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

   1 ;;; wid-edit.el --- Functions for creating and using widgets.
   2 ;;
   3 ;; Copyright (C) 1996, 1997 Free Software Foundation, Inc.
   4 ;;
   5 ;; Author: Per Abrahamsen <abraham@dina.kvl.dk>
   6 ;; Keywords: extensions
   7 ;; Version: 1.97
   8 ;; X-URL: http://www.dina.kvl.dk/~abraham/custom/
   9
  10 ;; This file is part of GNU Emacs.
  11
  12 ;; GNU Emacs is free software; you can redistribute it and/or modify
  13 ;; it under the terms of the GNU General Public License as published by
  14 ;; the Free Software Foundation; either version 2, or (at your option)
  15 ;; any later version.
  16
  17 ;; GNU Emacs is distributed in the hope that it will be useful,
  18 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  19 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  20 ;; GNU General Public License for more details.
  21
  22 ;; You should have received a copy of the GNU General Public License
  23 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  24 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  25 ;; Boston, MA 02111-1307, USA.
  26
  27 ;;; Commentary:
  28 ;;
  29 ;; See `widget.el'.
  30
  31 ;;; Code:
  32
  33 (require 'widget)
  34
  35 (eval-when-compile (require 'cl))
  36
  37 ;;; Compatibility.
  38
  39 (eval-and-compile
  40   (autoload 'pp-to-string "pp")
  41   (autoload 'Info-goto-node "info")
  42
  43   (when (string-match "XEmacs" emacs-version)
  44     (condition-case nil
  45         (require 'overlay)
  46       (error (load-library "x-overlay"))))
  47
  48   (if (string-match "XEmacs" emacs-version)
  49       ;; XEmacs spell `intangible' as `atomic'.
  50       (defun widget-make-intangible (from to side)
  51         "Make text between FROM and TO atomic with regard to movement.
  52 Third argument should be `start-open' if it should be sticky to the rear,
  53 and `end-open' if it should sticky to the front."
  54         (require 'atomic-extents)
  55         (let ((ext (make-extent from to)))
  56            ;; XEmacs doesn't understant different kinds of read-only, so
  57            ;; we have to use extents instead.
  58           (put-text-property from to 'read-only nil)
  59           (set-extent-property ext 'read-only t)
  60           (set-extent-property ext 'start-open nil)
  61           (set-extent-property ext 'end-open nil)
  62           (set-extent-property ext side t)
  63           (set-extent-property ext 'atomic t)))
  64     (defun widget-make-intangible (from to size)
  65       "Make text between FROM and TO intangible."
  66       (put-text-property from to 'intangible 'front)))
  67
  68   (if (string-match "XEmacs" emacs-version)
  69       (defun widget-event-point (event)
  70         "Character position of the end of event if that exists, or nil."
  71         (if (mouse-event-p event)
  72             (event-point event)
  73           nil))
  74     (defun widget-event-point (event)
  75       "Character position of the end of event if that exists, or nil."
  76       (posn-point (event-end event))))
  77
  78 ;; The following should go away when bundled with Emacs.
  79   (condition-case ()
  80       (require 'custom)
  81     (error nil))
  82
  83   (unless (and (featurep 'custom) (fboundp 'custom-declare-variable))
  84     ;; We have the old custom-library, hack around it!
  85     (defmacro defgroup (&rest args) nil)
  86     (defmacro defcustom (var value doc &rest args)
  87       (` (defvar (, var) (, value) (, doc))))
  88     (defmacro defface (&rest args) nil)
  89     (define-widget-keywords :prefix :tag :load :link :options :type :group)
  90     (when (fboundp 'copy-face)
  91       (copy-face 'default 'widget-documentation-face)
  92       (copy-face 'bold 'widget-button-face)
  93       (copy-face 'italic 'widget-field-face)))
  94
  95   (unless (fboundp 'button-release-event-p)
  96     ;; XEmacs function missing from Emacs.
  97     (defun button-release-event-p (event)
  98       "Non-nil if EVENT is a mouse-button-release event object."
  99       (and (eventp event)
 100            (memq (event-basic-type event) '(mouse-1 mouse-2 mouse-3))
 101            (or (memq 'click (event-modifiers event))
 102                (memq  'drag (event-modifiers event))))))
 103
 104   (unless (fboundp 'error-message-string)
 105     ;; Emacs function missing in XEmacs.
 106     (defun error-message-string (obj)
 107       "Convert an error value to an error message."
 108       (let ((buf (get-buffer-create " *error-message*")))
 109         (erase-buffer buf)
 110         (display-error obj buf)
 111         (buffer-string buf)))))
 112
 113 ;;; Customization.
 114
 115 (defgroup widgets nil
 116   "Customization support for the Widget Library."
 117   :link '(custom-manual "(widget)Top")
 118   :link '(url-link :tag "Development Page"
 119                    "http://www.dina.kvl.dk/~abraham/custom/")
 120   :prefix "widget-"
 121   :group 'extensions
 122   :group 'faces
 123   :group 'hypermedia)
 124
 125 (defface widget-documentation-face '((((class color)
 126                                        (background dark))
 127                                       (:foreground "lime green"))
 128                                      (((class color)
 129                                        (background light))
 130                                       (:foreground "dark green"))
 131                                      (t nil))
 132   "Face used for documentation text."
 133   :group 'widgets)
 134
 135 (defface widget-button-face '((t (:bold t)))
 136   "Face used for widget buttons."
 137   :group 'widgets)
 138
 139 (defcustom widget-mouse-face 'highlight
 140   "Face used for widget buttons when the mouse is above them."
 141   :type 'face
 142   :group 'widgets)
 143
 144 (defface widget-field-face '((((class grayscale color)
 145                                (background light))
 146                               (:background "gray85"))
 147                              (((class grayscale color)
 148                                (background dark))
 149                               (:background "dark gray"))
 150                              (t
 151                               (:italic t)))
 152   "Face used for editable fields."
 153   :group 'widgets)
 154
 155 ;;; Utility functions.
 156 ;;
 157 ;; These are not really widget specific.
 158
 159 (defsubst widget-plist-member (plist prop)
 160   ;; Return non-nil if PLIST has the property PROP.
 161   ;; PLIST is a property list, which is a list of the form
 162   ;; (PROP1 VALUE1 PROP2 VALUE2 ...).  PROP is a symbol.
 163   ;; Unlike `plist-get', this allows you to distinguish between a missing
 164   ;; property and a property with the value nil.
 165   ;; The value is actually the tail of PLIST whose car is PROP.
 166   (while (and plist (not (eq (car plist) prop)))
 167     (setq plist (cdr (cdr plist))))
 168   plist)
 169
 170 (defun widget-princ-to-string (object)
 171   ;; Return string representation of OBJECT, any Lisp object.
 172   ;; No quoting characters are used; no delimiters are printed around
 173   ;; the contents of strings.
 174   (save-excursion
 175     (set-buffer (get-buffer-create " *widget-tmp*"))
 176     (erase-buffer)
 177     (let ((standard-output (current-buffer)))
 178       (princ object))
 179     (buffer-string)))
 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 (defun widget-choose (title items &optional event)
 193   "Choose an item from a list.
 194
 195 First argument TITLE is the name of the list.
 196 Second argument ITEMS is an list whose members are either
 197  (NAME . VALUE), to indicate selectable items, or just strings to
 198  indicate unselectable items.
