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, 1997, 1999, 2000, 2001, 2002, 2003, 2004, 2005,
   4 ;;   2006, 2007, 2008, 2009, 2010, 2011  Free Software Foundation, Inc.
   5 ;;
   6 ;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
   7 ;; Maintainer: FSF
   8 ;; Keywords: extensions
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software: you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation, either version 3 of the License, or
  15 ;; (at your option) any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  24
  25 ;;; Wishlist items (from widget.texi):
  26
  27 ;; * The `menu-choice' tag should be prettier, something like the
  28 ;;   abbreviated menus in Open Look.
  29
  30 ;; * Finish `:tab-order'.
  31
  32 ;; * Make indentation work with glyphs and proportional fonts.
  33
  34 ;; * Add commands to show overview of object and class hierarchies to
  35 ;;   the browser.
  36
  37 ;; * Find a way to disable mouse highlight for inactive widgets.
  38
  39 ;; * Find a way to make glyphs look inactive.
  40
  41 ;; * Add `key-binding' widget.
  42
  43 ;; * Add `widget' widget for editing widget specifications.
  44
  45 ;; * Find clean way to implement variable length list.  See
  46 ;;   `TeX-printer-list' for an explanation.
  47
  48 ;; * `C-h' in `widget-prompt-value' should give type specific help.
  49
  50 ;; * A mailto widget. [This should work OK as a url-link if with
  51 ;;   browse-url-browser-function' set up appropriately.]
  52
  53 ;;; Commentary:
  54 ;;
  55 ;; See `widget.el'.
  56
  57 ;;; Code:
  58
  59 (defvar widget)
  60
  61 ;;; Compatibility.
  62
  63 (defun widget-event-point (event)
  64   "Character position of the end of event if that exists, or nil."
  65   (posn-point (event-end event)))
  66
  67 (defun widget-button-release-event-p (event)
  68   "Non-nil if EVENT is a mouse-button-release event object."
  69   (and (eventp event)
  70        (memq (event-basic-type event) '(mouse-1 mouse-2 mouse-3))
  71        (or (memq 'click (event-modifiers event))
  72            (memq  'drag (event-modifiers event)))))
  73
  74 ;;; Customization.
  75
  76 (defgroup widgets nil
  77   "Customization support for the Widget Library."
  78   :link '(custom-manual "(widget)Top")
  79   :link '(emacs-library-link :tag "Lisp File" "widget.el")
  80   :prefix "widget-"
  81   :group 'extensions
  82   :group 'hypermedia)
  83
  84 (defgroup widget-documentation nil
  85   "Options controlling the display of documentation strings."
  86   :group 'widgets)
  87
  88 (defgroup widget-faces nil
  89   "Faces used by the widget library."
  90   :group 'widgets
  91   :group 'faces)
  92
  93 (defvar widget-documentation-face 'widget-documentation
  94   "Face used for documentation strings in widgets.
  95 This exists as a variable so it can be set locally in certain buffers.")
  96
  97 (defface widget-documentation '((((class color)
  98                                   (background dark))
  99                                  (:foreground "lime green"))
 100                                 (((class color)
 101                                   (background light))
 102                                  (:foreground "dark green"))
 103                                 (t nil))
 104   "Face used for documentation text."
 105   :group 'widget-documentation
 106   :group 'widget-faces)
 107 (define-obsolete-face-alias 'widget-documentation-face
 108   'widget-documentation "22.1")
 109
 110 (defvar widget-button-face 'widget-button
 111   "Face used for buttons in widgets.
 112 This exists as a variable so it can be set locally in certain buffers.")
 113
 114 (defface widget-button '((t (:weight bold)))
 115   "Face used for widget buttons."
 116   :group 'widget-faces)
 117 (define-obsolete-face-alias 'widget-button-face 'widget-button "22.1")
 118
 119 (defcustom widget-mouse-face 'highlight
 120   "Face used for widget buttons when the mouse is above them."
 121   :type 'face
 122   :group 'widget-faces)
 123
 124 ;; TTY gets special definitions here and in the next defface, because
 125 ;; the gray colors defined for other displays cause black text on a black
 126 ;; background, at least on light-background TTYs.
 127 (defface widget-field '((((type tty))
 128                          :background "yellow3"
 129                          :foreground "black")
 130                         (((class grayscale color)
 131                           (background light))
 132                          :background "gray85")
 133                         (((class grayscale color)
 134                           (background dark))
 135                          :background "dim gray")
 136                         (t
 137                          :slant italic))
 138   "Face used for editable fields."
 139   :group 'widget-faces)
 140 (define-obsolete-face-alias 'widget-field-face 'widget-field "22.1")
 141
 142 (defface widget-single-line-field '((((type tty))
 143                                      :background "green3"
 144                                      :foreground "black")
 145                                     (((class grayscale color)
 146                                       (background light))
 147                                      :background "gray85")
 148                                     (((class grayscale color)
 149                                       (background dark))
 150                                      :background "dim gray")
 151                                     (t
 152                                      :slant italic))
 153   "Face used for editable fields spanning only a single line."
 154   :group 'widget-faces)
 155 (define-obsolete-face-alias 'widget-single-line-field-face
 156   'widget-single-line-field "22.1")
 157
 158 ;;; This causes display-table to be loaded, and not usefully.
 159 ;;;(defvar widget-single-line-display-table
 160 ;;;  (let ((table (make-display-table)))
 161 ;;;    (aset table 9  "^I")
 162 ;;;    (aset table 10 "^J")
 163 ;;;    table)
 164 ;;;  "Display table used for single-line editable fields.")
 165
 166 ;;;(when (fboundp 'set-face-display-table)
 167 ;;;  (set-face-display-table 'widget-single-line-field-face
 168 ;;;                       widget-single-line-display-table))
 169
 170 ;;; Utility functions.
 171 ;;
 172 ;; These are not really widget specific.
 173
 174 (defun widget-princ-to-string (object)
 175   "Return string representation of OBJECT, any Lisp object.
 176 No quoting characters are used; no delimiters are printed around
 177 the contents of strings."
 178   (with-output-to-string
 179       (princ object)))
 180
 181 (defun widget-clear-undo ()
 182   "Clear all undo information."
 183   (buffer-disable-undo (current-buffer))
 184   (buffer-enable-undo))
 185
 186 (defcustom widget-menu-max-size 40
 187   "Largest number of items allowed in a popup-menu.
 188 Larger menus are read through the minibuffer."
 189   :group 'widgets
 190   :type 'integer)
 191
 192 (defcustom widget-menu-max-shortcuts 40
 193   "Largest number of items for which it works to choose one with a character.
 194 For a larger number of items, the minibuffer is used."
 195   :group 'widgets
 196   :type 'integer)
 197
 198 (defcustom widget-menu-minibuffer-flag nil
 199   "Control how to ask for a choice from the keyboard.
 200 Non-nil means use the minibuffer;
 201 nil means read a single character."
 202   :group 'widgets
 203   :type 'boolean)
 204
 205 (defun widget-choose (title items &optional event)
 206   "Choose an item from a list.
 207
 208 First argument TITLE is the name of the list.
 209 Second argument ITEMS is a list whose members are either
 210  (NAME . VALUE), to indicate selectable items, or just strings to
 211  indicate unselectable items.
 212 Optional third argument EVENT is an input event.
 213
 214 The user is asked to choose between each NAME from the items alist,
 215 and the VALUE of the chosen element will be returned.  If EVENT is a
 216 mouse event, and the number of elements in items is less than
 217 `widget-menu-max-size', a popup menu will be used, otherwise the
 218 minibuffer."
 219   (cond ((and (< (length items) widget-menu-max-size)
 220               event (display-popup-menus-p))
 221          ;; Mouse click.
 222          (x-popup-menu event
 223                        (list title (cons "" items))))
 224         ((or widget-menu-minibuffer-flag
 225              (> (length items) widget-menu-max-shortcuts))
 226          ;; Read the choice of name from the minibuffer.
 227          (setq items (widget-remove-if 'stringp items))
 228          (let ((val (completing-read (concat title ": ") items nil t)))
 229            (if (stringp val)
 230                (let ((try (try-completion val items)))
 231                  (when (stringp try)
 232                    (setq val try))
 233                  (cdr (assoc val items))))))
 234         (t
 235          ;; Construct a menu of the choices
 236          ;; and then use it for prompting for a single character.
 237          (let* ((overriding-terminal-local-map (make-sparse-keymap))
 238                 (next-digit ?0)
 239                 map choice some-choice-enabled value)
 240            ;; Define SPC as a prefix char to get to this menu.
 241            (define-key overriding-terminal-local-map " "
 242              (setq map (make-sparse-keymap title)))
 243            (with-current-buffer (get-buffer-create " widget-choose")
 244              (erase-buffer)
 245              (insert "Available choices:\n\n")
 246              (while items
 247                (setq choice (car items) items (cdr items))
 248                (if (consp choice)
 249                    (let* ((name (car choice))
 250                          (function (cdr choice)))
 251                      (insert (format "%c = %s\n" next-digit name))
 252                      (define-key map (vector next-digit) function)
 253                      (setq some-choice-enabled t)))
 254                ;; Allocate digits to disabled alternatives
 255                ;; so that the digit of a given alternative never varies.
 256                (setq next-digit (1+ next-digit)))
 257              (insert "\nC-g = Quit"))
 258            (or some-choice-enabled
 259                (error "None of the choices is currently meaningful"))
 260            (define-key map [?\C-g] 'keyboard-quit)
 261            (define-key map [t] 'keyboard-quit)
 262            (define-key map [?\M-\C-v] 'scroll-other-window)
 263            (define-key map [?\M--] 'negative-argument)
 264            (setcdr map (nreverse (cdr map)))
 265            ;; Read a char with the menu, and return the result
 266            ;; that corresponds to it.
 267            (save-window-excursion
 268              (let ((buf (get-buffer " widget-choose")))
 269                (fit-window-to-buffer (display-buffer buf))
 270                (let ((cursor-in-echo-area t)
 271                      keys
 272                      (char 0)
 273                      (arg 1))
 274                  (while (not (or (and (integerp char)
 275                                       (>= char ?0) (< char next-digit))
 276                                  (eq value 'keyboard-quit)))
 277                    ;; Unread a SPC to lead to our new menu.
 278                    (setq unread-command-events (cons ?\s unread-command-events))
 279                    (setq keys (read-key-sequence title))
 280                    (setq value
 281                          (lookup-key overriding-terminal-local-map keys t)
 282                          char (aref keys 1))
 283                    (cond ((eq value 'scroll-other-window)
 284                           (let ((minibuffer-scroll-window
 285                                  (get-buffer-window buf)))
 286                             (if (> 0 arg)
 287                                 (scroll-other-window-down
 288                                  (window-height minibuffer-scroll-window))
 289                               (scroll-other-window))
 290                             (setq arg 1)))
 291                          ((eq value 'negative-argument)
 292                           (setq arg -1))
 293                          (t
 294                           (setq arg 1)))))))
 295            (when (eq value 'keyboard-quit)
 296              (error "Canceled"))
 297            value))))
 298
 299 (defun widget-remove-if (predictate list)
 300   (let (result (tail list))
 301     (while tail
 302       (or (funcall predictate (car tail))
 303           (setq result (cons (car tail) result)))
 304       (setq tail (cdr tail)))
 305     (nreverse result)))
 306
 307 ;;; Widget text specifications.
 308 ;;
 309 ;; These functions are for specifying text properties.
 310
 311 ;; We can set it to nil now that get_local_map uses get_pos_property.
 312 (defconst widget-field-add-space nil
 313   "Non-nil means add extra space at the end of editable text fields.
 314 If you don't add the space, it will become impossible to edit a zero
 315 size field.")
 316
 317 (defvar widget-field-use-before-change t
 318   "Non-nil means use `before-change-functions' to track editable fields.
 319 This enables the use of undo.  Using before hooks also means that
 320 the :notify function can't know the new value.")
 321
 322 (defun widget-specify-field (widget from to)
 323   "Specify editable button for WIDGET between FROM and TO."
 324   ;; Terminating space is not part of the field, but necessary in
 325   ;; order for local-map to work.  Remove next sexp if local-map works
 326   ;; at the end of the overlay.
 327   (save-excursion
 328     (goto-char to)
 329     (cond ((null (widget-get widget :size))
 330            (forward-char 1))
 331           (widget-field-add-space
 332            (insert-and-inherit " ")))
 333     (setq to (point)))
 334   (let ((keymap (widget-get widget :keymap))
 335         (face (or (widget-get widget :value-face) 'widget-field))
 336         (help-echo (widget-get widget :help-echo))
 337         (follow-link (widget-get widget :follow-link))
 338         (rear-sticky
 339          (or (not widget-field-add-space) (widget-get widget :size))))
 340     (if (functionp help-echo)
 341       (setq help-echo 'widget-mouse-help))
 342     (when (= (char-before to) ?\n)
 343       ;; When the last character in the field is a newline, we want to
 344       ;; give it a `field' char-property of `boundary', which helps the
 345       ;; C-n/C-p act more naturally when entering/leaving the field.  We
 346      ;; do this by making a small secondary overlay to contain just that
 347       ;; one character.
 348       (let ((overlay (make-overlay (1- to) to nil t nil)))
 349         (overlay-put overlay 'field 'boundary)
 350         ;; We need the real field for tabbing.
 351         (overlay-put overlay 'real-field widget)
 352         ;; Use `local-map' here, not `keymap', so that normal editing
 353         ;; works in the field when, say, Custom uses `suppress-keymap'.
 354         (overlay-put overlay 'local-map keymap)
 355         (overlay-put overlay 'face face)
 356         (overlay-put overlay 'follow-link follow-link)
 357         (overlay-put overlay 'help-echo help-echo))
 358       (setq to (1- to))
 359       (setq rear-sticky t))
 360     (let ((overlay (make-overlay from to nil nil rear-sticky)))
 361       (widget-put widget :field-overlay overlay)
 362       ;;(overlay-put overlay 'detachable nil)
 363       (overlay-put overlay 'field widget)
 364       (overlay-put overlay 'local-map keymap)
 365       (overlay-put overlay 'face face)
 366       (overlay-put overlay 'follow-link follow-link)
 367       (overlay-put overlay 'help-echo help-echo)))
 368   (widget-specify-secret widget))
 369
 370 (defun widget-specify-secret (field)
 371   "Replace text in FIELD with value of `:secret', if non-nil."
 372   (let ((secret (widget-get field :secret))
 373         (size (widget-get field :size)))
 374     (when secret
 375       (let ((begin (widget-field-start field))
 376             (end (widget-field-end field)))
 377         (when size
 378           (while (and (> end begin)
 379                       (eq (char-after (1- end)) ?\s))
 380             (setq end (1- end))))
 381         (while (< begin end)
 382           (let ((old (char-after begin)))
 383             (unless (eq old secret)
 384               (subst-char-in-region begin (1+ begin) old secret)
 385               (put-text-property begin (1+ begin) 'secret old))
 386             (setq begin (1+ begin))))))))
 387
 388 (defun widget-specify-button (widget from to)
 389   "Specify button for WIDGET between FROM and TO."
 390   (let ((overlay (make-overlay from to nil t nil))
 391         (follow-link (widget-get widget :follow-link))
 392         (help-echo (widget-get widget :help-echo)))
 393     (widget-put widget :button-overlay overlay)
 394     (if (functionp help-echo)
 395       (setq help-echo 'widget-mouse-help))
 396     (overlay-put overlay 'button widget)
 397     (overlay-put overlay 'keymap (widget-get widget :keymap))
 398     (overlay-put overlay 'evaporate t)
 399     ;; We want to avoid the face with image buttons.
 400     (unless (widget-get widget :suppress-face)
 401       (overlay-put overlay 'face (widget-apply widget :button-face-get))
 402       (overlay-put overlay 'mouse-face
 403                    ;; Make new list structure for the mouse-face value
 404                    ;; so that different widgets will have
 405                    ;; different `mouse-face' property values
 406                    ;; and will highlight separately.
 407                    (let ((mouse-face-value
 408                           (widget-apply widget :mouse-face-get)))
 409                      ;; If it's a list, copy it.
 410                      (if (listp mouse-face-value)
 411                          (copy-sequence mouse-face-value)
 412                        ;; If it's a symbol, put it in a list.
 413                        (list mouse-face-value)))))
 414     (overlay-put overlay 'pointer 'hand)
 415     (overlay-put overlay 'follow-link follow-link)
 416     (overlay-put overlay 'help-echo help-echo)))
 417
 418 (defun widget-mouse-help (window overlay point)
 419   "Help-echo callback for widgets whose :help-echo is a function."
 420   (with-current-buffer (overlay-buffer overlay)
 421     (let* ((widget (widget-at (overlay-start overlay)))
 422            (help-echo (if widget (widget-get widget :help-echo))))
 423       (if (functionp help-echo)
 424           (funcall help-echo widget)
 425         help-echo))))
 426
 427 (defun widget-specify-sample (widget from to)
 428   "Specify sample for WIDGET between FROM and TO."
 429   (let ((overlay (make-overlay from to nil t nil)))
 430     (overlay-put overlay 'face (widget-apply widget :sample-face-get))
 431     (overlay-put overlay 'evaporate t)
 432     (widget-put widget :sample-overlay overlay)))
 433
 434 (defun widget-specify-doc (widget from to)
 435   "Specify documentation for WIDGET between FROM and TO."
 436   (let ((overlay (make-overlay from to nil t nil)))
 437     (overlay-put overlay 'widget-doc widget)
 438     (overlay-put overlay 'face widget-documentation-face)
 439     (overlay-put overlay 'evaporate t)
 440     (widget-put widget :doc-overlay overlay)))
 441
 442 (defmacro widget-specify-insert (&rest form)
 443   "Execute FORM without inheriting any text properties."
 444   `(save-restriction
 445     (let ((inhibit-read-only t)
 446           (inhibit-modification-hooks t))
 447       (narrow-to-region (point) (point))
 448       (prog1 (progn ,@form)
 449         (goto-char (point-max))))))
 450
 451 (defface widget-inactive
 452   '((t :inherit shadow))
 453   "Face used for inactive widgets."
 454   :group 'widget-faces)
 455 (define-obsolete-face-alias 'widget-inactive-face
 456   'widget-inactive "22.1")
 457
 458 (defun widget-specify-inactive (widget from to)
 459   "Make WIDGET inactive for user modifications."
