code.delx.au - gnu-emacs/blob - lisp/wid-edit.el

   1 ;;; wid-edit.el --- Functions for creating and using widgets -*-byte-compile-dynamic: t;-*-
   2 ;;
   3 ;; Copyright (C) 1996,97,1999,2000,01,02,2003  Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
   6 ;; Maintainer: FSF
   7 ;; Keywords: extensions
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, USA.
  25
  26 ;;; Wishlist items (from widget.texi):
  27
  28 ;; * The `menu-choice' tag should be prettier, something like the
  29 ;;   abbreviated menus in Open Look.
  30
  31 ;; * Finish `:tab-order'.
  32
  33 ;; * Make indentation work with glyphs and proportional fonts.
  34
  35 ;; * Add commands to show overview of object and class hierarchies to
  36 ;;   the browser.
  37
  38 ;; * Find a way to disable mouse highlight for inactive widgets.
  39
  40 ;; * Find a way to make glyphs look inactive.
  41
  42 ;; * Add `key-binding' widget.
  43
  44 ;; * Add `widget' widget for editing widget specifications.
  45
  46 ;; * Find clean way to implement variable length list.  See
  47 ;;   `TeX-printer-list' for an explanation.
  48
  49 ;; * `C-h' in `widget-prompt-value' should give type specific help.
  50
  51 ;; * A mailto widget. [This should work OK as a url-link if with
  52 ;;   browse-url-browser-function' set up appropriately.]
  53
  54 ;;; Commentary:
  55 ;;
  56 ;; See `widget.el'.
  57
  58 ;;; Code:
  59
  60 ;;; Compatibility.
  61
  62 (defun widget-event-point (event)
  63   "Character position of the end of event if that exists, or nil."
  64   (posn-point (event-end event)))
  65
  66 (defun widget-button-release-event-p (event)
  67   "Non-nil if EVENT is a mouse-button-release event object."
  68   (and (eventp event)
  69        (memq (event-basic-type event) '(mouse-1 mouse-2 mouse-3))
  70        (or (memq 'click (event-modifiers event))
  71            (memq  'drag (event-modifiers event)))))
  72
  73 ;;; Customization.
  74
  75 (defgroup widgets nil
  76   "Customization support for the Widget Library."
  77   :link '(custom-manual "(widget)Top")
  78   :link '(emacs-library-link :tag "Lisp File" "widget.el")
  79   :prefix "widget-"
  80   :group 'extensions
  81   :group 'hypermedia)
  82
  83 (defgroup widget-documentation nil
  84   "Options controling the display of documentation strings."
  85   :group 'widgets)
  86
  87 (defgroup widget-faces nil
  88   "Faces used by the widget library."
  89   :group 'widgets
  90   :group 'faces)
  91
  92 (defvar widget-documentation-face 'widget-documentation-face
  93   "Face used for documentation strings in widgets.
  94 This exists as a variable so it can be set locally in certain buffers.")
  95
  96 (defface widget-documentation-face '((((class color)
  97                                        (background dark))
  98                                       (:foreground "lime green"))
  99                                      (((class color)
 100                                        (background light))
 101                                       (:foreground "dark green"))
 102                                      (t nil))
 103   "Face used for documentation text."
 104   :group 'widget-documentation
 105   :group 'widget-faces)
 106
 107 (defvar widget-button-face 'widget-button-face
 108   "Face used for buttons in widgets.
 109 This exists as a variable so it can be set locally in certain buffers.")
 110
 111 (defface widget-button-face '((t (:weight bold)))
 112   "Face used for widget buttons."
 113   :group 'widget-faces)
 114
 115 (defcustom widget-mouse-face 'highlight
 116   "Face used for widget buttons when the mouse is above them."
 117   :type 'face
 118   :group 'widget-faces)
 119
 120 ;; TTY gets special definitions here and in the next defface, because
 121 ;; the gray colors defined for other displays cause black text on a black
 122 ;; background, at least on light-background TTYs.
 123 (defface widget-field-face '((((type tty))
 124                               :background "yellow3"
 125                               :foreground "black")
 126                              (((class grayscale color)
 127                                (background light))
 128                               :background "gray85")
 129                              (((class grayscale color)
 130                                (background dark))
 131                               :background "dim gray")
 132                              (t
 133                               :slant italic))
 134   "Face used for editable fields."
 135   :group 'widget-faces)
 136
 137 (defface widget-single-line-field-face '((((type tty))
 138                                           :background "green3"
 139                                           :foreground "black")
 140                                          (((class grayscale color)
 141                                            (background light))
 142                                           :background "gray85")
 143                                          (((class grayscale color)
 144                                            (background dark))
 145                                           :background "dim gray")
 146                                          (t
 147                                           :slant italic))
 148   "Face used for editable fields spanning only a single line."
 149   :group 'widget-faces)
 150
 151 ;;; This causes display-table to be loaded, and not usefully.
 152 ;;;(defvar widget-single-line-display-table
 153 ;;;  (let ((table (make-display-table)))
 154 ;;;    (aset table 9  "^I")
 155 ;;;    (aset table 10 "^J")
 156 ;;;    table)
 157 ;;;  "Display table used for single-line editable fields.")
 158
 159 ;;;(when (fboundp 'set-face-display-table)
 160 ;;;  (set-face-display-table 'widget-single-line-field-face
 161 ;;;                       widget-single-line-display-table))
 162
 163 ;;; Utility functions.
 164 ;;
 165 ;; These are not really widget specific.
 166
 167 (defun widget-princ-to-string (object)
 168   "Return string representation of OBJECT, any Lisp object.
 169 No quoting characters are used; no delimiters are printed around
 170 the contents of strings."
 171   (with-output-to-string
 172       (princ object)))
 173
 174 (defun widget-clear-undo ()
 175   "Clear all undo information."
 176   (buffer-disable-undo (current-buffer))
 177   (buffer-enable-undo))
 178
 179 (defcustom widget-menu-max-size 40
 180   "Largest number of items allowed in a popup-menu.
 181 Larger menus are read through the minibuffer."
 182   :group 'widgets
 183   :type 'integer)
 184
 185 (defcustom widget-menu-max-shortcuts 40
 186   "Largest number of items for which it works to choose one with a character.
 187 For a larger number of items, the minibuffer is used."
 188   :group 'widgets
 189   :type 'integer)
 190
 191 (defcustom widget-menu-minibuffer-flag nil
 192   "*Control how to ask for a choice from the keyboard.
 193 Non-nil means use the minibuffer;
 194 nil means read a single character."
 195   :group 'widgets
 196   :type 'boolean)
 197
 198 (defun widget-choose (title items &optional event)
 199   "Choose an item from a list.
 200
 201 First argument TITLE is the name of the list.
 202 Second argument ITEMS is a list whose members are either
 203  (NAME . VALUE), to indicate selectable items, or just strings to
 204  indicate unselectable items.
 205 Optional third argument EVENT is an input event.
 206
 207 The user is asked to choose between each NAME from the items alist,
 208 and the VALUE of the chosen element will be returned.  If EVENT is a
 209 mouse event, and the number of elements in items is less than
 210 `widget-menu-max-size', a popup menu will be used, otherwise the
 211 minibuffer."
 212   (cond ((and (< (length items) widget-menu-max-size)
 213               event (display-popup-menus-p))
 214          ;; Mouse click.
 215          (x-popup-menu event
 216                        (list title (cons "" items))))
 217         ((or widget-menu-minibuffer-flag
 218              (> (length items) widget-menu-max-shortcuts))
 219          ;; Read the choice of name from the minibuffer.
 220          (setq items (widget-remove-if 'stringp items))
 221          (let ((val (completing-read (concat title ": ") items nil t)))
 222            (if (stringp val)
 223                (let ((try (try-completion val items)))
 224                  (when (stringp try)
 225                    (setq val try))
 226                  (cdr (assoc val items))))))
 227         (t
 228          ;; Construct a menu of the choices
 229          ;; and then use it for prompting for a single character.
 230          (let* ((overriding-terminal-local-map (make-sparse-keymap))
 231                 (next-digit ?0)
 232                 map choice some-choice-enabled value)
 233            ;; Define SPC as a prefix char to get to this menu.
 234            (define-key overriding-terminal-local-map " "
 235              (setq map (make-sparse-keymap title)))
 236            (with-current-buffer (get-buffer-create " widget-choose")
 237              (erase-buffer)
 238              (insert "Available choices:\n\n")
 239              (while items
 240                (setq choice (car items) items (cdr items))
 241                (if (consp choice)
 242                    (let* ((name (car choice))
 243                          (function (cdr choice)))
 244                      (insert (format "%c = %s\n" next-digit name))
 245                      (define-key map (vector next-digit) function)
 246                      (setq some-choice-enabled t)))
 247                ;; Allocate digits to disabled alternatives
 248                ;; so that the digit of a given alternative never varies.
 249                (setq next-digit (1+ next-digit)))
 250              (insert "\nC-g = Quit"))
 251            (or some-choice-enabled
 252                (error "None of the choices is currently meaningful"))
 253            (define-key map [?\C-g] 'keyboard-quit)
 254            (define-key map [t] 'keyboard-quit)
 255            (define-key map [?\M-\C-v] 'scroll-other-window)
 256            (define-key map [?\M--] 'negative-argument)
 257            (setcdr map (nreverse (cdr map)))
 258            ;; Read a char with the menu, and return the result
 259            ;; that corresponds to it.
 260            (save-window-excursion
 261              (let ((buf (get-buffer " widget-choose")))
 262                (fit-window-to-buffer (display-buffer buf))
 263                (let ((cursor-in-echo-area t)
 264                      keys
 265                      (char 0)
 266                      (arg 1))
 267                  (while (not (or (and (>= char ?0) (< char next-digit))
 268                                  (eq value 'keyboard-quit)))
 269                    ;; Unread a SPC to lead to our new menu.
 270                    (setq unread-command-events (cons ?\  unread-command-events))
 271                    (setq keys (read-key-sequence title))
 272                    (setq value
 273                          (lookup-key overriding-terminal-local-map keys t)
 274                          char (string-to-char (substring keys 1)))
 275                    (cond ((eq value 'scroll-other-window)
 276                           (let ((minibuffer-scroll-window
 277                                  (get-buffer-window buf)))
 278                             (if (> 0 arg)
 279                                 (scroll-other-window-down
 280                                  (window-height minibuffer-scroll-window))
 281                               (scroll-other-window))
 282                             (setq arg 1)))
 283                          ((eq value 'negative-argument)
 284                           (setq arg -1))
 285                          (t
 286                           (setq arg 1)))))))
 287            (when (eq value 'keyboard-quit)
 288              (error "Canceled"))
 289            value))))
 290
 291 (defun widget-remove-if (predictate list)
 292   (let (result (tail list))
 293     (while tail
 294       (or (funcall predictate (car tail))
 295           (setq result (cons (car tail) result)))
 296       (setq tail (cdr tail)))
 297     (nreverse result)))
 298
 299 ;;; Widget text specifications.
 300 ;;
 301 ;; These functions are for specifying text properties.
 302
 303 ;; We can set it to nil now that get_local_map uses get_pos_property.
 304 (defconst widget-field-add-space nil
 305   "Non-nil means add extra space at the end of editable text fields.
 306 If you don't add the space, it will become impossible to edit a zero
 307 size field.")
 308
 309 (defvar widget-field-use-before-change t
 310   "Non-nil means use `before-change-functions' to track editable fields.
 311 This enables the use of undo, but doesn't work on Emacs 19.34 and earlier.
 312 Using before hooks also means that the :notify function can't know the
 313 new value.")
 314
 315 (defun widget-specify-field (widget from to)
 316   "Specify editable button for WIDGET between FROM and TO."
 317   ;; Terminating space is not part of the field, but necessary in
 318   ;; order for local-map to work.  Remove next sexp if local-map works
 319   ;; at the end of the overlay.
 320   (save-excursion
 321     (goto-char to)
 322     (cond ((null (widget-get widget :size))
 323            (forward-char 1))
 324           (widget-field-add-space
 325            (insert-and-inherit " ")))
 326     (setq to (point)))
 327   (let ((keymap (widget-get widget :keymap))
 328         (face (or (widget-get widget :value-face) 'widget-field-face))
 329         (help-echo (widget-get widget :help-echo))
 330         (rear-sticky
 331          (or (not widget-field-add-space) (widget-get widget :size))))
 332     (if (functionp help-echo)
 333       (setq help-echo 'widget-mouse-help))
 334     (when (= (char-before to) ?\n)
 335       ;; When the last character in the field is a newline, we want to
 336       ;; give it a `field' char-property of `boundary', which helps the
 337       ;; C-n/C-p act more naturally when entering/leaving the field.  We
 338      ;; do this by making a small secondary overlay to contain just that
 339       ;; one character.
 340       (let ((overlay (make-overlay (1- to) to nil t nil)))
 341         (overlay-put overlay 'field 'boundary)
 342         ;; Use `local-map' here, not `keymap', so that normal editing
 343         ;; works in the field when, say, Custom uses `suppress-keymap'.
 344         (overlay-put overlay 'local-map keymap)
 345         (overlay-put overlay 'face face)
 346         (overlay-put overlay 'help-echo help-echo))
 347       (setq to (1- to))
 348       (setq rear-sticky t))
 349     (let ((overlay (make-overlay from to nil nil rear-sticky)))
 350       (widget-put widget :field-overlay overlay)
 351       ;;(overlay-put overlay 'detachable nil)
 352       (overlay-put overlay 'field widget)
 353       (overlay-put overlay 'local-map keymap)
 354       (overlay-put overlay 'face face)
 355       (overlay-put overlay 'help-echo help-echo)))
 356   (widget-specify-secret widget))
 357
 358 (defun widget-specify-secret (field)
 359   "Replace text in FIELD with value of `:secret', if non-nil."
 360   (let ((secret (widget-get field :secret))
 361         (size (widget-get field :size)))
 362     (when secret
 363       (let ((begin (widget-field-start field))
 364             (end (widget-field-end field)))
 365         (when size
 366           (while (and (> end begin)
 367                       (eq (char-after (1- end)) ?\ ))
 368             (setq end (1- end))))
 369         (while (< begin end)
 370           (let ((old (char-after begin)))
 371             (unless (eq old secret)
 372               (subst-char-in-region begin (1+ begin) old secret)
 373               (put-text-property begin (1+ begin) 'secret old))
 374             (setq begin (1+ begin))))))))
 375
 376 (defun widget-specify-button (widget from to)
 377   "Specify button for WIDGET between FROM and TO."
 378   (let ((overlay (make-overlay from to nil t nil))
 379         (help-echo (widget-get widget :help-echo)))
 380     (widget-put widget :button-overlay overlay)
 381     (if (functionp help-echo)
 382       (setq help-echo 'widget-mouse-help))
 383     (overlay-put overlay 'button widget)
 384     (overlay-put overlay 'keymap (widget-get widget :keymap))
 385     ;; We want to avoid the face with image buttons.
 386     (unless (widget-get widget :suppress-face)
 387       (overlay-put overlay 'face (widget-apply widget :button-face-get))
 388       (overlay-put overlay 'mouse-face widget-mouse-face))
 389     (overlay-put overlay 'help-echo help-echo)))
 390
 391 (defun widget-mouse-help (window overlay point)
 392   "Help-echo callback for widgets whose :help-echo is a function."
 393   (with-current-buffer (overlay-buffer overlay)
 394     (let* ((widget (widget-at (overlay-start overlay)))
 395            (help-echo (if widget (widget-get widget :help-echo))))
 396       (if (functionp help-echo)
 397           (funcall help-echo widget)
 398         help-echo))))
 399
 400 (defun widget-specify-sample (widget from to)
 401   "Specify sample for WIDGET between FROM and TO."
 402   (let ((overlay (make-overlay from to nil t nil)))
 403     (overlay-put overlay 'face (widget-apply widget :sample-face-get))
 404     (widget-put widget :sample-overlay overlay)))
 405
 406 (defun widget-specify-doc (widget from to)
 407   "Specify documentation for WIDGET between FROM and TO."
 408   (let ((overlay (make-overlay from to nil t nil)))
 409     (overlay-put overlay 'widget-doc widget)
 410     (overlay-put overlay 'face widget-documentation-face)
 411     (widget-put widget :doc-overlay overlay)))
 412
 413 (defmacro widget-specify-insert (&rest form)
 414   "Execute FORM without inheriting any text properties."
 415   `(save-restriction
 416     (let ((inhibit-read-only t)
 417           (inhibit-modification-hooks t))
 418       (narrow-to-region (point) (point))
 419       (prog1 (progn ,@form)
 420         (goto-char (point-max))))))
 421
 422 (defface widget-inactive-face '((((class grayscale color)
 423                                   (background dark))
 424                                  (:foreground "light gray"))
 425                                 (((class grayscale color)
 426                                   (background light))
 427                                  (:foreground "dim gray"))
 428                                 (t
 429                                  (:slant italic)))
 430   "Face used for inactive widgets."