 199 Optional third argument EVENT is an input event.
 200
 201 The user is asked to choose between each NAME from the items alist,
 202 and the VALUE of the chosen element will be returned.  If EVENT is a
 203 mouse event, and the number of elements in items is less than
 204 `widget-menu-max-size', a popup menu will be used, otherwise the
 205 minibuffer."
 206   (cond ((and (< (length items) widget-menu-max-size)
 207               event (fboundp 'x-popup-menu) window-system)
 208          ;; We are in Emacs-19, pressed by the mouse
 209          (x-popup-menu event
 210                        (list title (cons "" items))))
 211         ((and (< (length items) widget-menu-max-size)
 212               event (fboundp 'popup-menu) window-system)
 213          ;; We are in XEmacs, pressed by the mouse
 214          (let ((val (get-popup-menu-response
 215                      (cons title
 216                            (mapcar
 217                             (function
 218                              (lambda (x)
 219                                (if (stringp x)
 220                                    (vector x nil nil)
 221                                  (vector (car x) (list (car x)) t))))
 222                             items)))))
 223            (setq val (and val
 224                           (listp (event-object val))
 225                           (stringp (car-safe (event-object val)))
 226                           (car (event-object val))))
 227            (cdr (assoc val items))))
 228         (t
 229          (setq items (remove-if 'stringp items))
 230          (let ((val (completing-read (concat title ": ") items nil t)))
 231            (if (stringp val)
 232                (let ((try (try-completion val items)))
 233                  (when (stringp try)
 234                    (setq val try))
 235                  (cdr (assoc val items)))
 236              nil)))))
 237
 238 ;;; Widget text specifications.
 239 ;;
 240 ;; These functions are for specifying text properties.
 241
 242 (defun widget-specify-none (from to)
 243   ;; Clear all text properties between FROM and TO.
 244   (set-text-properties from to nil))
 245
 246 (defun widget-specify-text (from to)
 247   ;; Default properties.
 248   (add-text-properties from to (list 'read-only t
 249                                      'front-sticky t
 250                                      'start-open t
 251                                      'end-open t
 252                                      'rear-nonsticky nil)))
 253
 254 (defun widget-specify-field (widget from to)
 255   ;; Specify editable button for WIDGET between FROM and TO.
 256   (widget-specify-field-update widget from to)
 257
 258   ;; Make it possible to edit the front end of the field.
 259   (add-text-properties (1- from) from (list 'rear-nonsticky t
 260                                               'end-open t
 261                                               'invisible t))
 262   (when (or (string-match "\\(.\\|\n\\)%v" (widget-get widget :format))
 263             (widget-get widget :hide-front-space))
 264     ;; WARNING: This is going to lose horrible if the character just
 265     ;; before the field can be modified (e.g. if it belongs to a
 266     ;; choice widget).  We try to compensate by checking the format
 267     ;; string, and hope the user hasn't changed the :create method.
 268     (widget-make-intangible (- from 2) from 'end-open))
 269
 270   ;; Make it possible to edit back end of the field.
 271   (add-text-properties to (1+ to) (list 'front-sticky nil
 272                                         'read-only t
 273                                         'start-open t))
 274
 275   (cond ((widget-get widget :size)
 276          (put-text-property to (1+ to) 'invisible t)
 277          (when (or (string-match "%v\\(.\\|\n\\)" (widget-get widget :format))
 278                    (widget-get widget :hide-rear-space))
 279            ;; WARNING: This is going to lose horrible if the character just
 280            ;; after the field can be modified (e.g. if it belongs to a
 281            ;; choice widget).  We try to compensate by checking the format
 282            ;; string, and hope the user hasn't changed the :create method.
 283            (widget-make-intangible to (+ to 2) 'start-open)))
 284         ((string-match "XEmacs" emacs-version)
 285          ;; XEmacs does not allow you to insert before a read-only
 286          ;; character, even if it is start.open.
 287          ;; XEmacs does allow you to delete an read-only extent, so
 288          ;; making the terminating newline read only doesn't help.
 289          ;; I tried putting an invisible intangible read-only space
 290          ;; before the newline, which gave really weird effects.
 291          ;; So for now, we just have trust the user not to delete the
 292          ;; newline.
 293          (put-text-property to (1+ to) 'read-only nil))))
 294
 295 (defun widget-specify-field-update (widget from to)
 296   ;; Specify editable button for WIDGET between FROM and TO.
 297   (let ((map (widget-get widget :keymap))
 298         (secret (widget-get widget :secret))
 299         (secret-to to)
 300         (size (widget-get widget :size))
 301         (face (or (widget-get widget :value-face)
 302                   'widget-field-face))
 303         (help-echo (widget-get widget :help-echo))
 304         (help-property (if (featurep 'balloon-help)
 305                            'balloon-help
 306                          'help-echo)))
 307     (unless (or (stringp help-echo) (null help-echo))
 308       (setq help-echo 'widget-mouse-help))
 309
 310     (when secret
 311       (while (and size
 312                   (not (zerop size))
 313                   (> secret-to from)
 314                   (eq (char-after (1- secret-to)) ?\ ))
 315         (setq secret-to (1- secret-to)))
 316
 317       (save-excursion
 318         (goto-char from)
 319         (while (< (point) secret-to)
 320           (let ((old (get-text-property (point) 'secret)))
 321             (when old
 322               (subst-char-in-region (point) (1+ (point)) secret old)))
 323           (forward-char))))
 324
 325     (set-text-properties from to (list 'field widget
 326                                        'read-only nil
 327                                        'keymap map
 328                                        'local-map map
 329                                        help-property help-echo
 330                                        'face face))
 331
 332     (when secret
 333       (save-excursion
 334         (goto-char from)
 335         (while (< (point) secret-to)
 336           (let ((old (following-char)))
 337             (subst-char-in-region (point) (1+ (point)) old secret)
 338             (put-text-property (point) (1+ (point)) 'secret old))
 339           (forward-char))))
 340
 341     (unless (widget-get widget :size)
 342       (add-text-properties to (1+ to) (list 'field widget
 343                                             help-property help-echo
 344                                             'face face)))
 345     (add-text-properties to (1+ to) (list 'local-map map
 346                                           'keymap map))))
 347
 348 (defun widget-specify-button (widget from to)
 349   ;; Specify button for WIDGET between FROM and TO.
 350   (let ((face (widget-apply widget :button-face-get))
 351         (help-echo (widget-get widget :help-echo))
 352         (help-property (if (featurep 'balloon-help)
 353                            'balloon-help
 354                          'help-echo)))
 355     (unless (or (null help-echo) (stringp help-echo))
 356       (setq help-echo 'widget-mouse-help))
 357     (add-text-properties from to (list 'button widget
 358                                        'mouse-face widget-mouse-face
 359                                        'start-open t
 360                                        'end-open t
 361                                        help-property help-echo
 362                                        'face face))))
 363
 364 (defun widget-mouse-help (extent)
 365   "Find mouse help string for button in extent."
 366   (let* ((widget (widget-at (extent-start-position extent)))
 367          (help-echo (and widget (widget-get widget :help-echo))))
 368     (cond ((stringp help-echo)
 369            help-echo)
 370           ((and (symbolp help-echo) (fboundp help-echo)
 371                 (stringp (setq help-echo (funcall help-echo widget))))
 372            help-echo)
 373           (t
 374            (format "(widget %S :help-echo %S)" widget help-echo)))))
 375
 376 (defun widget-specify-sample (widget from to)
 377   ;; Specify sample for WIDGET between FROM and TO.