 460   (unless (widget-get widget :inactive)
 461     (let ((overlay (make-overlay from to nil t nil)))
 462       (overlay-put overlay 'face 'widget-inactive)
 463       ;; This is disabled, as it makes the mouse cursor change shape.
 464       ;; (overlay-put overlay 'mouse-face 'widget-inactive)
 465       (overlay-put overlay 'evaporate t)
 466       (overlay-put overlay 'priority 100)
 467       (overlay-put overlay 'modification-hooks '(widget-overlay-inactive))
 468       (widget-put widget :inactive overlay))))
 469
 470 (defun widget-overlay-inactive (&rest junk)
 471   "Ignoring the arguments, signal an error."
 472   (unless inhibit-read-only
 473     (error "The widget here is not active")))
 474
 475
 476 (defun widget-specify-active (widget)
 477   "Make WIDGET active for user modifications."
 478   (let ((inactive (widget-get widget :inactive)))
 479     (when inactive
 480       (delete-overlay inactive)
 481       (widget-put widget :inactive nil))))
 482
 483 ;;; Widget Properties.
 484
 485 (defsubst widget-type (widget)
 486   "Return the type of WIDGET.  The type is a symbol."
 487   (car widget))
 488
 489 ;;;###autoload
 490 (defun widgetp (widget)
 491   "Return non-nil if WIDGET is a widget."
 492   (if (symbolp widget)
 493       (get widget 'widget-type)
 494     (and (consp widget)
 495          (symbolp (car widget))
 496          (get (car widget) 'widget-type))))
 497
 498 (defun widget-get-indirect (widget property)
 499   "In WIDGET, get the value of PROPERTY.
 500 If the value is a symbol, return its binding.
 501 Otherwise, just return the value."
 502   (let ((value (widget-get widget property)))
 503     (if (symbolp value)
 504         (symbol-value value)
 505       value)))
 506
 507 (defun widget-member (widget property)
 508   "Non-nil if there is a definition in WIDGET for PROPERTY."
 509   (cond ((plist-member (cdr widget) property)
 510          t)
 511         ((car widget)
 512          (widget-member (get (car widget) 'widget-type) property))
 513         (t nil)))
 514
 515 (defun widget-value (widget)
 516   "Extract the current value of WIDGET."
 517   (widget-apply widget
 518                 :value-to-external (widget-apply widget :value-get)))
 519
 520 (defun widget-value-set (widget value)
 521   "Set the current value of WIDGET to VALUE."
 522   (widget-apply widget
 523                 :value-set (widget-apply widget
 524                                          :value-to-internal value)))
 525
 526 (defun widget-default-get (widget)
 527   "Extract the default external value of WIDGET."
 528   (widget-apply widget :value-to-external
 529                 (or (widget-get widget :value)
 530                     (widget-apply widget :default-get))))
 531
 532 (defun widget-match-inline (widget vals)
 533   "In WIDGET, match the start of VALS."
 534   (cond ((widget-get widget :inline)
 535          (widget-apply widget :match-inline vals))
 536         ((and (listp vals)
 537               (widget-apply widget :match (car vals)))
 538          (cons (list (car vals)) (cdr vals)))
 539         (t nil)))
 540
 541 (defun widget-apply-action (widget &optional event)
 542   "Apply :action in WIDGET in response to EVENT."
 543   (if (widget-apply widget :active)
 544       (widget-apply widget :action event)
 545     (error "Attempt to perform action on inactive widget")))
 546
 547 ;;; Helper functions.
 548 ;;
 549 ;; These are widget specific.
 550
 551 ;;;###autoload
 552 (defun widget-prompt-value (widget prompt &optional value unbound)
 553   "Prompt for a value matching WIDGET, using PROMPT.
 554 The current value is assumed to be VALUE, unless UNBOUND is non-nil."
 555   (unless (listp widget)
 556     (setq widget (list widget)))
 557   (setq prompt (format "[%s] %s" (widget-type widget) prompt))
 558   (setq widget (widget-convert widget))
 559   (let ((answer (widget-apply widget :prompt-value prompt value unbound)))
 560     (unless (widget-apply widget :match answer)
 561       (error "Value does not match %S type" (car widget)))
 562     answer))
 563
 564 (defun widget-get-sibling (widget)
 565   "Get the item WIDGET is assumed to toggle.
 566 This is only meaningful for radio buttons or checkboxes in a list."
 567   (let* ((children (widget-get (widget-get widget :parent) :children))
 568          child)
 569     (catch 'child
 570       (while children
 571         (setq child (car children)
 572               children (cdr children))
 573         (when (eq (widget-get child :button) widget)
 574           (throw 'child child)))
 575       nil)))
 576
 577 (defun widget-map-buttons (function &optional buffer maparg)
 578   "Map FUNCTION over the buttons in BUFFER.
 579 FUNCTION is called with the arguments WIDGET and MAPARG.
 580
 581 If FUNCTION returns non-nil, the walk is cancelled.
 582
 583 The arguments MAPARG, and BUFFER default to nil and (current-buffer),
 584 respectively."
 585   (let ((cur (point-min))
 586         (widget nil)
 587         (overlays (if buffer
 588                       (with-current-buffer buffer (overlay-lists))
 589                     (overlay-lists))))
 590     (setq overlays (append (car overlays) (cdr overlays)))
 591     (while (setq cur (pop overlays))
 592       (setq widget (overlay-get cur 'button))
 593       (if (and widget (funcall function widget maparg))
 594           (setq overlays nil)))))
 595
 596 ;;; Images.
 597
 598 (defcustom widget-image-directory (file-name-as-directory
 599                                    (expand-file-name "images/custom" data-directory))
 600   "Where widget button images are located.
 601 If this variable is nil, widget will try to locate the directory
 602 automatically."
 603   :group 'widgets
 604   :type 'directory)
 605
 606 (defcustom widget-image-enable t
 607   "If non-nil, use image buttons in widgets when available."
 608   :version "21.1"
 609   :group 'widgets
 610   :type 'boolean)
 611
 612 (defcustom widget-image-conversion
 613   '((xpm ".xpm") (gif ".gif") (png ".png") (jpeg ".jpg" ".jpeg")
 614     (xbm ".xbm"))
 615   "Conversion alist from image formats to file name suffixes."
 616   :group 'widgets
 617   :type '(repeat (cons :format "%v"
 618                        (symbol :tag "Image Format" unknown)
 619                        (repeat :tag "Suffixes"
 620                                (string :format "%v")))))
 621
 622 (defun widget-image-find (image)
 623   "Create a graphical button from IMAGE.
 624 IMAGE should either already be an image, or be a file name sans
 625 extension (xpm, xbm, gif, jpg, or png) located in
 626 `widget-image-directory' or otherwise where `find-image' will find it."
 627   (cond ((not (and image widget-image-enable (display-graphic-p)))
 628          ;; We don't want or can't use images.
 629          nil)
 630         ((and (consp image)
 631               (eq 'image (car image)))
 632          ;; Already an image spec.  Use it.
 633          image)
 634         ((stringp image)
 635          ;; A string.  Look it up in relevant directories.
 636          (let* ((load-path (cons widget-image-directory load-path))
 637                 specs)
 638            (dolist (elt widget-image-conversion)
 639              (dolist (ext (cdr elt))
 640                (push (list :type (car elt) :file (concat image ext)) specs)))
 641            (setq specs (nreverse specs))
 642            (find-image specs)))
 643         (t
 644          ;; Oh well.
 645          nil)))
 646
 647 (defvar widget-button-pressed-face 'widget-button-pressed
 648   "Face used for pressed buttons in widgets.
 649 This exists as a variable so it can be set locally in certain
 650 buffers.")
 651
 652 (defun widget-image-insert (widget tag image &optional down inactive)
 653   "In WIDGET, insert the text TAG or, if supported, IMAGE.
 654 IMAGE should either be an image or an image file name sans extension
 655 \(xpm, xbm, gif, jpg, or png) located in `widget-image-directory'.
 656
 657 Optional arguments DOWN and INACTIVE are used instead of IMAGE when the
 658 button is pressed or inactive, respectively.  These are currently ignored."
 659   (if (and (display-graphic-p)
 660            (setq image (widget-image-find image)))
 661       (progn (widget-put widget :suppress-face t)
 662              (insert-image image tag))
 663     (insert tag)))
 664
 665 (defun widget-move-and-invoke (event)
 666   "Move to where you click, and if it is an active field, invoke it."
 667   (interactive "e")
 668   (mouse-set-point event)
 669   (let ((pos (widget-event-point event)))
 670     (if (and pos (get-char-property pos 'button))
 671         (widget-button-click event))))
 672
 673 ;;; Buttons.
 674
 675 (defgroup widget-button nil
 676   "The look of various kinds of buttons."
 677   :group 'widgets)
 678
 679 (defcustom widget-button-prefix ""
 680   "String used as prefix for buttons."
 681   :type 'string
 682   :group 'widget-button)
 683
 684 (defcustom widget-button-suffix ""
 685   "String used as suffix for buttons."
 686   :type 'string
 687   :group 'widget-button)
 688
 689 ;;; Creating Widgets.
 690
 691 ;;;###autoload
 692 (defun widget-create (type &rest args)
 693   "Create widget of TYPE.
 694 The optional ARGS are additional keyword arguments."
 695   (let ((widget (apply 'widget-convert type args)))
 696     (widget-apply widget :create)
 697     widget))
 698
 699 (defun widget-create-child-and-convert (parent type &rest args)
 700   "As part of the widget PARENT, create a child widget TYPE.
 701 The child is converted, using the keyword arguments ARGS."
 702   (let ((widget (apply 'widget-convert type args)))
 703     (widget-put widget :parent parent)
 704     (unless (widget-get widget :indent)
 705       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 706                                     (or (widget-get widget :extra-offset) 0)
 707                                     (widget-get parent :offset))))
 708     (widget-apply widget :create)
 709     widget))
 710
 711 (defun widget-create-child (parent type)
 712   "Create widget of TYPE."
 713   (let ((widget (widget-copy type)))
 714     (widget-put widget :parent parent)
 715     (unless (widget-get widget :indent)
 716       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 717                                     (or (widget-get widget :extra-offset) 0)
 718                                     (widget-get parent :offset))))
 719     (widget-apply widget :create)
 720     widget))
 721
 722 (defun widget-create-child-value (parent type value)
 723   "Create widget of TYPE with value VALUE."
 724   (let ((widget (widget-copy type)))
 725     (widget-put widget :value (widget-apply widget :value-to-internal value))
 726     (widget-put widget :parent parent)
 727     (unless (widget-get widget :indent)
 728       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 729                                     (or (widget-get widget :extra-offset) 0)
 730                                     (widget-get parent :offset))))
 731     (widget-apply widget :create)
 732     widget))
 733
 734 ;;;###autoload
 735 (defun widget-delete (widget)
 736   "Delete WIDGET."
 737   (widget-apply widget :delete))
 738
 739 (defun widget-copy (widget)
 740   "Make a deep copy of WIDGET."
 741   (widget-apply (copy-sequence widget) :copy))
 742
 743 (defun widget-convert (type &rest args)
 744   "Convert TYPE to a widget without inserting it in the buffer.
 745 The optional ARGS are additional keyword arguments."
 746   ;; Don't touch the type.
 747   (let* ((widget (if (symbolp type)
 748                      (list type)
 749                    (copy-sequence type)))
 750          (current widget)
 751          done
 752          (keys args))
 753     ;; First set the :args keyword.
 754     (while (cdr current)                ;Look in the type.
 755       (if (and (keywordp (cadr current))
 756                ;; If the last element is a keyword,
 757                ;; it is still the :args element,
 758                ;; even though it is a keyword.
 759                (cddr current))
 760           (if (eq (cadr current) :args)
 761               ;; If :args is explicitly specified, obey it.
 762               (setq current nil)
 763             ;; Some other irrelevant keyword.
 764             (setq current (cdr (cdr current))))
 765         (setcdr current (list :args (cdr current)))
 766         (setq current nil)))
 767     (while (and args (not done))        ;Look in ARGS.
 768       (cond ((eq (car args) :args)
 769              ;; Handle explicit specification of :args.
 770              (setq args (cadr args)
 771                    done t))
 772             ((keywordp (car args))
 773              (setq args (cddr args)))
 774             (t (setq done t))))
 775     (when done
 776       (widget-put widget :args args))
 777     ;; Then Convert the widget.
 778     (setq type widget)
 779     (while type
 780       (let ((convert-widget (plist-get (cdr type) :convert-widget)))
 781         (if convert-widget
 782             (setq widget (funcall convert-widget widget))))
 783       (setq type (get (car type) 'widget-type)))
 784     ;; Finally set the keyword args.
 785     (while keys
 786       (let ((next (nth 0 keys)))
 787         (if (keywordp next)
 788             (progn
 789               (widget-put widget next (nth 1 keys))
 790               (setq keys (nthcdr 2 keys)))
 791           (setq keys nil))))
 792     ;; Convert the :value to internal format.
 793     (if (widget-member widget :value)
 794         (widget-put widget
 795                     :value (widget-apply widget
 796                                          :value-to-internal
 797                                          (widget-get widget :value))))
 798     ;; Return the newly create widget.
 799     widget))
 800
 801 ;;;###autoload
 802 (defun widget-insert (&rest args)
 803   "Call `insert' with ARGS even if surrounding text is read only."
 804   (let ((inhibit-read-only t)
 805         (inhibit-modification-hooks t))
 806     (apply 'insert args)))
 807
 808 (defun widget-convert-text (type from to
 809                                  &optional button-from button-to
 810                                  &rest args)
 811   "Return a widget of type TYPE with endpoint FROM TO.
 812 No text will be inserted to the buffer, instead the text between FROM
 813 and TO will be used as the widgets end points.  If optional arguments
 814 BUTTON-FROM and BUTTON-TO are given, these will be used as the widgets
 815 button end points.
 816 Optional ARGS are extra keyword arguments for TYPE."
 817   (let ((widget (apply 'widget-convert type :delete 'widget-leave-text args))
 818         (from (copy-marker from))
 819         (to (copy-marker to)))
 820     (set-marker-insertion-type from t)
 821     (set-marker-insertion-type to nil)
 822     (widget-put widget :from from)
 823     (widget-put widget :to to)
 824     (when button-from
 825       (widget-specify-button widget button-from button-to))
 826     widget))
 827
 828 (defun widget-convert-button (type from to &rest args)
 829   "Return a widget of type TYPE with endpoint FROM TO.
 830 Optional ARGS are extra keyword arguments for TYPE.
 831 No text will be inserted to the buffer, instead the text between FROM
 832 and TO will be used as the widgets end points, as well as the widgets
 833 button end points."
 834   (apply 'widget-convert-text type from to from to args))
 835
 836 (defun widget-leave-text (widget)
 837   "Remove markers and overlays from WIDGET and its children."
 838   (let ((button (widget-get widget :button-overlay))
 839         (sample (widget-get widget :sample-overlay))
 840         (doc (widget-get widget :doc-overlay))
 841         (field (widget-get widget :field-overlay)))
 842     (set-marker (widget-get widget :from) nil)
 843     (set-marker (widget-get widget :to) nil)
 844     (when button
 845       (delete-overlay button))
 846     (when sample
 847       (delete-overlay sample))
 848     (when doc
 849       (delete-overlay doc))
 850     (when field
 851       (delete-overlay field))
 852     (mapc 'widget-leave-text (widget-get widget :children))))
 853
 854 ;;; Keymap and Commands.
 855
 856 ;; This alias exists only so that one can choose in doc-strings (e.g.
 857 ;; Custom-mode) which key-binding of widget-keymap one wants to refer to.
 858 ;; http://lists.gnu.org/archive/html/emacs-devel/2008-11/msg00480.html
 859 (define-obsolete-function-alias 'advertised-widget-backward
 860   'widget-backward "23.2")
 861
 862 ;;;###autoload
 863 (defvar widget-keymap
 864   (let ((map (make-sparse-keymap)))
 865     (define-key map "\t" 'widget-forward)
 866     (define-key map "\e\t" 'widget-backward)
 867     (define-key map [(shift tab)] 'widget-backward)
 868     (put 'widget-backward :advertised-binding [(shift tab)])
 869     (define-key map [backtab] 'widget-backward)
 870     (define-key map [down-mouse-2] 'widget-button-click)
 871     (define-key map [down-mouse-1] 'widget-button-click)
 872     ;; The following definition needs to avoid using escape sequences that
 873     ;; might get converted to ^M when building loaddefs.el
 874     (define-key map [(control ?m)] 'widget-button-press)
 875     map)
 876   "Keymap containing useful binding for buffers containing widgets.
 877 Recommended as a parent keymap for modes using widgets.
 878 Note that such modes will need to require wid-edit.")
 879
 880 (defvar widget-global-map global-map
 881   "Keymap used for events a widget does not handle itself.")
 882 (make-variable-buffer-local 'widget-global-map)
 883
 884 (defvar widget-field-keymap
 885   (let ((map (copy-keymap widget-keymap)))
 886     (define-key map "\C-k" 'widget-kill-line)
 887     (define-key map "\M-\t" 'widget-complete)
 888     (define-key map "\C-m" 'widget-field-activate)
 889     ;; Since the widget code uses a `field' property to identify fields,
 890     ;; ordinary beginning-of-line does the right thing.
 891     ;;  (define-key map "\C-a" 'widget-beginning-of-line)
 892     (define-key map "\C-e" 'widget-end-of-line)
 893     map)
 894   "Keymap used inside an editable field.")
 895
 896 (defvar widget-text-keymap
 897   (let ((map (copy-keymap widget-keymap)))
 898     ;; Since the widget code uses a `field' property to identify fields,
 899     ;; ordinary beginning-of-line does the right thing.
 900     ;;  (define-key map "\C-a" 'widget-beginning-of-line)
 901     (define-key map "\C-e" 'widget-end-of-line)
 902     map)
 903   "Keymap used inside a text field.")
 904
 905 (defun widget-field-activate (pos &optional event)
 906   "Invoke the editable field at point."