 431   :group 'widget-faces)
 432
 433 (defun widget-specify-inactive (widget from to)
 434   "Make WIDGET inactive for user modifications."
 435   (unless (widget-get widget :inactive)
 436     (let ((overlay (make-overlay from to nil t nil)))
 437       (overlay-put overlay 'face 'widget-inactive-face)
 438       ;; This is disabled, as it makes the mouse cursor change shape.
 439       ;; (overlay-put overlay 'mouse-face 'widget-inactive-face)
 440       (overlay-put overlay 'evaporate t)
 441       (overlay-put overlay 'priority 100)
 442       (overlay-put overlay 'modification-hooks '(widget-overlay-inactive))
 443       (widget-put widget :inactive overlay))))
 444
 445 (defun widget-overlay-inactive (&rest junk)
 446   "Ignoring the arguments, signal an error."
 447   (unless inhibit-read-only
 448     (error "The widget here is not active")))
 449
 450
 451 (defun widget-specify-active (widget)
 452   "Make WIDGET active for user modifications."
 453   (let ((inactive (widget-get widget :inactive)))
 454     (when inactive
 455       (delete-overlay inactive)
 456       (widget-put widget :inactive nil))))
 457
 458 ;;; Widget Properties.
 459
 460 (defsubst widget-type (widget)
 461   "Return the type of WIDGET, a symbol."
 462   (car widget))
 463
 464 ;;;###autoload
 465 (defun widgetp (widget)
 466   "Return non-nil iff WIDGET is a widget."
 467   (if (symbolp widget)
 468       (get widget 'widget-type)
 469     (and (consp widget)
 470          (symbolp (car widget))
 471          (get (car widget) 'widget-type))))
 472
 473 (defun widget-get-indirect (widget property)
 474   "In WIDGET, get the value of PROPERTY.
 475 If the value is a symbol, return its binding.
 476 Otherwise, just return the value."
 477   (let ((value (widget-get widget property)))
 478     (if (symbolp value)
 479         (symbol-value value)
 480       value)))
 481
 482 (defun widget-member (widget property)
 483   "Non-nil iff there is a definition in WIDGET for PROPERTY."
 484   (cond ((plist-member (cdr widget) property)
 485          t)
 486         ((car widget)
 487          (widget-member (get (car widget) 'widget-type) property))
 488         (t nil)))
 489
 490 (defun widget-value (widget)
 491   "Extract the current value of WIDGET."
 492   (widget-apply widget
 493                 :value-to-external (widget-apply widget :value-get)))
 494
 495 (defun widget-value-set (widget value)
 496   "Set the current value of WIDGET to VALUE."
 497   (widget-apply widget
 498                 :value-set (widget-apply widget
 499                                          :value-to-internal value)))
 500
 501 (defun widget-default-get (widget)
 502   "Extract the default external value of WIDGET."
 503   (widget-apply widget :value-to-external
 504                 (or (widget-get widget :value)
 505                     (widget-apply widget :default-get))))
 506
 507 (defun widget-match-inline (widget vals)
 508   "In WIDGET, match the start of VALS."
 509   (cond ((widget-get widget :inline)
 510          (widget-apply widget :match-inline vals))
 511         ((and (listp vals)
 512               (widget-apply widget :match (car vals)))
 513          (cons (list (car vals)) (cdr vals)))
 514         (t nil)))
 515
 516 (defun widget-apply-action (widget &optional event)
 517   "Apply :action in WIDGET in response to EVENT."
 518   (if (widget-apply widget :active)
 519       (widget-apply widget :action event)
 520     (error "Attempt to perform action on inactive widget")))
 521
 522 ;;; Helper functions.
 523 ;;
 524 ;; These are widget specific.
 525
 526 ;;;###autoload
 527 (defun widget-prompt-value (widget prompt &optional value unbound)
 528   "Prompt for a value matching WIDGET, using PROMPT.
 529 The current value is assumed to be VALUE, unless UNBOUND is non-nil."
 530   (unless (listp widget)
 531     (setq widget (list widget)))
 532   (setq prompt (format "[%s] %s" (widget-type widget) prompt))
 533   (setq widget (widget-convert widget))
 534   (let ((answer (widget-apply widget :prompt-value prompt value unbound)))
 535     (unless (widget-apply widget :match answer)
 536       (error "Value does not match %S type" (car widget)))
 537     answer))
 538
 539 (defun widget-get-sibling (widget)
 540   "Get the item WIDGET is assumed to toggle.
 541 This is only meaningful for radio buttons or checkboxes in a list."
 542   (let* ((children (widget-get (widget-get widget :parent) :children))
 543          child)
 544     (catch 'child
 545       (while children
 546         (setq child (car children)
 547               children (cdr children))
 548         (when (eq (widget-get child :button) widget)
 549           (throw 'child child)))
 550       nil)))
 551
 552 (defun widget-map-buttons (function &optional buffer maparg)
 553   "Map FUNCTION over the buttons in BUFFER.
 554 FUNCTION is called with the arguments WIDGET and MAPARG.
 555
 556 If FUNCTION returns non-nil, the walk is cancelled.
 557
 558 The arguments MAPARG, and BUFFER default to nil and (current-buffer),
 559 respectively."
 560   (let ((cur (point-min))
 561         (widget nil)
 562         (overlays (if buffer
 563                       (with-current-buffer buffer (overlay-lists))
 564                     (overlay-lists))))
 565     (setq overlays (append (car overlays) (cdr overlays)))
 566     (while (setq cur (pop overlays))
 567       (setq widget (overlay-get cur 'button))
 568       (if (and widget (funcall function widget maparg))
 569           (setq overlays nil)))))
 570
 571 ;;; Images.
 572
 573 (defcustom widget-image-directory (file-name-as-directory
 574                                    (expand-file-name "custom" data-directory))
 575   "Where widget button images are located.
 576 If this variable is nil, widget will try to locate the directory
 577 automatically."
 578   :group 'widgets
 579   :type 'directory)
 580
 581 (defcustom widget-image-enable t
 582   "If non nil, use image buttons in widgets when available."
 583   :version "21.1"
 584   :group 'widgets
 585   :type 'boolean)
 586
 587 (defcustom widget-image-conversion
 588   '((xpm ".xpm") (gif ".gif") (png ".png") (jpeg ".jpg" ".jpeg")
 589     (xbm ".xbm"))
 590   "Conversion alist from image formats to file name suffixes."
 591   :group 'widgets
 592   :type '(repeat (cons :format "%v"
 593                        (symbol :tag "Image Format" unknown)
 594                        (repeat :tag "Suffixes"
 595                                (string :format "%v")))))
 596
 597 (defun widget-image-find (image)
 598   "Create a graphical button from IMAGE.
 599 IMAGE should either already be an image, or be a file name sans
 600 extension (xpm, xbm, gif, jpg, or png) located in
 601 `widget-image-directory' or otherwise where `find-image' will find it."
 602   (cond ((not (and image widget-image-enable (display-graphic-p)))
 603          ;; We don't want or can't use images.
 604          nil)
 605         ((and (consp image)
 606               (eq 'image (car image)))
 607          ;; Already an image spec.  Use it.
 608          image)
 609         ((stringp image)
 610          ;; A string.  Look it up in relevant directories.
 611          (let* ((load-path (cons widget-image-directory load-path))
 612                 specs)
 613            (dolist (elt widget-image-conversion)
 614              (dolist (ext (cdr elt))
 615                (push (list :type (car elt) :file (concat image ext)) specs)))
 616            (setq specs (nreverse specs))
 617            (find-image specs)))
 618         (t
 619          ;; Oh well.
 620          nil)))
 621
 622 (defvar widget-button-pressed-face 'widget-button-pressed-face
 623   "Face used for pressed buttons in widgets.
 624 This exists as a variable so it can be set locally in certain
 625 buffers.")
 626
 627 (defun widget-image-insert (widget tag image &optional down inactive)
 628   "In WIDGET, insert the text TAG or, if supported, IMAGE.
 629 IMAGE should either be an image or an image file name sans extension
 630 \(xpm, xbm, gif, jpg, or png) located in `widget-image-directory'.
 631
 632 Optional arguments DOWN and INACTIVE are used instead of IMAGE when the
 633 button is pressed or inactive, respectively.  These are currently ignored."
 634   (if (and (display-graphic-p)
 635            (setq image (widget-image-find image)))
 636       (progn (widget-put widget :suppress-face t)
 637              (insert-image image
 638                            (propertize
 639                             tag 'mouse-face widget-button-pressed-face)))
 640     (insert tag)))
 641
 642 ;;; Buttons.
 643
 644 (defgroup widget-button nil
 645   "The look of various kinds of buttons."
 646   :group 'widgets)
 647
 648 (defcustom widget-button-prefix ""
 649   "String used as prefix for buttons."
 650   :type 'string
 651   :group 'widget-button)
 652
 653 (defcustom widget-button-suffix ""
 654   "String used as suffix for buttons."
 655   :type 'string
 656   :group 'widget-button)
 657
 658 ;;; Creating Widgets.
 659
 660 ;;;###autoload
 661 (defun widget-create (type &rest args)
 662   "Create widget of TYPE.
 663 The optional ARGS are additional keyword arguments."
 664   (let ((widget (apply 'widget-convert type args)))
 665     (widget-apply widget :create)
 666     widget))
 667
 668 (defun widget-create-child-and-convert (parent type &rest args)
 669   "As part of the widget PARENT, create a child widget TYPE.
 670 The child is converted, using the keyword arguments ARGS."
 671   (let ((widget (apply 'widget-convert type args)))
 672     (widget-put widget :parent parent)
 673     (unless (widget-get widget :indent)
 674       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 675                                     (or (widget-get widget :extra-offset) 0)
 676                                     (widget-get parent :offset))))
 677     (widget-apply widget :create)
 678     widget))
 679
 680 (defun widget-create-child (parent type)
 681   "Create widget of TYPE."
 682   (let ((widget (widget-copy type)))
 683     (widget-put widget :parent parent)
 684     (unless (widget-get widget :indent)
 685       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 686                                     (or (widget-get widget :extra-offset) 0)
 687                                     (widget-get parent :offset))))
 688     (widget-apply widget :create)
 689     widget))
 690
 691 (defun widget-create-child-value (parent type value)
 692   "Create widget of TYPE with value VALUE."
 693   (let ((widget (widget-copy type)))
 694     (widget-put widget :value (widget-apply widget :value-to-internal value))
 695     (widget-put widget :parent parent)
 696     (unless (widget-get widget :indent)
 697       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 698                                     (or (widget-get widget :extra-offset) 0)
 699                                     (widget-get parent :offset))))
 700     (widget-apply widget :create)
 701     widget))
 702
 703 ;;;###autoload
 704 (defun widget-delete (widget)
 705   "Delete WIDGET."
 706   (widget-apply widget :delete))
 707
 708 (defun widget-copy (widget)
 709   "Make a deep copy of WIDGET."
 710   (widget-apply (copy-sequence widget) :copy))
 711
 712 (defun widget-convert (type &rest args)
 713   "Convert TYPE to a widget without inserting it in the buffer.
 714 The optional ARGS are additional keyword arguments."
 715   ;; Don't touch the type.
 716   (let* ((widget (if (symbolp type)
 717                      (list type)
 718                    (copy-sequence type)))
 719          (current widget)
 720          done
 721          (keys args))
 722     ;; First set the :args keyword.
 723     (while (cdr current)                ;Look in the type.
 724       (if (and (keywordp (cadr current))
 725                ;; If the last element is a keyword,
 726                ;; it is still the :args element,
 727                ;; even though it is a keyword.
 728                (cddr current))
 729           (if (eq (cadr current) :args)
 730               ;; If :args is explicitly specified, obey it.
 731               (setq current nil)
 732             ;; Some other irrelevant keyword.
 733             (setq current (cdr (cdr current))))
 734         (setcdr current (list :args (cdr current)))
 735         (setq current nil)))
 736     (while (and args (not done))        ;Look in ARGS.
 737       (cond ((eq (car args) :args)
 738              ;; Handle explicit specification of :args.
 739              (setq args (cadr args)
 740                    done t))
 741             ((keywordp (car args))
 742              (setq args (cddr args)))
 743             (t (setq done t))))
 744     (when done
 745       (widget-put widget :args args))
 746     ;; Then Convert the widget.
 747     (setq type widget)
 748     (while type
 749       (let ((convert-widget (plist-get (cdr type) :convert-widget)))
 750         (if convert-widget
 751             (setq widget (funcall convert-widget widget))))
 752       (setq type (get (car type) 'widget-type)))
 753     ;; Finally set the keyword args.
 754     (while keys
 755       (let ((next (nth 0 keys)))
 756         (if (keywordp next)
 757             (progn
 758               (widget-put widget next (nth 1 keys))
 759               (setq keys (nthcdr 2 keys)))
 760           (setq keys nil))))
 761     ;; Convert the :value to internal format.
 762     (if (widget-member widget :value)
 763         (widget-put widget
 764                     :value (widget-apply widget
 765                                          :value-to-internal
 766                                          (widget-get widget :value))))
 767     ;; Return the newly create widget.
 768     widget))
 769
 770 ;;;###autoload
 771 (defun widget-insert (&rest args)
 772   "Call `insert' with ARGS even if surrounding text is read only."
 773   (let ((inhibit-read-only t)
 774         (inhibit-modification-hooks t))
 775     (apply 'insert args)))
 776
 777 (defun widget-convert-text (type from to
 778                                  &optional button-from button-to
 779                                  &rest args)
 780   "Return a widget of type TYPE with endpoint FROM TO.
 781 Optional ARGS are extra keyword arguments for TYPE.
 782 and TO will be used as the widgets end points. If optional arguments
 783 BUTTON-FROM and BUTTON-TO are given, these will be used as the widgets
 784 button end points.
 785 Optional ARGS are extra keyword arguments for TYPE."
 786   (let ((widget (apply 'widget-convert type :delete 'widget-leave-text args))
 787         (from (copy-marker from))
 788         (to (copy-marker to)))
 789     (set-marker-insertion-type from t)
 790     (set-marker-insertion-type to nil)
 791     (widget-put widget :from from)
 792     (widget-put widget :to to)
 793     (when button-from
 794       (widget-specify-button widget button-from button-to))
 795     widget))
 796
 797 (defun widget-convert-button (type from to &rest args)
 798   "Return a widget of type TYPE with endpoint FROM TO.
 799 Optional ARGS are extra keyword arguments for TYPE.
 800 No text will be inserted to the buffer, instead the text between FROM
 801 and TO will be used as the widgets end points, as well as the widgets
 802 button end points."
 803   (apply 'widget-convert-text type from to from to args))
 804
 805 (defun widget-leave-text (widget)
 806   "Remove markers and overlays from WIDGET and its children."
 807   (let ((button (widget-get widget :button-overlay))
 808         (sample (widget-get widget :sample-overlay))
 809         (doc (widget-get widget :doc-overlay))
 810         (field (widget-get widget :field-overlay)))
 811     (set-marker (widget-get widget :from) nil)
 812     (set-marker (widget-get widget :to) nil)
 813     (when button
 814       (delete-overlay button))
 815     (when sample
 816       (delete-overlay sample))
 817     (when doc
 818       (delete-overlay doc))
 819     (when field
 820       (delete-overlay field))
 821     (mapc 'widget-leave-text (widget-get widget :children))))
 822
 823 ;;; Keymap and Commands.
 824
 825 ;;;###autoload
 826 (defvar widget-keymap
 827   (let ((map (make-sparse-keymap)))
 828     (define-key map "\t" 'widget-forward)
 829     (define-key map [(shift tab)] 'widget-backward)
 830     (define-key map [backtab] 'widget-backward)
 831     (define-key map [down-mouse-2] 'widget-button-click)
 832     (define-key map "\C-m" 'widget-button-press)
 833     map)
 834   "Keymap containing useful binding for buffers containing widgets.
 835 Recommended as a parent keymap for modes using widgets.")
 836
 837 (defvar widget-global-map global-map
 838   "Keymap used for events a widget does not handle itself.")
 839 (make-variable-buffer-local 'widget-global-map)
 840
 841 (defvar widget-field-keymap
 842   (let ((map (copy-keymap widget-keymap)))
 843     (define-key map "\C-k" 'widget-kill-line)
 844     (define-key map "\M-\t" 'widget-complete)
 845     (define-key map "\C-m" 'widget-field-activate)
 846     ;; Since the widget code uses a `field' property to identify fields,
 847     ;; ordinary beginning-of-line does the right thing.
 848     ;;  (define-key map "\C-a" 'widget-beginning-of-line)
 849     (define-key map "\C-e" 'widget-end-of-line)
 850     map)
 851   "Keymap used inside an editable field.")
 852
 853 (defvar widget-text-keymap
 854   (let ((map (copy-keymap widget-keymap)))
 855     ;; Since the widget code uses a `field' property to identify fields,
 856     ;; ordinary beginning-of-line does the right thing.