 378   (let ((face (widget-apply widget :sample-face-get)))
 379     (when face
 380       (add-text-properties from to (list 'start-open t
 381                                          'end-open t
 382                                          'face face)))))
 383
 384 (defun widget-specify-doc (widget from to)
 385   ;; Specify documentation for WIDGET between FROM and TO.
 386   (add-text-properties from to (list 'widget-doc widget
 387                                      'face 'widget-documentation-face)))
 388
 389 (defmacro widget-specify-insert (&rest form)
 390   ;; Execute FORM without inheriting any text properties.
 391   (`
 392    (save-restriction
 393      (let ((inhibit-read-only t)
 394            result
 395            after-change-functions)
 396        (insert "<>")
 397        (narrow-to-region (- (point) 2) (point))
 398        (widget-specify-none (point-min) (point-max))
 399        (goto-char (1+ (point-min)))
 400        (setq result (progn (,@ form)))
 401        (delete-region (point-min) (1+ (point-min)))
 402        (delete-region (1- (point-max)) (point-max))
 403        (goto-char (point-max))
 404        result))))
 405
 406 (defface widget-inactive-face '((((class grayscale color)
 407                                   (background dark))
 408                                  (:foreground "light gray"))
 409                                 (((class grayscale color)
 410                                   (background light))
 411                                  (:foreground "dark gray"))
 412                                 (t
 413                                  (:italic t)))
 414   "Face used for inactive widgets."
 415   :group 'widgets)
 416
 417 (defun widget-specify-inactive (widget from to)
 418   "Make WIDGET inactive for user modifications."
 419   (unless (widget-get widget :inactive)
 420     (let ((overlay (make-overlay from to nil t nil)))
 421       (overlay-put overlay 'face 'widget-inactive-face)
 422       (overlay-put overlay 'evaporate t)
 423       (overlay-put overlay 'priority 100)
 424       (overlay-put overlay (if (string-match "XEmacs" emacs-version)
 425                                'read-only
 426                              'modification-hooks) '(widget-overlay-inactive))
 427       (widget-put widget :inactive overlay))))
 428
 429 (defun widget-overlay-inactive (&rest junk)
 430   "Ignoring the arguments, signal an error."
 431   (unless inhibit-read-only
 432     (error "Attempt to modify inactive widget")))
 433
 434
 435 (defun widget-specify-active (widget)
 436   "Make WIDGET active for user modifications."
 437   (let ((inactive (widget-get widget :inactive)))
 438     (when inactive
 439       (delete-overlay inactive)
 440       (widget-put widget :inactive nil))))
 441
 442 ;;; Widget Properties.
 443
 444 (defsubst widget-type (widget)
 445   "Return the type of WIDGET, a symbol."
 446   (car widget))
 447
 448 (defun widget-put (widget property value)
 449   "In WIDGET set PROPERTY to VALUE.
 450 The value can later be retrived with `widget-get'."
 451   (setcdr widget (plist-put (cdr widget) property value)))
 452
 453 (defun widget-get (widget property)
 454   "In WIDGET, get the value of PROPERTY.
 455 The value could either be specified when the widget was created, or
 456 later with `widget-put'."
 457   (let ((missing t)
 458         value tmp)
 459     (while missing
 460       (cond ((setq tmp (widget-plist-member (cdr widget) property))
 461              (setq value (car (cdr tmp))
 462                    missing nil))
 463             ((setq tmp (car widget))
 464              (setq widget (get tmp 'widget-type)))
 465             (t
 466              (setq missing nil))))
 467     value))
 468
 469 (defun widget-member (widget property)
 470   "Non-nil iff there is a definition in WIDGET for PROPERTY."
 471   (cond ((widget-plist-member (cdr widget) property)
 472          t)
 473         ((car widget)
 474          (widget-member (get (car widget) 'widget-type) property))
 475         (t nil)))
 476
 477 ;;;###autoload
 478 (defun widget-apply (widget property &rest args)
 479   "Apply the value of WIDGET's PROPERTY to the widget itself.
 480 ARGS are passed as extra arguments to the function."
 481   (apply (widget-get widget property) widget args))
 482
 483 (defun widget-value (widget)
 484   "Extract the current value of WIDGET."
 485   (widget-apply widget
 486                 :value-to-external (widget-apply widget :value-get)))
 487
 488 (defun widget-value-set (widget value)
 489   "Set the current value of WIDGET to VALUE."
 490   (widget-apply widget
 491                 :value-set (widget-apply widget
 492                                          :value-to-internal value)))
 493
 494 (defun widget-match-inline (widget vals)
 495   ;; In WIDGET, match the start of VALS.
 496   (cond ((widget-get widget :inline)
 497          (widget-apply widget :match-inline vals))
 498         ((and vals
 499               (widget-apply widget :match (car vals)))
 500          (cons (list (car vals)) (cdr vals)))
 501         (t nil)))
 502
 503 (defun widget-apply-action (widget &optional event)
 504   "Apply :action in WIDGET in response to EVENT."
 505   (if (widget-apply widget :active)
 506       (widget-apply widget :action event)
 507     (error "Attempt to perform action on inactive widget")))
 508
 509 ;;; Helper functions.
 510 ;;
 511 ;; These are widget specific.
 512
 513 ;;;###autoload
 514 (defun widget-prompt-value (widget prompt &optional value unbound)
 515   "Prompt for a value matching WIDGET, using PROMPT.
 516 The current value is assumed to be VALUE, unless UNBOUND is non-nil."
 517   (unless (listp widget)
 518     (setq widget (list widget)))
 519   (setq prompt (format "[%s] %s" (widget-type widget) prompt))
 520   (setq widget (widget-convert widget))
 521   (let ((answer (widget-apply widget :prompt-value prompt value unbound)))
 522     (unless (widget-apply widget :match answer)
 523       (error "Value does not match %S type." (car widget)))
 524     answer))
 525
 526 (defun widget-get-sibling (widget)
 527   "Get the item WIDGET is assumed to toggle.
 528 This is only meaningful for radio buttons or checkboxes in a list."
 529   (let* ((parent (widget-get widget :parent))
 530          (children (widget-get parent :children))
 531          child)
 532     (catch 'child
 533       (while children
 534         (setq child (car children)
 535               children (cdr children))
 536         (when (eq (widget-get child :button) widget)
 537           (throw 'child child)))
 538       nil)))
 539
 540 ;;; Glyphs.
 541
 542 (defcustom widget-glyph-directory (concat data-directory "custom/")
 543   "Where widget glyphs are located.
 544 If this variable is nil, widget will try to locate the directory
 545 automatically. This does not work yet."
 546   :group 'widgets
 547   :type 'directory)
 548
 549 (defcustom widget-glyph-enable t
 550   "If non nil, use glyphs in images when available."
 551   :group 'widgets
 552   :type 'boolean)
 553
 554 (defun widget-glyph-insert (widget tag image)
 555   "In WIDGET, insert the text TAG or, if supported, IMAGE.
 556 IMAGE should either be a glyph, or a name sans extension of an xpm or
 557 xbm file located in `widget-glyph-directory'.
 558
 559 WARNING: If you call this with a glyph, and you want the user to be
 560 able to activate the glyph, make sure it is unique.  If you use the
 561 same glyph for multiple widgets, activating any of the glyphs will
 562 cause the last created widget to be activated."
 563   (cond ((not (and (string-match "XEmacs" emacs-version)
 564                    widget-glyph-enable
 565                    (fboundp 'make-glyph)
 566                    image))
 567          ;; We don't want or can't use glyphs.