 907   (interactive "@d")
 908   (let ((field (widget-field-at pos)))
 909     (if field
 910         (widget-apply-action field event)
 911       (call-interactively
 912        (lookup-key widget-global-map (this-command-keys))))))
 913
 914 (defface widget-button-pressed
 915   '((((min-colors 88) (class color))
 916      (:foreground "red1"))
 917     (((class color))
 918      (:foreground "red"))
 919     (t
 920      (:weight bold :underline t)))
 921   "Face used for pressed buttons."
 922   :group 'widget-faces)
 923 (define-obsolete-face-alias 'widget-button-pressed-face
 924   'widget-button-pressed "22.1")
 925
 926 (defvar widget-button-click-moves-point nil
 927   "If non-nil, `widget-button-click' moves point to a button after invoking it.
 928 If nil, point returns to its original position after invoking a button.")
 929
 930 (defun widget-button-click (event)
 931   "Invoke the button that the mouse is pointing at."
 932   (interactive "e")
 933   (if (widget-event-point event)
 934       (let* ((oevent event)
 935              (mouse-1 (memq (event-basic-type event) '(mouse-1 down-mouse-1)))
 936              (pos (widget-event-point event))
 937              (start (event-start event))
 938              (button (get-char-property
 939                       pos 'button (and (windowp (posn-window start))
 940                                        (window-buffer (posn-window start)))))
 941              newpoint)
 942         (when (or (null button)
 943                   (catch 'button-press-cancelled
 944               ;; Mouse click on a widget button.  Do the following
 945               ;; in a save-excursion so that the click on the button
 946               ;; doesn't change point.
 947               (save-selected-window
 948                 (select-window (posn-window (event-start event)))
 949                 (save-excursion
 950                   (goto-char (posn-point (event-start event)))
 951                   (let* ((overlay (widget-get button :button-overlay))
 952                          (pressed-face (or (widget-get button :pressed-face)
 953                                            widget-button-pressed-face))
 954                          (face (overlay-get overlay 'face))
 955                          (mouse-face (overlay-get overlay 'mouse-face)))
 956                     (unwind-protect
 957                         ;; Read events, including mouse-movement
 958                         ;; events, waiting for a release event.  If we
 959                         ;; began with a mouse-1 event and receive a
 960                         ;; movement event, that means the user wants
 961                         ;; to perform drag-selection, so cancel the
 962                         ;; button press and do the default mouse-1
 963                         ;; action.  For mouse-2, just highlight/
 964                         ;; unhighlight the button the mouse was
 965                         ;; initially on when we move over it.
 966                         (save-excursion
 967                           (when face    ; avoid changing around image
 968                             (overlay-put overlay 'face pressed-face)
 969                             (overlay-put overlay 'mouse-face pressed-face))
 970                           (unless (widget-apply button :mouse-down-action event)
 971                             (let ((track-mouse t))
 972                               (while (not (widget-button-release-event-p event))
 973                                 (setq event (read-event))
 974                                 (when (and mouse-1 (mouse-movement-p event))
 975                                   (push event unread-command-events)
 976                                   (setq event oevent)
 977                                   (throw 'button-press-cancelled t))
 978                                 (unless (or (integerp event)
 979                                             (memq (car event) '(switch-frame select-window))
 980                                             (eq (car event) 'scroll-bar-movement))
 981                                   (setq pos (widget-event-point event))
 982                                   (if (and pos
 983                                            (eq (get-char-property pos 'button)
 984                                                button))
 985                                       (when face
 986                                         (overlay-put overlay 'face pressed-face)
 987                                         (overlay-put overlay 'mouse-face pressed-face))
 988                                     (overlay-put overlay 'face face)
 989                                     (overlay-put overlay 'mouse-face mouse-face))))))
 990
 991                           ;; When mouse is released over the button, run
 992                           ;; its action function.
 993                           (when (and pos (eq (get-char-property pos 'button) button))
 994                             (goto-char pos)
 995                             (widget-apply-action button event)
 996                             (if widget-button-click-moves-point
 997                                 (setq newpoint (point)))))
 998                       (overlay-put overlay 'face face)
 999                       (overlay-put overlay 'mouse-face mouse-face))))
1000
1001                 (if newpoint (goto-char newpoint))
1002                 ;; This loses if the widget action switches windows. -- cyd
1003                 ;; (unless (pos-visible-in-window-p (widget-event-point event))
1004                 ;;   (mouse-set-point event)
1005                 ;;   (beginning-of-line)
1006                 ;;   (recenter))
1007                 )
1008               nil))
1009           (let ((up t) command)
1010             ;; Mouse click not on a widget button.  Find the global
1011             ;; command to run, and check whether it is bound to an
1012             ;; up event.
1013             (if mouse-1
1014                 (cond ((setq command    ;down event
1015                              (lookup-key widget-global-map [down-mouse-1]))
1016                        (setq up nil))
1017                       ((setq command    ;up event
1018                              (lookup-key widget-global-map [mouse-1]))))
1019               (cond ((setq command      ;down event
1020                            (lookup-key widget-global-map [down-mouse-2]))
1021                      (setq up nil))
1022                     ((setq command      ;up event
1023                            (lookup-key widget-global-map [mouse-2])))))
1024             (when up
1025               ;; Don't execute up events twice.
1026               (while (not (widget-button-release-event-p event))
1027                 (setq event (read-event))))
1028             (when command
1029               (call-interactively command)))))
1030     (message "You clicked somewhere weird.")))
1031
1032 (defun widget-button-press (pos &optional event)
1033   "Invoke button at POS."
1034   (interactive "@d")
1035   (let ((button (get-char-property pos 'button)))
1036     (if button
1037         (widget-apply-action button event)
1038       (let ((command (lookup-key widget-global-map (this-command-keys))))
1039         (when (commandp command)
1040           (call-interactively command))))))
1041
1042 (defun widget-tabable-at (&optional pos)
1043   "Return the tabable widget at POS, or nil.
1044 POS defaults to the value of (point)."
1045   (let ((widget (widget-at pos)))
1046     (if widget
1047         (let ((order (widget-get widget :tab-order)))
1048           (if order
1049               (if (>= order 0)
1050                   widget)
1051             widget)))))
1052
1053 (defvar widget-use-overlay-change t
1054   "If non-nil, use overlay change functions to tab around in the buffer.
1055 This is much faster.")
1056
1057 (defun widget-move (arg)
1058   "Move point to the ARG next field or button.
1059 ARG may be negative to move backward."
1060   (or (bobp) (> arg 0) (backward-char))
1061   (let ((wrapped 0)
1062         (number arg)
1063         (old (widget-tabable-at)))
1064     ;; Forward.
1065     (while (> arg 0)
1066       (cond ((eobp)
1067              (goto-char (point-min))
1068              (setq wrapped (1+ wrapped)))
1069             (widget-use-overlay-change
1070              (goto-char (next-overlay-change (point))))
1071             (t
1072              (forward-char 1)))
1073       (and (= wrapped 2)
1074            (eq arg number)
1075            (error "No buttons or fields found"))
1076       (let ((new (widget-tabable-at)))
1077         (when new
1078           (unless (eq new old)
1079             (setq arg (1- arg))
1080             (setq old new)))))
1081     ;; Backward.
1082     (while (< arg 0)
1083       (cond ((bobp)
1084              (goto-char (point-max))
1085              (setq wrapped (1+ wrapped)))
1086             (widget-use-overlay-change
1087              (goto-char (previous-overlay-change (point))))
1088             (t
1089              (backward-char 1)))
1090       (and (= wrapped 2)
1091            (eq arg number)
1092            (error "No buttons or fields found"))
1093       (let ((new (widget-tabable-at)))
1094         (when new
1095           (unless (eq new old)
1096             (setq arg (1+ arg))))))
1097     (let ((new (widget-tabable-at)))
1098       (while (eq (widget-tabable-at) new)
1099         (backward-char)))
1100     (forward-char))
1101   (widget-echo-help (point))
1102   (run-hooks 'widget-move-hook))
1103
1104 (defun widget-forward (arg)
1105   "Move point to the next field or button.
1106 With optional ARG, move across that many fields."
1107   (interactive "p")
1108   (run-hooks 'widget-forward-hook)
1109   (widget-move arg))
1110
1111 (defun widget-backward (arg)
1112   "Move point to the previous field or button.
1113 With optional ARG, move across that many fields."
1114   (interactive "p")
1115   (run-hooks 'widget-backward-hook)
1116   (widget-move (- arg)))
1117
1118 ;; Since the widget code uses a `field' property to identify fields,
1119 ;; ordinary beginning-of-line does the right thing.
1120 (defalias 'widget-beginning-of-line 'beginning-of-line)
1121
1122 (defun widget-end-of-line ()
1123   "Go to end of field or end of line, whichever is first.
1124 Trailing spaces at the end of padded fields are not considered part of
1125 the field."
1126   (interactive)
1127   ;; Ordinary end-of-line does the right thing, because we're inside
1128   ;; text with a `field' property.
1129   (end-of-line)
1130   (unless (eolp)
1131     ;; ... except that we want to ignore trailing spaces in fields that
1132     ;; aren't terminated by a newline, because they are used as padding,
1133     ;; and ignored when extracting the entered value of the field.
1134     (skip-chars-backward " " (field-beginning (1- (point))))))
1135
1136 (defun widget-kill-line ()
1137   "Kill to end of field or end of line, whichever is first."
1138   (interactive)
1139   (let* ((field (widget-field-find (point)))
1140          (end (and field (widget-field-end field))))
1141     (if (and field (> (line-beginning-position 2) end))
1142         (kill-region (point) end)
1143       (call-interactively 'kill-line))))
1144
1145 (defcustom widget-complete-field (lookup-key global-map "\M-\t")
1146   "Default function to call for completion inside fields."
1147   :options '(ispell-complete-word complete-tag lisp-complete-symbol)
1148   :type 'function
1149   :group 'widgets)
1150
1151 (defun widget-narrow-to-field ()
1152   "Narrow to field."
1153   (interactive)
1154   (let ((field (widget-field-find (point))))
1155     (if field
1156         (narrow-to-region (line-beginning-position) (line-end-position)))))
1157
1158 ;; This used to say:
1159 ;; "When not inside a field, move to the previous button or field."
1160 ;; but AFAICS, it has always just thrown an error.
1161 (defun widget-complete ()
1162   "Complete content of editable field from point.
1163 When not inside a field, signal an error."
1164   (interactive)
1165   (let ((field (widget-field-find (point))))
1166     (if field
1167         (widget-apply field :complete)
1168       (error "Not in an editable field"))))
1169
1170 ;;; Setting up the buffer.
1171
1172 (defvar widget-field-new nil
1173   "List of all newly created editable fields in the buffer.")
1174 (make-variable-buffer-local 'widget-field-new)
1175
1176 (defvar widget-field-list nil
1177   "List of all editable fields in the buffer.")
1178 (make-variable-buffer-local 'widget-field-list)
1179
1180 (defun widget-at (&optional pos)
1181   "The button or field at POS (default, point)."
1182   (or (get-char-property (or pos (point)) 'button)
1183       (widget-field-at pos)))
1184
1185 ;;;###autoload
1186 (defun widget-setup ()
1187   "Setup current buffer so editing string widgets works."
1188   (let ((inhibit-read-only t)
1189         (inhibit-modification-hooks t)
1190         field)
1191     (while widget-field-new
1192       (setq field (car widget-field-new)
1193             widget-field-new (cdr widget-field-new)
1194             widget-field-list (cons field widget-field-list))
1195       (let ((from (car (widget-get field :field-overlay)))
1196             (to (cdr (widget-get field :field-overlay))))
1197         (widget-specify-field field
1198                               (marker-position from) (marker-position to))
1199         (set-marker from nil)
1200         (set-marker to nil))))
1201   (widget-clear-undo)
1202   (widget-add-change))
1203
1204 (defvar widget-field-last nil)
1205 ;; Last field containing point.
1206 (make-variable-buffer-local 'widget-field-last)
1207
1208 (defvar widget-field-was nil)
1209 ;; The widget data before the change.
1210 (make-variable-buffer-local 'widget-field-was)
1211
1212 (defun widget-field-at (pos)
1213   "Return the widget field at POS, or nil if none."
1214   (let ((field (get-char-property (or pos (point)) 'field)))
1215     (if (eq field 'boundary)
1216         (get-char-property (or pos (point)) 'real-field)
1217       field)))
1218
1219 (defun widget-field-buffer (widget)
1220   "Return the buffer of WIDGET's editing field."
1221   (let ((overlay (widget-get widget :field-overlay)))
1222     (cond ((overlayp overlay)
1223            (overlay-buffer overlay))
1224           ((consp overlay)
1225            (marker-buffer (car overlay))))))
1226
1227 (defun widget-field-start (widget)
1228   "Return the start of WIDGET's editing field."
1229   (let ((overlay (widget-get widget :field-overlay)))
1230     (if (overlayp overlay)
1231         (overlay-start overlay)
1232       (car overlay))))
1233
1234 (defun widget-field-end (widget)
1235   "Return the end of WIDGET's editing field."
1236   (let ((overlay (widget-get widget :field-overlay)))
1237     ;; Don't subtract one if local-map works at the end of the overlay,
1238     ;; or if a special `boundary' field has been added after the widget
1239     ;; field.
1240     (if (overlayp overlay)
1241         ;; Don't proceed if overlay has been removed from buffer.
1242         (when (overlay-buffer overlay)
1243           (if (and (not (eq (with-current-buffer
1244                                 (widget-field-buffer widget)
1245                               (save-restriction
1246                                 ;; `widget-narrow-to-field' can be
1247                                 ;; active when this function is called
1248                                 ;; from an change-functions hook. So
1249                                 ;; temporarily remove field narrowing
1250                                 ;; before to call `get-char-property'.
1251                                 (widen)
1252                                 (get-char-property (overlay-end overlay)
1253                                                    'field)))
1254                             'boundary))
1255                    (or widget-field-add-space
1256                        (null (widget-get widget :size))))
1257               (1- (overlay-end overlay))
1258             (overlay-end overlay)))
1259       (cdr overlay))))
1260
1261 (defun widget-field-text-end (widget)
1262   (let ((to   (widget-field-end widget))
1263         (size (widget-get widget :size)))
1264     (if (or (null size) (zerop size))
1265         to
1266       (let ((from (widget-field-start widget)))
1267         (if (and from to)
1268             (with-current-buffer (widget-field-buffer widget)
1269               (while (and (> to from)
1270                           (eq (char-after (1- to)) ?\s))
1271                 (setq to (1- to)))
1272               to))))))
1273
1274 (defun widget-field-find (pos)
1275   "Return the field at POS.
1276 Unlike (get-char-property POS 'field), this works with empty fields too."
1277   (let ((fields widget-field-list)
1278         field found)
1279     (while fields
1280       (setq field (car fields)
1281             fields (cdr fields))
1282       (when (and (<= (widget-field-start field) pos)
1283                  (<= pos (widget-field-end field)))
1284         (when found
1285           (error "Overlapping fields"))
1286         (setq found field)))
1287     found))
1288
1289 (defun widget-before-change (from to)
1290   ;; This is how, for example, a variable changes its state to `modified'.
1291   ;; when it is being edited.
1292   (unless inhibit-read-only
1293     (let ((from-field (widget-field-find from))
1294           (to-field (widget-field-find to)))
1295       (cond ((not (eq from-field to-field))
1296              (add-hook 'post-command-hook 'widget-add-change nil t)
1297              (signal 'text-read-only
1298                      '("Change should be restricted to a single field")))
1299             ((null from-field)
1300              (add-hook 'post-command-hook 'widget-add-change nil t)
1301              (signal 'text-read-only
1302                      '("Attempt to change text outside editable field")))
1303             (widget-field-use-before-change
1304              (widget-apply from-field :notify from-field))))))
1305
1306 (defun widget-add-change ()
1307   (remove-hook 'post-command-hook 'widget-add-change t)
1308   (add-hook 'before-change-functions 'widget-before-change nil t)
1309   (add-hook 'after-change-functions 'widget-after-change nil t))
1310
1311 (defun widget-after-change (from to old)
1312   "Adjust field size and text properties."
1313   (let ((field (widget-field-find from))
1314         (other (widget-field-find to)))
1315     (when field
1316       (unless (eq field other)
1317         (error "Change in different fields"))
1318       (let ((size (widget-get field :size)))
1319         (when size
1320           (let ((begin (widget-field-start field))
1321                 (end (widget-field-end field)))
1322             (cond ((< (- end begin) size)
1323                    ;; Field too small.
1324                    (save-excursion
1325                      (goto-char end)
1326                      (insert-char ?\s (- (+ begin size) end))))
1327                   ((> (- end begin) size)
1328                    ;; Field too large and
1329                    (if (or (< (point) (+ begin size))
1330                            (> (point) end))
1331                        ;; Point is outside extra space.
1332                        (setq begin (+ begin size))
1333                      ;; Point is within the extra space.
1334                      (setq begin (point)))
1335                    (save-excursion
1336                      (goto-char end)
1337                      (while (and (eq (preceding-char) ?\s)
1338                                  (> (point) begin))
1339                        (delete-backward-char 1)))))))
1340         (widget-specify-secret field))
1341       (widget-apply field :notify field))))
1342
1343 ;;; Widget Functions
1344 ;;
1345 ;; These functions are used in the definition of multiple widgets.
1346
1347 (defun widget-parent-action (widget &optional event)
1348   "Tell :parent of WIDGET to handle the :action.
1349 Optional EVENT is the event that triggered the action."
1350   (widget-apply (widget-get widget :parent) :action event))
1351
1352 (defun widget-children-value-delete (widget)
1353   "Delete all :children and :buttons in WIDGET."
1354   (mapc 'widget-delete (widget-get widget :children))
1355   (widget-put widget :children nil)
1356   (mapc 'widget-delete (widget-get widget :buttons))
1357   (widget-put widget :buttons nil))
1358
1359 (defun widget-children-validate (widget)
1360   "All the :children must be valid."
1361   (let ((children (widget-get widget :children))
1362         child found)
1363     (while (and children (not found))
1364       (setq child (car children)
1365             children (cdr children)
1366             found (widget-apply child :validate)))
1367     found))
1368
1369 (defun widget-child-value-get (widget)
1370   "Get the value of the first member of :children in WIDGET."
1371   (widget-value (car (widget-get widget :children))))
1372
1373 (defun widget-child-value-inline (widget)
1374   "Get the inline value of the first member of :children in WIDGET."
