2869   (widget-value-set widget (widget-value widget)))
2870
2871 ;;; The Sexp Widgets.
2872
2873 (define-widget 'const 'item
2874   "An immutable sexp."
2875   :prompt-value 'widget-const-prompt-value
2876   :format "%t\n%d")
2877
2878 (defun widget-const-prompt-value (widget prompt value unbound)
2879   ;; Return the value of the const.
2880   (widget-value widget))
2881
2882 (define-widget 'function-item 'const
2883   "An immutable function name."
2884   :format "%v\n%h"
2885   :documentation-property (lambda (symbol)
2886                             (condition-case nil
2887                                 (documentation symbol t)
2888                               (error nil))))
2889
2890 (define-widget 'variable-item 'const
2891   "An immutable variable name."
2892   :format "%v\n%h"
2893   :documentation-property 'variable-documentation)
2894
2895 (defvar widget-string-prompt-value-history nil
2896   "History of input to `widget-string-prompt-value'.")
2897
2898 (define-widget 'string 'editable-field
2899   "A string"
2900   :tag "String"
2901   :format "%{%t%}: %v"
2902   :complete-function 'ispell-complete-word
2903   :prompt-history 'widget-string-prompt-value-history)
2904
2905 (define-widget 'regexp 'string
2906   "A regular expression."
2907   :match 'widget-regexp-match
2908   :validate 'widget-regexp-validate
2909   :value-face 'widget-single-line-field-face
2910   :tag "Regexp")
2911
2912 (defun widget-regexp-match (widget value)
2913   ;; Match valid regexps.
2914   (and (stringp value)
2915        (condition-case nil
2916            (prog1 t
2917              (string-match value ""))
2918          (error nil))))
2919
2920 (defun widget-regexp-validate (widget)
2921   "Check that the value of WIDGET is a valid regexp."
2922   (let ((val (widget-value widget)))
2923     (condition-case data
2924         (prog1 nil
2925           (string-match val ""))
2926       (error (widget-put widget :error (error-message-string data))
2927              widget))))
2928
2929 (define-widget 'file 'string
2930   "A file widget.
2931 It will read a file name from the minibuffer when invoked."
2932   :complete-function 'widget-file-complete
2933   :prompt-value 'widget-file-prompt-value
2934   :format "%{%t%}: %v"
2935   :value-face 'widget-single-line-field-face
2936   :tag "File")
2937
2938 (defun widget-file-complete ()
2939   "Perform completion on file name preceding point."
2940   (interactive)
2941   (let* ((end (point))
2942          (beg (save-excursion
2943                 (skip-chars-backward "^ ")
2944                 (point)))
2945          (pattern (buffer-substring beg end))
2946          (name-part (file-name-nondirectory pattern))
2947          (directory (file-name-directory pattern))
2948          (completion (file-name-completion name-part directory)))
2949     (cond ((eq completion t))
2950           ((null completion)
2951            (message "Can't find completion for \"%s\"" pattern)
2952            (ding))
2953           ((not (string= name-part completion))
2954            (delete-region beg end)
2955            (insert (expand-file-name completion directory)))
2956           (t
2957            (message "Making completion list...")
2958            (let ((list (file-name-all-completions name-part directory)))
2959              (setq list (sort list 'string<))
2960              (with-output-to-temp-buffer "*Completions*"
2961                (display-completion-list list)))
2962            (message "Making completion list...%s" "done")))))
2963
2964 (defun widget-file-prompt-value (widget prompt value unbound)
2965   ;; Read file from minibuffer.
2966   (abbreviate-file-name
2967    (if unbound
2968        (read-file-name prompt)
2969      (let ((prompt2 (format "%s (default %s) " prompt value))
2970            (dir (file-name-directory value))
2971            (file (file-name-nondirectory value))
2972            (must-match (widget-get widget :must-match)))
2973        (read-file-name prompt2 dir nil must-match file)))))
2974
2975 ;;;(defun widget-file-action (widget &optional event)
2976 ;;;  ;; Read a file name from the minibuffer.