 857     ;;  (define-key map "\C-a" 'widget-beginning-of-line)
 858     (define-key map "\C-e" 'widget-end-of-line)
 859     map)
 860   "Keymap used inside a text field.")
 861
 862 (defun widget-field-activate (pos &optional event)
 863   "Invoke the editable field at point."
 864   (interactive "@d")
 865   (let ((field (widget-field-at pos)))
 866     (if field
 867         (widget-apply-action field event)
 868       (call-interactively
 869        (lookup-key widget-global-map (this-command-keys))))))
 870
 871 (defface widget-button-pressed-face
 872   '((((class color))
 873      (:foreground "red"))
 874     (t
 875      (:weight bold :underline t)))
 876   "Face used for pressed buttons."
 877   :group 'widget-faces)
 878
 879 (defun widget-button-click (event)
 880   "Invoke the button that the mouse is pointing at."
 881   (interactive "e")
 882   (if (widget-event-point event)
 883       (let* ((pos (widget-event-point event))
 884              (start (event-start event))
 885              (button (get-char-property
 886                       pos 'button (and (windowp (posn-window start))
 887                                        (window-buffer (posn-window start))))))
 888         (if button
 889             ;; Mouse click on a widget button.  Do the following
 890             ;; in a save-excursion so that the click on the button
 891             ;; doesn't change point.
 892             (save-selected-window
 893               (select-window (posn-window (event-start event)))
 894               (save-excursion
 895                 (goto-char (posn-point (event-start event)))
 896                 (let* ((overlay (widget-get button :button-overlay))
 897                        (face (overlay-get overlay 'face))
 898                        (mouse-face (overlay-get overlay 'mouse-face)))
 899                   (unwind-protect
 900                       ;; Read events, including mouse-movement events
 901                       ;; until we receive a release event.  Highlight/
 902                       ;; unhighlight the button the mouse was initially
 903                       ;; on when we move over it.
 904                       (let ((track-mouse t))
 905                         (save-excursion
 906                           (when face    ; avoid changing around image
 907                             (overlay-put overlay
 908                                          'face widget-button-pressed-face)
 909                             (overlay-put overlay
 910                                          'mouse-face widget-button-pressed-face))
 911                           (unless (widget-apply button :mouse-down-action event)
 912                             (while (not (widget-button-release-event-p event))
 913                               (setq event (read-event)
 914                                     pos (widget-event-point event))
 915                               (if (and pos
 916                                        (eq (get-char-property pos 'button)
 917                                            button))
 918                                   (when face
 919                                     (overlay-put overlay
 920                                                  'face
 921                                                  widget-button-pressed-face)
 922                                     (overlay-put overlay
 923                                                  'mouse-face
 924                                                  widget-button-pressed-face))
 925                                 (overlay-put overlay 'face face)
 926                                 (overlay-put overlay 'mouse-face mouse-face))))
 927
 928                           ;; When mouse is released over the button, run
 929                           ;; its action function.
 930                           (when (and pos
 931                                      (eq (get-char-property pos 'button) button))
 932                             (widget-apply-action button event))))
 933                     (overlay-put overlay 'face face)
 934                     (overlay-put overlay 'mouse-face mouse-face))))
 935
 936               (unless (pos-visible-in-window-p (widget-event-point event))
 937                 (mouse-set-point event)
 938                 (beginning-of-line)
 939                 (recenter))
 940               )
 941
 942             (let ((up t) command)
 943               ;; Mouse click not on a widget button.  Find the global
 944               ;; command to run, and check whether it is bound to an
 945               ;; up event.
 946               (mouse-set-point event)
 947               (if (memq (event-basic-type event) '(mouse-1 down-mouse-1))
 948                   (cond ((setq command  ;down event
 949                                (lookup-key widget-global-map [down-mouse-1]))
 950                          (setq up nil))
 951                         ((setq command  ;up event
 952                                (lookup-key widget-global-map [mouse-1]))))
 953                 (cond ((setq command    ;down event
 954                              (lookup-key widget-global-map [down-mouse-2]))
 955                        (setq up nil))
 956                       ((setq command    ;up event
 957                              (lookup-key widget-global-map [mouse-2])))))
 958               (when up
 959                 ;; Don't execute up events twice.
 960                 (while (not (widget-button-release-event-p event))
 961                   (setq event (read-event))))
 962               (when command
 963                 (call-interactively command)))))
 964     (message "You clicked somewhere weird.")))
 965
 966 (defun widget-button-press (pos &optional event)
 967   "Invoke button at POS."
 968   (interactive "@d")
 969   (let ((button (get-char-property pos 'button)))
 970     (if button
 971         (widget-apply-action button event)
 972       (let ((command (lookup-key widget-global-map (this-command-keys))))
 973         (when (commandp command)
 974           (call-interactively command))))))
 975
 976 (defun widget-tabable-at (&optional pos)
 977   "Return the tabable widget at POS, or nil.
 978 POS defaults to the value of (point)."
 979   (let ((widget (widget-at pos)))
 980     (if widget
 981         (let ((order (widget-get widget :tab-order)))
 982           (if order
 983               (if (>= order 0)
 984                   widget)
 985             widget)))))
 986
 987 (defvar widget-use-overlay-change t
 988   "If non-nil, use overlay change functions to tab around in the buffer.
 989 This is much faster, but doesn't work reliably on Emacs 19.34.")
 990
 991 (defun widget-move (arg)
 992   "Move point to the ARG next field or button.
 993 ARG may be negative to move backward."
 994   (or (bobp) (> arg 0) (backward-char))
 995   (let ((wrapped 0)
 996         (number arg)
 997         (old (widget-tabable-at)))
 998     ;; Forward.
 999     (while (> arg 0)
1000       (cond ((eobp)
1001              (goto-char (point-min))
1002              (setq wrapped (1+ wrapped)))
1003             (widget-use-overlay-change
1004              (goto-char (next-overlay-change (point))))
1005             (t
1006              (forward-char 1)))
1007       (and (= wrapped 2)
1008            (eq arg number)
1009            (error "No buttons or fields found"))
1010       (let ((new (widget-tabable-at)))
1011         (when new
1012           (unless (eq new old)
1013             (setq arg (1- arg))
1014             (setq old new)))))
1015     ;; Backward.
1016     (while (< arg 0)
1017       (cond ((bobp)
1018              (goto-char (point-max))
1019              (setq wrapped (1+ wrapped)))
1020             (widget-use-overlay-change
1021              (goto-char (previous-overlay-change (point))))
1022             (t
1023              (backward-char 1)))
1024       (and (= wrapped 2)
1025            (eq arg number)
1026            (error "No buttons or fields found"))
1027       (let ((new (widget-tabable-at)))
1028         (when new
1029           (unless (eq new old)
1030             (setq arg (1+ arg))))))
1031     (let ((new (widget-tabable-at)))
1032       (while (eq (widget-tabable-at) new)
1033         (backward-char)))
1034     (forward-char))
1035   (widget-echo-help (point))
1036   (run-hooks 'widget-move-hook))
1037
1038 (defun widget-forward (arg)
1039   "Move point to the next field or button.
1040 With optional ARG, move across that many fields."
1041   (interactive "p")
1042   (run-hooks 'widget-forward-hook)
1043   (widget-move arg))
1044
1045 (defun widget-backward (arg)
1046   "Move point to the previous field or button.
1047 With optional ARG, move across that many fields."
1048   (interactive "p")
1049   (run-hooks 'widget-backward-hook)
1050   (widget-move (- arg)))
1051
1052 ;; Since the widget code uses a `field' property to identify fields,
1053 ;; ordinary beginning-of-line does the right thing.
1054 (defalias 'widget-beginning-of-line 'beginning-of-line)
1055
1056 (defun widget-end-of-line ()
1057   "Go to end of field or end of line, whichever is first.
1058 Trailing spaces at the end of padded fields are not considered part of
1059 the field."
1060   (interactive)
1061   ;; Ordinary end-of-line does the right thing, because we're inside
1062   ;; text with a `field' property.
1063   (end-of-line)
1064   (unless (eolp)
1065     ;; ... except that we want to ignore trailing spaces in fields that
1066     ;; aren't terminated by a newline, because they are used as padding,
1067     ;; and ignored when extracting the entered value of the field.
1068     (skip-chars-backward " " (field-beginning (1- (point))))))
1069
1070 (defun widget-kill-line ()
1071   "Kill to end of field or end of line, whichever is first."
1072   (interactive)
1073   (let* ((field (widget-field-find (point)))
1074          (end (and field (widget-field-end field))))
1075     (if (and field (> (line-beginning-position 2) end))
1076         (kill-region (point) end)
1077       (call-interactively 'kill-line))))
1078
1079 (defcustom widget-complete-field (lookup-key global-map "\M-\t")
1080   "Default function to call for completion inside fields."
1081   :options '(ispell-complete-word complete-tag lisp-complete-symbol)
1082   :type 'function
1083   :group 'widgets)
1084
1085 (defun widget-complete ()
1086   "Complete content of editable field from point.
1087 When not inside a field, move to the previous button or field."
1088   (interactive)
1089   (let ((field (widget-field-find (point))))
1090     (if field
1091         (widget-apply field :complete)
1092       (error "Not in an editable field"))))
1093
1094 ;;; Setting up the buffer.
1095
1096 (defvar widget-field-new nil
1097   "List of all newly created editable fields in the buffer.")
1098 (make-variable-buffer-local 'widget-field-new)
1099
1100 (defvar widget-field-list nil
1101   "List of all editable fields in the buffer.")
1102 (make-variable-buffer-local 'widget-field-list)
1103
1104 (defun widget-at (&optional pos)
1105   "The button or field at POS (default, point)."
1106   (or (get-char-property (or pos (point)) 'button)
1107       (widget-field-at pos)))
1108
1109 ;;;###autoload
1110 (defun widget-setup ()
1111   "Setup current buffer so editing string widgets works."
1112   (let ((inhibit-read-only t)
1113         (inhibit-modification-hooks t)
1114         field)
1115     (while widget-field-new
1116       (setq field (car widget-field-new)
1117             widget-field-new (cdr widget-field-new)
1118             widget-field-list (cons field widget-field-list))
1119       (let ((from (car (widget-get field :field-overlay)))
1120             (to (cdr (widget-get field :field-overlay))))
1121         (widget-specify-field field
1122                               (marker-position from) (marker-position to))
1123         (set-marker from nil)
1124         (set-marker to nil))))
1125   (widget-clear-undo)
1126   (widget-add-change))
1127
1128 (defvar widget-field-last nil)
1129 ;; Last field containing point.
1130 (make-variable-buffer-local 'widget-field-last)
1131
1132 (defvar widget-field-was nil)
1133 ;; The widget data before the change.
1134 (make-variable-buffer-local 'widget-field-was)
1135
1136 (defun widget-field-at (pos)
1137   "Return the widget field at POS, or nil if none."
1138   (let ((field (get-char-property (or pos (point)) 'field)))
1139     (if (eq field 'boundary)
1140         nil
1141       field)))
1142
1143 (defun widget-field-buffer (widget)
1144   "Return the start of WIDGET's editing field."
1145   (let ((overlay (widget-get widget :field-overlay)))
1146     (cond ((overlayp overlay)
1147            (overlay-buffer overlay))
1148           ((consp overlay)
1149            (marker-buffer (car overlay))))))
1150
1151 (defun widget-field-start (widget)
1152   "Return the start of WIDGET's editing field."
1153   (let ((overlay (widget-get widget :field-overlay)))
1154     (if (overlayp overlay)
1155         (overlay-start overlay)
1156       (car overlay))))
1157
1158 (defun widget-field-end (widget)
1159   "Return the end of WIDGET's editing field."
1160   (let ((overlay (widget-get widget :field-overlay)))
1161     ;; Don't subtract one if local-map works at the end of the overlay,
1162     ;; or if a special `boundary' field has been added after the widget
1163     ;; field.
1164     (if (overlayp overlay)
1165         (if (and (not (eq (get-char-property (overlay-end overlay)
1166                                              'field
1167                                              (widget-field-buffer widget))
1168                           'boundary))
1169                  (or widget-field-add-space
1170                      (null (widget-get widget :size))))
1171             (1- (overlay-end overlay))
1172           (overlay-end overlay))
1173       (cdr overlay))))
1174
1175 (defun widget-field-find (pos)
1176   "Return the field at POS.
1177 Unlike (get-char-property POS 'field) this, works with empty fields too."
1178   (let ((fields widget-field-list)
1179         field found)
1180     (while fields
1181       (setq field (car fields)
1182             fields (cdr fields))
1183       (when (and (<= (widget-field-start field) pos)
1184                  (<= pos (widget-field-end field)))
1185         (when found
1186           (error "Overlapping fields"))
1187         (setq found field)))
1188     found))
1189
1190 (defun widget-before-change (from to)
1191   ;; This is how, for example, a variable changes its state to `modified'.
1192   ;; when it is being edited.
1193   (unless inhibit-read-only
1194     (let ((from-field (widget-field-find from))
1195           (to-field (widget-field-find to)))
1196       (cond ((not (eq from-field to-field))
1197              (add-hook 'post-command-hook 'widget-add-change nil t)
1198              (signal 'text-read-only
1199                      '("Change should be restricted to a single field")))
1200             ((null from-field)
1201              (add-hook 'post-command-hook 'widget-add-change nil t)
1202              (signal 'text-read-only
1203                      '("Attempt to change text outside editable field")))
1204             (widget-field-use-before-change
1205              (widget-apply from-field :notify from-field))))))
1206
1207 (defun widget-add-change ()
1208   (remove-hook 'post-command-hook 'widget-add-change t)
1209   (add-hook 'before-change-functions 'widget-before-change nil t)
1210   (add-hook 'after-change-functions 'widget-after-change nil t))
1211
1212 (defun widget-after-change (from to old)
1213   "Adjust field size and text properties."
1214   (let ((field (widget-field-find from))
1215         (other (widget-field-find to)))
1216     (when field
1217       (unless (eq field other)
1218         (error "Change in different fields"))
1219       (let ((size (widget-get field :size)))
1220         (when size
1221           (let ((begin (widget-field-start field))
1222                 (end (widget-field-end field)))
1223             (cond ((< (- end begin) size)
1224                    ;; Field too small.
1225                    (save-excursion
1226                      (goto-char end)
1227                      (insert-char ?\  (- (+ begin size) end))))
1228                   ((> (- end begin) size)
1229                    ;; Field too large and
1230                    (if (or (< (point) (+ begin size))
1231                            (> (point) end))
1232                        ;; Point is outside extra space.
1233                        (setq begin (+ begin size))
1234                      ;; Point is within the extra space.
1235                      (setq begin (point)))
1236                    (save-excursion
1237                      (goto-char end)
1238                      (while (and (eq (preceding-char) ?\ )
1239                                  (> (point) begin))
1240                        (delete-backward-char 1)))))))
1241         (widget-specify-secret field))
1242       (widget-apply field :notify field))))
1243
1244 ;;; Widget Functions
1245 ;;
1246 ;; These functions are used in the definition of multiple widgets.
1247
1248 (defun widget-parent-action (widget &optional event)
1249   "Tell :parent of WIDGET to handle the :action.
1250 Optional EVENT is the event that triggered the action."
1251   (widget-apply (widget-get widget :parent) :action event))
1252
1253 (defun widget-children-value-delete (widget)
1254   "Delete all :children and :buttons in WIDGET."
1255   (mapc 'widget-delete (widget-get widget :children))
1256   (widget-put widget :children nil)
1257   (mapc 'widget-delete (widget-get widget :buttons))
1258   (widget-put widget :buttons nil))
1259
1260 (defun widget-children-validate (widget)
1261   "All the :children must be valid."
1262   (let ((children (widget-get widget :children))
1263         child found)
1264     (while (and children (not found))
1265       (setq child (car children)
1266             children (cdr children)
1267             found (widget-apply child :validate)))
1268     found))
1269
1270 (defun widget-types-copy (widget)
1271   "Copy :args as widget types in WIDGET."
1272   (widget-put widget :args (mapcar 'widget-copy (widget-get widget :args)))
1273   widget)
1274
1275 ;; Made defsubst to speed up face editor creation.
1276 (defsubst widget-types-convert-widget (widget)
1277   "Convert :args as widget types in WIDGET."
1278   (widget-put widget :args (mapcar 'widget-convert (widget-get widget :args)))
1279   widget)
1280
1281 (defun widget-value-convert-widget (widget)
1282   "Initialize :value from :args in WIDGET."
1283   (let ((args (widget-get widget :args)))
1284     (when args
1285       (widget-put widget :value (car args))
1286       ;; Don't convert :value here, as this is done in `widget-convert'.
1287       ;; (widget-put widget :value (widget-apply widget
1288       ;;                                      :value-to-internal (car args)))
1289       (widget-put widget :args nil)))
1290   widget)
1291
1292 (defun widget-value-value-get (widget)
1293   "Return the :value property of WIDGET."
1294   (widget-get widget :value))
1295
1296 ;;; The `default' Widget.
1297
1298 (define-widget 'default nil
1299   "Basic widget other widgets are derived from."