 568          (insert tag))
 569         ((and (fboundp 'glyphp)
 570               (glyphp image))
 571          ;; Already a glyph.  Insert it.
 572          (widget-glyph-insert-glyph widget tag image))
 573         (t
 574          ;; A string.  Look it up in.
 575          (let ((file (concat widget-glyph-directory
 576                             (if (string-match "/\\'" widget-glyph-directory)
 577                                 ""
 578                               "/")
 579                             image
 580                             (if (featurep 'xpm) ".xpm" ".xbm"))))
 581            (if (file-readable-p file)
 582                (widget-glyph-insert-glyph widget tag (make-glyph file))
 583              ;; File not readable, give up.
 584              (insert tag))))))
 585
 586 (defun widget-glyph-insert-glyph (widget tag glyph &optional down inactive)
 587   "In WIDGET, with alternative text TAG, insert GLYPH."
 588   (set-glyph-image glyph (cons 'tty tag))
 589   (set-glyph-property glyph 'widget widget)
 590   (when down
 591     (set-glyph-image down (cons 'tty tag))
 592     (set-glyph-property down 'widget widget))
 593   (when inactive
 594     (set-glyph-image inactive (cons 'tty tag))
 595     (set-glyph-property inactive 'widget widget))
 596   (insert "*")
 597   (add-text-properties (1- (point)) (point)
 598                        (list 'invisible t
 599                              'end-glyph glyph))
 600   (widget-put widget :glyph-up glyph)
 601   (when down (widget-put widget :glyph-down down))
 602   (when inactive (widget-put widget :glyph-inactive inactive))
 603   (let ((help-echo (widget-get widget :help-echo)))
 604     (when help-echo
 605       (let ((extent (extent-at (1- (point)) nil 'end-glyph))
 606             (help-property (if (featurep 'balloon-help)
 607                                'balloon-help
 608                              'help-echo)))
 609         (set-extent-property extent help-property (if (stringp help-echo)
 610                                                       help-echo
 611                                                     'widget-mouse-help))))))
 612
 613 ;;; Creating Widgets.
 614
 615 ;;;###autoload
 616 (defun widget-create (type &rest args)
 617   "Create widget of TYPE.
 618 The optional ARGS are additional keyword arguments."
 619   (let ((widget (apply 'widget-convert type args)))
 620     (widget-apply widget :create)
 621     widget))
 622
 623 (defun widget-create-child-and-convert (parent type &rest args)
 624   "As part of the widget PARENT, create a child widget TYPE.
 625 The child is converted, using the keyword arguments ARGS."
 626   (let ((widget (apply 'widget-convert type args)))
 627     (widget-put widget :parent parent)
 628     (unless (widget-get widget :indent)
 629       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 630                                     (or (widget-get widget :extra-offset) 0)
 631                                     (widget-get parent :offset))))
 632     (widget-apply widget :create)
 633     widget))
 634
 635 (defun widget-create-child (parent type)
 636   "Create widget of TYPE."
 637   (let ((widget (copy-sequence type)))
 638     (widget-put widget :parent parent)
 639     (unless (widget-get widget :indent)
 640       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 641                                     (or (widget-get widget :extra-offset) 0)
 642                                     (widget-get parent :offset))))
 643     (widget-apply widget :create)
 644     widget))
 645
 646 (defun widget-create-child-value (parent type value)
 647   "Create widget of TYPE with value VALUE."
 648   (let ((widget (copy-sequence type)))
 649     (widget-put widget :value (widget-apply widget :value-to-internal value))
 650     (widget-put widget :parent parent)
 651     (unless (widget-get widget :indent)
 652       (widget-put widget :indent (+ (or (widget-get parent :indent) 0)
 653                                     (or (widget-get widget :extra-offset) 0)
 654                                     (widget-get parent :offset))))
 655     (widget-apply widget :create)
 656     widget))
 657
 658 ;;;###autoload
 659 (defun widget-delete (widget)
 660   "Delete WIDGET."
 661   (widget-apply widget :delete))
 662
 663 (defun widget-convert (type &rest args)
 664   "Convert TYPE to a widget without inserting it in the buffer.
 665 The optional ARGS are additional keyword arguments."
 666   ;; Don't touch the type.
 667   (let* ((widget (if (symbolp type)
 668                      (list type)
 669                    (copy-sequence type)))
 670          (current widget)
 671          (keys args))
 672     ;; First set the :args keyword.
 673     (while (cdr current)                ;Look in the type.
 674       (let ((next (car (cdr current))))
 675         (if (and (symbolp next) (eq (aref (symbol-name next) 0) ?:))
 676             (setq current (cdr (cdr current)))
 677           (setcdr current (list :args (cdr current)))
 678           (setq current nil))))
 679     (while args                         ;Look in the args.
 680       (let ((next (nth 0 args)))
 681         (if (and (symbolp next) (eq (aref (symbol-name next) 0) ?:))
 682             (setq args (nthcdr 2 args))
 683           (widget-put widget :args args)
 684           (setq args nil))))
 685     ;; Then Convert the widget.
 686     (setq type widget)
 687     (while type
 688       (let ((convert-widget (plist-get (cdr type) :convert-widget)))
 689         (if convert-widget
 690             (setq widget (funcall convert-widget widget))))
 691       (setq type (get (car type) 'widget-type)))
 692     ;; Finally set the keyword args.
 693     (while keys
 694       (let ((next (nth 0 keys)))
 695         (if (and (symbolp next) (eq (aref (symbol-name next) 0) ?:))
 696             (progn
 697               (widget-put widget next (nth 1 keys))
 698               (setq keys (nthcdr 2 keys)))
 699           (setq keys nil))))
 700     ;; Convert the :value to internal format.
 701     (if (widget-member widget :value)
 702         (let ((value (widget-get widget :value)))
 703           (widget-put widget
 704                       :value (widget-apply widget :value-to-internal value))))
 705     ;; Return the newly create widget.
 706     widget))
 707
 708 (defun widget-insert (&rest args)
 709   "Call `insert' with ARGS and make the text read only."
 710   (let ((inhibit-read-only t)
 711         after-change-functions
 712         (from (point)))
 713     (apply 'insert args)
 714     (widget-specify-text from (point))))
 715
 716 ;;; Keymap and Commands.
 717
 718 (defvar widget-keymap nil
 719   "Keymap containing useful binding for buffers containing widgets.
 720 Recommended as a parent keymap for modes using widgets.")
 721
 722 (unless widget-keymap
 723   (setq widget-keymap (make-sparse-keymap))
 724   (define-key widget-keymap "\C-k" 'widget-kill-line)
 725   (define-key widget-keymap "\t" 'widget-forward)
 726   (define-key widget-keymap "\M-\t" 'widget-backward)
 727   (define-key widget-keymap [(shift tab)] 'widget-backward)
 728   (define-key widget-keymap [backtab] 'widget-backward)
 729   (if (string-match "XEmacs" emacs-version)
 730       (progn
 731         ;;Glyph support.
 732         (define-key widget-keymap [button1] 'widget-button1-click)
 733         (define-key widget-keymap [button2] 'widget-button-click))
 734     (define-key widget-keymap [down-mouse-2] 'widget-button-click))
 735   (define-key widget-keymap "\C-m" 'widget-button-press))
 736
 737 (defvar widget-global-map global-map
 738   "Keymap used for events the widget does not handle themselves.")