1375   (widget-apply (car (widget-get widget :children)) :value-inline))
1376
1377 (defun widget-child-validate (widget)
1378   "The result of validating the first member of :children in WIDGET."
1379   (widget-apply (car (widget-get widget :children)) :validate))
1380
1381 (defun widget-type-value-create (widget)
1382   "Convert and instantiate the value of the :type attribute of WIDGET.
1383 Store the newly created widget in the :children attribute.
1384
1385 The value of the :type attribute should be an unconverted widget type."
1386   (let ((value (widget-get widget :value))
1387         (type (widget-get widget :type)))
1388     (widget-put widget :children
1389                 (list (widget-create-child-value widget
1390                                                  (widget-convert type)
1391                                                  value)))))
1392
1393 (defun widget-type-default-get (widget)
1394   "Get default value from the :type attribute of WIDGET.
1395
1396 The value of the :type attribute should be an unconverted widget type."
1397   (widget-default-get (widget-convert (widget-get widget :type))))
1398
1399 (defun widget-type-match (widget value)
1400   "Non-nil if the :type value of WIDGET matches VALUE.
1401
1402 The value of the :type attribute should be an unconverted widget type."
1403   (widget-apply (widget-convert (widget-get widget :type)) :match value))
1404
1405 (defun widget-types-copy (widget)
1406   "Copy :args as widget types in WIDGET."
1407   (widget-put widget :args (mapcar 'widget-copy (widget-get widget :args)))
1408   widget)
1409
1410 ;; Made defsubst to speed up face editor creation.
1411 (defsubst widget-types-convert-widget (widget)
1412   "Convert :args as widget types in WIDGET."
1413   (widget-put widget :args (mapcar 'widget-convert (widget-get widget :args)))
1414   widget)
1415
1416 (defun widget-value-convert-widget (widget)
1417   "Initialize :value from :args in WIDGET."
1418   (let ((args (widget-get widget :args)))
1419     (when args
1420       (widget-put widget :value (car args))
1421       ;; Don't convert :value here, as this is done in `widget-convert'.
1422       ;; (widget-put widget :value (widget-apply widget
1423       ;;                                      :value-to-internal (car args)))
1424       (widget-put widget :args nil)))
1425   widget)
1426
1427 (defun widget-value-value-get (widget)
1428   "Return the :value property of WIDGET."
1429   (widget-get widget :value))
1430
1431 ;;; The `default' Widget.
1432
1433 (define-widget 'default nil
1434   "Basic widget other widgets are derived from."
1435   :value-to-internal (lambda (widget value) value)
1436   :value-to-external (lambda (widget value) value)
1437   :button-prefix 'widget-button-prefix
1438   :button-suffix 'widget-button-suffix
1439   :complete 'widget-default-complete
1440   :create 'widget-default-create
1441   :indent nil
1442   :offset 0
1443   :format-handler 'widget-default-format-handler
1444   :button-face-get 'widget-default-button-face-get
1445   :mouse-face-get 'widget-default-mouse-face-get
1446   :sample-face-get 'widget-default-sample-face-get
1447   :delete 'widget-default-delete
1448   :copy 'identity
1449   :value-set 'widget-default-value-set
1450   :value-inline 'widget-default-value-inline
1451   :value-delete 'ignore
1452   :default-get 'widget-default-default-get
1453   :menu-tag-get 'widget-default-menu-tag-get
1454   :validate #'ignore
1455   :active 'widget-default-active
1456   :activate 'widget-specify-active
1457   :deactivate 'widget-default-deactivate
1458   :mouse-down-action #'ignore
1459   :action 'widget-default-action
1460   :notify 'widget-default-notify
1461   :prompt-value 'widget-default-prompt-value)
1462
1463 (defun widget-default-complete (widget)
1464   "Call the value of the :complete-function property of WIDGET.
1465 If that does not exist, call the value of `widget-complete-field'."
1466   (call-interactively (or (widget-get widget :complete-function)
1467                           widget-complete-field)))
1468
1469 (defun widget-default-create (widget)
1470   "Create WIDGET at point in the current buffer."
1471   (widget-specify-insert
1472    (let ((from (point))
1473          button-begin button-end
1474          sample-begin sample-end
1475          doc-begin doc-end
1476          value-pos)
1477      (insert (widget-get widget :format))
1478      (goto-char from)
1479      ;; Parse escapes in format.
1480      (while (re-search-forward "%\\(.\\)" nil t)
1481        (let ((escape (char-after (match-beginning 1))))
1482          (delete-backward-char 2)
1483          (cond ((eq escape ?%)
1484                 (insert ?%))
1485                ((eq escape ?\[)
1486                 (setq button-begin (point))
1487                 (insert (widget-get-indirect widget :button-prefix)))
1488                ((eq escape ?\])
1489                 (insert (widget-get-indirect widget :button-suffix))
1490                 (setq button-end (point)))
1491                ((eq escape ?\{)
1492                 (setq sample-begin (point)))
1493                ((eq escape ?\})
1494                 (setq sample-end (point)))
1495                ((eq escape ?n)
1496                 (when (widget-get widget :indent)
1497                   (insert ?\n)
1498                   (insert-char ?\s (widget-get widget :indent))))
1499                ((eq escape ?t)
1500                 (let ((image (widget-get widget :tag-glyph))
1501                       (tag (widget-get widget :tag)))
1502                   (cond (image
1503                          (widget-image-insert widget (or tag "image") image))
1504                         (tag
1505                          (insert tag))
1506                         (t
1507                          (princ (widget-get widget :value)
1508                                 (current-buffer))))))
1509                ((eq escape ?d)
1510                 (let ((doc (widget-get widget :doc)))
1511                   (when doc
1512                     (setq doc-begin (point))
1513                     (insert doc)
1514                     (while (eq (preceding-char) ?\n)
1515                       (delete-backward-char 1))
1516                     (insert ?\n)
1517                     (setq doc-end (point)))))
1518                ((eq escape ?h)
1519                 (widget-add-documentation-string-button widget))
1520                ((eq escape ?v)
1521                 (if (and button-begin (not button-end))
1522                     (widget-apply widget :value-create)
1523                   (setq value-pos (point))))
1524                (t
1525                 (widget-apply widget :format-handler escape)))))
1526      ;; Specify button, sample, and doc, and insert value.
1527      (and button-begin button-end
1528           (widget-specify-button widget button-begin button-end))
1529      (and sample-begin sample-end
1530           (widget-specify-sample widget sample-begin sample-end))
1531      (and doc-begin doc-end
1532           (widget-specify-doc widget doc-begin doc-end))
1533      (when value-pos
1534        (goto-char value-pos)
1535        (widget-apply widget :value-create)))
1536    (let ((from (point-min-marker))
1537          (to (point-max-marker)))
1538      (set-marker-insertion-type from t)
1539      (set-marker-insertion-type to nil)
1540      (widget-put widget :from from)
1541      (widget-put widget :to to)))
1542   (widget-clear-undo))
1543
1544 (defun widget-default-format-handler (widget escape)
1545   (error "Unknown escape `%c'" escape))
1546
1547 (defun widget-default-button-face-get (widget)
1548   ;; Use :button-face or widget-button-face
1549   (or (widget-get widget :button-face)
1550       (let ((parent (widget-get widget :parent)))
1551         (if parent
1552             (widget-apply parent :button-face-get)
1553           widget-button-face))))
1554
1555 (defun widget-default-mouse-face-get (widget)
1556   ;; Use :mouse-face or widget-mouse-face
1557   (or (widget-get widget :mouse-face)
1558       (let ((parent (widget-get widget :parent)))
1559         (if parent
1560             (widget-apply parent :mouse-face-get)
1561           widget-mouse-face))))
1562
1563 (defun widget-default-sample-face-get (widget)
1564   ;; Use :sample-face.
1565   (widget-get widget :sample-face))
1566
1567 (defun widget-default-delete (widget)
1568   "Remove widget from the buffer."
1569   (let ((from (widget-get widget :from))
1570         (to (widget-get widget :to))
1571         (inactive-overlay (widget-get widget :inactive))
1572         (button-overlay (widget-get widget :button-overlay))
1573         (sample-overlay (widget-get widget :sample-overlay))
1574         (doc-overlay (widget-get widget :doc-overlay))
1575         (inhibit-modification-hooks t)
1576         (inhibit-read-only t))
1577     (widget-apply widget :value-delete)
1578     (widget-children-value-delete widget)
1579     (when inactive-overlay
1580       (delete-overlay inactive-overlay))
1581     (when button-overlay
1582       (delete-overlay button-overlay))
1583     (when sample-overlay
1584       (delete-overlay sample-overlay))
1585     (when doc-overlay
1586       (delete-overlay doc-overlay))
1587     (when (< from to)
1588       ;; Kludge: this doesn't need to be true for empty formats.
1589       (delete-region from to))
1590     (set-marker from nil)
1591     (set-marker to nil))
1592   (widget-clear-undo))
1593
1594 (defun widget-default-value-set (widget value)
1595   "Recreate widget with new value."
1596   (let* ((old-pos (point))
1597          (from (copy-marker (widget-get widget :from)))
1598          (to (copy-marker (widget-get widget :to)))
1599          (offset (if (and (<= from old-pos) (<= old-pos to))
1600                      (if (>= old-pos (1- to))
1601                          (- old-pos to 1)
1602                        (- old-pos from)))))
1603     ;;??? Bug: this ought to insert the new value before deleting the old one,
1604     ;; so that markers on either side of the value automatically
1605     ;; stay on the same side.  -- rms.
1606     (save-excursion
1607       (goto-char (widget-get widget :from))
1608       (widget-apply widget :delete)
1609       (widget-put widget :value value)
1610       (widget-apply widget :create))
1611     (if offset
1612         (if (< offset 0)
1613             (goto-char (+ (widget-get widget :to) offset 1))
1614           (goto-char (min (+ from offset) (1- (widget-get widget :to))))))))
1615
1616 (defun widget-default-value-inline (widget)
1617   "Wrap value in a list unless it is inline."
1618   (if (widget-get widget :inline)
1619       (widget-value widget)
1620     (list (widget-value widget))))
1621
1622 (defun widget-default-default-get (widget)
1623   "Get `:value'."
1624   (widget-get widget :value))
1625
1626 (defun widget-default-menu-tag-get (widget)
1627   "Use tag or value for menus."
1628   (or (widget-get widget :menu-tag)
1629       (widget-get widget :tag)
1630       (widget-princ-to-string (widget-get widget :value))))
1631
1632 (defun widget-default-active (widget)
1633   "Return t if this widget is active (user modifiable)."
1634   (or (widget-get widget :always-active)
1635       (and (not (widget-get widget :inactive))
1636            (let ((parent (widget-get widget :parent)))
1637              (or (null parent)
1638                  (widget-apply parent :active))))))
1639
1640 (defun widget-default-deactivate (widget)
1641   "Make WIDGET inactive for user modifications."
1642   (widget-specify-inactive widget
1643                            (widget-get widget :from)
1644                            (widget-get widget :to)))
1645
1646 (defun widget-default-action (widget &optional event)
1647   "Notify the parent when a widget changes."
1648   (let ((parent (widget-get widget :parent)))
1649     (when parent
1650       (widget-apply parent :notify widget event))))
1651
1652 (defun widget-default-notify (widget child &optional event)
1653   "Pass notification to parent."
1654   (widget-default-action widget event))
1655
1656 (defun widget-default-prompt-value (widget prompt value unbound)
1657   "Read an arbitrary value."
1658   (eval-minibuffer prompt))
1659
1660 (defun widget-docstring (widget)
1661   "Return the documentation string specificied by WIDGET, or nil if none.
1662 If WIDGET has a `:doc' property, that specifies the documentation string.
1663 Otherwise, try the `:documentation-property' property.  If this
1664 is a function, call it with the widget's value as an argument; if
1665 it is a symbol, use this symbol together with the widget's value
1666 as the argument to `documentation-property'."
1667   (let ((doc (or (widget-get widget :doc)
1668                  (let ((doc-prop (widget-get widget :documentation-property))
1669                        (value (widget-get widget :value)))
1670                    (cond ((functionp doc-prop)
1671                           (funcall doc-prop value))
1672                          ((symbolp doc-prop)
1673                           (documentation-property value doc-prop)))))))
1674     (when (and (stringp doc) (> (length doc) 0))
1675       ;; Remove any redundant `*' in the beginning.
1676       (when (eq (aref doc 0) ?*)
1677         (setq doc (substring doc 1)))
1678       ;; Remove trailing newlines.
1679       (when (string-match "\n+\\'" doc)
1680         (setq doc (substring doc 0 (match-beginning 0))))
1681       doc)))
1682
1683 ;;; The `item' Widget.
1684
1685 (define-widget 'item 'default
1686   "Constant items for inclusion in other widgets."
1687   :convert-widget 'widget-value-convert-widget
1688   :value-create 'widget-item-value-create
1689   :value-delete 'ignore
1690   :value-get 'widget-value-value-get
1691   :match 'widget-item-match
1692   :match-inline 'widget-item-match-inline
1693   :action 'widget-item-action
1694   :format "%t\n")
1695
1696 (defun widget-item-value-create (widget)
1697   "Insert the printed representation of the value."
1698   (princ (widget-get widget :value) (current-buffer)))
1699
1700 (defun widget-item-match (widget value)
1701   ;; Match if the value is the same.
1702   (equal (widget-get widget :value) value))
1703
1704 (defun widget-item-match-inline (widget values)
1705   ;; Match if the value is the same.
1706   (let ((value (widget-get widget :value)))
1707     (and (listp value)
1708          (<= (length value) (length values))
1709          (let ((head (widget-sublist values 0 (length value))))
1710            (and (equal head value)
1711                 (cons head (widget-sublist values (length value))))))))
1712
1713 (defun widget-sublist (list start &optional end)
1714   "Return the sublist of LIST from START to END.
1715 If END is omitted, it defaults to the length of LIST."
1716   (if (> start 0) (setq list (nthcdr start list)))
1717   (if end
1718       (unless (<= end start)
1719         (setq list (copy-sequence list))
1720         (setcdr (nthcdr (- end start 1) list) nil)
1721         list)
1722     (copy-sequence list)))
1723
1724 (defun widget-item-action (widget &optional event)
1725   ;; Just notify itself.
1726   (widget-apply widget :notify widget event))
1727
1728 ;;; The `push-button' Widget.
1729
1730 ;; (defcustom widget-push-button-gui t
1731 ;;   "If non-nil, use GUI push buttons when available."
1732 ;;   :group 'widgets
1733 ;;   :type 'boolean)
1734
1735 ;; Cache already created GUI objects.
1736 ;; (defvar widget-push-button-cache nil)
1737
1738 (defcustom widget-push-button-prefix "["
1739   "String used as prefix for buttons."
1740   :type 'string
1741   :group 'widget-button)
1742
1743 (defcustom widget-push-button-suffix "]"
1744   "String used as suffix for buttons."
1745   :type 'string
1746   :group 'widget-button)
1747
1748 (define-widget 'push-button 'item
1749   "A pushable button."
1750   :button-prefix ""
1751   :button-suffix ""
1752   :value-create 'widget-push-button-value-create
1753   :format "%[%v%]")
1754
1755 (defun widget-push-button-value-create (widget)
1756   "Insert text representing the `on' and `off' states."
1757   (let* ((tag (or (widget-get widget :tag)
1758                   (widget-get widget :value)))
1759          (tag-glyph (widget-get widget :tag-glyph))
1760          (text (concat widget-push-button-prefix
1761                        tag widget-push-button-suffix)))
1762     (if tag-glyph
1763         (widget-image-insert widget text tag-glyph)
1764       (insert text))))
1765
1766 ;; (defun widget-gui-action (widget)
1767 ;;   "Apply :action for WIDGET."
1768 ;;   (widget-apply-action widget (this-command-keys)))
1769
1770 ;;; The `link' Widget.
1771
1772 (defcustom widget-link-prefix "["
1773   "String used as prefix for links."
1774   :type 'string
1775   :group 'widget-button)
1776
1777 (defcustom widget-link-suffix "]"
1778   "String used as suffix for links."
1779   :type 'string
1780   :group 'widget-button)
1781
1782 (define-widget 'link 'item
1783   "An embedded link."
1784   :button-prefix 'widget-link-prefix
1785   :button-suffix 'widget-link-suffix
1786   :follow-link 'mouse-face
1787   :help-echo "Follow the link."
1788   :format "%[%t%]")
1789
1790 ;;; The `info-link' Widget.
1791
1792 (define-widget 'info-link 'link
1793   "A link to an info file."
1794   :action 'widget-info-link-action)
1795
1796 (defun widget-info-link-action (widget &optional event)
1797   "Open the info node specified by WIDGET."
1798   (info (widget-value widget)))
1799
1800 ;;; The `url-link' Widget.
1801
1802 (define-widget 'url-link 'link
1803   "A link to an www page."
1804   :action 'widget-url-link-action)
1805
1806 (defun widget-url-link-action (widget &optional event)
1807   "Open the URL specified by WIDGET."
1808   (browse-url (widget-value widget)))
1809
1810 ;;; The `function-link' Widget.
1811
1812 (define-widget 'function-link 'link
1813   "A link to an Emacs function."
1814   :action 'widget-function-link-action)
1815
1816 (defun widget-function-link-action (widget &optional event)
1817   "Show the function specified by WIDGET."
1818   (describe-function (widget-value widget)))
1819
1820 ;;; The `variable-link' Widget.
1821
1822 (define-widget 'variable-link 'link
1823   "A link to an Emacs variable."
1824   :action 'widget-variable-link-action)
1825
1826 (defun widget-variable-link-action (widget &optional event)
1827   "Show the variable specified by WIDGET."
1828   (describe-variable (widget-value widget)))
1829
1830 ;;; The `file-link' Widget.
1831
1832 (define-widget 'file-link 'link
1833   "A link to a file."
1834   :action 'widget-file-link-action)
1835
1836 (defun widget-file-link-action (widget &optional event)
1837   "Find the file specified by WIDGET."
1838   (find-file (widget-value widget)))
1839
1840 ;;; The `emacs-library-link' Widget.
1841
1842 (define-widget 'emacs-library-link 'link
1843   "A link to an Emacs Lisp library file."
1844   :action 'widget-emacs-library-link-action)
1845
1846 (defun widget-emacs-library-link-action (widget &optional event)
1847   "Find the Emacs library file specified by WIDGET."