1300   :value-to-internal (lambda (widget value) value)
1301   :value-to-external (lambda (widget value) value)
1302   :button-prefix 'widget-button-prefix
1303   :button-suffix 'widget-button-suffix
1304   :complete 'widget-default-complete
1305   :create 'widget-default-create
1306   :indent nil
1307   :offset 0
1308   :format-handler 'widget-default-format-handler
1309   :button-face-get 'widget-default-button-face-get
1310   :sample-face-get 'widget-default-sample-face-get
1311   :delete 'widget-default-delete
1312   :copy 'identity
1313   :value-set 'widget-default-value-set
1314   :value-inline 'widget-default-value-inline
1315   :default-get 'widget-default-default-get
1316   :menu-tag-get 'widget-default-menu-tag-get
1317   :validate #'ignore
1318   :active 'widget-default-active
1319   :activate 'widget-specify-active
1320   :deactivate 'widget-default-deactivate
1321   :mouse-down-action #'ignore
1322   :action 'widget-default-action
1323   :notify 'widget-default-notify
1324   :prompt-value 'widget-default-prompt-value)
1325
1326 (defun widget-default-complete (widget)
1327   "Call the value of the :complete-function property of WIDGET.
1328 If that does not exists, call the value of `widget-complete-field'."
1329   (call-interactively (or (widget-get widget :complete-function)
1330                           widget-complete-field)))
1331
1332 (defun widget-default-create (widget)
1333   "Create WIDGET at point in the current buffer."
1334   (widget-specify-insert
1335    (let ((from (point))
1336          button-begin button-end
1337          sample-begin sample-end
1338          doc-begin doc-end
1339          value-pos)
1340      (insert (widget-get widget :format))
1341      (goto-char from)
1342      ;; Parse escapes in format.
1343      (while (re-search-forward "%\\(.\\)" nil t)
1344        (let ((escape (char-after (match-beginning 1))))
1345          (delete-backward-char 2)
1346          (cond ((eq escape ?%)
1347                 (insert ?%))
1348                ((eq escape ?\[)
1349                 (setq button-begin (point))
1350                 (insert (widget-get-indirect widget :button-prefix)))
1351                ((eq escape ?\])
1352                 (insert (widget-get-indirect widget :button-suffix))
1353                 (setq button-end (point)))
1354                ((eq escape ?\{)
1355                 (setq sample-begin (point)))
1356                ((eq escape ?\})
1357                 (setq sample-end (point)))
1358                ((eq escape ?n)
1359                 (when (widget-get widget :indent)
1360                   (insert ?\n)
1361                   (insert-char ?  (widget-get widget :indent))))
1362                ((eq escape ?t)
1363                 (let ((image (widget-get widget :tag-glyph))
1364                       (tag (widget-get widget :tag)))
1365                   (cond (image
1366                          (widget-image-insert widget (or tag "image") image))
1367                         (tag
1368                          (insert tag))
1369                         (t
1370                          (princ (widget-get widget :value)
1371                                 (current-buffer))))))
1372                ((eq escape ?d)
1373                 (let ((doc (widget-get widget :doc)))
1374                   (when doc
1375                     (setq doc-begin (point))
1376                     (insert doc)
1377                     (while (eq (preceding-char) ?\n)
1378                       (delete-backward-char 1))
1379                     (insert ?\n)
1380                     (setq doc-end (point)))))
1381                ((eq escape ?v)
1382                 (if (and button-begin (not button-end))
1383                     (widget-apply widget :value-create)
1384                   (setq value-pos (point))))
1385                (t
1386                 (widget-apply widget :format-handler escape)))))
1387      ;; Specify button, sample, and doc, and insert value.
1388      (and button-begin button-end
1389           (widget-specify-button widget button-begin button-end))
1390      (and sample-begin sample-end
1391           (widget-specify-sample widget sample-begin sample-end))
1392      (and doc-begin doc-end
1393           (widget-specify-doc widget doc-begin doc-end))
1394      (when value-pos
1395        (goto-char value-pos)
1396        (widget-apply widget :value-create)))
1397    (let ((from (point-min-marker))
1398          (to (point-max-marker)))
1399      (set-marker-insertion-type from t)
1400      (set-marker-insertion-type to nil)
1401      (widget-put widget :from from)
1402      (widget-put widget :to to)))
1403   (widget-clear-undo))
1404
1405 (defun widget-default-format-handler (widget escape)
1406   ;; We recognize the %h escape by default.
1407   (let* ((buttons (widget-get widget :buttons)))
1408     (cond ((eq escape ?h)
1409            (let* ((doc-property (widget-get widget :documentation-property))
1410                   (doc-try (cond ((widget-get widget :doc))
1411                                  ((functionp doc-property)
1412                                   (funcall doc-property
1413                                            (widget-get widget :value)))
1414                                  ((symbolp doc-property)
1415                                   (documentation-property
1416                                    (widget-get widget :value)
1417                                    doc-property))))
1418                   (doc-text (and (stringp doc-try)
1419                                  (> (length doc-try) 1)
1420                                  doc-try))
1421                   (doc-indent (widget-get widget :documentation-indent)))
1422              (when doc-text
1423                (and (eq (preceding-char) ?\n)
1424                     (widget-get widget :indent)
1425                     (insert-char ?  (widget-get widget :indent)))
1426                ;; The `*' in the beginning is redundant.
1427                (when (eq (aref doc-text  0) ?*)
1428                  (setq doc-text (substring doc-text 1)))
1429                ;; Get rid of trailing newlines.
1430                (when (string-match "\n+\\'" doc-text)
1431                  (setq doc-text (substring doc-text 0 (match-beginning 0))))
1432                (push (widget-create-child-and-convert
1433                       widget 'documentation-string
1434                       :indent (cond ((numberp doc-indent )
1435                                      doc-indent)
1436                                     ((null doc-indent)
1437                                      nil)
1438                                     (t 0))
1439                       doc-text)
1440                      buttons))))
1441           (t
1442            (error "Unknown escape `%c'" escape)))
1443     (widget-put widget :buttons buttons)))
1444
1445 (defun widget-default-button-face-get (widget)
1446   ;; Use :button-face or widget-button-face
1447   (or (widget-get widget :button-face)
1448       (let ((parent (widget-get widget :parent)))
1449         (if parent
1450             (widget-apply parent :button-face-get)
1451           widget-button-face))))
1452
1453 (defun widget-default-sample-face-get (widget)
1454   ;; Use :sample-face.
1455   (widget-get widget :sample-face))
1456
1457 (defun widget-default-delete (widget)
1458   "Remove widget from the buffer."
1459   (let ((from (widget-get widget :from))
1460         (to (widget-get widget :to))
1461         (inactive-overlay (widget-get widget :inactive))
1462         (button-overlay (widget-get widget :button-overlay))
1463         (sample-overlay (widget-get widget :sample-overlay))
1464         (doc-overlay (widget-get widget :doc-overlay))
1465         (inhibit-modification-hooks t)
1466         (inhibit-read-only t))
1467     (widget-apply widget :value-delete)
1468     (when inactive-overlay
1469       (delete-overlay inactive-overlay))
1470     (when button-overlay
1471       (delete-overlay button-overlay))
1472     (when sample-overlay
1473       (delete-overlay sample-overlay))
1474     (when doc-overlay
1475       (delete-overlay doc-overlay))
1476     (when (< from to)
1477       ;; Kludge: this doesn't need to be true for empty formats.
1478       (delete-region from to))
1479     (set-marker from nil)
1480     (set-marker to nil))
1481   (widget-clear-undo))
1482
1483 (defun widget-default-value-set (widget value)
1484   "Recreate widget with new value."
1485   (let* ((old-pos (point))
1486          (from (copy-marker (widget-get widget :from)))
1487          (to (copy-marker (widget-get widget :to)))
1488          (offset (if (and (<= from old-pos) (<= old-pos to))
1489                      (if (>= old-pos (1- to))
1490                          (- old-pos to 1)
1491                        (- old-pos from)))))
1492     ;;??? Bug: this ought to insert the new value before deleting the old one,
1493     ;; so that markers on either side of the value automatically
1494     ;; stay on the same side.  -- rms.
1495     (save-excursion
1496       (goto-char (widget-get widget :from))
1497       (widget-apply widget :delete)
1498       (widget-put widget :value value)
1499       (widget-apply widget :create))
1500     (if offset
1501         (if (< offset 0)
1502             (goto-char (+ (widget-get widget :to) offset 1))
1503           (goto-char (min (+ from offset) (1- (widget-get widget :to))))))))
1504
1505 (defun widget-default-value-inline (widget)
1506   "Wrap value in a list unless it is inline."
1507   (if (widget-get widget :inline)
1508       (widget-value widget)
1509     (list (widget-value widget))))
1510
1511 (defun widget-default-default-get (widget)
1512   "Get `:value'."
1513   (widget-get widget :value))
1514
1515 (defun widget-default-menu-tag-get (widget)
1516   "Use tag or value for menus."
1517   (or (widget-get widget :menu-tag)
1518       (widget-get widget :tag)
1519       (widget-princ-to-string (widget-get widget :value))))
1520
1521 (defun widget-default-active (widget)
1522   "Return t iff this widget active (user modifiable)."
1523   (or (widget-get widget :always-active)
1524       (and (not (widget-get widget :inactive))
1525            (let ((parent (widget-get widget :parent)))
1526              (or (null parent)
1527                  (widget-apply parent :active))))))
1528
1529 (defun widget-default-deactivate (widget)
1530   "Make WIDGET inactive for user modifications."
1531   (widget-specify-inactive widget
1532                            (widget-get widget :from)
1533                            (widget-get widget :to)))
1534
1535 (defun widget-default-action (widget &optional event)
1536   "Notify the parent when a widget changes."
1537   (let ((parent (widget-get widget :parent)))
1538     (when parent
1539       (widget-apply parent :notify widget event))))
1540
1541 (defun widget-default-notify (widget child &optional event)
1542   "Pass notification to parent."
1543   (widget-default-action widget event))
1544
1545 (defun widget-default-prompt-value (widget prompt value unbound)
1546   "Read an arbitrary value.  Stolen from `set-variable'."
1547 ;; (let ((initial (if unbound
1548 ;; nil
1549 ;; It would be nice if we could do a `(cons val 1)' here.
1550 ;; (prin1-to-string (custom-quote value))))))
1551   (eval-minibuffer prompt))
1552
1553 ;;; The `item' Widget.
1554
1555 (define-widget 'item 'default
1556   "Constant items for inclusion in other widgets."
1557   :convert-widget 'widget-value-convert-widget
1558   :value-create 'widget-item-value-create
1559   :value-delete 'ignore
1560   :value-get 'widget-value-value-get
1561   :match 'widget-item-match
1562   :match-inline 'widget-item-match-inline
1563   :action 'widget-item-action
1564   :format "%t\n")
1565
1566 (defun widget-item-value-create (widget)
1567   "Insert the printed representation of the value."
1568   (princ (widget-get widget :value) (current-buffer)))
1569
1570 (defun widget-item-match (widget value)
1571   ;; Match if the value is the same.
1572   (equal (widget-get widget :value) value))
1573
1574 (defun widget-item-match-inline (widget values)
1575   ;; Match if the value is the same.
1576   (let ((value (widget-get widget :value)))
1577     (and (listp value)
1578          (<= (length value) (length values))
1579          (let ((head (widget-sublist values 0 (length value))))
1580            (and (equal head value)
1581                 (cons head (widget-sublist values (length value))))))))
1582
1583 (defun widget-sublist (list start &optional end)
1584   "Return the sublist of LIST from START to END.
1585 If END is omitted, it defaults to the length of LIST."
1586   (if (> start 0) (setq list (nthcdr start list)))
1587   (if end
1588       (unless (<= end start)
1589         (setq list (copy-sequence list))
1590         (setcdr (nthcdr (- end start 1) list) nil)
1591         list)
1592     (copy-sequence list)))
1593
1594 (defun widget-item-action (widget &optional event)
1595   ;; Just notify itself.
1596   (widget-apply widget :notify widget event))
1597
1598 ;;; The `push-button' Widget.
1599
1600 ;; (defcustom widget-push-button-gui t
1601 ;;   "If non nil, use GUI push buttons when available."
1602 ;;   :group 'widgets
1603 ;;   :type 'boolean)
1604
1605 ;; Cache already created GUI objects.
1606 ;; (defvar widget-push-button-cache nil)
1607
1608 (defcustom widget-push-button-prefix "["
1609   "String used as prefix for buttons."
1610   :type 'string
1611   :group 'widget-button)
1612
1613 (defcustom widget-push-button-suffix "]"
1614   "String used as suffix for buttons."
1615   :type 'string
1616   :group 'widget-button)
1617
1618 (define-widget 'push-button 'item
1619   "A pushable button."
1620   :button-prefix ""
1621   :button-suffix ""
1622   :value-create 'widget-push-button-value-create
1623   :format "%[%v%]")
1624
1625 (defun widget-push-button-value-create (widget)
1626   "Insert text representing the `on' and `off' states."
1627   (let* ((tag (or (widget-get widget :tag)
1628                   (widget-get widget :value)))
1629          (tag-glyph (widget-get widget :tag-glyph))
1630          (text (concat widget-push-button-prefix
1631                        tag widget-push-button-suffix)))
1632     (if tag-glyph
1633         (widget-image-insert widget text tag-glyph)
1634       (insert text))))
1635
1636 ;; (defun widget-gui-action (widget)
1637 ;;   "Apply :action for WIDGET."
1638 ;;   (widget-apply-action widget (this-command-keys)))
1639
1640 ;;; The `link' Widget.
1641
1642 (defcustom widget-link-prefix "["
1643   "String used as prefix for links."
1644   :type 'string
1645   :group 'widget-button)
1646
1647 (defcustom widget-link-suffix "]"
1648   "String used as suffix for links."
1649   :type 'string
1650   :group 'widget-button)
1651
1652 (define-widget 'link 'item
1653   "An embedded link."
1654   :button-prefix 'widget-link-prefix
1655   :button-suffix 'widget-link-suffix
1656   :help-echo "Follow the link."
1657   :format "%[%t%]")
1658
1659 ;;; The `info-link' Widget.
1660
1661 (define-widget 'info-link 'link
1662   "A link to an info file."
1663   :action 'widget-info-link-action)
1664
1665 (defun widget-info-link-action (widget &optional event)
1666   "Open the info node specified by WIDGET."
1667   (info (widget-value widget)))
1668
1669 ;;; The `url-link' Widget.
1670
1671 (define-widget 'url-link 'link
1672   "A link to an www page."
1673   :action 'widget-url-link-action)
1674
1675 (defun widget-url-link-action (widget &optional event)
1676   "Open the url specified by WIDGET."
1677   (browse-url (widget-value widget)))
1678
1679 ;;; The `function-link' Widget.
1680
1681 (define-widget 'function-link 'link
1682   "A link to an Emacs function."
1683   :action 'widget-function-link-action)
1684
1685 (defun widget-function-link-action (widget &optional event)
1686   "Show the function specified by WIDGET."
1687   (describe-function (widget-value widget)))
1688
1689 ;;; The `variable-link' Widget.
1690
1691 (define-widget 'variable-link 'link
1692   "A link to an Emacs variable."
1693   :action 'widget-variable-link-action)
1694
1695 (defun widget-variable-link-action (widget &optional event)
1696   "Show the variable specified by WIDGET."
1697   (describe-variable (widget-value widget)))
1698
1699 ;;; The `file-link' Widget.
1700
1701 (define-widget 'file-link 'link
1702   "A link to a file."
1703   :action 'widget-file-link-action)
1704
1705 (defun widget-file-link-action (widget &optional event)
1706   "Find the file specified by WIDGET."
1707   (find-file (widget-value widget)))
1708
1709 ;;; The `emacs-library-link' Widget.
1710
1711 (define-widget 'emacs-library-link 'link
1712   "A link to an Emacs Lisp library file."
1713   :action 'widget-emacs-library-link-action)
1714
1715 (defun widget-emacs-library-link-action (widget &optional event)
1716   "Find the Emacs Library file specified by WIDGET."
1717   (find-file (locate-library (widget-value widget))))
1718
1719 ;;; The `emacs-commentary-link' Widget.
1720
1721 (define-widget 'emacs-commentary-link 'link
1722   "A link to Commentary in an Emacs Lisp library file."
1723   :action 'widget-emacs-commentary-link-action)
1724
1725 (defun widget-emacs-commentary-link-action (widget &optional event)
1726   "Find the Commentary section of the Emacs file specified by WIDGET."
1727   (finder-commentary (widget-value widget)))
1728
1729 ;;; The `editable-field' Widget.
1730
1731 (define-widget 'editable-field 'default
1732   "An editable text field."