2977 ;;;  (let* ((value (widget-value widget))
2978 ;;;      (dir (file-name-directory value))
2979 ;;;      (file (file-name-nondirectory value))
2980 ;;;      (menu-tag (widget-apply widget :menu-tag-get))
2981 ;;;      (must-match (widget-get widget :must-match))
2982 ;;;      (answer (read-file-name (concat menu-tag ": (default `" value "') ")
2983 ;;;                              dir nil must-match file)))
2984 ;;;    (widget-value-set widget (abbreviate-file-name answer))
2985 ;;;    (widget-setup)
2986 ;;;    (widget-apply widget :notify widget event)))
2987
2988 (define-widget 'directory 'file
2989   "A directory widget.
2990 It will read a directory name from the minibuffer when invoked."
2991   :tag "Directory")
2992
2993 (defvar widget-symbol-prompt-value-history nil
2994   "History of input to `widget-symbol-prompt-value'.")
2995
2996 (define-widget 'symbol 'editable-field
2997   "A lisp symbol."
2998   :value nil
2999   :tag "Symbol"
3000   :format "%{%t%}: %v"
3001   :match (lambda (widget value) (symbolp value))
3002   :complete-function 'lisp-complete-symbol
3003   :prompt-internal 'widget-symbol-prompt-internal
3004   :prompt-match 'symbolp
3005   :prompt-history 'widget-symbol-prompt-value-history
3006   :value-to-internal (lambda (widget value)
3007                        (if (symbolp value)
3008                            (symbol-name value)
3009                          value))
3010   :value-to-external (lambda (widget value)
3011                        (if (stringp value)
3012                            (intern value)
3013                          value)))
3014
3015 (defun widget-symbol-prompt-internal (widget prompt initial history)
3016   ;; Read file from minibuffer.
3017   (let ((answer (completing-read prompt obarray
3018                                  (widget-get widget :prompt-match)
3019                                  nil initial history)))
3020     (if (and (stringp answer)
3021              (not (zerop (length answer))))
3022         answer
3023       (error "No value"))))
3024
3025 (defvar widget-function-prompt-value-history nil
3026   "History of input to `widget-function-prompt-value'.")
3027
3028 (define-widget 'function 'sexp
3029   "A lisp function."
3030   :complete-function 'lisp-complete-symbol
3031   :prompt-value 'widget-field-prompt-value
3032   :prompt-internal 'widget-symbol-prompt-internal
3033   :prompt-match 'fboundp
3034   :prompt-history 'widget-function-prompt-value-history
3035   :action 'widget-field-action
3036   :tag "Function")
3037
3038 (defvar widget-variable-prompt-value-history nil
3039   "History of input to `widget-variable-prompt-value'.")
3040
3041 (define-widget 'variable 'symbol
3042   ;; Should complete on variables.
3043   "A lisp variable."
3044   :prompt-match 'boundp
3045   :prompt-history 'widget-variable-prompt-value-history
3046   :tag "Variable")
3047
3048 (when (featurep 'mule)
3049   (defvar widget-coding-system-prompt-value-history nil
3050     "History of input to `widget-coding-system-prompt-value'.")
3051
3052   (define-widget 'coding-system 'symbol
3053     "A MULE coding-system."
3054     :format "%{%t%}: %v"
3055     :tag "Coding system"
3056     :prompt-history 'widget-coding-system-prompt-value-history
3057     :prompt-value 'widget-coding-system-prompt-value
3058     :action 'widget-coding-system-action)
3059
3060   (defun widget-coding-system-prompt-value (widget prompt value unbound)
3061     ;; Read coding-system from minibuffer.
3062     (intern
3063      (completing-read (format "%s (default %s) " prompt value)
3064                       (mapcar (function
3065                                (lambda (sym)
3066                                  (list (symbol-name sym))
3067                                  ))
3068                               (coding-system-list)))))
3069
3070   (defun widget-coding-system-action (widget &optional event)
3071     ;; Read a file name from the minibuffer.