 739 (make-variable-buffer-local 'widget-global-map)
 740
 741 (defvar widget-field-keymap nil
 742   "Keymap used inside an editable field.")
 743
 744 (unless widget-field-keymap
 745   (setq widget-field-keymap (copy-keymap widget-keymap))
 746   (unless (string-match "XEmacs" (emacs-version))
 747     (define-key widget-field-keymap [menu-bar] 'nil))
 748   (define-key widget-field-keymap "\C-m" 'widget-field-activate)
 749   (define-key widget-field-keymap "\C-a" 'widget-beginning-of-line)
 750   (define-key widget-field-keymap "\C-e" 'widget-end-of-line)
 751   (set-keymap-parent widget-field-keymap global-map))
 752
 753 (defvar widget-text-keymap nil
 754   "Keymap used inside a text field.")
 755
 756 (unless widget-text-keymap
 757   (setq widget-text-keymap (copy-keymap widget-keymap))
 758   (unless (string-match "XEmacs" (emacs-version))
 759     (define-key widget-text-keymap [menu-bar] 'nil))
 760   (define-key widget-text-keymap "\C-a" 'widget-beginning-of-line)
 761   (define-key widget-text-keymap "\C-e" 'widget-end-of-line)
 762   (set-keymap-parent widget-text-keymap global-map))
 763
 764 (defun widget-field-activate (pos &optional event)
 765   "Activate the ediable field at point."
 766   (interactive "@d")
 767   (let ((field (get-text-property pos 'field)))
 768     (if field
 769         (widget-apply-action field event)
 770       (call-interactively
 771        (lookup-key widget-global-map (this-command-keys))))))
 772
 773 (defface widget-button-pressed-face
 774   '((((class color))
 775      (:foreground "red"))
 776     (t
 777      (:bold t :underline t)))
 778   "Face used for pressed buttons."
 779   :group 'widgets)
 780
 781 (defun widget-button-click (event)
 782   "Activate button below mouse pointer."
 783   (interactive "@e")
 784   (cond ((and (fboundp 'event-glyph)
 785               (event-glyph event))
 786          (widget-glyph-click event))
 787         ((widget-event-point event)
 788          (let* ((pos (widget-event-point event))
 789                 (button (get-text-property pos 'button)))
 790            (if button
 791                (let ((begin (previous-single-property-change (1+ pos) 'button))
 792                      (end (next-single-property-change pos 'button))
 793                      overlay)
 794                  (unwind-protect
 795                      (let ((track-mouse t))
 796                        (setq overlay (make-overlay begin end))
 797                        (overlay-put overlay 'face 'widget-button-pressed-face)
 798                        (overlay-put overlay
 799                                     'mouse-face 'widget-button-pressed-face)
 800                        (unless (widget-apply button :mouse-down-action event)
 801                          (while (not (button-release-event-p event))
 802                            (setq event (if (fboundp 'read-event)
 803                                            (read-event)
 804                                          (next-event))
 805                                  pos (widget-event-point event))
 806                            (if (and pos
 807                                     (eq (get-text-property pos 'button)
 808                                         button))
 809                                (progn
 810                                  (overlay-put overlay
 811                                               'face
 812                                               'widget-button-pressed-face)
 813                                  (overlay-put overlay
 814                                               'mouse-face
 815                                               'widget-button-pressed-face))
 816                              (overlay-put overlay 'face nil)
 817                              (overlay-put overlay 'mouse-face nil))))
 818
 819                        (when (and pos
 820                                   (eq (get-text-property pos 'button) button))
 821                          (widget-apply-action button event)))
 822                    (delete-overlay overlay)))
 823              (call-interactively
 824               (or (lookup-key widget-global-map [ button2 ])
 825                   (lookup-key widget-global-map [ down-mouse-2 ])
 826                   (lookup-key widget-global-map [ mouse-2]))))))
 827         (t
 828          (message "You clicked somewhere weird."))))
 829
 830 (defun widget-button1-click (event)
 831   "Activate glyph below mouse pointer."
 832   (interactive "@e")
 833   (if (and (fboundp 'event-glyph)
 834            (event-glyph event))
 835       (widget-glyph-click event)
 836     (call-interactively (lookup-key widget-global-map (this-command-keys)))))
 837
 838 (defun widget-glyph-click (event)
 839   "Handle click on a glyph."
 840   (let* ((glyph (event-glyph event))
 841          (widget (glyph-property glyph 'widget))
 842          (extent (event-glyph-extent event))
 843          (down-glyph (or (and widget (widget-get widget :glyph-down)) glyph))
 844          (up-glyph (or (and widget (widget-get widget :glyph-up)) glyph))
 845          (last event))
 846     ;; Wait for the release.
 847     (while (not (button-release-event-p last))
 848       (if (eq extent (event-glyph-extent last))
 849           (set-extent-property extent 'end-glyph down-glyph)
 850         (set-extent-property extent 'end-glyph up-glyph))
 851       (setq last (next-event event)))
 852     ;; Release glyph.
 853     (when down-glyph
 854       (set-extent-property extent 'end-glyph up-glyph))
 855     ;; Apply widget action.
 856     (when (eq extent (event-glyph-extent last))
 857       (let ((widget (glyph-property (event-glyph event) 'widget)))
 858         (cond ((null widget)
 859                (message "You clicked on a glyph."))
 860               ((not (widget-apply widget :active))
 861                (message "This glyph is inactive."))
 862               (t
 863                (widget-apply-action widget event)))))))
 864
 865 (defun widget-button-press (pos &optional event)
 866   "Activate button at POS."
 867   (interactive "@d")
 868   (let ((button (get-text-property pos 'button)))
 869     (if button
 870         (widget-apply-action button event)
 871       (let ((command (lookup-key widget-global-map (this-command-keys))))
 872         (when (commandp command)
 873           (call-interactively command))))))
 874
 875 (defun widget-move (arg)
 876   "Move point to the ARG next field or button.