1848   (find-file (locate-library (widget-value widget))))
1849
1850 ;;; The `emacs-commentary-link' Widget.
1851
1852 (define-widget 'emacs-commentary-link 'link
1853   "A link to Commentary in an Emacs Lisp library file."
1854   :action 'widget-emacs-commentary-link-action)
1855
1856 (defun widget-emacs-commentary-link-action (widget &optional event)
1857   "Find the Commentary section of the Emacs file specified by WIDGET."
1858   (finder-commentary (widget-value widget)))
1859
1860 ;;; The `editable-field' Widget.
1861
1862 (define-widget 'editable-field 'default
1863   "An editable text field.
1864 Note: In an `editable-field' widget, the `%v' escape must be preceded
1865 by some other text in the `:format' string (if specified)."
1866   :convert-widget 'widget-value-convert-widget
1867   :keymap widget-field-keymap
1868   :format "%v"
1869   :help-echo "M-TAB: complete field; RET: enter value"
1870   :value ""
1871   :prompt-internal 'widget-field-prompt-internal
1872   :prompt-history 'widget-field-history
1873   :prompt-value 'widget-field-prompt-value
1874   :action 'widget-field-action
1875   :validate 'widget-field-validate
1876   :valid-regexp ""
1877   :error "Field's value doesn't match allowed forms"
1878   :value-create 'widget-field-value-create
1879   :value-delete 'widget-field-value-delete
1880   :value-get 'widget-field-value-get
1881   :match 'widget-field-match)
1882
1883 (defvar widget-field-history nil
1884   "History of field minibuffer edits.")
1885
1886 (defun widget-field-prompt-internal (widget prompt initial history)
1887   "Read string for WIDGET prompting with PROMPT.
1888 INITIAL is the initial input and HISTORY is a symbol containing
1889 the earlier input."
1890   (read-string prompt initial history))
1891
1892 (defun widget-field-prompt-value (widget prompt value unbound)
1893   "Prompt for a string."
1894   (widget-apply widget
1895                 :value-to-external
1896                 (widget-apply widget
1897                               :prompt-internal prompt
1898                               (unless unbound
1899                                 (cons (widget-apply widget
1900                                                     :value-to-internal value)
1901                                       0))
1902                               (widget-get widget :prompt-history))))
1903
1904 (defvar widget-edit-functions nil)
1905
1906 (defun widget-field-action (widget &optional event)
1907   "Move to next field."
1908   (widget-forward 1)
1909   (run-hook-with-args 'widget-edit-functions widget))
1910
1911 (defun widget-field-validate (widget)
1912   "Valid if the content matches `:valid-regexp'."
1913   (unless (string-match (widget-get widget :valid-regexp)
1914                         (widget-apply widget :value-get))
1915     widget))
1916
1917 (defun widget-field-value-create (widget)
1918   "Create an editable text field."
1919   (let ((size (widget-get widget :size))
1920         (value (widget-get widget :value))
1921         (from (point))
1922         ;; This is changed to a real overlay in `widget-setup'.  We
1923         ;; need the end points to behave differently until
1924         ;; `widget-setup' is called.
1925         (overlay (cons (make-marker) (make-marker))))
1926     (widget-put widget :field-overlay overlay)
1927     (insert value)
1928     (and size
1929          (< (length value) size)
1930          (insert-char ?\s (- size (length value))))
1931     (unless (memq widget widget-field-list)
1932       (setq widget-field-new (cons widget widget-field-new)))
1933     (move-marker (cdr overlay) (point))
1934     (set-marker-insertion-type (cdr overlay) nil)
1935     (when (null size)
1936       (insert ?\n))
1937     (move-marker (car overlay) from)
1938     (set-marker-insertion-type (car overlay) t)))
1939
1940 (defun widget-field-value-delete (widget)
1941   "Remove the widget from the list of active editing fields."
1942   (setq widget-field-list (delq widget widget-field-list))
1943   (setq widget-field-new (delq widget widget-field-new))
1944   ;; These are nil if the :format string doesn't contain `%v'.
1945   (let ((overlay (widget-get widget :field-overlay)))
1946     (when (overlayp overlay)
1947       (delete-overlay overlay))))
1948
1949 (defun widget-field-value-get (widget)
1950   "Return current text in editing field."
1951   (let ((from (widget-field-start widget))
1952         (to (widget-field-text-end widget))
1953         (buffer (widget-field-buffer widget))
1954         (size (widget-get widget :size))
1955         (secret (widget-get widget :secret))
1956         (old (current-buffer)))
1957     (if (and from to)
1958         (progn
1959           (set-buffer buffer)
1960           (let ((result (buffer-substring-no-properties from to)))
1961             (when secret
1962               (let ((index 0))
1963                 (while (< (+ from index) to)
1964                   (aset result index
1965                         (get-char-property (+ from index) 'secret))
1966                   (setq index (1+ index)))))
1967             (set-buffer old)
1968             result))
1969       (widget-get widget :value))))
1970
1971 (defun widget-field-match (widget value)
1972   ;; Match any string.
1973   (stringp value))
1974
1975 ;;; The `text' Widget.
1976
1977 (define-widget 'text 'editable-field
1978   "A multiline text area."
1979   :keymap widget-text-keymap)
1980
1981 ;;; The `menu-choice' Widget.
1982
1983 (define-widget 'menu-choice 'default
1984   "A menu of options."
1985   :convert-widget  'widget-types-convert-widget
1986   :copy 'widget-types-copy
1987   :format "%[%t%]: %v"
1988   :case-fold t
1989   :tag "choice"
1990   :void '(item :format "invalid (%t)\n")
1991   :value-create 'widget-choice-value-create
1992   :value-get 'widget-child-value-get
1993   :value-inline 'widget-child-value-inline
1994   :default-get 'widget-choice-default-get
1995   :mouse-down-action 'widget-choice-mouse-down-action
1996   :action 'widget-choice-action
1997   :error "Make a choice"
1998   :validate 'widget-choice-validate
1999   :match 'widget-choice-match
2000   :match-inline 'widget-choice-match-inline)
2001
2002 (defun widget-choice-value-create (widget)
2003   "Insert the first choice that matches the value."
2004   (let ((value (widget-get widget :value))
2005         (args (widget-get widget :args))
2006         (explicit (widget-get widget :explicit-choice))
2007         current)
2008     (if explicit
2009         (progn
2010           ;; If the user specified the choice for this value,
2011           ;; respect that choice.
2012           (widget-put widget :children (list (widget-create-child-value
2013                                               widget explicit value)))
2014           (widget-put widget :choice explicit)
2015           (widget-put widget :explicit-choice nil))
2016       (while args
2017         (setq current (car args)
2018               args (cdr args))
2019         (when (widget-apply current :match value)
2020           (widget-put widget :children (list (widget-create-child-value
2021                                               widget current value)))
2022           (widget-put widget :choice current)
2023           (setq args nil
2024                 current nil)))
2025       (when current
2026         (let ((void (widget-get widget :void)))
2027           (widget-put widget :children (list (widget-create-child-and-convert
2028                                               widget void :value value)))
2029           (widget-put widget :choice void))))))
2030
2031 (defun widget-choice-default-get (widget)
2032   ;; Get default for the first choice.
2033   (widget-default-get (car (widget-get widget :args))))
2034
2035 (defcustom widget-choice-toggle nil
2036   "If non-nil, a binary choice will just toggle between the values.
2037 Otherwise, the user will explicitly have to choose between the values
2038 when he invoked the menu."
2039   :type 'boolean
2040   :group 'widgets)
2041
2042 (defun widget-choice-mouse-down-action (widget &optional event)
2043   ;; Return non-nil if we need a menu.
2044   (let ((args (widget-get widget :args))
2045         (old (widget-get widget :choice)))
2046     (cond ((not (display-popup-menus-p))
2047            ;; No place to pop up a menu.
2048            nil)
2049           ((< (length args) 2)
2050            ;; Empty or singleton list, just return the value.
2051            nil)
2052           ((> (length args) widget-menu-max-size)
2053            ;; Too long, prompt.
2054            nil)
2055           ((> (length args) 2)
2056            ;; Reasonable sized list, use menu.
2057            t)
2058           ((and widget-choice-toggle (memq old args))
2059            ;; We toggle.
2060            nil)
2061           (t
2062            ;; Ask which of the two.
2063            t))))
2064
2065 (defun widget-choice-action (widget &optional event)
2066   ;; Make a choice.
2067   (let ((args (widget-get widget :args))
2068         (old (widget-get widget :choice))
2069         (tag (widget-apply widget :menu-tag-get))
2070         (completion-ignore-case (widget-get widget :case-fold))
2071         this-explicit
2072         current choices)
2073     ;; Remember old value.
2074     (if (and old (not (widget-apply widget :validate)))
2075         (let* ((external (widget-value widget))
2076                (internal (widget-apply old :value-to-internal external)))
2077           (widget-put old :value internal)))
2078     ;; Find new choice.
2079     (setq current
2080           (cond ((= (length args) 0)
2081                  nil)
2082                 ((= (length args) 1)
2083                  (nth 0 args))
2084                 ((and widget-choice-toggle
2085                       (= (length args) 2)
2086                       (memq old args))
2087                  (if (eq old (nth 0 args))
2088                      (nth 1 args)
2089                    (nth 0 args)))
2090                 (t
2091                  (while args
2092                    (setq current (car args)
2093                          args (cdr args))
2094                    (setq choices
2095                          (cons (cons (widget-apply current :menu-tag-get)
2096                                      current)
2097                                choices)))
2098                  (setq this-explicit t)
2099                  (widget-choose tag (reverse choices) event))))
2100     (when current
2101       ;; If this was an explicit user choice, record the choice,
2102       ;; so that widget-choice-value-create will respect it.
2103       (when this-explicit
2104         (widget-put widget :explicit-choice current))
2105       (widget-value-set widget (widget-default-get current))
2106       (widget-setup)
2107       (widget-apply widget :notify widget event)))
2108   (run-hook-with-args 'widget-edit-functions widget))
2109
2110 (defun widget-choice-validate (widget)
2111   ;; Valid if we have made a valid choice.
2112   (if (eq (widget-get widget :void) (widget-get widget :choice))
2113       widget
2114     (widget-apply (car (widget-get widget :children)) :validate)))
2115
2116 (defun widget-choice-match (widget value)
2117   ;; Matches if one of the choices matches.
2118   (let ((args (widget-get widget :args))
2119         current found)
2120     (while (and args (not found))
2121       (setq current (car args)
2122             args (cdr args)
2123             found (widget-apply current :match value)))
2124     found))
2125
2126 (defun widget-choice-match-inline (widget values)
2127   ;; Matches if one of the choices matches.
2128   (let ((args (widget-get widget :args))
2129         current found)
2130     (while (and args (null found))
2131       (setq current (car args)
2132             args (cdr args)
2133             found (widget-match-inline current values)))
2134     found))
2135
2136 ;;; The `toggle' Widget.
2137
2138 (define-widget 'toggle 'item
2139   "Toggle between two states."
2140   :format "%[%v%]\n"
2141   :value-create 'widget-toggle-value-create
2142   :action 'widget-toggle-action
2143   :match (lambda (widget value) t)
2144   :on "on"
2145   :off "off")
2146
2147 (defun widget-toggle-value-create (widget)
2148   "Insert text representing the `on' and `off' states."
2149   (if (widget-value widget)
2150       (let ((image (widget-get widget :on-glyph)))
2151         (and (display-graphic-p)
2152              (listp image)
2153              (not (eq (car image) 'image))
2154              (widget-put widget :on-glyph (setq image (eval image))))
2155         (widget-image-insert widget
2156                              (widget-get widget :on)
2157                              image))
2158     (let ((image (widget-get widget :off-glyph)))
2159       (and (display-graphic-p)
2160            (listp image)
2161            (not (eq (car image) 'image))
2162            (widget-put widget :off-glyph (setq image (eval image))))
2163       (widget-image-insert widget (widget-get widget :off) image))))
2164
2165 (defun widget-toggle-action (widget &optional event)
2166   ;; Toggle value.
2167   (widget-value-set widget (not (widget-value widget)))
2168   (widget-apply widget :notify widget event)
2169   (run-hook-with-args 'widget-edit-functions widget))
2170
2171 ;;; The `checkbox' Widget.
2172
2173 (define-widget 'checkbox 'toggle
2174   "A checkbox toggle."
2175   :button-suffix ""
2176   :button-prefix ""
2177   :format "%[%v%]"
2178   :on "[X]"
2179   ;; We could probably do the same job as the images using single
2180   ;; space characters in a boxed face with a stretch specification to
2181   ;; make them square.
2182   :on-glyph '(create-image "\300\300\141\143\067\076\034\030"
2183                            'xbm t :width 8 :height 8
2184                            :background "grey75" ; like default mode line
2185                            :foreground "black"
2186                            :relief -2
2187                            :ascent 'center)
2188   :off "[ ]"
2189   :off-glyph '(create-image (make-string 8 0)
2190                             'xbm t :width 8 :height 8
2191                             :background "grey75"
2192                             :foreground "black"
2193                             :relief -2
2194                             :ascent 'center)
2195   :help-echo "Toggle this item."
2196   :action 'widget-checkbox-action)
2197
2198 (defun widget-checkbox-action (widget &optional event)
2199   "Toggle checkbox, notify parent, and set active state of sibling."
2200   (widget-toggle-action widget event)
2201   (let ((sibling (widget-get-sibling widget)))
2202     (when sibling
2203       (if (widget-value widget)
2204           (widget-apply sibling :activate)
2205         (widget-apply sibling :deactivate))
2206       (widget-clear-undo))))
2207
2208 ;;; The `checklist' Widget.
2209
2210 (define-widget 'checklist 'default
2211   "A multiple choice widget."
2212   :convert-widget 'widget-types-convert-widget
2213   :copy 'widget-types-copy
2214   :format "%v"
2215   :offset 4
2216   :entry-format "%b %v"
2217   :greedy nil
2218   :value-create 'widget-checklist-value-create
2219   :value-get 'widget-checklist-value-get
2220   :validate 'widget-checklist-validate
2221   :match 'widget-checklist-match
2222   :match-inline 'widget-checklist-match-inline)
2223
2224 (defun widget-checklist-value-create (widget)
2225   ;; Insert all values
2226   (let ((alist (widget-checklist-match-find widget (widget-get widget :value)))
2227         (args (widget-get widget :args)))
2228     (while args
2229       (widget-checklist-add-item widget (car args) (assq (car args) alist))
2230       (setq args (cdr args)))
2231     (widget-put widget :children (nreverse (widget-get widget :children)))))
2232
2233 (defun widget-checklist-add-item (widget type chosen)
2234   "Create checklist item in WIDGET of type TYPE.
2235 If the item is checked, CHOSEN is a cons whose cdr is the value."
2236   (and (eq (preceding-char) ?\n)
2237        (widget-get widget :indent)
2238        (insert-char ?\s (widget-get widget :indent)))
2239   (widget-specify-insert
2240    (let* ((children (widget-get widget :children))
2241           (buttons (widget-get widget :buttons))
2242           (button-args (or (widget-get type :sibling-args)
2243                            (widget-get widget :button-args)))
2244           (from (point))
2245           child button)
2246      (insert (widget-get widget :entry-format))
2247      (goto-char from)
2248      ;; Parse % escapes in format.
2249      (while (re-search-forward "%\\([bv%]\\)" nil t)
2250        (let ((escape (char-after (match-beginning 1))))
2251          (delete-backward-char 2)
2252          (cond ((eq escape ?%)
2253                 (insert ?%))
2254                ((eq escape ?b)
2255                 (setq button (apply 'widget-create-child-and-convert
2256                                     widget 'checkbox
2257                                     :value (not (null chosen))
2258                                     button-args)))
2259                ((eq escape ?v)
2260                 (setq child
2261                       (cond ((not chosen)
2262                              (let ((child (widget-create-child widget type)))
2263                                (widget-apply child :deactivate)
2264                                child))
2265                             ((widget-get type :inline)
2266                              (widget-create-child-value
2267                               widget type (cdr chosen)))
2268                             (t
2269                              (widget-create-child-value
2270                               widget type (car (cdr chosen)))))))
2271                (t
2272                 (error "Unknown escape `%c'" escape)))))
2273      ;; Update properties.
2274      (and button child (widget-put child :button button))
2275      (and button (widget-put widget :buttons (cons button buttons)))
2276      (and child (widget-put widget :children (cons child children))))))
2277
2278 (defun widget-checklist-match (widget values)
2279   ;; All values must match a type in the checklist.
2280   (and (listp values)
2281        (null (cdr (widget-checklist-match-inline widget values)))))
2282
2283 (defun widget-checklist-match-inline (widget values)
2284   ;; Find the values which match a type in the checklist.
2285   (let ((greedy (widget-get widget :greedy))
2286         (args (copy-sequence (widget-get widget :args)))
2287         found rest)
2288     (while values
2289       (let ((answer (widget-checklist-match-up args values)))
2290         (cond (answer
2291                (let ((vals (widget-match-inline answer values)))
2292                  (setq found (append found (car vals))
2293                        values (cdr vals)
2294                        args (delq answer args))))
2295               (greedy
2296                (setq rest (append rest (list (car values)))
2297                      values (cdr values)))
2298               (t
2299                (setq rest (append rest values)
2300                      values nil)))))
2301     (cons found rest)))
2302
2303 (defun widget-checklist-match-find (widget vals)
2304   "Find the vals which match a type in the checklist.
2305 Return an alist of (TYPE MATCH)."
2306   (let ((greedy (widget-get widget :greedy))
2307         (args (copy-sequence (widget-get widget :args)))
2308         found)
2309     (while vals
2310       (let ((answer (widget-checklist-match-up args vals)))
2311         (cond (answer
2312                (let ((match (widget-match-inline answer vals)))
2313                  (setq found (cons (cons answer (car match)) found)
2314                        vals (cdr match)
2315                        args (delq answer args))))
2316               (greedy
2317                (setq vals (cdr vals)))
2318               (t
2319                (setq vals nil)))))
2320     found))
2321
2322 (defun widget-checklist-match-up (args vals)
2323   "Return the first type from ARGS that matches VALS."