3072     (let ((answer
3073            (widget-coding-system-prompt-value
3074             widget
3075             (widget-apply widget :menu-tag-get)
3076             (widget-value widget)
3077             t)))
3078       (widget-value-set widget answer)
3079       (widget-apply widget :notify widget event)
3080       (widget-setup)))
3081   )
3082
3083 (define-widget 'sexp 'editable-field
3084   "An arbitrary lisp expression."
3085   :tag "Lisp expression"
3086   :format "%{%t%}: %v"
3087   :value nil
3088   :validate 'widget-sexp-validate
3089   :match (lambda (widget value) t)
3090   :value-to-internal 'widget-sexp-value-to-internal
3091   :value-to-external (lambda (widget value) (read value))
3092   :prompt-history 'widget-sexp-prompt-value-history
3093   :prompt-value 'widget-sexp-prompt-value)
3094
3095 (defun widget-sexp-value-to-internal (widget value)
3096   ;; Use pp for printer representation.
3097   (let ((pp (if (symbolp value)
3098                 (prin1-to-string value)
3099               (pp-to-string value))))
3100     (while (string-match "\n\\'" pp)
3101       (setq pp (substring pp 0 -1)))
3102     (if (or (string-match "\n\\'" pp)
3103             (> (length pp) 40))
3104         (concat "\n" pp)
3105       pp)))
3106
3107 (defun widget-sexp-validate (widget)
3108   ;; Valid if we can read the string and there is no junk left after it.
3109   (save-excursion
3110     (let ((buffer (set-buffer (get-buffer-create " *Widget Scratch*"))))
3111       (erase-buffer)
3112       (insert (widget-apply widget :value-get))
3113       (goto-char (point-min))
3114       (condition-case data
3115           (let ((value (read buffer)))
3116             (if (eobp)
3117                 (if (widget-apply widget :match value)
3118                     nil
3119                   (widget-put widget :error (widget-get widget :type-error))
3120                   widget)
3121               (widget-put widget
3122                           :error (format "Junk at end of expression: %s"
3123                                          (buffer-substring (point)
3124                                                            (point-max))))
3125               widget))
3126         (error (widget-put widget :error (error-message-string data))
3127                widget)))))
3128
3129 (defvar widget-sexp-prompt-value-history nil
3130   "History of input to `widget-sexp-prompt-value'.")
3131
3132 (defun widget-sexp-prompt-value (widget prompt value unbound)
3133   ;; Read an arbitrary sexp.
3134   (let ((found (read-string prompt
3135                             (if unbound nil (cons (prin1-to-string value) 0))
3136                             (widget-get widget :prompt-history))))
3137     (save-excursion
3138       (let ((buffer (set-buffer (get-buffer-create " *Widget Scratch*"))))
3139         (erase-buffer)
3140         (insert found)
3141         (goto-char (point-min))
3142         (let ((answer (read buffer)))
3143           (unless (eobp)
3144             (error "Junk at end of expression: %s"
3145                    (buffer-substring (point) (point-max))))
3146           answer)))))
3147
3148 (define-widget 'restricted-sexp 'sexp
3149   "A Lisp expression restricted to values that match.
3150 To use this type, you must define :match or :match-alternatives."
3151   :type-error "The specified value is not valid"
3152   :match 'widget-restricted-sexp-match
3153   :value-to-internal (lambda (widget value)
3154                        (if (widget-apply widget :match value)
3155                            (prin1-to-string value)
3156                          value)))
3157
3158 (defun widget-restricted-sexp-match (widget value)
3159   (let ((alternatives (widget-get widget :match-alternatives))
3160         matched)
3161     (while (and alternatives (not matched))
3162       (if (cond ((functionp (car alternatives))
3163                  (funcall (car alternatives) value))
3164                 ((and (consp (car alternatives))
3165                       (eq (car (car alternatives)) 'quote))
3166                  (eq value (nth 1 (car alternatives)))))
3167           (setq matched t))
3168       (setq alternatives (cdr alternatives)))
3169     matched))
3170
3171 (define-widget 'integer 'restricted-sexp
3172   "An integer."