 877 ARG may be negative to move backward."
 878   (while (> arg 0)
 879     (setq arg (1- arg))
 880     (let ((next (cond ((get-text-property (point) 'button)
 881                        (next-single-property-change (point) 'button))
 882                       ((get-text-property (point) 'field)
 883                        (next-single-property-change (point) 'field))
 884                       (t
 885                        (point)))))
 886       (if (null next)                   ; Widget extends to end. of buffer
 887           (setq next (point-min)))
 888       (let ((button (next-single-property-change next 'button))
 889             (field (next-single-property-change next 'field)))
 890         (cond ((or (get-text-property next 'button)
 891                    (get-text-property next 'field))
 892                (goto-char next))
 893               ((and button field)
 894                (goto-char (min button field)))
 895               (button (goto-char button))
 896               (field (goto-char field))
 897               (t
 898                (let ((button (next-single-property-change (point-min) 'button))
 899                      (field (next-single-property-change (point-min) 'field)))
 900                  (cond ((and button field) (goto-char (min button field)))
 901                        (button (goto-char button))
 902                        (field (goto-char field))
 903                        (t
 904                         (error "No buttons or fields found"))))))
 905         (setq button (widget-at (point)))
 906         (if (or (and button (widget-get button :tab-order)
 907                      (< (widget-get button :tab-order) 0))
 908                 (and button (not (widget-apply button :active))))
 909             (setq arg (1+ arg))))))
 910   (while (< arg 0)
 911     (if (= (point-min) (point))
 912         (forward-char 1))
 913     (setq arg (1+ arg))
 914     (let ((previous (cond ((get-text-property (1- (point)) 'button)
 915                            (previous-single-property-change (point) 'button))
 916                           ((get-text-property (1- (point)) 'field)
 917                            (previous-single-property-change (point) 'field))
 918                           (t
 919                            (point)))))
 920       (if (null previous)               ; Widget extends to beg. of buffer
 921           (setq previous (point-max)))
 922       (let ((button (previous-single-property-change previous 'button))
 923             (field (previous-single-property-change previous 'field)))
 924         (cond ((and button field)
 925                (goto-char (max button field)))
 926               (button (goto-char button))
 927               (field (goto-char field))
 928               (t
 929                (let ((button (previous-single-property-change
 930                               (point-max) 'button))
 931                      (field (previous-single-property-change
 932                              (point-max) 'field)))
 933                  (cond ((and button field) (goto-char (max button field)))
 934                        (button (goto-char button))
 935                        (field (goto-char field))
 936                        (t
 937                         (error "No buttons or fields found"))))))))
 938     (let ((button (previous-single-property-change (point) 'button))
 939           (field (previous-single-property-change (point) 'field)))
 940       (cond ((and button field)
 941              (goto-char (max button field)))
 942             (button (goto-char button))
 943             (field (goto-char field)))
 944       (setq button (widget-at (point)))
 945       (if (or (and button (widget-get button :tab-order)
 946                    (< (widget-get button :tab-order) 0))
 947               (and button (not (widget-apply button :active))))
 948           (setq arg (1- arg)))))
 949   (widget-echo-help (point))
 950   (run-hooks 'widget-move-hook))
 951
 952 (defun widget-forward (arg)
 953   "Move point to the next field or button.
 954 With optional ARG, move across that many fields."
 955   (interactive "p")
 956   (run-hooks 'widget-forward-hook)
 957   (widget-move arg))
 958
 959 (defun widget-backward (arg)
 960   "Move point to the previous field or button.
 961 With optional ARG, move across that many fields."
 962   (interactive "p")
 963   (run-hooks 'widget-backward-hook)
 964   (widget-move (- arg)))
 965
 966 (defun widget-beginning-of-line ()
 967   "Go to beginning of field or beginning of line, whichever is first."
 968   (interactive)
 969   (let ((bol (save-excursion (beginning-of-line) (point)))
 970         (prev (previous-single-property-change (point) 'field)))
 971     (goto-char (max bol (or prev bol)))))
 972
 973 (defun widget-end-of-line ()
 974   "Go to end of field or end of line, whichever is first."
 975   (interactive)
 976   (let ((bol (save-excursion (end-of-line) (point)))
 977         (prev (next-single-property-change (point) 'field)))
 978     (goto-char (min bol (or prev bol)))))
 979
 980 (defun widget-kill-line ()
 981   "Kill to end of field or end of line, whichever is first."
 982   (interactive)
 983   (let ((field (get-text-property (point) 'field))
 984         (newline (save-excursion (search-forward "\n")))
 985         (next (next-single-property-change (point) 'field)))
 986     (if (and field (> newline next))
 987         (kill-region (point) next)
 988       (call-interactively 'kill-line))))
 989
 990 ;;; Setting up the buffer.
 991
 992 (defvar widget-field-new nil)
 993 ;; List of all newly created editable fields in the buffer.
 994 (make-variable-buffer-local 'widget-field-new)
 995
 996 (defvar widget-field-list nil)
 997 ;; List of all editable fields in the buffer.
 998 (make-variable-buffer-local 'widget-field-list)
 999
1000 (defun widget-setup ()
1001   "Setup current buffer so editing string widgets works."
1002   (let ((inhibit-read-only t)
1003         (after-change-functions nil)
1004         field)
1005     (while widget-field-new
1006       (setq field (car widget-field-new)
1007             widget-field-new (cdr widget-field-new)
1008             widget-field-list (cons field widget-field-list))
1009       (let ((from (widget-get field :value-from))
1010             (to (widget-get field :value-to)))
1011         (widget-specify-field field from to)
1012         (move-marker from (1- from))
1013         (move-marker to (1+ to)))))
1014   (widget-clear-undo)
1015   ;; We need to maintain text properties and size of the editing fields.
1016   (make-local-variable 'after-change-functions)
1017   (if widget-field-list
1018       (setq after-change-functions '(widget-after-change))
1019     (setq after-change-functions nil)))
1020
1021 (defvar widget-field-last nil)
1022 ;; Last field containing point.
1023 (make-variable-buffer-local 'widget-field-last)
1024
1025 (defvar widget-field-was nil)
1026 ;; The widget data before the change.
1027 (make-variable-buffer-local 'widget-field-was)
1028
1029 (defun widget-field-find (pos)
1030   ;; Find widget whose editing field is located at POS.
1031   ;; Return nil if POS is not inside and editing field.
1032   ;;
1033   ;; This is only used in `widget-field-modified', since ordinarily
1034   ;; you would just test the field property.
1035   (let ((fields widget-field-list)
1036         field found)
1037     (while fields
1038       (setq field (car fields)
1039             fields (cdr fields))
1040       (let ((from (widget-get field :value-from))
1041             (to (widget-get field :value-to)))
1042         (if (and from to (< from pos) (> to  pos))
1043             (setq fields nil
1044                   found field))))
1045     found))
1046
1047 (defun widget-after-change (from to old)
1048   ;; Adjust field size and text properties.
1049   (condition-case nil
1050       (let ((field (widget-field-find from))
1051             (inhibit-read-only t))
1052         (cond ((null field))
1053               ((not (eq field (widget-field-find to)))
1054                (debug)
1055                (message "Error: `widget-after-change' called on two fields"))
1056               (t
1057                (let ((size (widget-get field :size)))
1058                  (if size
1059                      (let ((begin (1+ (widget-get field :value-from)))
1060                            (end (1- (widget-get field :value-to))))
1061                        (widget-specify-field-update field begin end)
1062                        (cond ((< (- end begin) size)
1063                               ;; Field too small.
1064                               (save-excursion
1065                                 (goto-char end)
1066                                 (insert-char ?\  (- (+ begin size) end))
1067                                 (widget-specify-field-update field
1068                                                              begin
1069                                                              (+ begin size))))
1070                              ((> (- end begin) size)
1071                               ;; Field too large and
1072                               (if (or (< (point) (+ begin size))
1073                                       (> (point) end))
1074                                   ;; Point is outside extra space.
1075                                   (setq begin (+ begin size))
1076                                 ;; Point is within the extra space.
1077                                 (setq begin (point)))
1078                               (save-excursion
1079                                 (goto-char end)
1080                                 (while (and (eq (preceding-char) ?\ )
1081                                             (> (point) begin))
1082                                   (delete-backward-char 1))))))
1083                    (widget-specify-field-update field from to)))
1084                (widget-apply field :notify field))))
1085     (error (debug))))
1086
1087 ;;; Widget Functions
1088 ;;
1089 ;; These functions are used in the definition of multiple widgets.
1090
1091 (defun widget-parent-action (widget &optional event)
1092   "Tell :parent of WIDGET to handle the :action.
1093 Optional EVENT is the event that triggered the action."
1094   (widget-apply (widget-get widget :parent) :action event))
1095
1096 (defun widget-children-value-delete (widget)
1097   "Delete all :children and :buttons in WIDGET."
1098   (mapcar 'widget-delete (widget-get widget :children))
1099   (widget-put widget :children nil)
1100   (mapcar 'widget-delete (widget-get widget :buttons))
1101   (widget-put widget :buttons nil))
1102
1103 (defun widget-children-validate (widget)
1104   "All the :children must be valid."