1733   :convert-widget 'widget-value-convert-widget
1734   :keymap widget-field-keymap
1735   :format "%v"
1736   :help-echo "M-TAB: complete field; RET: enter value"
1737   :value ""
1738   :prompt-internal 'widget-field-prompt-internal
1739   :prompt-history 'widget-field-history
1740   :prompt-value 'widget-field-prompt-value
1741   :action 'widget-field-action
1742   :validate 'widget-field-validate
1743   :valid-regexp ""
1744   :error "Field's value doesn't match allowed forms"
1745   :value-create 'widget-field-value-create
1746   :value-delete 'widget-field-value-delete
1747   :value-get 'widget-field-value-get
1748   :match 'widget-field-match)
1749
1750 (defvar widget-field-history nil
1751   "History of field minibuffer edits.")
1752
1753 (defun widget-field-prompt-internal (widget prompt initial history)
1754   "Read string for WIDGET promptinhg with PROMPT.
1755 INITIAL is the initial input and HISTORY is a symbol containing
1756 the earlier input."
1757   (read-string prompt initial history))
1758
1759 (defun widget-field-prompt-value (widget prompt value unbound)
1760   "Prompt for a string."
1761   (widget-apply widget
1762                 :value-to-external
1763                 (widget-apply widget
1764                               :prompt-internal prompt
1765                               (unless unbound
1766                                 (cons (widget-apply widget
1767                                                     :value-to-internal value)
1768                                       0))
1769                               (widget-get widget :prompt-history))))
1770
1771 (defvar widget-edit-functions nil)
1772
1773 (defun widget-field-action (widget &optional event)
1774   "Move to next field."
1775   (widget-forward 1)
1776   (run-hook-with-args 'widget-edit-functions widget))
1777
1778 (defun widget-field-validate (widget)
1779   "Valid if the content matches `:valid-regexp'."
1780   (unless (string-match (widget-get widget :valid-regexp)
1781                         (widget-apply widget :value-get))
1782     widget))
1783
1784 (defun widget-field-value-create (widget)
1785   "Create an editable text field."
1786   (let ((size (widget-get widget :size))
1787         (value (widget-get widget :value))
1788         (from (point))
1789         ;; This is changed to a real overlay in `widget-setup'.  We
1790         ;; need the end points to behave differently until
1791         ;; `widget-setup' is called.
1792         (overlay (cons (make-marker) (make-marker))))
1793     (widget-put widget :field-overlay overlay)
1794     (insert value)
1795     (and size
1796          (< (length value) size)
1797          (insert-char ?\  (- size (length value))))
1798     (unless (memq widget widget-field-list)
1799       (setq widget-field-new (cons widget widget-field-new)))
1800     (move-marker (cdr overlay) (point))
1801     (set-marker-insertion-type (cdr overlay) nil)
1802     (when (null size)
1803       (insert ?\n))
1804     (move-marker (car overlay) from)
1805     (set-marker-insertion-type (car overlay) t)))
1806
1807 (defun widget-field-value-delete (widget)
1808   "Remove the widget from the list of active editing fields."
1809   (setq widget-field-list (delq widget widget-field-list))
1810   (setq widget-field-new (delq widget widget-field-new))
1811   ;; These are nil if the :format string doesn't contain `%v'.
1812   (let ((overlay (widget-get widget :field-overlay)))
1813     (when (overlayp overlay)
1814       (delete-overlay overlay))))
1815
1816 (defun widget-field-value-get (widget)
1817   "Return current text in editing field."
1818   (let ((from (widget-field-start widget))
1819         (to (widget-field-end widget))
1820         (buffer (widget-field-buffer widget))
1821         (size (widget-get widget :size))
1822         (secret (widget-get widget :secret))
1823         (old (current-buffer)))
1824     (if (and from to)
1825         (progn
1826           (set-buffer buffer)
1827           (while (and size
1828                       (not (zerop size))
1829                       (> to from)
1830                       (eq (char-after (1- to)) ?\ ))
1831             (setq to (1- to)))
1832           (let ((result (buffer-substring-no-properties from to)))
1833             (when secret
1834               (let ((index 0))
1835                 (while (< (+ from index) to)
1836                   (aset result index
1837                         (get-char-property (+ from index) 'secret))
1838                   (setq index (1+ index)))))
1839             (set-buffer old)
1840             result))
1841       (widget-get widget :value))))
1842
1843 (defun widget-field-match (widget value)
1844   ;; Match any string.
1845   (stringp value))
1846
1847 ;;; The `text' Widget.
1848
1849 (define-widget 'text 'editable-field
1850   "A multiline text area."
1851   :keymap widget-text-keymap)
1852
1853 ;;; The `menu-choice' Widget.
1854
1855 (define-widget 'menu-choice 'default
1856   "A menu of options."
1857   :convert-widget  'widget-types-convert-widget
1858   :copy 'widget-types-copy
1859   :format "%[%t%]: %v"
1860   :case-fold t
1861   :tag "choice"
1862   :void '(item :format "invalid (%t)\n")
1863   :value-create 'widget-choice-value-create
1864   :value-delete 'widget-children-value-delete
1865   :value-get 'widget-choice-value-get
1866   :value-inline 'widget-choice-value-inline
1867   :default-get 'widget-choice-default-get
1868   :mouse-down-action 'widget-choice-mouse-down-action
1869   :action 'widget-choice-action
1870   :error "Make a choice"
1871   :validate 'widget-choice-validate
1872   :match 'widget-choice-match
1873   :match-inline 'widget-choice-match-inline)
1874
1875 (defun widget-choice-value-create (widget)
1876   "Insert the first choice that matches the value."
1877   (let ((value (widget-get widget :value))
1878         (args (widget-get widget :args))
1879         (explicit (widget-get widget :explicit-choice))
1880         current)
1881     (if (and explicit (equal value (widget-get widget :explicit-choice-value)))
1882         (progn
1883           ;; If the user specified the choice for this value,
1884           ;; respect that choice as long as the value is the same.
1885           (widget-put widget :children (list (widget-create-child-value
1886                                               widget explicit value)))
1887           (widget-put widget :choice explicit))
1888       (while args
1889         (setq current (car args)
1890               args (cdr args))
1891         (when (widget-apply current :match value)
1892           (widget-put widget :children (list (widget-create-child-value
1893                                               widget current value)))
1894           (widget-put widget :choice current)
1895           (setq args nil
1896                 current nil)))
1897       (when current
1898         (let ((void (widget-get widget :void)))
1899           (widget-put widget :children (list (widget-create-child-and-convert
1900                                               widget void :value value)))
1901           (widget-put widget :choice void))))))
1902
1903 (defun widget-choice-value-get (widget)
1904   ;; Get value of the child widget.
1905   (widget-value (car (widget-get widget :children))))
1906
1907 (defun widget-choice-value-inline (widget)
1908   ;; Get value of the child widget.
1909   (widget-apply (car (widget-get widget :children)) :value-inline))
1910
1911 (defun widget-choice-default-get (widget)
1912   ;; Get default for the first choice.
1913   (widget-default-get (car (widget-get widget :args))))
1914
1915 (defcustom widget-choice-toggle nil
1916   "If non-nil, a binary choice will just toggle between the values.
1917 Otherwise, the user will explicitly have to choose between the values
1918 when he invoked the menu."
1919   :type 'boolean
1920   :group 'widgets)
1921
1922 (defun widget-choice-mouse-down-action (widget &optional event)
1923   ;; Return non-nil if we need a menu.
1924   (let ((args (widget-get widget :args))
1925         (old (widget-get widget :choice)))
1926     (cond ((not (display-popup-menus-p))
1927            ;; No place to pop up a menu.
1928            nil)
1929           ((< (length args) 2)
1930            ;; Empty or singleton list, just return the value.
1931            nil)
1932           ((> (length args) widget-menu-max-size)
1933            ;; Too long, prompt.
1934            nil)
1935           ((> (length args) 2)
1936            ;; Reasonable sized list, use menu.
1937            t)
1938           ((and widget-choice-toggle (memq old args))
1939            ;; We toggle.
1940            nil)
1941           (t
1942            ;; Ask which of the two.
1943            t))))
1944
1945 (defun widget-choice-action (widget &optional event)
1946   ;; Make a choice.
1947   (let ((args (widget-get widget :args))
1948         (old (widget-get widget :choice))
1949         (tag (widget-apply widget :menu-tag-get))
1950         (completion-ignore-case (widget-get widget :case-fold))
1951         this-explicit
1952         current choices)
1953     ;; Remember old value.
1954     (if (and old (not (widget-apply widget :validate)))
1955         (let* ((external (widget-value widget))
1956                (internal (widget-apply old :value-to-internal external)))
1957           (widget-put old :value internal)))
1958     ;; Find new choice.
1959     (setq current
1960           (cond ((= (length args) 0)
1961                  nil)
1962                 ((= (length args) 1)
1963                  (nth 0 args))
1964                 ((and widget-choice-toggle
1965                       (= (length args) 2)
1966                       (memq old args))
1967                  (if (eq old (nth 0 args))
1968                      (nth 1 args)
1969                    (nth 0 args)))
1970                 (t
1971                  (while args
1972                    (setq current (car args)
1973                          args (cdr args))
1974                    (setq choices
1975                          (cons (cons (widget-apply current :menu-tag-get)
1976                                      current)
1977                                choices)))
1978                  (setq this-explicit t)
1979                  (widget-choose tag (reverse choices) event))))
1980     (when current
1981       ;; If this was an explicit user choice,
1982       ;; record the choice, and the record the value it was made for.
1983       ;; widget-choice-value-create will respect this choice,
1984       ;; as long as the value is the same.
1985       (when this-explicit
1986         (widget-put widget :explicit-choice current)
1987         (widget-put widget :explicit-choice-value (widget-get widget :value)))
1988       (widget-value-set widget (widget-default-get current))
1989       (widget-setup)
1990       (widget-apply widget :notify widget event)))
1991   (run-hook-with-args 'widget-edit-functions widget))
1992
1993 (defun widget-choice-validate (widget)
1994   ;; Valid if we have made a valid choice.
1995   (if (eq (widget-get widget :void) (widget-get widget :choice))
1996       widget
1997     (widget-apply (car (widget-get widget :children)) :validate)))
1998
1999 (defun widget-choice-match (widget value)
2000   ;; Matches if one of the choices matches.
2001   (let ((args (widget-get widget :args))
2002         current found)
2003     (while (and args (not found))
2004       (setq current (car args)
2005             args (cdr args)
2006             found (widget-apply current :match value)))
2007     found))
2008
2009 (defun widget-choice-match-inline (widget values)
2010   ;; Matches if one of the choices matches.
2011   (let ((args (widget-get widget :args))
2012         current found)
2013     (while (and args (null found))
2014       (setq current (car args)
2015             args (cdr args)
2016             found (widget-match-inline current values)))
2017     found))
2018
2019 ;;; The `toggle' Widget.
2020
2021 (define-widget 'toggle 'item
2022   "Toggle between two states."
2023   :format "%[%v%]\n"
2024   :value-create 'widget-toggle-value-create
2025   :action 'widget-toggle-action
2026   :match (lambda (widget value) t)
2027   :on "on"
2028   :off "off")
2029
2030 (defun widget-toggle-value-create (widget)
2031   "Insert text representing the `on' and `off' states."
2032   (if (widget-value widget)
2033       (let ((image (widget-get widget :on-glyph)))
2034         (and (display-graphic-p)
2035              (listp image)
2036              (not (eq (car image) 'image))
2037              (widget-put widget :on-glyph (setq image (eval image))))
2038         (widget-image-insert widget
2039                              (widget-get widget :on)
2040                              image))
2041     (let ((image (widget-get widget :off-glyph)))
2042       (and (display-graphic-p)
2043            (listp image)
2044            (not (eq (car image) 'image))
2045            (widget-put widget :off-glyph (setq image (eval image))))
2046       (widget-image-insert widget (widget-get widget :off) image))))
2047
2048 (defun widget-toggle-action (widget &optional event)
2049   ;; Toggle value.
2050   (widget-value-set widget (not (widget-value widget)))
2051   (widget-apply widget :notify widget event)
2052   (run-hook-with-args 'widget-edit-functions widget))
2053
2054 ;;; The `checkbox' Widget.
2055
2056 (define-widget 'checkbox 'toggle
2057   "A checkbox toggle."
2058   :button-suffix ""
2059   :button-prefix ""
2060   :format "%[%v%]"
2061   :on "[X]"
2062   ;; We could probably do the same job as the images using single
2063   ;; space characters in a boxed face with a stretch specification to
2064   ;; make them square.
2065   :on-glyph '(create-image "\300\300\141\143\067\076\034\030"
2066                            'xbm t :width 8 :height 8
2067                            :background "grey75" ; like default mode line
2068                            :foreground "black"
2069                            :relief -2
2070                            :ascent 'center)
2071   :off "[ ]"
2072   :off-glyph '(create-image (make-string 8 0)
2073                             'xbm t :width 8 :height 8
2074                             :background "grey75"
2075                             :foreground "black"
2076                             :relief -2
2077                             :ascent 'center)
2078   :help-echo "Toggle this item."
2079   :action 'widget-checkbox-action)
2080
2081 (defun widget-checkbox-action (widget &optional event)
2082   "Toggle checkbox, notify parent, and set active state of sibling."
2083   (widget-toggle-action widget event)
2084   (let ((sibling (widget-get-sibling widget)))
2085     (when sibling
2086       (if (widget-value widget)
2087           (widget-apply sibling :activate)
2088         (widget-apply sibling :deactivate)))))
2089
2090 ;;; The `checklist' Widget.
2091
2092 (define-widget 'checklist 'default
2093   "A multiple choice widget."
2094   :convert-widget 'widget-types-convert-widget
2095   :copy 'widget-types-copy
2096   :format "%v"
2097   :offset 4
2098   :entry-format "%b %v"
2099   :greedy nil
2100   :value-create 'widget-checklist-value-create
2101   :value-delete 'widget-children-value-delete
2102   :value-get 'widget-checklist-value-get
2103   :validate 'widget-checklist-validate
2104   :match 'widget-checklist-match
2105   :match-inline 'widget-checklist-match-inline)
2106
2107 (defun widget-checklist-value-create (widget)
2108   ;; Insert all values
2109   (let ((alist (widget-checklist-match-find widget (widget-get widget :value)))
2110         (args (widget-get widget :args)))
2111     (while args
2112       (widget-checklist-add-item widget (car args) (assq (car args) alist))
2113       (setq args (cdr args)))
2114     (widget-put widget :children (nreverse (widget-get widget :children)))))
2115
2116 (defun widget-checklist-add-item (widget type chosen)
2117   "Create checklist item in WIDGET of type TYPE.
2118 If the item is checked, CHOSEN is a cons whose cdr is the value."
2119   (and (eq (preceding-char) ?\n)
2120        (widget-get widget :indent)
2121        (insert-char ?  (widget-get widget :indent)))
2122   (widget-specify-insert
2123    (let* ((children (widget-get widget :children))
2124           (buttons (widget-get widget :buttons))
2125           (button-args (or (widget-get type :sibling-args)
2126                            (widget-get widget :button-args)))
2127           (from (point))
2128           child button)
2129      (insert (widget-get widget :entry-format))
2130      (goto-char from)
2131      ;; Parse % escapes in format.
2132      (while (re-search-forward "%\\([bv%]\\)" nil t)
2133        (let ((escape (char-after (match-beginning 1))))
2134          (delete-backward-char 2)
2135          (cond ((eq escape ?%)
2136                 (insert ?%))
2137                ((eq escape ?b)
2138                 (setq button (apply 'widget-create-child-and-convert
2139                                     widget 'checkbox
2140                                     :value (not (null chosen))
2141                                     button-args)))
2142                ((eq escape ?v)
2143                 (setq child
2144                       (cond ((not chosen)
2145                              (let ((child (widget-create-child widget type)))
2146                                (widget-apply child :deactivate)
2147                                child))
2148                             ((widget-get type :inline)
2149                              (widget-create-child-value
2150                               widget type (cdr chosen)))
2151                             (t
2152                              (widget-create-child-value
2153                               widget type (car (cdr chosen)))))))
2154                (t
2155                 (error "Unknown escape `%c'" escape)))))
2156      ;; Update properties.
2157      (and button child (widget-put child :button button))
2158      (and button (widget-put widget :buttons (cons button buttons)))
2159      (and child (widget-put widget :children (cons child children))))))
2160
2161 (defun widget-checklist-match (widget values)
2162   ;; All values must match a type in the checklist.
2163   (and (listp values)
2164        (null (cdr (widget-checklist-match-inline widget values)))))
2165
2166 (defun widget-checklist-match-inline (widget values)
2167   ;; Find the values which match a type in the checklist.
2168   (let ((greedy (widget-get widget :greedy))
2169         (args (copy-sequence (widget-get widget :args)))
2170         found rest)
2171     (while values
2172       (let ((answer (widget-checklist-match-up args values)))
2173         (cond (answer
2174                (let ((vals (widget-match-inline answer values)))
2175                  (setq found (append found (car vals))
2176                        values (cdr vals)
2177                        args (delq answer args))))
2178               (greedy
2179                (setq rest (append rest (list (car values)))
2180                      values (cdr values)))
2181               (t
2182                (setq rest (append rest values)
2183                      values nil)))))
2184     (cons found rest)))
2185
2186 (defun widget-checklist-match-find (widget vals)
2187   "Find the vals which match a type in the checklist.