2324   (let (current found)
2325     (while (and args (null found))
2326       (setq current (car args)
2327             args (cdr args)
2328             found (widget-match-inline current vals)))
2329     (if found
2330         current)))
2331
2332 (defun widget-checklist-value-get (widget)
2333   ;; The values of all selected items.
2334   (let ((children (widget-get widget :children))
2335         child result)
2336     (while children
2337       (setq child (car children)
2338             children (cdr children))
2339       (if (widget-value (widget-get child :button))
2340           (setq result (append result (widget-apply child :value-inline)))))
2341     result))
2342
2343 (defun widget-checklist-validate (widget)
2344   ;; Ticked chilren must be valid.
2345   (let ((children (widget-get widget :children))
2346         child button found)
2347     (while (and children (not found))
2348       (setq child (car children)
2349             children (cdr children)
2350             button (widget-get child :button)
2351             found (and (widget-value button)
2352                        (widget-apply child :validate))))
2353     found))
2354
2355 ;;; The `option' Widget
2356
2357 (define-widget 'option 'checklist
2358   "An widget with an optional item."
2359   :inline t)
2360
2361 ;;; The `choice-item' Widget.
2362
2363 (define-widget 'choice-item 'item
2364   "Button items that delegate action events to their parents."
2365   :action 'widget-parent-action
2366   :format "%[%t%] \n")
2367
2368 ;;; The `radio-button' Widget.
2369
2370 (define-widget 'radio-button 'toggle
2371   "A radio button for use in the `radio' widget."
2372   :notify 'widget-radio-button-notify
2373   :format "%[%v%]"
2374   :button-suffix ""
2375   :button-prefix ""
2376   :on "(*)"
2377   :on-glyph "radio1"
2378   :off "( )"
2379   :off-glyph "radio0")
2380
2381 (defun widget-radio-button-notify (widget child &optional event)
2382   ;; Tell daddy.
2383   (widget-apply (widget-get widget :parent) :action widget event))
2384
2385 ;;; The `radio-button-choice' Widget.
2386
2387 (define-widget 'radio-button-choice 'default
2388   "Select one of multiple options."
2389   :convert-widget 'widget-types-convert-widget
2390   :copy 'widget-types-copy
2391   :offset 4
2392   :format "%v"
2393   :entry-format "%b %v"
2394   :value-create 'widget-radio-value-create
2395   :value-get 'widget-radio-value-get
2396   :value-inline 'widget-radio-value-inline
2397   :value-set 'widget-radio-value-set
2398   :error "You must push one of the buttons"
2399   :validate 'widget-radio-validate
2400   :match 'widget-choice-match
2401   :match-inline 'widget-choice-match-inline
2402   :action 'widget-radio-action)
2403
2404 (defun widget-radio-value-create (widget)
2405   ;; Insert all values
2406   (let ((args (widget-get widget :args))
2407         arg)
2408     (while args
2409       (setq arg (car args)
2410             args (cdr args))
2411       (widget-radio-add-item widget arg))))
2412
2413 (defun widget-radio-add-item (widget type)
2414   "Add to radio widget WIDGET a new radio button item of type TYPE."
2415   ;; (setq type (widget-convert type))
2416   (and (eq (preceding-char) ?\n)
2417        (widget-get widget :indent)
2418        (insert-char ?\s (widget-get widget :indent)))
2419   (widget-specify-insert
2420    (let* ((value (widget-get widget :value))
2421           (children (widget-get widget :children))
2422           (buttons (widget-get widget :buttons))
2423           (button-args (or (widget-get type :sibling-args)
2424                            (widget-get widget :button-args)))
2425           (from (point))
2426           (chosen (and (null (widget-get widget :choice))
2427                        (widget-apply type :match value)))
2428           child button)
2429      (insert (widget-get widget :entry-format))
2430      (goto-char from)
2431      ;; Parse % escapes in format.
2432      (while (re-search-forward "%\\([bv%]\\)" nil t)
2433        (let ((escape (char-after (match-beginning 1))))
2434          (delete-backward-char 2)
2435          (cond ((eq escape ?%)
2436                 (insert ?%))
2437                ((eq escape ?b)
2438                 (setq button (apply 'widget-create-child-and-convert
2439                                     widget 'radio-button
2440                                     :value (not (null chosen))
2441                                     button-args)))
2442                ((eq escape ?v)
2443                 (setq child (if chosen
2444                                 (widget-create-child-value
2445                                  widget type value)
2446                               (widget-create-child widget type)))
2447                 (unless chosen
2448                   (widget-apply child :deactivate)))
2449                (t
2450                 (error "Unknown escape `%c'" escape)))))
2451      ;; Update properties.
2452      (when chosen
2453        (widget-put widget :choice type))
2454      (when button
2455        (widget-put child :button button)
2456        (widget-put widget :buttons (nconc buttons (list button))))
2457      (when child
2458        (widget-put widget :children (nconc children (list child))))
2459      child)))
2460
2461 (defun widget-radio-value-get (widget)
2462   ;; Get value of the child widget.
2463   (let ((chosen (widget-radio-chosen widget)))
2464     (and chosen (widget-value chosen))))
2465
2466 (defun widget-radio-chosen (widget)
2467   "Return the widget representing the chosen radio button."
2468   (let ((children (widget-get widget :children))
2469         current found)
2470     (while children
2471       (setq current (car children)
2472             children (cdr children))
2473       (when (widget-apply (widget-get current :button) :value-get)
2474         (setq found current
2475               children nil)))
2476     found))
2477
2478 (defun widget-radio-value-inline (widget)
2479   ;; Get value of the child widget.
2480   (let ((children (widget-get widget :children))
2481         current found)
2482     (while children
2483       (setq current (car children)
2484             children (cdr children))
2485       (when (widget-apply (widget-get current :button) :value-get)
2486         (setq found (widget-apply current :value-inline)
2487               children nil)))
2488     found))
2489
2490 (defun widget-radio-value-set (widget value)
2491   ;; We can't just delete and recreate a radio widget, since children
2492   ;; can be added after the original creation and won't be recreated
2493   ;; by `:create'.
2494   (let ((children (widget-get widget :children))
2495         current found)
2496     (while children
2497       (setq current (car children)
2498             children (cdr children))
2499       (let* ((button (widget-get current :button))
2500              (match (and (not found)
2501                          (widget-apply current :match value))))
2502         (widget-value-set button match)
2503         (if match
2504             (progn
2505               (widget-value-set current value)
2506               (widget-apply current :activate))
2507           (widget-apply current :deactivate))
2508         (setq found (or found match))))))
2509
2510 (defun widget-radio-validate (widget)
2511   ;; Valid if we have made a valid choice.
2512   (let ((children (widget-get widget :children))
2513         current found button)
2514     (while (and children (not found))
2515       (setq current (car children)
2516             children (cdr children)
2517             button (widget-get current :button)
2518             found (widget-apply button :value-get)))
2519     (if found
2520         (widget-apply current :validate)
2521       widget)))
2522
2523 (defun widget-radio-action (widget child event)
2524   ;; Check if a radio button was pressed.
2525   (let ((children (widget-get widget :children))
2526         (buttons (widget-get widget :buttons))
2527         current)
2528     (when (memq child buttons)
2529       (while children
2530         (setq current (car children)
2531               children (cdr children))
2532         (let* ((button (widget-get current :button)))
2533           (cond ((eq child button)
2534                  (widget-value-set button t)
2535                  (widget-apply current :activate))
2536                 ((widget-value button)
2537                  (widget-value-set button nil)
2538                  (widget-apply current :deactivate)))))))
2539   ;; Pass notification to parent.
2540   (widget-apply widget :notify child event))
2541
2542 ;;; The `insert-button' Widget.
2543
2544 (define-widget 'insert-button 'push-button
2545   "An insert button for the `editable-list' widget."
2546   :tag "INS"
2547   :help-echo "Insert a new item into the list at this position."
2548   :action 'widget-insert-button-action)
2549
2550 (defun widget-insert-button-action (widget &optional event)
2551   ;; Ask the parent to insert a new item.
2552   (widget-apply (widget-get widget :parent)
2553                 :insert-before (widget-get widget :widget)))
2554
2555 ;;; The `delete-button' Widget.
2556
2557 (define-widget 'delete-button 'push-button
2558   "A delete button for the `editable-list' widget."
2559   :tag "DEL"
2560   :help-echo "Delete this item from the list."
2561   :action 'widget-delete-button-action)
2562
2563 (defun widget-delete-button-action (widget &optional event)
2564   ;; Ask the parent to insert a new item.
2565   (widget-apply (widget-get widget :parent)
2566                 :delete-at (widget-get widget :widget)))
2567
2568 ;;; The `editable-list' Widget.
2569
2570 ;; (defcustom widget-editable-list-gui nil
2571 ;;   "If non-nil, use GUI push-buttons in editable list when available."
2572 ;;   :type 'boolean
2573 ;;   :group 'widgets)
2574
2575 (define-widget 'editable-list 'default
2576   "A variable list of widgets of the same type."
2577   :convert-widget 'widget-types-convert-widget
2578   :copy 'widget-types-copy
2579   :offset 12
2580   :format "%v%i\n"
2581   :format-handler 'widget-editable-list-format-handler
2582   :entry-format "%i %d %v"
2583   :value-create 'widget-editable-list-value-create
2584   :value-get 'widget-editable-list-value-get
2585   :validate 'widget-children-validate
2586   :match 'widget-editable-list-match
2587   :match-inline 'widget-editable-list-match-inline
2588   :insert-before 'widget-editable-list-insert-before
2589   :delete-at 'widget-editable-list-delete-at)
2590
2591 (defun widget-editable-list-format-handler (widget escape)
2592   ;; We recognize the insert button.
2593     ;; (let ((widget-push-button-gui widget-editable-list-gui))
2594     (cond ((eq escape ?i)
2595            (and (widget-get widget :indent)
2596                 (insert-char ?\s (widget-get widget :indent)))
2597            (apply 'widget-create-child-and-convert
2598                   widget 'insert-button
2599                   (widget-get widget :append-button-args)))
2600           (t
2601            (widget-default-format-handler widget escape)))
2602     ;; )
2603   )
2604
2605 (defun widget-editable-list-value-create (widget)
2606   ;; Insert all values
2607   (let* ((value (widget-get widget :value))
2608          (type (nth 0 (widget-get widget :args)))
2609          children)
2610     (widget-put widget :value-pos (copy-marker (point)))
2611     (set-marker-insertion-type (widget-get widget :value-pos) t)
2612     (while value
2613       (let ((answer (widget-match-inline type value)))
2614         (if answer
2615             (setq children (cons (widget-editable-list-entry-create
2616                                   widget
2617                                   (if (widget-get type :inline)
2618                                       (car answer)
2619                                     (car (car answer)))
2620                                   t)
2621                                  children)
2622                   value (cdr answer))
2623           (setq value nil))))
2624     (widget-put widget :children (nreverse children))))
2625
2626 (defun widget-editable-list-value-get (widget)
2627   ;; Get value of the child widget.
2628   (apply 'append (mapcar (lambda (child) (widget-apply child :value-inline))
2629                          (widget-get widget :children))))
2630
2631 (defun widget-editable-list-match (widget value)
2632   ;; Value must be a list and all the members must match the type.
2633   (and (listp value)
2634        (null (cdr (widget-editable-list-match-inline widget value)))))
2635
2636 (defun widget-editable-list-match-inline (widget value)
2637   (let ((type (nth 0 (widget-get widget :args)))
2638         (ok t)
2639         found)
2640     (while (and value ok)
2641       (let ((answer (widget-match-inline type value)))
2642         (if answer
2643             (setq found (append found (car answer))
2644                   value (cdr answer))
2645           (setq ok nil))))
2646     (cons found value)))
2647
2648 (defun widget-editable-list-insert-before (widget before)
2649   ;; Insert a new child in the list of children.
2650   (save-excursion
2651     (let ((children (widget-get widget :children))
2652           (inhibit-read-only t)
2653           before-change-functions
2654           after-change-functions)
2655       (cond (before
2656              (goto-char (widget-get before :entry-from)))
2657             (t
2658              (goto-char (widget-get widget :value-pos))))
2659       (let ((child (widget-editable-list-entry-create
2660                     widget nil nil)))
2661         (when (< (widget-get child :entry-from) (widget-get widget :from))
2662           (set-marker (widget-get widget :from)
2663                       (widget-get child :entry-from)))
2664         (if (eq (car children) before)
2665             (widget-put widget :children (cons child children))
2666           (while (not (eq (car (cdr children)) before))
2667             (setq children (cdr children)))
2668           (setcdr children (cons child (cdr children)))))))
2669   (widget-setup)
2670   (widget-apply widget :notify widget))
2671
2672 (defun widget-editable-list-delete-at (widget child)
2673   ;; Delete child from list of children.
2674   (save-excursion
2675     (let ((buttons (copy-sequence (widget-get widget :buttons)))
2676           button
2677           (inhibit-read-only t)
2678           before-change-functions
2679           after-change-functions)
2680       (while buttons
2681         (setq button (car buttons)
2682               buttons (cdr buttons))
2683         (when (eq (widget-get button :widget) child)
2684           (widget-put widget
2685                       :buttons (delq button (widget-get widget :buttons)))
2686           (widget-delete button))))
2687     (let ((entry-from (widget-get child :entry-from))
2688           (entry-to (widget-get child :entry-to))
2689           (inhibit-read-only t)
2690           before-change-functions
2691           after-change-functions)
2692       (widget-delete child)
2693       (delete-region entry-from entry-to)
2694       (set-marker entry-from nil)
2695       (set-marker entry-to nil))
2696     (widget-put widget :children (delq child (widget-get widget :children))))
2697   (widget-setup)
2698   (widget-apply widget :notify widget))
2699
2700 (defun widget-editable-list-entry-create (widget value conv)
2701   ;; Create a new entry to the list.
2702   (let ((type (nth 0 (widget-get widget :args)))
2703         ;; (widget-push-button-gui widget-editable-list-gui)
2704         child delete insert)
2705     (widget-specify-insert
2706      (save-excursion
2707        (and (widget-get widget :indent)
2708             (insert-char ?\s (widget-get widget :indent)))
2709        (insert (widget-get widget :entry-format)))
2710      ;; Parse % escapes in format.
2711      (while (re-search-forward "%\\(.\\)" nil t)
2712        (let ((escape (char-after (match-beginning 1))))
2713          (delete-backward-char 2)
2714          (cond ((eq escape ?%)
2715                 (insert ?%))
2716                ((eq escape ?i)
2717                 (setq insert (apply 'widget-create-child-and-convert
2718                                     widget 'insert-button
2719                                     (widget-get widget :insert-button-args))))
2720                ((eq escape ?d)
2721                 (setq delete (apply 'widget-create-child-and-convert
2722                                     widget 'delete-button
2723                                     (widget-get widget :delete-button-args))))
2724                ((eq escape ?v)
2725                 (if conv
2726                     (setq child (widget-create-child-value
2727                                  widget type value))
2728                   (setq child (widget-create-child-value
2729                                widget type (widget-default-get type)))))
2730                (t
2731                 (error "Unknown escape `%c'" escape)))))
2732      (let ((buttons (widget-get widget :buttons)))
2733        (if insert (push insert buttons))
2734        (if delete (push delete buttons))
2735        (widget-put widget :buttons buttons))
2736      (let ((entry-from (point-min-marker))
2737            (entry-to (point-max-marker)))
2738        (set-marker-insertion-type entry-from t)
2739        (set-marker-insertion-type entry-to nil)
2740        (widget-put child :entry-from entry-from)
2741        (widget-put child :entry-to entry-to)))
2742     (if insert (widget-put insert :widget child))
2743     (if delete (widget-put delete :widget child))
2744     child))
2745
2746 ;;; The `group' Widget.
2747
2748 (define-widget 'group 'default
2749   "A widget which groups other widgets inside."
2750   :convert-widget 'widget-types-convert-widget
2751   :copy 'widget-types-copy
2752   :format "%v"
2753   :value-create 'widget-group-value-create
2754   :value-get 'widget-editable-list-value-get
2755   :default-get 'widget-group-default-get
2756   :validate 'widget-children-validate
2757   :match 'widget-group-match
2758   :match-inline 'widget-group-match-inline)
2759
2760 (defun widget-group-value-create (widget)
2761   ;; Create each component.
2762   (let ((args (widget-get widget :args))
2763         (value (widget-get widget :value))
2764         arg answer children)
2765     (while args
2766       (setq arg (car args)
2767             args (cdr args)
2768             answer (widget-match-inline arg value)
2769             value (cdr answer))
2770       (and (eq (preceding-char) ?\n)
2771            (widget-get widget :indent)
2772            (insert-char ?\s (widget-get widget :indent)))
2773       (push (cond ((null answer)
2774                    (widget-create-child widget arg))
2775                   ((widget-get arg :inline)
2776                    (widget-create-child-value widget arg (car answer)))
2777                   (t
2778                    (widget-create-child-value widget arg (car (car answer)))))
2779             children))
2780     (widget-put widget :children (nreverse children))))
2781
2782 (defun widget-group-default-get (widget)
2783   ;; Get the default of the components.
2784   (mapcar 'widget-default-get (widget-get widget :args)))
2785
2786 (defun widget-group-match (widget values)
2787   ;; Match if the components match.
2788   (and (listp values)
2789        (let ((match (widget-group-match-inline widget values)))
2790          (and match (null (cdr match))))))
2791
2792 (defun widget-group-match-inline (widget vals)
2793   ;; Match if the components match.
2794   (let ((args (widget-get widget :args))
2795         argument answer found)
2796     (while args
2797       (setq argument (car args)
2798             args (cdr args)
2799             answer (widget-match-inline argument vals))
2800       (if answer
2801           (setq vals (cdr answer)
2802                 found (append found (car answer)))
2803         (setq vals nil
2804               args nil)))
2805     (if answer
2806         (cons found vals))))
2807
2808 ;;; The `visibility' Widget.
2809
2810 (define-widget 'visibility 'item
2811   "An indicator and manipulator for hidden items."
2812   :format "%[%v%]"
2813   :button-prefix ""
2814   :button-suffix ""
2815   :on "Hide"
2816   :off "Show"
2817   :value-create 'widget-visibility-value-create
2818   :action 'widget-toggle-action
2819   :match (lambda (widget value) t))
2820
2821 (defun widget-visibility-value-create (widget)
2822   ;; Insert text representing the `on' and `off' states.