1105   (let ((children (widget-get widget :children))
1106         child found)
1107     (while (and children (not found))
1108       (setq child (car children)
1109             children (cdr children)
1110             found (widget-apply child :validate)))
1111     found))
1112
1113 (defun widget-types-convert-widget (widget)
1114   "Convert :args as widget types in WIDGET."
1115   (widget-put widget :args (mapcar 'widget-convert (widget-get widget :args)))
1116   widget)
1117
1118 (defun widget-value-convert-widget (widget)
1119   "Initialize :value from :args in WIDGET."
1120   (let ((args (widget-get widget :args)))
1121     (when args
1122       (widget-put widget :value (car args))
1123       ;; Don't convert :value here, as this is done in `widget-convert'.
1124       ;; (widget-put widget :value (widget-apply widget
1125       ;;                                      :value-to-internal (car args)))
1126       (widget-put widget :args nil)))
1127   widget)
1128
1129 (defun widget-value-value-get (widget)
1130   "Return the :value property of WIDGET."
1131   (widget-get widget :value))
1132
1133 ;;; The `default' Widget.
1134
1135 (define-widget 'default nil
1136   "Basic widget other widgets are derived from."
1137   :value-to-internal (lambda (widget value) value)
1138   :value-to-external (lambda (widget value) value)
1139   :create 'widget-default-create
1140   :indent nil
1141   :offset 0
1142   :format-handler 'widget-default-format-handler
1143   :button-face-get 'widget-default-button-face-get
1144   :sample-face-get 'widget-default-sample-face-get
1145   :delete 'widget-default-delete
1146   :value-set 'widget-default-value-set
1147   :value-inline 'widget-default-value-inline
1148   :menu-tag-get 'widget-default-menu-tag-get
1149   :validate (lambda (widget) nil)
1150   :active 'widget-default-active
1151   :activate 'widget-specify-active
1152   :deactivate 'widget-default-deactivate
1153   :mouse-down-action (lambda (widget event) nil)
1154   :action 'widget-default-action
1155   :notify 'widget-default-notify
1156   :prompt-value 'widget-default-prompt-value)
1157
1158 (defun widget-default-create (widget)
1159   "Create WIDGET at point in the current buffer."
1160   (widget-specify-insert
1161    (let ((from (point))
1162          (tag (widget-get widget :tag))
1163          (glyph (widget-get widget :tag-glyph))
1164          (doc (widget-get widget :doc))
1165          button-begin button-end
1166          sample-begin sample-end
1167          doc-begin doc-end
1168          value-pos)
1169      (insert (widget-get widget :format))
1170      (goto-char from)
1171      ;; Parse escapes in format.
1172      (while (re-search-forward "%\\(.\\)" nil t)
1173        (let ((escape (aref (match-string 1) 0)))
1174          (replace-match "" t t)
1175          (cond ((eq escape ?%)
1176                 (insert "%"))
1177                ((eq escape ?\[)
1178                 (setq button-begin (point)))
1179                ((eq escape ?\])
1180                 (setq button-end (point)))
1181                ((eq escape ?\{)
1182                 (setq sample-begin (point)))
1183                ((eq escape ?\})
1184                 (setq sample-end (point)))
1185                ((eq escape ?n)
1186                 (when (widget-get widget :indent)
1187                   (insert "\n")
1188                   (insert-char ?  (widget-get widget :indent))))
1189                ((eq escape ?t)
1190                 (cond (glyph
1191                        (widget-glyph-insert widget (or tag "image") glyph))
1192                       (tag
1193                        (insert tag))
1194                       (t
1195                        (let ((standard-output (current-buffer)))
1196                          (princ (widget-get widget :value))))))
1197                ((eq escape ?d)
1198                 (when doc
1199                   (setq doc-begin (point))
1200                   (insert doc)
1201                   (while (eq (preceding-char) ?\n)
1202                     (delete-backward-char 1))
1203                   (insert "\n")
1204                   (setq doc-end (point))))
1205                ((eq escape ?v)
1206                 (if (and button-begin (not button-end))
1207                     (widget-apply widget :value-create)
1208                   (setq value-pos (point))))
1209                (t
1210                 (widget-apply widget :format-handler escape)))))
1211      ;; Specify button, sample, and doc, and insert value.
1212      (and button-begin button-end
1213           (widget-specify-button widget button-begin button-end))
1214      (and sample-begin sample-end
1215           (widget-specify-sample widget sample-begin sample-end))
1216      (and doc-begin doc-end
1217           (widget-specify-doc widget doc-begin doc-end))
1218      (when value-pos
1219        (goto-char value-pos)
1220        (widget-apply widget :value-create)))
1221    (let ((from (copy-marker (point-min)))
1222          (to (copy-marker (point-max))))
1223      (widget-specify-text from to)
1224      (set-marker-insertion-type from t)
1225      (set-marker-insertion-type to nil)
1226      (widget-put widget :from from)
1227      (widget-put widget :to to)))
1228   (widget-clear-undo))
1229
1230 (defun widget-default-format-handler (widget escape)
1231   ;; We recognize the %h escape by default.
1232   (let* ((buttons (widget-get widget :buttons))
1233          (doc-property (widget-get widget :documentation-property))
1234          (doc-try (cond ((widget-get widget :doc))
1235                         ((symbolp doc-property)
1236                          (documentation-property (widget-get widget :value)
1237                                                  doc-property))
1238                         (t
1239                          (funcall doc-property (widget-get widget :value)))))
1240          (doc-text (and (stringp doc-try)
1241                         (> (length doc-try) 1)
1242                         doc-try)))
1243     (cond ((eq escape ?h)
1244            (when doc-text
1245              (and (eq (preceding-char) ?\n)
1246                   (widget-get widget :indent)
1247                   (insert-char ?  (widget-get widget :indent)))
1248              ;; The `*' in the beginning is redundant.
1249              (when (eq (aref doc-text  0) ?*)
1250                (setq doc-text (substring doc-text 1)))
1251              ;; Get rid of trailing newlines.
1252              (when (string-match "\n+\\'" doc-text)
1253                (setq doc-text (substring doc-text 0 (match-beginning 0))))
1254              (push (if (string-match "\n." doc-text)
1255                        ;; Allow multiline doc to be hiden.
1256                        (widget-create-child-and-convert
1257                         widget 'widget-help
1258                         :doc (progn
1259                                (string-match "\\`.*" doc-text)
1260                                (match-string 0 doc-text))
1261                         :widget-doc doc-text
1262                         "?")
1263                      ;; A single line is just inserted.
1264                      (widget-create-child-and-convert
1265                       widget 'item :format "%d" :doc doc-text nil))
1266                    buttons)))
1267           (t
1268            (error "Unknown escape `%c'" escape)))
1269     (widget-put widget :buttons buttons)))
1270
1271 (defun widget-default-button-face-get (widget)
1272   ;; Use :button-face or widget-button-face
1273   (or (widget-get widget :button-face) 'widget-button-face))
1274
1275 (defun widget-default-sample-face-get (widget)
1276   ;; Use :sample-face.
1277   (widget-get widget :sample-face))
1278
1279 (defun widget-default-delete (widget)
1280   ;; Remove widget from the buffer.
1281   (let ((from (widget-get widget :from))
1282         (to (widget-get widget :to))
1283         (inhibit-read-only t)
1284         after-change-functions)
1285     (widget-apply widget :value-delete)
1286     (when (< from to)
1287       ;; Kludge: this doesn't need to be true for empty formats.