2188 Return an alist of (TYPE MATCH)."
2189   (let ((greedy (widget-get widget :greedy))
2190         (args (copy-sequence (widget-get widget :args)))
2191         found)
2192     (while vals
2193       (let ((answer (widget-checklist-match-up args vals)))
2194         (cond (answer
2195                (let ((match (widget-match-inline answer vals)))
2196                  (setq found (cons (cons answer (car match)) found)
2197                        vals (cdr match)
2198                        args (delq answer args))))
2199               (greedy
2200                (setq vals (cdr vals)))
2201               (t
2202                (setq vals nil)))))
2203     found))
2204
2205 (defun widget-checklist-match-up (args vals)
2206   "Return the first type from ARGS that matches VALS."
2207   (let (current found)
2208     (while (and args (null found))
2209       (setq current (car args)
2210             args (cdr args)
2211             found (widget-match-inline current vals)))
2212     (if found
2213         current)))
2214
2215 (defun widget-checklist-value-get (widget)
2216   ;; The values of all selected items.
2217   (let ((children (widget-get widget :children))
2218         child result)
2219     (while children
2220       (setq child (car children)
2221             children (cdr children))
2222       (if (widget-value (widget-get child :button))
2223           (setq result (append result (widget-apply child :value-inline)))))
2224     result))
2225
2226 (defun widget-checklist-validate (widget)
2227   ;; Ticked chilren must be valid.
2228   (let ((children (widget-get widget :children))
2229         child button found)
2230     (while (and children (not found))
2231       (setq child (car children)
2232             children (cdr children)
2233             button (widget-get child :button)
2234             found (and (widget-value button)
2235                        (widget-apply child :validate))))
2236     found))
2237
2238 ;;; The `option' Widget
2239
2240 (define-widget 'option 'checklist
2241   "An widget with an optional item."
2242   :inline t)
2243
2244 ;;; The `choice-item' Widget.
2245
2246 (define-widget 'choice-item 'item
2247   "Button items that delegate action events to their parents."
2248   :action 'widget-parent-action
2249   :format "%[%t%] \n")
2250
2251 ;;; The `radio-button' Widget.
2252
2253 (define-widget 'radio-button 'toggle
2254   "A radio button for use in the `radio' widget."
2255   :notify 'widget-radio-button-notify
2256   :format "%[%v%]"
2257   :button-suffix ""
2258   :button-prefix ""
2259   :on "(*)"
2260   :on-glyph "radio1"
2261   :off "( )"
2262   :off-glyph "radio0")
2263
2264 (defun widget-radio-button-notify (widget child &optional event)
2265   ;; Tell daddy.
2266   (widget-apply (widget-get widget :parent) :action widget event))
2267
2268 ;;; The `radio-button-choice' Widget.
2269
2270 (define-widget 'radio-button-choice 'default
2271   "Select one of multiple options."
2272   :convert-widget 'widget-types-convert-widget
2273   :copy 'widget-types-copy
2274   :offset 4
2275   :format "%v"
2276   :entry-format "%b %v"
2277   :value-create 'widget-radio-value-create
2278   :value-delete 'widget-children-value-delete
2279   :value-get 'widget-radio-value-get
2280   :value-inline 'widget-radio-value-inline
2281   :value-set 'widget-radio-value-set
2282   :error "You must push one of the buttons"
2283   :validate 'widget-radio-validate
2284   :match 'widget-choice-match
2285   :match-inline 'widget-choice-match-inline
2286   :action 'widget-radio-action)
2287
2288 (defun widget-radio-value-create (widget)
2289   ;; Insert all values
2290   (let ((args (widget-get widget :args))
2291         arg)
2292     (while args
2293       (setq arg (car args)
2294             args (cdr args))
2295       (widget-radio-add-item widget arg))))
2296
2297 (defun widget-radio-add-item (widget type)
2298   "Add to radio widget WIDGET a new radio button item of type TYPE."
2299   ;; (setq type (widget-convert type))
2300   (and (eq (preceding-char) ?\n)
2301        (widget-get widget :indent)
2302        (insert-char ?  (widget-get widget :indent)))
2303   (widget-specify-insert
2304    (let* ((value (widget-get widget :value))
2305           (children (widget-get widget :children))
2306           (buttons (widget-get widget :buttons))
2307           (button-args (or (widget-get type :sibling-args)
2308                            (widget-get widget :button-args)))
2309           (from (point))
2310           (chosen (and (null (widget-get widget :choice))
2311                        (widget-apply type :match value)))
2312           child button)
2313      (insert (widget-get widget :entry-format))
2314      (goto-char from)
2315      ;; Parse % escapes in format.
2316      (while (re-search-forward "%\\([bv%]\\)" nil t)
2317        (let ((escape (char-after (match-beginning 1))))
2318          (delete-backward-char 2)
2319          (cond ((eq escape ?%)
2320                 (insert ?%))
2321                ((eq escape ?b)
2322                 (setq button (apply 'widget-create-child-and-convert
2323                                     widget 'radio-button
2324                                     :value (not (null chosen))
2325                                     button-args)))
2326                ((eq escape ?v)
2327                 (setq child (if chosen
2328                                 (widget-create-child-value
2329                                  widget type value)
2330                               (widget-create-child widget type)))
2331                 (unless chosen
2332                   (widget-apply child :deactivate)))
2333                (t
2334                 (error "Unknown escape `%c'" escape)))))
2335      ;; Update properties.
2336      (when chosen
2337        (widget-put widget :choice type))
2338      (when button
2339        (widget-put child :button button)
2340        (widget-put widget :buttons (nconc buttons (list button))))
2341      (when child
2342        (widget-put widget :children (nconc children (list child))))
2343      child)))
2344
2345 (defun widget-radio-value-get (widget)
2346   ;; Get value of the child widget.
2347   (let ((chosen (widget-radio-chosen widget)))
2348     (and chosen (widget-value chosen))))
2349
2350 (defun widget-radio-chosen (widget)
2351   "Return the widget representing the chosen radio button."
2352   (let ((children (widget-get widget :children))
2353         current found)
2354     (while children
2355       (setq current (car children)
2356             children (cdr children))
2357       (when (widget-apply (widget-get current :button) :value-get)
2358         (setq found current
2359               children nil)))
2360     found))
2361
2362 (defun widget-radio-value-inline (widget)
2363   ;; Get value of the child widget.
2364   (let ((children (widget-get widget :children))
2365         current found)
2366     (while children
2367       (setq current (car children)
2368             children (cdr children))
2369       (when (widget-apply (widget-get current :button) :value-get)
2370         (setq found (widget-apply current :value-inline)
2371               children nil)))
2372     found))
2373
2374 (defun widget-radio-value-set (widget value)
2375   ;; We can't just delete and recreate a radio widget, since children
2376   ;; can be added after the original creation and won't be recreated
2377   ;; by `:create'.
2378   (let ((children (widget-get widget :children))
2379         current found)
2380     (while children
2381       (setq current (car children)
2382             children (cdr children))
2383       (let* ((button (widget-get current :button))
2384              (match (and (not found)
2385                          (widget-apply current :match value))))
2386         (widget-value-set button match)
2387         (if match
2388             (progn
2389               (widget-value-set current value)
2390               (widget-apply current :activate))
2391           (widget-apply current :deactivate))
2392         (setq found (or found match))))))
2393
2394 (defun widget-radio-validate (widget)
2395   ;; Valid if we have made a valid choice.
2396   (let ((children (widget-get widget :children))
2397         current found button)
2398     (while (and children (not found))
2399       (setq current (car children)
2400             children (cdr children)
2401             button (widget-get current :button)
2402             found (widget-apply button :value-get)))
2403     (if found
2404         (widget-apply current :validate)
2405       widget)))
2406
2407 (defun widget-radio-action (widget child event)
2408   ;; Check if a radio button was pressed.
2409   (let ((children (widget-get widget :children))
2410         (buttons (widget-get widget :buttons))
2411         current)
2412     (when (memq child buttons)
2413       (while children
2414         (setq current (car children)
2415               children (cdr children))
2416         (let* ((button (widget-get current :button)))
2417           (cond ((eq child button)
2418                  (widget-value-set button t)
2419                  (widget-apply current :activate))
2420                 ((widget-value button)
2421                  (widget-value-set button nil)
2422                  (widget-apply current :deactivate)))))))
2423   ;; Pass notification to parent.
2424   (widget-apply widget :notify child event))
2425
2426 ;;; The `insert-button' Widget.
2427
2428 (define-widget 'insert-button 'push-button
2429   "An insert button for the `editable-list' widget."
2430   :tag "INS"
2431   :help-echo "Insert a new item into the list at this position."
2432   :action 'widget-insert-button-action)
2433
2434 (defun widget-insert-button-action (widget &optional event)
2435   ;; Ask the parent to insert a new item.
2436   (widget-apply (widget-get widget :parent)
2437                 :insert-before (widget-get widget :widget)))
2438
2439 ;;; The `delete-button' Widget.
2440
2441 (define-widget 'delete-button 'push-button
2442   "A delete button for the `editable-list' widget."
2443   :tag "DEL"
2444   :help-echo "Delete this item from the list."
2445   :action 'widget-delete-button-action)
2446
2447 (defun widget-delete-button-action (widget &optional event)
2448   ;; Ask the parent to insert a new item.
2449   (widget-apply (widget-get widget :parent)
2450                 :delete-at (widget-get widget :widget)))
2451
2452 ;;; The `editable-list' Widget.
2453
2454 ;; (defcustom widget-editable-list-gui nil
2455 ;;   "If non nil, use GUI push-buttons in editable list when available."
2456 ;;   :type 'boolean
2457 ;;   :group 'widgets)
2458
2459 (define-widget 'editable-list 'default
2460   "A variable list of widgets of the same type."
2461   :convert-widget 'widget-types-convert-widget
2462   :copy 'widget-types-copy
2463   :offset 12
2464   :format "%v%i\n"
2465   :format-handler 'widget-editable-list-format-handler
2466   :entry-format "%i %d %v"
2467   :value-create 'widget-editable-list-value-create
2468   :value-delete 'widget-children-value-delete
2469   :value-get 'widget-editable-list-value-get
2470   :validate 'widget-children-validate
2471   :match 'widget-editable-list-match
2472   :match-inline 'widget-editable-list-match-inline
2473   :insert-before 'widget-editable-list-insert-before
2474   :delete-at 'widget-editable-list-delete-at)
2475
2476 (defun widget-editable-list-format-handler (widget escape)
2477   ;; We recognize the insert button.
2478     ;; (let ((widget-push-button-gui widget-editable-list-gui))
2479     (cond ((eq escape ?i)
2480            (and (widget-get widget :indent)
2481                 (insert-char ?\  (widget-get widget :indent)))
2482            (apply 'widget-create-child-and-convert
2483                   widget 'insert-button
2484                   (widget-get widget :append-button-args)))
2485           (t
2486            (widget-default-format-handler widget escape)))
2487     ;; )
2488   )
2489
2490 (defun widget-editable-list-value-create (widget)
2491   ;; Insert all values
2492   (let* ((value (widget-get widget :value))
2493          (type (nth 0 (widget-get widget :args)))
2494          children)
2495     (widget-put widget :value-pos (copy-marker (point)))
2496     (set-marker-insertion-type (widget-get widget :value-pos) t)
2497     (while value
2498       (let ((answer (widget-match-inline type value)))
2499         (if answer
2500             (setq children (cons (widget-editable-list-entry-create
2501                                   widget
2502                                   (if (widget-get type :inline)
2503                                       (car answer)
2504                                     (car (car answer)))
2505                                   t)
2506                                  children)
2507                   value (cdr answer))
2508           (setq value nil))))
2509     (widget-put widget :children (nreverse children))))
2510
2511 (defun widget-editable-list-value-get (widget)
2512   ;; Get value of the child widget.
2513   (apply 'append (mapcar (lambda (child) (widget-apply child :value-inline))
2514                          (widget-get widget :children))))
2515
2516 (defun widget-editable-list-match (widget value)
2517   ;; Value must be a list and all the members must match the type.
2518   (and (listp value)
2519        (null (cdr (widget-editable-list-match-inline widget value)))))
2520
2521 (defun widget-editable-list-match-inline (widget value)
2522   (let ((type (nth 0 (widget-get widget :args)))
2523         (ok t)
2524         found)
2525     (while (and value ok)
2526       (let ((answer (widget-match-inline type value)))
2527         (if answer
2528             (setq found (append found (car answer))
2529                   value (cdr answer))
2530           (setq ok nil))))
2531     (cons found value)))
2532
2533 (defun widget-editable-list-insert-before (widget before)
2534   ;; Insert a new child in the list of children.
2535   (save-excursion
2536     (let ((children (widget-get widget :children))
2537           (inhibit-read-only t)
2538           before-change-functions
2539           after-change-functions)
2540       (cond (before
2541              (goto-char (widget-get before :entry-from)))
2542             (t
2543              (goto-char (widget-get widget :value-pos))))
2544       (let ((child (widget-editable-list-entry-create
2545                     widget nil nil)))
2546         (when (< (widget-get child :entry-from) (widget-get widget :from))
2547           (set-marker (widget-get widget :from)
2548                       (widget-get child :entry-from)))
2549         (if (eq (car children) before)
2550             (widget-put widget :children (cons child children))
2551           (while (not (eq (car (cdr children)) before))
2552             (setq children (cdr children)))
2553           (setcdr children (cons child (cdr children)))))))
2554   (widget-setup)
2555   (widget-apply widget :notify widget))
2556
2557 (defun widget-editable-list-delete-at (widget child)
2558   ;; Delete child from list of children.
2559   (save-excursion
2560     (let ((buttons (copy-sequence (widget-get widget :buttons)))
2561           button
2562           (inhibit-read-only t)
2563           before-change-functions
2564           after-change-functions)
2565       (while buttons
2566         (setq button (car buttons)
2567               buttons (cdr buttons))
2568         (when (eq (widget-get button :widget) child)
2569           (widget-put widget
2570                       :buttons (delq button (widget-get widget :buttons)))
2571           (widget-delete button))))
2572     (let ((entry-from (widget-get child :entry-from))
2573           (entry-to (widget-get child :entry-to))
2574           (inhibit-read-only t)
2575           before-change-functions
2576           after-change-functions)
2577       (widget-delete child)
2578       (delete-region entry-from entry-to)
2579       (set-marker entry-from nil)
2580       (set-marker entry-to nil))
2581     (widget-put widget :children (delq child (widget-get widget :children))))
2582   (widget-setup)
2583   (widget-apply widget :notify widget))
2584
2585 (defun widget-editable-list-entry-create (widget value conv)
2586   ;; Create a new entry to the list.
2587   (let ((type (nth 0 (widget-get widget :args)))
2588         ;; (widget-push-button-gui widget-editable-list-gui)
2589         child delete insert)
2590     (widget-specify-insert
2591      (save-excursion
2592        (and (widget-get widget :indent)
2593             (insert-char ?\  (widget-get widget :indent)))
2594        (insert (widget-get widget :entry-format)))
2595      ;; Parse % escapes in format.
2596      (while (re-search-forward "%\\(.\\)" nil t)
2597        (let ((escape (char-after (match-beginning 1))))
2598          (delete-backward-char 2)
2599          (cond ((eq escape ?%)
2600                 (insert ?%))
2601                ((eq escape ?i)
2602                 (setq insert (apply 'widget-create-child-and-convert
2603                                     widget 'insert-button
2604                                     (widget-get widget :insert-button-args))))
2605                ((eq escape ?d)
2606                 (setq delete (apply 'widget-create-child-and-convert
2607                                     widget 'delete-button
2608                                     (widget-get widget :delete-button-args))))
2609                ((eq escape ?v)
2610                 (if conv
2611                     (setq child (widget-create-child-value
2612                                  widget type value))
2613                   (setq child (widget-create-child-value
2614                                widget type (widget-default-get type)))))
2615                (t
2616                 (error "Unknown escape `%c'" escape)))))
2617      (let ((buttons (widget-get widget :buttons)))
2618        (if insert (push insert buttons))
2619        (if delete (push delete buttons))
2620        (widget-put widget :buttons buttons))
2621      (let ((entry-from (point-min-marker))
2622            (entry-to (point-max-marker)))
2623        (set-marker-insertion-type entry-from t)
2624        (set-marker-insertion-type entry-to nil)
2625        (widget-put child :entry-from entry-from)
2626        (widget-put child :entry-to entry-to)))
2627     (if insert (widget-put insert :widget child))
2628     (if delete (widget-put delete :widget child))
2629     child))
2630
2631 ;;; The `group' Widget.
2632
2633 (define-widget 'group 'default
2634   "A widget which groups other widgets inside."