2823   (let ((on (widget-get widget :on))
2824         (off (widget-get widget :off)))
2825     (if on
2826         (setq on (concat widget-push-button-prefix
2827                          on
2828                          widget-push-button-suffix))
2829       (setq on ""))
2830     (if off
2831         (setq off (concat widget-push-button-prefix
2832                           off
2833                           widget-push-button-suffix))
2834       (setq off ""))
2835     (if (widget-value widget)
2836         (widget-image-insert widget on "down" "down-pushed")
2837       (widget-image-insert widget off "right" "right-pushed"))))
2838
2839 ;;; The `documentation-link' Widget.
2840 ;;
2841 ;; This is a helper widget for `documentation-string'.
2842
2843 (define-widget 'documentation-link 'link
2844   "Link type used in documentation strings."
2845   :tab-order -1
2846   :help-echo "Describe this symbol"
2847   :action 'widget-documentation-link-action)
2848
2849 (defun widget-documentation-link-action (widget &optional event)
2850   "Display documentation for WIDGET's value.  Ignore optional argument EVENT."
2851   (let* ((string (widget-get widget :value))
2852          (symbol (intern string)))
2853     (if (and (fboundp symbol) (boundp symbol))
2854         ;; If there are two doc strings, give the user a way to pick one.
2855         (apropos (concat "\\`" (regexp-quote string) "\\'"))
2856       (if (fboundp symbol)
2857           (describe-function symbol)
2858         (describe-variable symbol)))))
2859
2860 (defcustom widget-documentation-links t
2861   "Add hyperlinks to documentation strings when non-nil."
2862   :type 'boolean
2863   :group 'widget-documentation)
2864
2865 (defcustom widget-documentation-link-regexp "`\\([^\n`' ]+\\)'"
2866   "Regexp for matching potential links in documentation strings.
2867 The first group should be the link itself."
2868   :type 'regexp
2869   :group 'widget-documentation)
2870
2871 (defcustom widget-documentation-link-p 'intern-soft
2872   "Predicate used to test if a string is useful as a link.
2873 The value should be a function.  The function will be called with one
2874 argument, a string, and should return non-nil if there should be a
2875 link for that string."
2876   :type 'function
2877   :options '(widget-documentation-link-p)
2878   :group 'widget-documentation)
2879
2880 (defcustom widget-documentation-link-type 'documentation-link
2881   "Widget type used for links in documentation strings."
2882   :type 'symbol
2883   :group 'widget-documentation)
2884
2885 (defun widget-documentation-link-add (widget from to)
2886   (widget-specify-doc widget from to)
2887   (when widget-documentation-links
2888     (let ((regexp widget-documentation-link-regexp)
2889           (buttons (widget-get widget :buttons))
2890           (widget-mouse-face (default-value 'widget-mouse-face))
2891           (widget-button-face widget-documentation-face)
2892           (widget-button-pressed-face widget-documentation-face))
2893       (save-excursion
2894         (goto-char from)
2895         (while (re-search-forward regexp to t)
2896           (let ((name (match-string 1))
2897                 (begin (match-beginning 1))
2898                 (end (match-end 1)))
2899             (when (funcall widget-documentation-link-p name)
2900               (push (widget-convert-button widget-documentation-link-type
2901                                            begin end :value name)
2902                     buttons)))))
2903       (widget-put widget :buttons buttons)))
2904   (let ((indent (widget-get widget :indent)))
2905     (when (and indent (not (zerop indent)))
2906       (save-excursion
2907         (save-restriction
2908           (narrow-to-region from to)
2909           (goto-char (point-min))
2910           (while (search-forward "\n" nil t)
2911             (insert-char ?\s indent)))))))
2912
2913 ;;; The `documentation-string' Widget.
2914
2915 (define-widget 'documentation-string 'item
2916   "A documentation string."
2917   :format "%v"
2918   :action 'widget-documentation-string-action
2919   :value-create 'widget-documentation-string-value-create
2920   :visibility-widget 'visibility)
2921
2922 (defun widget-documentation-string-value-create (widget)
2923   ;; Insert documentation string.
2924   (let ((doc (widget-value widget))
2925         (indent (widget-get widget :indent))
2926         (shown (widget-get (widget-get widget :parent) :documentation-shown))
2927         (start (point)))
2928     (if (string-match "\n" doc)
2929         (let ((before (substring doc 0 (match-beginning 0)))
2930               (after (substring doc (match-beginning 0)))
2931               button)
2932           (when (and indent (not (zerop indent)))
2933             (insert-char ?\s indent))
2934           (insert before ?\s)
2935           (widget-documentation-link-add widget start (point))
2936           (setq button
2937                 (widget-create-child-and-convert
2938                  widget (widget-get widget :visibility-widget)
2939                  :help-echo "Show or hide rest of the documentation."
2940                  :on "Hide Rest"
2941                  :off "More"
2942                  :always-active t
2943                  :action 'widget-parent-action
2944                  shown))
2945           (when shown
2946             (setq start (point))
2947             (when (and indent (not (zerop indent)))
2948               (insert-char ?\s indent))
2949             (insert after)
2950             (widget-documentation-link-add widget start (point)))
2951           (widget-put widget :buttons (list button)))
2952       (when (and indent (not (zerop indent)))
2953         (insert-char ?\s indent))
2954       (insert doc)
2955       (widget-documentation-link-add widget start (point))))
2956   (insert ?\n))
2957
2958 (defun widget-documentation-string-action (widget &rest ignore)
2959   ;; Toggle documentation.
2960   (let ((parent (widget-get widget :parent)))
2961     (widget-put parent :documentation-shown
2962                 (not (widget-get parent :documentation-shown))))
2963   ;; Redraw.
2964   (widget-value-set widget (widget-value widget)))
2965
2966 (defun widget-add-documentation-string-button (widget &rest args)
2967   "Insert a new `documentation-string' widget based on WIDGET.
2968 The new widget becomes a child of WIDGET, and is also added to
2969 its `:buttons' list.  The documentation string is found from
2970 WIDGET using the function `widget-docstring'.
2971 Optional ARGS specifies additional keyword arguments for the
2972 `documentation-string' widget."
2973   (let ((doc (widget-docstring widget))
2974         (indent (widget-get widget :indent))
2975         (doc-indent (widget-get widget :documentation-indent)))
2976     (when doc
2977       (and (eq (preceding-char) ?\n)
2978            indent
2979            (insert-char ?\s indent))
2980       (unless (or (numberp doc-indent) (null doc-indent))
2981         (setq doc-indent 0))
2982       (widget-put widget :buttons
2983                   (cons (apply 'widget-create-child-and-convert
2984                                widget 'documentation-string
2985                                :indent doc-indent
2986                                (nconc args (list doc)))
2987                         (widget-get widget :buttons))))))
2988 \f
2989 ;;; The Sexp Widgets.
2990
2991 (define-widget 'const 'item
2992   "An immutable sexp."
2993   :prompt-value 'widget-const-prompt-value
2994   :format "%t\n%d")
2995
2996 (defun widget-const-prompt-value (widget prompt value unbound)
2997   ;; Return the value of the const.
2998   (widget-value widget))
2999
3000 (define-widget 'function-item 'const
3001   "An immutable function name."
3002   :format "%v\n%h"
3003   :documentation-property (lambda (symbol)
3004                             (condition-case nil
3005                                 (documentation symbol t)
3006                               (error nil))))
3007
3008 (define-widget 'variable-item 'const
3009   "An immutable variable name."
3010   :format "%v\n%h"
3011   :documentation-property 'variable-documentation)
3012
3013 (define-widget 'other 'sexp
3014   "Matches any value, but doesn't let the user edit the value.
3015 This is useful as last item in a `choice' widget.
3016 You should use this widget type with a default value,
3017 as in (other DEFAULT) or (other :tag \"NAME\" DEFAULT).
3018 If the user selects this alternative, that specifies DEFAULT
3019 as the value."
3020   :tag "Other"
3021   :format "%t%n"
3022   :value 'other)
3023
3024 (defvar widget-string-prompt-value-history nil
3025   "History of input to `widget-string-prompt-value'.")
3026
3027 (define-widget 'string 'editable-field
3028   "A string"
3029   :tag "String"
3030   :format "%{%t%}: %v"
3031   :complete-function 'ispell-complete-word
3032   :prompt-history 'widget-string-prompt-value-history)
3033
3034 (defvar widget)
3035
3036 (defun widget-string-complete ()
3037   "Complete contents of string field.
3038 Completions are taken from the :completion-alist property of the
3039 widget.  If that isn't a list, it's evalled and expected to yield a list."
3040   (interactive)
3041   (let* ((completion-ignore-case (widget-get widget :completion-ignore-case))
3042          (alist (widget-get widget :completion-alist))
3043          (_ (unless (listp alist)
3044               (setq alist (eval alist)))))
3045     (completion-in-region (widget-field-start widget)
3046                           (max (point) (widget-field-text-end widget))
3047                           alist)))
3048
3049 (define-widget 'regexp 'string
3050   "A regular expression."
3051   :match 'widget-regexp-match
3052   :validate 'widget-regexp-validate
3053   ;; Doesn't work well with terminating newline.
3054   ;; :value-face 'widget-single-line-field
3055   :tag "Regexp")
3056
3057 (defun widget-regexp-match (widget value)
3058   ;; Match valid regexps.
3059   (and (stringp value)
3060        (condition-case nil
3061            (prog1 t
3062              (string-match value ""))
3063          (error nil))))
3064
3065 (defun widget-regexp-validate (widget)
3066   "Check that the value of WIDGET is a valid regexp."
3067   (condition-case data
3068       (prog1 nil
3069         (string-match (widget-value widget) ""))
3070     (error (widget-put widget :error (error-message-string data))
3071            widget)))
3072
3073 (define-widget 'file 'string
3074   "A file widget.
3075 It reads a file name from an editable text field."
3076   :complete-function 'widget-file-complete
3077   :prompt-value 'widget-file-prompt-value
3078   :format "%{%t%}: %v"
3079   ;; Doesn't work well with terminating newline.
3080   ;; :value-face 'widget-single-line-field
3081   :tag "File")
3082
3083 (defun widget-file-complete ()
3084   "Perform completion on file name preceding point."
3085   (interactive)
3086   (completion-in-region (widget-field-start widget)
3087                         (max (point) (widget-field-text-end widget))
3088                         'completion-file-name-table))
3089
3090 (defun widget-file-prompt-value (widget prompt value unbound)
3091   ;; Read file from minibuffer.
3092   (abbreviate-file-name
3093    (if unbound
3094        (read-file-name prompt)
3095      (let ((prompt2 (format "%s (default %s): " prompt value))
3096            (dir (file-name-directory value))
3097            (file (file-name-nondirectory value))
3098            (must-match (widget-get widget :must-match)))
3099        (read-file-name prompt2 dir nil must-match file)))))
3100
3101 ;;;(defun widget-file-action (widget &optional event)
3102 ;;;  ;; Read a file name from the minibuffer.
3103 ;;;  (let* ((value (widget-value widget))
3104 ;;;      (dir (file-name-directory value))
3105 ;;;      (file (file-name-nondirectory value))
3106 ;;;      (menu-tag (widget-apply widget :menu-tag-get))
3107 ;;;      (must-match (widget-get widget :must-match))
3108 ;;;      (answer (read-file-name (concat menu-tag " (default " value "): ")
3109 ;;;                              dir nil must-match file)))
3110 ;;;    (widget-value-set widget (abbreviate-file-name answer))
3111 ;;;    (widget-setup)
3112 ;;;    (widget-apply widget :notify widget event)))
3113
3114 ;; Fixme: use file-name-as-directory.
3115 (define-widget 'directory 'file
3116   "A directory widget.
3117 It reads a directory name from an editable text field."
3118   :tag "Directory")
3119
3120 (defvar widget-symbol-prompt-value-history nil
3121   "History of input to `widget-symbol-prompt-value'.")
3122
3123 (define-widget 'symbol 'editable-field
3124   "A Lisp symbol."
3125   :value nil
3126   :tag "Symbol"
3127   :format "%{%t%}: %v"
3128   :match (lambda (widget value) (symbolp value))
3129   :complete-function 'lisp-complete-symbol
3130   :prompt-internal 'widget-symbol-prompt-internal
3131   :prompt-match 'symbolp
3132   :prompt-history 'widget-symbol-prompt-value-history
3133   :value-to-internal (lambda (widget value)
3134                        (if (symbolp value)
3135                            (symbol-name value)
3136                          value))
3137   :value-to-external (lambda (widget value)
3138                        (if (stringp value)
3139                            (intern value)
3140                          value)))
3141
3142 (defun widget-symbol-prompt-internal (widget prompt initial history)
3143   ;; Read file from minibuffer.
3144   (let ((answer (completing-read prompt obarray
3145                                  (widget-get widget :prompt-match)
3146                                  nil initial history)))
3147     (if (and (stringp answer)
3148              (not (zerop (length answer))))
3149         answer
3150       (error "No value"))))
3151
3152 (defvar widget-function-prompt-value-history nil
3153   "History of input to `widget-function-prompt-value'.")
3154
3155 (define-widget 'function 'restricted-sexp
3156   "A Lisp function."
3157   :complete-function (lambda ()
3158                        (interactive)
3159                        (lisp-complete-symbol 'fboundp))
3160   :prompt-value 'widget-field-prompt-value
3161   :prompt-internal 'widget-symbol-prompt-internal
3162   :prompt-match 'fboundp
3163   :prompt-history 'widget-function-prompt-value-history
3164   :action 'widget-field-action
3165   :match-alternatives '(functionp)
3166   :validate (lambda (widget)
3167               (unless (functionp (widget-value widget))
3168                 (widget-put widget :error (format "Invalid function: %S"
3169                                                   (widget-value widget)))
3170                 widget))
3171   :value 'ignore
3172   :tag "Function")
3173
3174 (defvar widget-variable-prompt-value-history nil
3175   "History of input to `widget-variable-prompt-value'.")
3176
3177 (define-widget 'variable 'symbol
3178   "A Lisp variable."
3179   :prompt-match 'boundp
3180   :prompt-history 'widget-variable-prompt-value-history
3181   :complete-function (lambda ()
3182                        (interactive)
3183                        (lisp-complete-symbol 'boundp))
3184   :tag "Variable")
3185
3186 (define-widget 'coding-system 'symbol
3187   "A MULE coding-system."
3188   :format "%{%t%}: %v"
3189   :tag "Coding system"
3190   :base-only nil
3191   :prompt-history 'coding-system-value-history
3192   :prompt-value 'widget-coding-system-prompt-value
3193   :action 'widget-coding-system-action
3194   :complete-function (lambda ()
3195                        (interactive)
3196                        (lisp-complete-symbol 'coding-system-p))
3197   :validate (lambda (widget)
3198               (unless (coding-system-p (widget-value widget))
3199                 (widget-put widget :error (format "Invalid coding system: %S"
3200                                                   (widget-value widget)))
3201                 widget))
3202   :value 'undecided
3203   :prompt-match 'coding-system-p)
3204
3205 (defun widget-coding-system-prompt-value (widget prompt value unbound)
3206   "Read coding-system from minibuffer."
3207   (if (widget-get widget :base-only)
3208       (intern
3209        (completing-read (format "%s (default %s): " prompt value)
3210                         (mapcar #'list (coding-system-list t)) nil nil nil
3211                         coding-system-history))
3212       (read-coding-system (format "%s (default %s): " prompt value) value)))
3213
3214 (defun widget-coding-system-action (widget &optional event)
3215   (let ((answer
3216          (widget-coding-system-prompt-value
3217           widget
3218           (widget-apply widget :menu-tag-get)
3219           (widget-value widget)
3220           t)))
3221     (widget-value-set widget answer)
3222     (widget-apply widget :notify widget event)
3223     (widget-setup)))
3224 \f
3225 ;;; I'm not sure about what this is good for?  KFS.
3226 (defvar widget-key-sequence-prompt-value-history nil
3227   "History of input to `widget-key-sequence-prompt-value'.")
3228
3229 (defvar widget-key-sequence-default-value [ignore]
3230   "Default value for an empty key sequence.")
3231
3232 (defvar widget-key-sequence-map
3233   (let ((map (make-sparse-keymap)))
3234     (set-keymap-parent map widget-field-keymap)
3235     (define-key map [(control ?q)] 'widget-key-sequence-read-event)
3236     map))
3237
3238 (define-widget 'key-sequence 'restricted-sexp
3239   "A key sequence."
3240   :prompt-value 'widget-field-prompt-value
3241   :prompt-internal 'widget-symbol-prompt-internal
3242 ; :prompt-match 'fboundp   ;; What was this good for?  KFS
3243   :prompt-history 'widget-key-sequence-prompt-value-history
3244   :action 'widget-field-action
3245   :match-alternatives '(stringp vectorp)
3246   :format "%{%t%}: %v"
3247   :validate 'widget-key-sequence-validate
3248   :value-to-internal 'widget-key-sequence-value-to-internal
3249   :value-to-external 'widget-key-sequence-value-to-external
3250   :value widget-key-sequence-default-value
3251   :keymap widget-key-sequence-map
3252   :help-echo "C-q: insert KEY, EVENT, or CODE; RET: enter value"
3253   :tag "Key sequence")
3254
3255 (defun widget-key-sequence-read-event (ev)
3256   (interactive (list
3257                 (let ((inhibit-quit t) quit-flag)
3258                   (read-event "Insert KEY, EVENT, or CODE: "))))
3259   (let ((ev2 (and (memq 'down (event-modifiers ev))
3260                   (read-event)))
3261         (tr (and (keymapp function-key-map)
3262                  (lookup-key function-key-map (vector ev)))))
3263     (when (and (integerp ev)
3264                (or (and (<= ?0 ev) (< ev (+ ?0 (min 10 read-quoted-char-radix))))
3265                    (and (<= ?a (downcase ev))
3266                         (< (downcase ev) (+ ?a -10 (min 36 read-quoted-char-radix))))))
3267       (setq unread-command-events (cons ev unread-command-events)
3268             ev (read-quoted-char (format "Enter code (radix %d)" read-quoted-char-radix))
3269             tr nil)
3270       (if (and (integerp ev) (not (characterp ev)))
3271           (insert (char-to-string ev))))  ;; throw invalid char error
3272     (setq ev (key-description (list ev)))
3273     (when (arrayp tr)
3274       (setq tr (key-description (list (aref tr 0))))
3275       (if (y-or-n-p (format "Key %s is translated to %s -- use %s? " ev tr tr))
3276           (setq ev tr ev2 nil)))
3277     (insert (if (= (char-before) ?\s)  "" " ") ev " ")
3278     (if ev2
3279         (insert (key-description (list ev2)) " "))))
3280
3281 (defun widget-key-sequence-validate (widget)
3282   (unless (or (stringp (widget-value widget))
3283               (vectorp (widget-value widget)))
3284     (widget-put widget :error (format "Invalid key sequence: %S"
3285                                       (widget-value widget)))
3286     widget))
3287
3288 (defun widget-key-sequence-value-to-internal (widget value)
3289   (if (widget-apply widget :match value)
3290       (if (equal value widget-key-sequence-default-value)
3291           ""
3292         (key-description value))
3293     value))
3294
3295 (defun widget-key-sequence-value-to-external (widget value)
3296   (if (stringp value)
3297       (if (string-match "\\`[[:space:]]*\\'" value)
3298           widget-key-sequence-default-value
3299         (read-kbd-macro value))
3300     value))
3301
3302 \f
3303 (define-widget 'sexp 'editable-field
3304   "An arbitrary Lisp expression."