3173   :tag "Integer"
3174   :value 0
3175   :type-error "This field should contain an integer"
3176   :match-alternatives '(integerp))
3177
3178 (define-widget 'number 'restricted-sexp
3179   "A floating point number."
3180   :tag "Number"
3181   :value 0.0
3182   :type-error "This field should contain a number"
3183   :match-alternatives '(numberp))
3184
3185 (define-widget 'character 'editable-field
3186   "A character."
3187   :tag "Character"
3188   :value 0
3189   :size 1
3190   :format "%{%t%}: %v\n"
3191   :valid-regexp "\\`.\\'"
3192   :error "This field should contain a single character"
3193   :value-to-internal (lambda (widget value)
3194                        (if (stringp value)
3195                            value
3196                          (char-to-string value)))
3197   :value-to-external (lambda (widget value)
3198                        (if (stringp value)
3199                            (aref value 0)
3200                          value))
3201   :match (lambda (widget value)
3202            (if (fboundp 'characterp)
3203                (characterp value)
3204              (integerp value))))
3205
3206 (define-widget 'list 'group
3207   "A lisp list."
3208   :tag "List"
3209   :format "%{%t%}:\n%v")
3210
3211 (define-widget 'vector 'group
3212   "A lisp vector."
3213   :tag "Vector"
3214   :format "%{%t%}:\n%v"
3215   :match 'widget-vector-match
3216   :value-to-internal (lambda (widget value) (append value nil))
3217   :value-to-external (lambda (widget value) (apply 'vector value)))
3218
3219 (defun widget-vector-match (widget value)
3220   (and (vectorp value)
3221        (widget-group-match widget
3222                            (widget-apply widget :value-to-internal value))))
3223
3224 (define-widget 'cons 'group
3225   "A cons-cell."
3226   :tag "Cons-cell"
3227   :format "%{%t%}:\n%v"
3228   :match 'widget-cons-match
3229   :value-to-internal (lambda (widget value)
3230                        (list (car value) (cdr value)))
3231   :value-to-external (lambda (widget value)
3232                        (cons (nth 0 value) (nth 1 value))))
3233
3234 (defun widget-cons-match (widget value)
3235   (and (consp value)
3236        (widget-group-match widget
3237                            (widget-apply widget :value-to-internal value))))
3238
3239 (define-widget 'choice 'menu-choice
3240   "A union of several sexp types."
3241   :tag "Choice"
3242   :format "%{%t%}: %[Value Menu%] %v"
3243   :button-prefix 'widget-push-button-prefix
3244   :button-suffix 'widget-push-button-suffix
3245   :prompt-value 'widget-choice-prompt-value)
3246
3247 (defun widget-choice-prompt-value (widget prompt value unbound)
3248   "Make a choice."
3249   (let ((args (widget-get widget :args))
3250         (completion-ignore-case (widget-get widget :case-fold))
3251         current choices old)
3252     ;; Find the first arg that match VALUE.
3253     (let ((look args))
3254       (while look
3255         (if (widget-apply (car look) :match value)
3256             (setq old (car look)
3257                   look nil)
3258           (setq look (cdr look)))))
3259     ;; Find new choice.