2635   :convert-widget 'widget-types-convert-widget
2636   :copy 'widget-types-copy
2637   :format "%v"
2638   :value-create 'widget-group-value-create
2639   :value-delete 'widget-children-value-delete
2640   :value-get 'widget-editable-list-value-get
2641   :default-get 'widget-group-default-get
2642   :validate 'widget-children-validate
2643   :match 'widget-group-match
2644   :match-inline 'widget-group-match-inline)
2645
2646 (defun widget-group-value-create (widget)
2647   ;; Create each component.
2648   (let ((args (widget-get widget :args))
2649         (value (widget-get widget :value))
2650         arg answer children)
2651     (while args
2652       (setq arg (car args)
2653             args (cdr args)
2654             answer (widget-match-inline arg value)
2655             value (cdr answer))
2656       (and (eq (preceding-char) ?\n)
2657            (widget-get widget :indent)
2658            (insert-char ?\  (widget-get widget :indent)))
2659       (push (cond ((null answer)
2660                    (widget-create-child widget arg))
2661                   ((widget-get arg :inline)
2662                    (widget-create-child-value widget arg (car answer)))
2663                   (t
2664                    (widget-create-child-value widget arg (car (car answer)))))
2665             children))
2666     (widget-put widget :children (nreverse children))))
2667
2668 (defun widget-group-default-get (widget)
2669   ;; Get the default of the components.
2670   (mapcar 'widget-default-get (widget-get widget :args)))
2671
2672 (defun widget-group-match (widget values)
2673   ;; Match if the components match.
2674   (and (listp values)
2675        (let ((match (widget-group-match-inline widget values)))
2676          (and match (null (cdr match))))))
2677
2678 (defun widget-group-match-inline (widget vals)
2679   ;; Match if the components match.
2680   (let ((args (widget-get widget :args))
2681         argument answer found)
2682     (while args
2683       (setq argument (car args)
2684             args (cdr args)
2685             answer (widget-match-inline argument vals))
2686       (if answer
2687           (setq vals (cdr answer)
2688                 found (append found (car answer)))
2689         (setq vals nil
2690               args nil)))
2691     (if answer
2692         (cons found vals))))
2693
2694 ;;; The `visibility' Widget.
2695
2696 (define-widget 'visibility 'item
2697   "An indicator and manipulator for hidden items."
2698   :format "%[%v%]"
2699   :button-prefix ""
2700   :button-suffix ""
2701   :on "Hide"
2702   :off "Show"
2703   :value-create 'widget-visibility-value-create
2704   :action 'widget-toggle-action
2705   :match (lambda (widget value) t))
2706
2707 (defun widget-visibility-value-create (widget)
2708   ;; Insert text representing the `on' and `off' states.
2709   (let ((on (widget-get widget :on))
2710         (off (widget-get widget :off)))
2711     (if on
2712         (setq on (concat widget-push-button-prefix
2713                          on
2714                          widget-push-button-suffix))
2715       (setq on ""))
2716     (if off
2717         (setq off (concat widget-push-button-prefix
2718                           off
2719                           widget-push-button-suffix))
2720       (setq off ""))
2721     (if (widget-value widget)
2722         (widget-image-insert widget on "down" "down-pushed")
2723       (widget-image-insert widget off "right" "right-pushed"))))
2724
2725 ;;; The `documentation-link' Widget.
2726 ;;
2727 ;; This is a helper widget for `documentation-string'.
2728
2729 (define-widget 'documentation-link 'link
2730   "Link type used in documentation strings."
2731   :tab-order -1
2732   :help-echo "Describe this symbol"
2733   :action 'widget-documentation-link-action)
2734
2735 (defun widget-documentation-link-action (widget &optional event)
2736   "Display documentation for WIDGET's value.  Ignore optional argument EVENT."
2737   (let* ((string (widget-get widget :value))
2738          (symbol (intern string)))
2739     (if (and (fboundp symbol) (boundp symbol))
2740         ;; If there are two doc strings, give the user a way to pick one.
2741         (apropos (concat "\\`" (regexp-quote string) "\\'"))
2742       (if (fboundp symbol)
2743           (describe-function symbol)
2744         (describe-variable symbol)))))
2745
2746 (defcustom widget-documentation-links t
2747   "Add hyperlinks to documentation strings when non-nil."
2748   :type 'boolean
2749   :group 'widget-documentation)
2750
2751 (defcustom widget-documentation-link-regexp "`\\([^\n`' ]+\\)'"
2752   "Regexp for matching potential links in documentation strings.
2753 The first group should be the link itself."
2754   :type 'regexp
2755   :group 'widget-documentation)
2756
2757 (defcustom widget-documentation-link-p 'intern-soft
2758   "Predicate used to test if a string is useful as a link.
2759 The value should be a function.  The function will be called one
2760 argument, a string, and should return non-nil if there should be a
2761 link for that string."
2762   :type 'function
2763   :options '(widget-documentation-link-p)
2764   :group 'widget-documentation)
2765
2766 (defcustom widget-documentation-link-type 'documentation-link
2767   "Widget type used for links in documentation strings."
2768   :type 'symbol
2769   :group 'widget-documentation)
2770
2771 (defun widget-documentation-link-add (widget from to)
2772   (widget-specify-doc widget from to)
2773   (when widget-documentation-links
2774     (let ((regexp widget-documentation-link-regexp)
2775           (buttons (widget-get widget :buttons))
2776           (widget-mouse-face (default-value 'widget-mouse-face))
2777           (widget-button-face widget-documentation-face)
2778           (widget-button-pressed-face widget-documentation-face))
2779       (save-excursion
2780         (goto-char from)
2781         (while (re-search-forward regexp to t)
2782           (let ((name (match-string 1))
2783                 (begin (match-beginning 1))
2784                 (end (match-end 1)))
2785             (when (funcall widget-documentation-link-p name)
2786               (push (widget-convert-button widget-documentation-link-type
2787                                            begin end :value name)
2788                     buttons)))))
2789       (widget-put widget :buttons buttons)))
2790   (let ((indent (widget-get widget :indent)))
2791     (when (and indent (not (zerop indent)))
2792       (save-excursion
2793         (save-restriction
2794           (narrow-to-region from to)
2795           (goto-char (point-min))
2796           (while (search-forward "\n" nil t)
2797             (insert-char ?\  indent)))))))
2798
2799 ;;; The `documentation-string' Widget.
2800
2801 (define-widget 'documentation-string 'item
2802   "A documentation string."
2803   :format "%v"
2804   :action 'widget-documentation-string-action
2805   :value-delete 'widget-children-value-delete
2806   :value-create 'widget-documentation-string-value-create)
2807
2808 (defun widget-documentation-string-value-create (widget)
2809   ;; Insert documentation string.
2810   (let ((doc (widget-value widget))
2811         (indent (widget-get widget :indent))
2812         (shown (widget-get (widget-get widget :parent) :documentation-shown))
2813         (start (point)))
2814     (if (string-match "\n" doc)
2815         (let ((before (substring doc 0 (match-beginning 0)))
2816               (after (substring doc (match-beginning 0)))
2817               button)
2818           (insert before ?\ )
2819           (widget-documentation-link-add widget start (point))
2820           (setq button
2821                 (widget-create-child-and-convert
2822                  widget 'visibility
2823                  :help-echo "Show or hide rest of the documentation."
2824                  :on "Hide Rest"
2825                  :off "More"
2826                  :always-active t
2827                  :action 'widget-parent-action
2828                  shown))
2829           (when shown
2830             (setq start (point))
2831             (when (and indent (not (zerop indent)))
2832               (insert-char ?\  indent))
2833             (insert after)
2834             (widget-documentation-link-add widget start (point)))
2835           (widget-put widget :buttons (list button)))
2836       (insert doc)
2837       (widget-documentation-link-add widget start (point))))
2838   (insert ?\n))
2839
2840 (defun widget-documentation-string-action (widget &rest ignore)
2841   ;; Toggle documentation.
2842   (let ((parent (widget-get widget :parent)))
2843     (widget-put parent :documentation-shown
2844                 (not (widget-get parent :documentation-shown))))
2845   ;; Redraw.
2846   (widget-value-set widget (widget-value widget)))
2847 \f
2848 ;;; The Sexp Widgets.
2849
2850 (define-widget 'const 'item
2851   "An immutable sexp."
2852   :prompt-value 'widget-const-prompt-value
2853   :format "%t\n%d")
2854
2855 (defun widget-const-prompt-value (widget prompt value unbound)
2856   ;; Return the value of the const.
2857   (widget-value widget))
2858
2859 (define-widget 'function-item 'const
2860   "An immutable function name."
2861   :format "%v\n%h"
2862   :documentation-property (lambda (symbol)
2863                             (condition-case nil
2864                                 (documentation symbol t)
2865                               (error nil))))
2866
2867 (define-widget 'variable-item 'const
2868   "An immutable variable name."
2869   :format "%v\n%h"
2870   :documentation-property 'variable-documentation)
2871
2872 (define-widget 'other 'sexp
2873   "Matches any value, but doesn't let the user edit the value.
2874 This is useful as last item in a `choice' widget.
2875 You should use this widget type with a default value,
2876 as in (other DEFAULT) or (other :tag \"NAME\" DEFAULT).
2877 If the user selects this alternative, that specifies DEFAULT
2878 as the value."
2879   :tag "Other"
2880   :format "%t%n"
2881   :value 'other)
2882
2883 (defvar widget-string-prompt-value-history nil
2884   "History of input to `widget-string-prompt-value'.")
2885
2886 (define-widget 'string 'editable-field
2887   "A string"
2888   :tag "String"
2889   :format "%{%t%}: %v"
2890   :complete-function 'ispell-complete-word
2891   :prompt-history 'widget-string-prompt-value-history)
2892
2893 (eval-when-compile (defvar widget))
2894
2895 (defun widget-string-complete ()
2896   "Complete contents of string field.
2897 Completions are taken from the :completion-alist property of the
2898 widget.  If that isn't a list, it's evalled and expected to yield a list."
2899   (interactive)
2900   (let* ((prefix (buffer-substring-no-properties (widget-field-start widget)
2901                                                  (point)))
2902          (completion-ignore-case (widget-get widget :completion-ignore-case))
2903          (alist (widget-get widget :completion-alist))
2904          (_ (unless (listp alist)
2905               (setq alist (eval alist))))
2906          (completion (try-completion prefix alist)))
2907     (cond ((eq completion t)
2908            (when completion-ignore-case
2909              ;; Replace field with completion in case its case is different.
2910              (delete-region (widget-field-start widget)
2911                             (widget-field-end widget))
2912              (insert-and-inherit (car (assoc-ignore-case prefix alist))))
2913            (message "Only match"))
2914           ((null completion)
2915            (error "No match"))
2916           ((not (eq t (compare-strings prefix nil nil completion nil nil
2917                                        completion-ignore-case)))
2918            (when completion-ignore-case
2919              ;; Replace field with completion in case its case is different.
2920              (delete-region (widget-field-start widget)
2921                             (widget-field-end widget))
2922              (insert-and-inherit completion)))
2923           (t
2924            (message "Making completion list...")
2925            (with-output-to-temp-buffer "*Completions*"
2926              (display-completion-list
2927               (all-completions prefix alist nil)))
2928            (message "Making completion list...done")))))
2929
2930 (define-widget 'regexp 'string
2931   "A regular expression."
2932   :match 'widget-regexp-match
2933   :validate 'widget-regexp-validate
2934   ;; Doesn't work well with terminating newline.
2935   ;; :value-face 'widget-single-line-field-face
2936   :tag "Regexp")
2937
2938 (defun widget-regexp-match (widget value)
2939   ;; Match valid regexps.
2940   (and (stringp value)
2941        (condition-case nil
2942            (prog1 t
2943              (string-match value ""))
2944          (error nil))))
2945
2946 (defun widget-regexp-validate (widget)
2947   "Check that the value of WIDGET is a valid regexp."
2948   (condition-case data
2949       (prog1 nil
2950         (string-match (widget-value widget) ""))
2951     (error (widget-put widget :error (error-message-string data))
2952            widget)))
2953
2954 (define-widget 'file 'string
2955   "A file widget.
2956 It will read a file name from the minibuffer when invoked."
2957   :complete-function 'widget-file-complete
2958   :prompt-value 'widget-file-prompt-value
2959   :format "%{%t%}: %v"
2960   ;; Doesn't work well with terminating newline.
2961   ;; :value-face 'widget-single-line-field-face
2962   :tag "File")
2963
2964 (defun widget-file-complete ()
2965   "Perform completion on file name preceding point."
2966   (interactive)
2967   (let* ((end (point))
2968          (beg (save-excursion
2969                 (skip-chars-backward "^ ")
2970                 (point)))
2971          (pattern (buffer-substring beg end))
2972          (name-part (file-name-nondirectory pattern))
2973          (directory (file-name-directory pattern))
2974          (completion (file-name-completion name-part directory)))
2975     (cond ((eq completion t))
2976           ((null completion)
2977            (message "Can't find completion for \"%s\"" pattern)
2978            (ding))
2979           ((not (string= name-part completion))
2980            (delete-region beg end)
2981            (insert (expand-file-name completion directory)))
2982           (t
2983            (message "Making completion list...")
2984            (with-output-to-temp-buffer "*Completions*"
2985              (display-completion-list
2986               (sort (file-name-all-completions name-part directory)
2987                     'string<)))
2988            (message "Making completion list...%s" "done")))))
2989
2990 (defun widget-file-prompt-value (widget prompt value unbound)
2991   ;; Read file from minibuffer.
2992   (abbreviate-file-name
2993    (if unbound
2994        (read-file-name prompt)
2995      (let ((prompt2 (format "%s (default %s) " prompt value))
2996            (dir (file-name-directory value))
2997            (file (file-name-nondirectory value))
2998            (must-match (widget-get widget :must-match)))
2999        (read-file-name prompt2 dir nil must-match file)))))
3000
3001 ;;;(defun widget-file-action (widget &optional event)
3002 ;;;  ;; Read a file name from the minibuffer.
3003 ;;;  (let* ((value (widget-value widget))
3004 ;;;      (dir (file-name-directory value))
3005 ;;;      (file (file-name-nondirectory value))
3006 ;;;      (menu-tag (widget-apply widget :menu-tag-get))
3007 ;;;      (must-match (widget-get widget :must-match))
3008 ;;;      (answer (read-file-name (concat menu-tag ": (default `" value "') ")
3009 ;;;                              dir nil must-match file)))
3010 ;;;    (widget-value-set widget (abbreviate-file-name answer))
3011 ;;;    (widget-setup)
3012 ;;;    (widget-apply widget :notify widget event)))
3013
3014 ;; Fixme: use file-name-as-directory.
3015 (define-widget 'directory 'file
3016   "A directory widget.
3017 It will read a directory name from the minibuffer when invoked."
3018   :tag "Directory")
3019
3020 (defvar widget-symbol-prompt-value-history nil
3021   "History of input to `widget-symbol-prompt-value'.")
3022
3023 (define-widget 'symbol 'editable-field
3024   "A Lisp symbol."
3025   :value nil
3026   :tag "Symbol"
3027   :format "%{%t%}: %v"
3028   :match (lambda (widget value) (symbolp value))
3029   :complete-function 'lisp-complete-symbol
3030   :prompt-internal 'widget-symbol-prompt-internal
3031   :prompt-match 'symbolp
3032   :prompt-history 'widget-symbol-prompt-value-history
3033   :value-to-internal (lambda (widget value)
3034                        (if (symbolp value)
3035                            (symbol-name value)
3036                          value))
3037   :value-to-external (lambda (widget value)
3038                        (if (stringp value)
3039                            (intern value)
3040                          value)))
3041
3042 (defun widget-symbol-prompt-internal (widget prompt initial history)
3043   ;; Read file from minibuffer.
3044   (let ((answer (completing-read prompt obarray
3045                                  (widget-get widget :prompt-match)
3046                                  nil initial history)))
3047     (if (and (stringp answer)
3048              (not (zerop (length answer))))
3049         answer
3050       (error "No value"))))
3051
3052 (defvar widget-function-prompt-value-history nil
3053   "History of input to `widget-function-prompt-value'.")
3054
3055 (define-widget 'function 'sexp
3056   "A Lisp function."
3057   :complete-function (lambda ()
3058                        (interactive)
3059                        (lisp-complete-symbol 'fboundp))
3060   :prompt-value 'widget-field-prompt-value
3061   :prompt-internal 'widget-symbol-prompt-internal
3062   :prompt-match 'fboundp
3063   :prompt-history 'widget-function-prompt-value-history
3064   :action 'widget-field-action
3065   :match-alternatives '(functionp)
3066   :validate (lambda (widget)
3067               (unless (functionp (widget-value widget))
3068                 (widget-put widget :error (format "Invalid function: %S"
3069                                                   (widget-value widget)))
3070                 widget))
3071   :value 'ignore
3072   :tag "Function")
3073
3074 (defvar widget-variable-prompt-value-history nil
3075   "History of input to `widget-variable-prompt-value'.")