3305   :tag "Lisp expression"
3306   :format "%{%t%}: %v"
3307   :value nil
3308   :validate 'widget-sexp-validate
3309   :match (lambda (widget value) t)
3310   :value-to-internal 'widget-sexp-value-to-internal
3311   :value-to-external (lambda (widget value) (read value))
3312   :prompt-history 'widget-sexp-prompt-value-history
3313   :prompt-value 'widget-sexp-prompt-value)
3314
3315 (defun widget-sexp-value-to-internal (widget value)
3316   ;; Use pp for printer representation.
3317   (let ((pp (if (symbolp value)
3318                 (prin1-to-string value)
3319               (pp-to-string value))))
3320     (while (string-match "\n\\'" pp)
3321       (setq pp (substring pp 0 -1)))
3322     (if (or (string-match "\n\\'" pp)
3323             (> (length pp) 40))
3324         (concat "\n" pp)
3325       pp)))
3326
3327 (defun widget-sexp-validate (widget)
3328   ;; Valid if we can read the string and there is no junk left after it.
3329   (with-temp-buffer
3330     (insert (widget-apply widget :value-get))
3331     (goto-char (point-min))
3332     (let (err)
3333       (condition-case data
3334           (progn
3335             ;; Avoid a confusing end-of-file error.
3336             (skip-syntax-forward "\\s-")
3337             (if (eobp)
3338                 (setq err "Empty sexp -- use `nil'?")
3339               (unless (widget-apply widget :match (read (current-buffer)))
3340                 (setq err (widget-get widget :type-error))))
3341             ;; Allow whitespace after expression.
3342             (skip-syntax-forward "\\s-")
3343             (if (and (not (eobp))
3344                      (not err))
3345                 (setq err (format "Junk at end of expression: %s"
3346                                   (buffer-substring (point)
3347                                                     (point-max))))))
3348         (end-of-file                    ; Avoid confusing error message.
3349          (setq err "Unbalanced sexp"))
3350         (error (setq err (error-message-string data))))
3351       (if (not err)
3352           nil
3353         (widget-put widget :error err)
3354         widget))))
3355
3356 (defvar widget-sexp-prompt-value-history nil
3357   "History of input to `widget-sexp-prompt-value'.")
3358
3359 (defun widget-sexp-prompt-value (widget prompt value unbound)
3360   ;; Read an arbitrary sexp.
3361   (let ((found (read-string prompt
3362                             (if unbound nil (cons (prin1-to-string value) 0))
3363                             (widget-get widget :prompt-history))))
3364     (let ((answer (read-from-string found)))
3365       (unless (= (cdr answer) (length found))
3366         (error "Junk at end of expression: %s"
3367                (substring found (cdr answer))))
3368       (car answer))))
3369
3370 (define-widget 'restricted-sexp 'sexp
3371   "A Lisp expression restricted to values that match.
3372 To use this type, you must define :match or :match-alternatives."
3373   :type-error "The specified value is not valid"
3374   :match 'widget-restricted-sexp-match
3375   :value-to-internal (lambda (widget value)
3376                        (if (widget-apply widget :match value)
3377                            (prin1-to-string value)
3378                          value)))
3379
3380 (defun widget-restricted-sexp-match (widget value)
3381   (let ((alternatives (widget-get widget :match-alternatives))
3382         matched)
3383     (while (and alternatives (not matched))
3384       (if (cond ((functionp (car alternatives))
3385                  (funcall (car alternatives) value))
3386                 ((and (consp (car alternatives))
3387                       (eq (car (car alternatives)) 'quote))
3388                  (eq value (nth 1 (car alternatives)))))
3389           (setq matched t))
3390       (setq alternatives (cdr alternatives)))
3391     matched))
3392 \f
3393 (define-widget 'integer 'restricted-sexp
3394   "An integer."
3395   :tag "Integer"
3396   :value 0
3397   :type-error "This field should contain an integer"
3398   :match-alternatives '(integerp))
3399
3400 (define-widget 'number 'restricted-sexp
3401   "A number (floating point or integer)."
3402   :tag "Number"
3403   :value 0.0
3404   :type-error "This field should contain a number (floating point or integer)"
3405   :match-alternatives '(numberp))
3406
3407 (define-widget 'float 'restricted-sexp
3408   "A floating point number."
3409   :tag "Floating point number"
3410   :value 0.0
3411   :type-error "This field should contain a floating point number"
3412   :match-alternatives '(floatp))
3413
3414 (define-widget 'character 'editable-field
3415   "A character."
3416   :tag "Character"
3417   :value 0
3418   :size 1
3419   :format "%{%t%}: %v\n"
3420   :valid-regexp "\\`.\\'"
3421   :error "This field should contain a single character"
3422   :value-to-internal (lambda (widget value)
3423                        (if (stringp value)
3424                            value
3425                          (char-to-string value)))
3426   :value-to-external (lambda (widget value)
3427                        (if (stringp value)
3428                            (aref value 0)
3429                          value))
3430   :match (lambda (widget value)
3431            (characterp value)))
3432
3433 (define-widget 'list 'group
3434   "A Lisp list."
3435   :tag "List"
3436   :format "%{%t%}:\n%v")
3437
3438 (define-widget 'vector 'group
3439   "A Lisp vector."
3440   :tag "Vector"
3441   :format "%{%t%}:\n%v"
3442   :match 'widget-vector-match
3443   :value-to-internal (lambda (widget value) (append value nil))
3444   :value-to-external (lambda (widget value) (apply 'vector value)))
3445
3446 (defun widget-vector-match (widget value)
3447   (and (vectorp value)
3448        (widget-group-match widget
3449                            (widget-apply widget :value-to-internal value))))
3450
3451 (define-widget 'cons 'group
3452   "A cons-cell."
3453   :tag "Cons-cell"
3454   :format "%{%t%}:\n%v"
3455   :match 'widget-cons-match
3456   :value-to-internal (lambda (widget value)
3457                        (list (car value) (cdr value)))
3458   :value-to-external (lambda (widget value)
3459                        (apply 'cons value)))
3460
3461 (defun widget-cons-match (widget value)
3462   (and (consp value)
3463        (widget-group-match widget
3464                            (widget-apply widget :value-to-internal value))))
3465 \f
3466 ;;; The `lazy' Widget.
3467 ;;
3468 ;; Recursive datatypes.
3469
3470 (define-widget 'lazy 'default
3471   "Base widget for recursive datastructures.
3472
3473 The `lazy' widget will, when instantiated, contain a single inferior
3474 widget, of the widget type specified by the :type parameter.  The
3475 value of the `lazy' widget is the same as the value of the inferior
3476 widget.  When deriving a new widget from the 'lazy' widget, the :type
3477 parameter is allowed to refer to the widget currently being defined,
3478 thus allowing recursive datastructures to be described.
3479
3480 The :type parameter takes the same arguments as the defcustom
3481 parameter with the same name.
3482
3483 Most composite widgets, i.e. widgets containing other widgets, does
3484 not allow recursion.  That is, when you define a new widget type, none
3485 of the inferior widgets may be of the same type you are currently
3486 defining.
3487
3488 In Lisp, however, it is custom to define datastructures in terms of
3489 themselves.  A list, for example, is defined as either nil, or a cons
3490 cell whose cdr itself is a list.  The obvious way to translate this
3491 into a widget type would be
3492
3493   (define-widget 'my-list 'choice
3494     \"A list of sexps.\"
3495     :tag \"Sexp list\"
3496     :args '((const nil) (cons :value (nil) sexp my-list)))
3497
3498 Here we attempt to define my-list as a choice of either the constant
3499 nil, or a cons-cell containing a sexp and my-lisp.  This will not work
3500 because the `choice' widget does not allow recursion.
3501
3502 Using the `lazy' widget you can overcome this problem, as in this
3503 example:
3504
3505   (define-widget 'sexp-list 'lazy
3506     \"A list of sexps.\"
3507     :tag \"Sexp list\"
3508     :type '(choice (const nil) (cons :value (nil) sexp sexp-list)))"
3509   :format "%{%t%}: %v"
3510   ;; We don't convert :type because we want to allow recursive
3511   ;; datastructures.  This is slow, so we should not create speed
3512   ;; critical widgets by deriving from this.
3513   :convert-widget 'widget-value-convert-widget
3514   :value-create 'widget-type-value-create
3515   :value-get 'widget-child-value-get
3516   :value-inline 'widget-child-value-inline
3517   :default-get 'widget-type-default-get
3518   :match 'widget-type-match
3519   :validate 'widget-child-validate)
3520
3521 \f
3522 ;;; The `plist' Widget.
3523 ;;
3524 ;; Property lists.
3525
3526 (define-widget 'plist 'list
3527   "A property list."
3528   :key-type '(symbol :tag "Key")
3529   :value-type '(sexp :tag "Value")
3530   :convert-widget 'widget-plist-convert-widget
3531   :tag "Plist")
3532
3533 (defvar widget-plist-value-type)        ;Dynamic variable
3534
3535 (defun widget-plist-convert-widget (widget)
3536   ;; Handle `:options'.
3537   (let* ((options (widget-get widget :options))
3538          (widget-plist-value-type (widget-get widget :value-type))
3539          (other `(editable-list :inline t
3540                                 (group :inline t
3541                                        ,(widget-get widget :key-type)
3542                                        ,widget-plist-value-type)))
3543          (args (if options
3544                    (list `(checklist :inline t
3545                                      :greedy t
3546                                      ,@(mapcar 'widget-plist-convert-option
3547                                                options))
3548                          other)
3549                  (list other))))
3550     (widget-put widget :args args)
3551     widget))
3552
3553 (defun widget-plist-convert-option (option)
3554   ;; Convert a single plist option.
3555   (let (key-type value-type)
3556     (if (listp option)
3557         (let ((key (nth 0 option)))
3558           (setq value-type (nth 1 option))
3559           (if (listp key)
3560               (setq key-type key)
3561             (setq key-type `(const ,key))))
3562       (setq key-type `(const ,option)
3563             value-type widget-plist-value-type))
3564     `(group :format "Key: %v" :inline t ,key-type ,value-type)))
3565
3566
3567 ;;; The `alist' Widget.
3568 ;;
3569 ;; Association lists.
3570
3571 (define-widget 'alist 'list
3572   "An association list."
3573   :key-type '(sexp :tag "Key")
3574   :value-type '(sexp :tag "Value")
3575   :convert-widget 'widget-alist-convert-widget
3576   :tag "Alist")
3577
3578 (defvar widget-alist-value-type)        ;Dynamic variable
3579
3580 (defun widget-alist-convert-widget (widget)
3581   ;; Handle `:options'.
3582   (let* ((options (widget-get widget :options))
3583          (widget-alist-value-type (widget-get widget :value-type))
3584          (other `(editable-list :inline t
3585                                 (cons :format "%v"
3586                                       ,(widget-get widget :key-type)
3587                                       ,widget-alist-value-type)))
3588          (args (if options
3589                    (list `(checklist :inline t
3590                                      :greedy t
3591                                      ,@(mapcar 'widget-alist-convert-option
3592                                                options))
3593                          other)
3594                  (list other))))
3595     (widget-put widget :args args)
3596     widget))
3597
3598 (defun widget-alist-convert-option (option)
3599   ;; Convert a single alist option.
3600   (let (key-type value-type)
3601     (if (listp option)
3602         (let ((key (nth 0 option)))
3603           (setq value-type (nth 1 option))
3604           (if (listp key)
3605               (setq key-type key)
3606             (setq key-type `(const ,key))))
3607       (setq key-type `(const ,option)
3608             value-type widget-alist-value-type))
3609     `(cons :format "Key: %v" ,key-type ,value-type)))
3610 \f
3611 (define-widget 'choice 'menu-choice
3612   "A union of several sexp types."
3613   :tag "Choice"
3614   :format "%{%t%}: %[Value Menu%] %v"
3615   :button-prefix 'widget-push-button-prefix
3616   :button-suffix 'widget-push-button-suffix
3617   :prompt-value 'widget-choice-prompt-value)
3618
3619 (defun widget-choice-prompt-value (widget prompt value unbound)
3620   "Make a choice."
3621   (let ((args (widget-get widget :args))
3622         (completion-ignore-case (widget-get widget :case-fold))
3623         current choices old)
3624     ;; Find the first arg that matches VALUE.
3625     (let ((look args))
3626       (while look
3627         (if (widget-apply (car look) :match value)
3628             (setq old (car look)
3629                   look nil)
3630           (setq look (cdr look)))))
3631     ;; Find new choice.
3632     (setq current
3633           (cond ((= (length args) 0)
3634                  nil)
3635                 ((= (length args) 1)
3636                  (nth 0 args))
3637                 ((and (= (length args) 2)
3638                       (memq old args))
3639                  (if (eq old (nth 0 args))
3640                      (nth 1 args)
3641                    (nth 0 args)))
3642                 (t
3643                  (while args
3644                    (setq current (car args)
3645                          args (cdr args))
3646                    (setq choices
3647                          (cons (cons (widget-apply current :menu-tag-get)
3648                                      current)
3649                                choices)))
3650                  (let ((val (completing-read prompt choices nil t)))
3651                    (if (stringp val)
3652                        (let ((try (try-completion val choices)))
3653                          (when (stringp try)
3654                            (setq val try))
3655                          (cdr (assoc val choices)))
3656                      nil)))))
3657     (if current
3658         (widget-prompt-value current prompt nil t)
3659       value)))
3660 \f
3661 (define-widget 'radio 'radio-button-choice
3662   "A union of several sexp types."
3663   :tag "Choice"
3664   :format "%{%t%}:\n%v"
3665   :prompt-value 'widget-choice-prompt-value)
3666
3667 (define-widget 'repeat 'editable-list
3668   "A variable length homogeneous list."
3669   :tag "Repeat"
3670   :format "%{%t%}:\n%v%i\n")
3671
3672 (define-widget 'set 'checklist
3673   "A list of members from a fixed set."
3674   :tag "Set"
3675   :format "%{%t%}:\n%v")
3676
3677 (define-widget 'boolean 'toggle
3678   "To be nil or non-nil, that is the question."
3679   :tag "Boolean"
3680   :prompt-value 'widget-boolean-prompt-value
3681   :button-prefix 'widget-push-button-prefix
3682   :button-suffix 'widget-push-button-suffix
3683   :format "%{%t%}: %[Toggle%]  %v\n"
3684   :on "on (non-nil)"
3685   :off "off (nil)")
3686
3687 (defun widget-boolean-prompt-value (widget prompt value unbound)
3688   ;; Toggle a boolean.
3689   (y-or-n-p prompt))
3690 \f
3691 ;;; The `color' Widget.
3692
3693 ;; Fixme: match
3694 (define-widget 'color 'editable-field
3695   "Choose a color name (with sample)."
3696   :format "%{%t%}: %v (%{sample%})\n"
3697   :size 10
3698   :tag "Color"
3699   :value "black"
3700   :complete 'widget-color-complete
3701   :sample-face-get 'widget-color-sample-face-get
3702   :notify 'widget-color-notify
3703   :action 'widget-color-action)
3704
3705 (defun widget-color-complete (widget)
3706   "Complete the color in WIDGET."
3707   (require 'facemenu)                   ; for facemenu-color-alist
3708   (completion-in-region (widget-field-start widget)
3709                         (max (point) (widget-field-text-end widget))
3710                         (or facemenu-color-alist
3711                             (sort (defined-colors) 'string-lessp))))
3712
3713 (defun widget-color-sample-face-get (widget)
3714   (let* ((value (condition-case nil
3715                     (widget-value widget)
3716                   (error (widget-get widget :value)))))
3717     (if (color-defined-p value)
3718         (list (cons 'foreground-color value))
3719       'default)))
3720
3721 (defun widget-color-action (widget &optional event)
3722   "Prompt for a color."
3723   (let* ((tag (widget-apply widget :menu-tag-get))
3724          (prompt (concat tag ": "))
3725          (value (widget-value widget))
3726          (start (widget-field-start widget))
3727          (answer (facemenu-read-color prompt)))
3728     (unless (zerop (length answer))
3729       (widget-value-set widget answer)
3730       (widget-setup)
3731       (widget-apply widget :notify widget event))))
3732
3733 (defun widget-color-notify (widget child &optional event)
3734   "Update the sample, and notify the parent."
3735   (overlay-put (widget-get widget :sample-overlay)
3736                'face (widget-apply widget :sample-face-get))
3737   (widget-default-notify widget child event))
3738 \f
3739 ;;; The Help Echo
3740
3741 (defun widget-echo-help (pos)
3742   "Display help-echo text for widget at POS."
3743   (let* ((widget (widget-at pos))
3744          (help-echo (and widget (widget-get widget :help-echo))))
3745     (if (functionp help-echo)
3746         (setq help-echo (funcall help-echo widget)))
3747     (if help-echo (message "%s" (eval help-echo)))))
3748
3749 ;;; The End:
3750
3751 (provide 'wid-edit)
3752
3753 ;;; wid-edit.el ends here