3260     (setq current
3261           (cond ((= (length args) 0)
3262                  nil)
3263                 ((= (length args) 1)
3264                  (nth 0 args))
3265                 ((and (= (length args) 2)
3266                       (memq old args))
3267                  (if (eq old (nth 0 args))
3268                      (nth 1 args)
3269                    (nth 0 args)))
3270                 (t
3271                  (while args
3272                    (setq current (car args)
3273                          args (cdr args))
3274                    (setq choices
3275                          (cons (cons (widget-apply current :menu-tag-get)
3276                                      current)
3277                                choices)))
3278                  (let ((val (completing-read prompt choices nil t)))
3279                    (if (stringp val)
3280                        (let ((try (try-completion val choices)))
3281                          (when (stringp try)
3282                            (setq val try))
3283                          (cdr (assoc val choices)))
3284                      nil)))))
3285     (if current
3286         (widget-prompt-value current prompt nil t)
3287       value)))
3288
3289 (define-widget 'radio 'radio-button-choice
3290   "A union of several sexp types."
3291   :tag "Choice"
3292   :format "%{%t%}:\n%v"
3293   :prompt-value 'widget-choice-prompt-value)
3294
3295 (define-widget 'repeat 'editable-list
3296   "A variable length homogeneous list."
3297   :tag "Repeat"
3298   :format "%{%t%}:\n%v%i\n")
3299
3300 (define-widget 'set 'checklist
3301   "A list of members from a fixed set."
3302   :tag "Set"
3303   :format "%{%t%}:\n%v")
3304
3305 (define-widget 'boolean 'toggle
3306   "To be nil or non-nil, that is the question."
3307   :tag "Boolean"
3308   :prompt-value 'widget-boolean-prompt-value
3309   :button-prefix 'widget-push-button-prefix
3310   :button-suffix 'widget-push-button-suffix
3311   :format "%{%t%}: %[Toggle%]  %v\n"
3312   :on "on (non-nil)"
3313   :off "off (nil)")
3314
3315 (defun widget-boolean-prompt-value (widget prompt value unbound)
3316   ;; Toggle a boolean.
3317   (y-or-n-p prompt))
3318
3319 ;;; The `color' Widget.
3320
3321 (define-widget 'color-item 'choice-item
3322   "A color name (with sample)."
3323   :format "%v (%{sample%})\n"
3324   :sample-face-get 'widget-color-item-button-face-get)
3325
3326 (defun widget-color-item-button-face-get (widget)
3327   (let ((symbol (intern (concat "fg:" (widget-value widget)))))
3328     (if (string-match "XEmacs" emacs-version)
3329         (prog1 symbol
3330           (or (find-face symbol)
3331               (set-face-foreground (make-face symbol) (widget-value widget))))
3332       (condition-case nil
3333           (facemenu-get-face symbol)
3334         (error 'default)))))
3335
3336 (define-widget 'color 'push-button
3337   "Choose a color name (with sample)."
3338   :format "%[%t%]: %v"
3339   :tag "Color"
3340   :value "black"
3341   :value-create 'widget-color-value-create
3342   :value-delete 'widget-children-value-delete
3343   :value-get 'widget-color-value-get
3344   :value-set 'widget-color-value-set
3345   :action 'widget-color-action
3346   :match 'widget-field-match
3347   :tag "Color")
3348
3349 (defvar widget-color-choice-list nil)
3350 ;; Variable holding the possible colors.
3351
3352 (defun widget-color-choice-list ()
3353   (unless widget-color-choice-list
3354     (setq widget-color-choice-list
3355           (mapcar '(lambda (color) (list color))
3356                   (x-defined-colors))))
3357   widget-color-choice-list)
3358
3359 (defun widget-color-value-create (widget)
3360   (let ((child (widget-create-child-and-convert
3361                 widget 'color-item (widget-get widget :value))))
3362     (widget-put widget :children (list child))))
3363
3364 (defun widget-color-value-get (widget)
3365   ;; Pass command to first child.
3366   (widget-apply (car (widget-get widget :children)) :value-get))
3367
3368 (defun widget-color-value-set (widget value)
3369   ;; Pass command to first child.
3370   (widget-apply (car (widget-get widget :children)) :value-set value))
3371
3372 (defvar widget-color-history nil
3373   "History of entered colors")
3374
3375 (defun widget-color-action (widget &optional event)
3376   ;; Prompt for a color.