3076
3077 (define-widget 'variable 'symbol
3078   "A Lisp variable."
3079   :prompt-match 'boundp
3080   :prompt-history 'widget-variable-prompt-value-history
3081   :complete-function (lambda ()
3082                        (interactive)
3083                        (lisp-complete-symbol 'boundp))
3084   :tag "Variable")
3085
3086 (define-widget 'coding-system 'symbol
3087   "A MULE coding-system."
3088   :format "%{%t%}: %v"
3089   :tag "Coding system"
3090   :base-only nil
3091   :prompt-history 'coding-system-value-history
3092   :prompt-value 'widget-coding-system-prompt-value
3093   :action 'widget-coding-system-action
3094   :complete-function (lambda ()
3095                        (interactive)
3096                        (lisp-complete-symbol 'coding-system-p))
3097   :validate (lambda (widget)
3098               (unless (coding-system-p (widget-value widget))
3099                 (widget-put widget :error (format "Invalid coding system: %S"
3100                                                   (widget-value widget)))
3101                 widget))
3102   :value 'undecided
3103   :prompt-match 'coding-system-p)
3104
3105 (defun widget-coding-system-prompt-value (widget prompt value unbound)
3106   "Read coding-system from minibuffer."
3107   (if (widget-get widget :base-only)
3108       (intern
3109        (completing-read (format "%s (default %s) " prompt value)
3110                         (mapcar #'list (coding-system-list t)) nil nil nil
3111                         coding-system-history))
3112       (read-coding-system (format "%s (default %s) " prompt value) value)))
3113
3114 (defun widget-coding-system-action (widget &optional event)
3115   (let ((answer
3116          (widget-coding-system-prompt-value
3117           widget
3118           (widget-apply widget :menu-tag-get)
3119           (widget-value widget)
3120           t)))
3121     (widget-value-set widget answer)
3122     (widget-apply widget :notify widget event)
3123     (widget-setup)))
3124 \f
3125 (define-widget 'sexp 'editable-field
3126   "An arbitrary Lisp expression."
3127   :tag "Lisp expression"
3128   :format "%{%t%}: %v"
3129   :value nil
3130   :validate 'widget-sexp-validate
3131   :match (lambda (widget value) t)
3132   :value-to-internal 'widget-sexp-value-to-internal
3133   :value-to-external (lambda (widget value) (read value))
3134   :prompt-history 'widget-sexp-prompt-value-history
3135   :prompt-value 'widget-sexp-prompt-value)
3136
3137 (defun widget-sexp-value-to-internal (widget value)
3138   ;; Use pp for printer representation.
3139   (let ((pp (if (symbolp value)
3140                 (prin1-to-string value)
3141               (pp-to-string value))))
3142     (while (string-match "\n\\'" pp)
3143       (setq pp (substring pp 0 -1)))
3144     (if (or (string-match "\n\\'" pp)
3145             (> (length pp) 40))
3146         (concat "\n" pp)
3147       pp)))
3148
3149 (defun widget-sexp-validate (widget)
3150   ;; Valid if we can read the string and there is no junk left after it.
3151   (with-temp-buffer
3152     (insert (widget-apply widget :value-get))
3153     (goto-char (point-min))
3154     (let (err)
3155       (condition-case data
3156           (progn
3157             ;; Avoid a confusing end-of-file error.
3158             (skip-syntax-forward "\\s-")
3159             (if (eobp)
3160                 (setq err "Empty sexp -- use `nil'?")
3161               (unless (widget-apply widget :match (read (current-buffer)))
3162                 (setq err (widget-get widget :type-error))))
3163             (if (and (not (eobp))
3164                      (not err))
3165                 (setq err (format "Junk at end of expression: %s"
3166                                   (buffer-substring (point)
3167                                                     (point-max))))))
3168         (end-of-file                    ; Avoid confusing error message.
3169          (setq err "Unbalanced sexp"))
3170         (error (setq err (error-message-string data))))
3171       (if (not err)
3172           nil
3173         (widget-put widget :error err)
3174         widget))))
3175
3176 (defvar widget-sexp-prompt-value-history nil
3177   "History of input to `widget-sexp-prompt-value'.")
3178
3179 (defun widget-sexp-prompt-value (widget prompt value unbound)
3180   ;; Read an arbitrary sexp.
3181   (let ((found (read-string prompt
3182                             (if unbound nil (cons (prin1-to-string value) 0))
3183                             (widget-get widget :prompt-history))))
3184     (let ((answer (read-from-string found)))
3185       (unless (= (cdr answer) (length found))
3186         (error "Junk at end of expression: %s"
3187                (substring found (cdr answer))))
3188       (car answer))))
3189
3190 (define-widget 'restricted-sexp 'sexp
3191   "A Lisp expression restricted to values that match.
3192 To use this type, you must define :match or :match-alternatives."
3193   :type-error "The specified value is not valid"
3194   :match 'widget-restricted-sexp-match
3195   :value-to-internal (lambda (widget value)
3196                        (if (widget-apply widget :match value)
3197                            (prin1-to-string value)
3198                          value)))
3199
3200 (defun widget-restricted-sexp-match (widget value)
3201   (let ((alternatives (widget-get widget :match-alternatives))
3202         matched)
3203     (while (and alternatives (not matched))
3204       (if (cond ((functionp (car alternatives))
3205                  (funcall (car alternatives) value))
3206                 ((and (consp (car alternatives))
3207                       (eq (car (car alternatives)) 'quote))
3208                  (eq value (nth 1 (car alternatives)))))
3209           (setq matched t))
3210       (setq alternatives (cdr alternatives)))
3211     matched))
3212 \f
3213 (define-widget 'integer 'restricted-sexp
3214   "An integer."
3215   :tag "Integer"
3216   :value 0
3217   :type-error "This field should contain an integer"
3218   :match-alternatives '(integerp))
3219
3220 (define-widget 'number 'restricted-sexp
3221   "A number (floating point or integer)."
3222   :tag "Number"
3223   :value 0.0
3224   :type-error "This field should contain a number (floating point or integer)"
3225   :match-alternatives '(numberp))
3226
3227 (define-widget 'float 'restricted-sexp
3228   "A floating point number."
3229   :tag "Floating point number"
3230   :value 0.0
3231   :type-error "This field should contain a floating point number"
3232   :match-alternatives '(floatp))
3233
3234 (define-widget 'character 'editable-field
3235   "A character."
3236   :tag "Character"
3237   :value 0
3238   :size 1
3239   :format "%{%t%}: %v\n"
3240   :valid-regexp "\\`.\\'"
3241   :error "This field should contain a single character"
3242   :value-to-internal (lambda (widget value)
3243                        (if (stringp value)
3244                            value
3245                          (char-to-string value)))
3246   :value-to-external (lambda (widget value)
3247                        (if (stringp value)
3248                            (aref value 0)
3249                          value))
3250   :match (lambda (widget value)
3251            (characterp value)))
3252
3253 (define-widget 'list 'group
3254   "A Lisp list."
3255   :tag "List"
3256   :format "%{%t%}:\n%v")
3257
3258 (define-widget 'vector 'group
3259   "A Lisp vector."
3260   :tag "Vector"
3261   :format "%{%t%}:\n%v"
3262   :match 'widget-vector-match
3263   :value-to-internal (lambda (widget value) (append value nil))
3264   :value-to-external (lambda (widget value) (apply 'vector value)))
3265
3266 (defun widget-vector-match (widget value)
3267   (and (vectorp value)
3268        (widget-group-match widget
3269                            (widget-apply widget :value-to-internal value))))
3270
3271 (define-widget 'cons 'group
3272   "A cons-cell."
3273   :tag "Cons-cell"
3274   :format "%{%t%}:\n%v"
3275   :match 'widget-cons-match
3276   :value-to-internal (lambda (widget value)
3277                        (list (car value) (cdr value)))
3278   :value-to-external (lambda (widget value)
3279                        (apply 'cons value)))
3280
3281 (defun widget-cons-match (widget value)
3282   (and (consp value)
3283        (widget-group-match widget
3284                            (widget-apply widget :value-to-internal value))))
3285 \f
3286 ;;; The `plist' Widget.
3287 ;;
3288 ;; Property lists.
3289
3290 (define-widget 'plist 'list
3291   "A property list."
3292   :key-type '(symbol :tag "Key")
3293   :value-type '(sexp :tag "Value")
3294   :convert-widget 'widget-plist-convert-widget
3295   :tag "Plist")
3296
3297 (defvar widget-plist-value-type)        ;Dynamic variable
3298
3299 (defun widget-plist-convert-widget (widget)
3300   ;; Handle `:options'.
3301   (let* ((options (widget-get widget :options))
3302          (widget-plist-value-type (widget-get widget :value-type))
3303          (other `(editable-list :inline t
3304                                 (group :inline t
3305                                        ,(widget-get widget :key-type)
3306                                        ,widget-plist-value-type)))
3307          (args (if options
3308                    (list `(checklist :inline t
3309                                      :greedy t
3310                                      ,@(mapcar 'widget-plist-convert-option
3311                                                options))
3312                          other)
3313                  (list other))))
3314     (widget-put widget :args args)
3315     widget))
3316
3317 (defun widget-plist-convert-option (option)
3318   ;; Convert a single plist option.
3319   (let (key-type value-type)
3320     (if (listp option)
3321         (let ((key (nth 0 option)))
3322           (setq value-type (nth 1 option))
3323           (if (listp key)
3324               (setq key-type key)
3325             (setq key-type `(const ,key))))
3326       (setq key-type `(const ,option)
3327             value-type widget-plist-value-type))
3328     `(group :format "Key: %v" :inline t ,key-type ,value-type)))
3329
3330
3331 ;;; The `alist' Widget.
3332 ;;
3333 ;; Association lists.
3334
3335 (define-widget 'alist 'list
3336   "An association list."
3337   :key-type '(sexp :tag "Key")
3338   :value-type '(sexp :tag "Value")
3339   :convert-widget 'widget-alist-convert-widget
3340   :tag "Alist")
3341
3342 (defvar widget-alist-value-type)        ;Dynamic variable
3343
3344 (defun widget-alist-convert-widget (widget)
3345   ;; Handle `:options'.
3346   (let* ((options (widget-get widget :options))
3347          (widget-alist-value-type (widget-get widget :value-type))
3348          (other `(editable-list :inline t
3349                                 (cons :format "%v"
3350                                       ,(widget-get widget :key-type)
3351                                       ,widget-alist-value-type)))
3352          (args (if options
3353                    (list `(checklist :inline t
3354                                      :greedy t
3355                                      ,@(mapcar 'widget-alist-convert-option
3356                                                options))
3357                          other)
3358                  (list other))))
3359     (widget-put widget :args args)
3360     widget))
3361
3362 (defun widget-alist-convert-option (option)
3363   ;; Convert a single alist option.
3364   (let (key-type value-type)
3365     (if (listp option)
3366         (let ((key (nth 0 option)))
3367           (setq value-type (nth 1 option))
3368           (if (listp key)
3369               (setq key-type key)
3370             (setq key-type `(const ,key))))
3371       (setq key-type `(const ,option)
3372             value-type widget-alist-value-type))
3373     `(cons :format "Key: %v" ,key-type ,value-type)))
3374 \f
3375 (define-widget 'choice 'menu-choice
3376   "A union of several sexp types."
3377   :tag "Choice"
3378   :format "%{%t%}: %[Value Menu%] %v"
3379   :button-prefix 'widget-push-button-prefix
3380   :button-suffix 'widget-push-button-suffix
3381   :prompt-value 'widget-choice-prompt-value)
3382
3383 (defun widget-choice-prompt-value (widget prompt value unbound)
3384   "Make a choice."
3385   (let ((args (widget-get widget :args))
3386         (completion-ignore-case (widget-get widget :case-fold))
3387         current choices old)
3388     ;; Find the first arg that matches VALUE.
3389     (let ((look args))
3390       (while look
3391         (if (widget-apply (car look) :match value)
3392             (setq old (car look)
3393                   look nil)
3394           (setq look (cdr look)))))
3395     ;; Find new choice.
3396     (setq current
3397           (cond ((= (length args) 0)
3398                  nil)
3399                 ((= (length args) 1)
3400                  (nth 0 args))
3401                 ((and (= (length args) 2)
3402                       (memq old args))
3403                  (if (eq old (nth 0 args))
3404                      (nth 1 args)
3405                    (nth 0 args)))
3406                 (t
3407                  (while args
3408                    (setq current (car args)
3409                          args (cdr args))
3410                    (setq choices
3411                          (cons (cons (widget-apply current :menu-tag-get)
3412                                      current)
3413                                choices)))
3414                  (let ((val (completing-read prompt choices nil t)))
3415                    (if (stringp val)
3416                        (let ((try (try-completion val choices)))
3417                          (when (stringp try)
3418                            (setq val try))
3419                          (cdr (assoc val choices)))
3420                      nil)))))
3421     (if current
3422         (widget-prompt-value current prompt nil t)
3423       value)))
3424 \f
3425 (define-widget 'radio 'radio-button-choice
3426   "A union of several sexp types."
3427   :tag "Choice"
3428   :format "%{%t%}:\n%v"
3429   :prompt-value 'widget-choice-prompt-value)
3430
3431 (define-widget 'repeat 'editable-list
3432   "A variable length homogeneous list."
3433   :tag "Repeat"
3434   :format "%{%t%}:\n%v%i\n")
3435
3436 (define-widget 'set 'checklist
3437   "A list of members from a fixed set."
3438   :tag "Set"
3439   :format "%{%t%}:\n%v")
3440
3441 (define-widget 'boolean 'toggle
3442   "To be nil or non-nil, that is the question."
3443   :tag "Boolean"
3444   :prompt-value 'widget-boolean-prompt-value
3445   :button-prefix 'widget-push-button-prefix
3446   :button-suffix 'widget-push-button-suffix
3447   :format "%{%t%}: %[Toggle%]  %v\n"
3448   :on "on (non-nil)"
3449   :off "off (nil)")
3450
3451 (defun widget-boolean-prompt-value (widget prompt value unbound)
3452   ;; Toggle a boolean.
3453   (y-or-n-p prompt))
3454 \f
3455 ;;; The `color' Widget.
3456
3457 ;; Fixme: match
3458 (define-widget 'color 'editable-field
3459   "Choose a color name (with sample)."
3460   :format "%t: %v (%{sample%})\n"
3461   :size 10
3462   :tag "Color"
3463   :value "black"
3464   :complete 'widget-color-complete
3465   :sample-face-get 'widget-color-sample-face-get
3466   :notify 'widget-color-notify
3467   :action 'widget-color-action)
3468
3469 (defun widget-color-complete (widget)
3470   "Complete the color in WIDGET."
3471   (require 'facemenu)                   ; for facemenu-color-alist
3472   (let* ((prefix (buffer-substring-no-properties (widget-field-start widget)
3473                                                  (point)))
3474          (list (or facemenu-color-alist (defined-colors)))
3475          (completion (try-completion prefix list)))
3476     (cond ((eq completion t)
3477            (message "Exact match."))
3478           ((null completion)
3479            (error "Can't find completion for \"%s\"" prefix))
3480           ((not (string-equal prefix completion))
3481            (insert-and-inherit (substring completion (length prefix))))
3482           (t
3483            (message "Making completion list...")
3484            (with-output-to-temp-buffer "*Completions*"
3485              (display-completion-list (all-completions prefix list nil)))
3486            (message "Making completion list...done")))))
3487
3488 (defun widget-color-sample-face-get (widget)
3489   (let* ((value (condition-case nil
3490                     (widget-value widget)
3491                   (error (widget-get widget :value)))))
3492     (if (color-defined-p value)
3493         (list (cons 'foreground-color value))
3494       'default)))
3495
3496 (defun widget-color-action (widget &optional event)
3497   "Prompt for a color."
3498   (let* ((tag (widget-apply widget :menu-tag-get))
3499          (prompt (concat tag ": "))
3500          (value (widget-value widget))
3501          (start (widget-field-start widget))
3502          (answer (facemenu-read-color prompt)))
3503     (unless (zerop (length answer))
3504       (widget-value-set widget answer)
3505       (widget-setup)
3506       (widget-apply widget :notify widget event))))
3507
3508 (defun widget-color-notify (widget child &optional event)
3509   "Update the sample, and notofy the parent."
3510   (overlay-put (widget-get widget :sample-overlay)
3511                'face (widget-apply widget :sample-face-get))
3512   (widget-default-notify widget child event))
3513 \f
3514 ;;; The Help Echo
3515
3516 (defun widget-echo-help (pos)
3517   "Display help-echo text for widget at POS."
3518   (let* ((widget (widget-at pos))
3519          (help-echo (and widget (widget-get widget :help-echo))))
3520     (if (functionp help-echo)
3521         (setq help-echo (funcall help-echo widget)))
3522     (if (stringp help-echo)
3523         (message "%s" help-echo))))
3524
3525 ;;; The End:
3526
3527 (provide 'wid-edit)
3528
3529 ;;; wid-edit.el ends here