3377   (let* ((tag (widget-apply widget :menu-tag-get))
3378          (prompt (concat tag ": "))
3379          (answer (cond ((string-match "XEmacs" emacs-version)
3380                         (read-color prompt))
3381                        ((fboundp 'x-defined-colors)
3382                         (completing-read (concat tag ": ")
3383                                          (widget-color-choice-list)
3384                                          nil nil nil 'widget-color-history))
3385                        (t
3386                         (read-string prompt (widget-value widget))))))
3387     (unless (zerop (length answer))
3388       (widget-value-set widget answer)
3389       (widget-setup)
3390       (widget-apply widget :notify widget event))))
3391
3392 ;;; The alternative `editable-color' widget and its subroutine.
3393
3394 (define-widget 'color-sample 'choice-item
3395   "A color name (with sample)."
3396   :format "(%{sample%})"
3397   :sample-face-get 'widget-color-item-button-face-get)
3398
3399 (define-widget 'editable-color 'editable-field
3400   "A color name, editable"
3401   :tag "Color"
3402   :format "%{%t%}: %v"
3403   :complete-function 'widget-color-complete
3404   :value-create 'widget-editable-color-value-create
3405   :prompt-match '(lambda (color) (member color widget-color-choice-list))
3406   :prompt-history 'widget-string-prompt-value-history)
3407
3408 (defun widget-editable-color-value-create (widget)
3409   (widget-field-value-create widget)
3410   (forward-line -1)
3411   (end-of-line)
3412   (let ((child (widget-create-child-and-convert
3413                 widget 'color-sample (widget-get widget :value))))
3414     (widget-put widget :children (list child))))
3415
3416 ;;; The Help Echo
3417
3418 (defun widget-echo-help-mouse ()
3419   "Display the help message for the widget under the mouse.
3420 Enable with (run-with-idle-timer 1 t 'widget-echo-help-mouse)"
3421   (let* ((pos (mouse-position))
3422          (frame (car pos))
3423          (x (car (cdr pos)))
3424          (y (cdr (cdr pos)))
3425          (win (window-at x y frame))
3426          (where (coordinates-in-window-p (cons x y) win)))
3427     (when (consp where)
3428       (save-window-excursion
3429         (progn ; save-excursion
3430           (select-window win)
3431           (let* ((result (compute-motion (window-start win)
3432                                          '(0 . 0)
3433                                          (window-end win)
3434                                          where
3435                                          (window-width win)
3436                                          (cons (window-hscroll) 0)
3437                                          win)))
3438             (when (and (eq (nth 1 result) x)
3439                        (eq (nth 2 result) y))
3440               (widget-echo-help (nth 0 result))))))))
3441   (unless track-mouse
3442     (setq track-mouse t)
3443     (add-hook 'post-command-hook 'widget-stop-mouse-tracking)))
3444
3445 (defun widget-stop-mouse-tracking (&rest args)
3446   "Stop the mouse tracking done while idle."
3447   (remove-hook 'post-command-hook 'widget-stop-mouse-tracking)
3448   (setq track-mouse nil))
3449
3450 (defun widget-at (pos)
3451   "The button or field at POS."
3452   (or (get-char-property pos 'button)
3453       (get-char-property pos 'field)))
3454
3455 (defun widget-echo-help (pos)
3456   "Display the help echo for widget at POS."
3457   (let* ((widget (widget-at pos))
3458          (help-echo (and widget (widget-get widget :help-echo))))
3459     (cond ((stringp help-echo)
3460            (message "%s" help-echo))
3461           ((and (symbolp help-echo) (fboundp help-echo)
3462                 (stringp (setq help-echo (funcall help-echo widget))))
3463            (message "%s" help-echo)))))
3464
3465 ;;; The End:
3466
3467 (provide 'wid-edit)
3468
3469 ;; wid-edit.el ends here