1288       (delete-region from to))
1289     (set-marker from nil)
1290     (set-marker to nil))
1291   (widget-clear-undo))
1292
1293 (defun widget-default-value-set (widget value)
1294   ;; Recreate widget with new value.
1295   (save-excursion
1296     (goto-char (widget-get widget :from))
1297     (widget-apply widget :delete)
1298     (widget-put widget :value value)
1299     (widget-apply widget :create)))
1300
1301 (defun widget-default-value-inline (widget)
1302   ;; Wrap value in a list unless it is inline.
1303   (if (widget-get widget :inline)
1304       (widget-value widget)
1305     (list (widget-value widget))))
1306
1307 (defun widget-default-menu-tag-get (widget)
1308   ;; Use tag or value for menus.
1309   (or (widget-get widget :menu-tag)
1310       (widget-get widget :tag)
1311       (widget-princ-to-string (widget-get widget :value))))
1312
1313 (defun widget-default-active (widget)
1314   "Return t iff this widget active (user modifiable)."
1315   (and (not (widget-get widget :inactive))
1316        (let ((parent (widget-get widget :parent)))
1317          (or (null parent)
1318              (widget-apply parent :active)))))
1319
1320 (defun widget-default-deactivate (widget)
1321   "Make WIDGET inactive for user modifications."
1322   (widget-specify-inactive widget
1323                            (widget-get widget :from)
1324                            (widget-get widget :to)))
1325
1326 (defun widget-default-action (widget &optional event)
1327   ;; Notify the parent when a widget change
1328   (let ((parent (widget-get widget :parent)))
1329     (when parent
1330       (widget-apply parent :notify widget event))))
1331
1332 (defun widget-default-notify (widget child &optional event)
1333   ;; Pass notification to parent.
1334   (widget-default-action widget event))
1335
1336 (defun widget-default-prompt-value (widget prompt value unbound)
1337   ;; Read an arbitrary value.  Stolen from `set-variable'.
1338 ;;  (let ((initial (if unbound
1339 ;;                   nil
1340 ;;                 ;; It would be nice if we could do a `(cons val 1)' here.
1341 ;;                 (prin1-to-string (custom-quote value))))))
1342   (eval-minibuffer prompt ))
1343
1344 ;;; The `item' Widget.
1345
1346 (define-widget 'item 'default
1347   "Constant items for inclusion in other widgets."
1348   :convert-widget 'widget-value-convert-widget
1349   :value-create 'widget-item-value-create
1350   :value-delete 'ignore
1351   :value-get 'widget-value-value-get
1352   :match 'widget-item-match
1353   :match-inline 'widget-item-match-inline
1354   :action 'widget-item-action
1355   :format "%t\n")
1356
1357 (defun widget-item-value-create (widget)
1358   ;; Insert the printed representation of the value.
1359   (let ((standard-output (current-buffer)))
1360     (princ (widget-get widget :value))))
1361
1362 (defun widget-item-match (widget value)
1363   ;; Match if the value is the same.
1364   (equal (widget-get widget :value) value))
1365
1366 (defun widget-item-match-inline (widget values)
1367   ;; Match if the value is the same.
1368   (let ((value (widget-get widget :value)))
1369     (and (listp value)
1370          (<= (length value) (length values))
1371          (let ((head (subseq values 0 (length value))))
1372            (and (equal head value)
1373                 (cons head (subseq values (length value))))))))
1374
1375 (defun widget-item-action (widget &optional event)
1376   ;; Just notify itself.
1377   (widget-apply widget :notify widget event))
1378
1379 ;;; The `push-button' Widget.
1380
1381 (defcustom widget-push-button-gui t
1382   "If non nil, use GUI push buttons when available."
1383   :group 'widgets
1384   :type 'boolean)
1385
1386 ;; Cache already created GUI objects.
1387 (defvar widget-push-button-cache nil)
1388
1389 (define-widget 'push-button 'item
1390   "A pushable button."
1391   :value-create 'widget-push-button-value-create
1392   :text-format "[%s]"
1393   :format "%[%v%]")
1394
1395 (defun widget-push-button-value-create (widget)
1396   ;; Insert text representing the `on' and `off' states.
1397   (let* ((tag (or (widget-get widget :tag)
1398                   (widget-get widget :value)))
1399          (text (format (widget-get widget :text-format) tag))
1400          (gui (cdr (assoc tag widget-push-button-cache))))
1401     (if (and (fboundp 'make-gui-button)
1402              (fboundp 'make-glyph)
1403              widget-push-button-gui
1404              (fboundp 'device-on-window-system-p)
1405              (device-on-window-system-p)
1406              (string-match "XEmacs" emacs-version))
1407         (progn
1408           (unless gui
1409             (setq gui (make-gui-button tag 'widget-gui-action widget))
1410             (push (cons tag gui) widget-push-button-cache))
1411           (widget-glyph-insert-glyph widget text
1412                                      (make-glyph (nth 0 (aref gui 1)))
1413                                      (make-glyph (nth 1 (aref gui 1)))
1414                                      (make-glyph (nth 2 (aref gui 1)))))
1415       (insert text))))
1416
1417 (defun widget-gui-action (widget)
1418   "Apply :action for WIDGET."
1419   (widget-apply-action widget (this-command-keys)))
1420
1421 ;;; The `link' Widget.
1422
1423 (define-widget 'link 'item
1424   "An embedded link."
1425   :help-echo "Follow the link."
1426   :format "%[_%t_%]")
1427
1428 ;;; The `info-link' Widget.
1429
1430 (define-widget 'info-link 'link
1431   "A link to an info file."
1432   :action 'widget-info-link-action)
1433
1434 (defun widget-info-link-action (widget &optional event)
1435   "Open the info node specified by WIDGET."
1436   (Info-goto-node (widget-value widget)))
1437
1438 ;;; The `url-link' Widget.
1439
1440 (define-widget 'url-link 'link
1441   "A link to an www page."
1442   :action 'widget-url-link-action)
1443
1444 (defun widget-url-link-action (widget &optional event)
1445   "Open the url specified by WIDGET."
1446   (require 'browse-url)
1447   (funcall browse-url-browser-function (widget-value widget)))
1448
1449 ;;; The `editable-field' Widget.
1450
1451 (define-widget 'editable-field 'default
1452   "An editable text field."
1453   :convert-widget 'widget-value-convert-widget
1454   :keymap widget-field-keymap
1455   :format "%v"
1456   :value ""
1457   :prompt-internal 'widget-field-prompt-internal
1458   :prompt-history 'widget-field-history
1459   :prompt-value 'widget-field-prompt-value
1460   :action 'widget-field-action
1461   :validate 'widget-field-validate
1462   :valid-regexp ""
1463   :error "No match"
1464   :value-create 'widget-field-value-create
1465   :value-delete 'widget-field-value-delete
1466   :value-get 'widget-field-value-get
1467   :match 'widget-field-match)
1468
1469 (defvar widget-field-history nil
1470   "History of field minibuffer edits.")
1471
1472 (defun widget-field-prompt-internal (widget prompt initial history)
1473   ;; Read string for WIDGET promptinhg with PROMPT.
1474   ;; INITIAL is the initial input and HISTORY is a symbol containing
1475   ;; the earlier input.
1476   (read-string prompt initial history))
1477
1478 (defun widget-field-prompt-value (widget prompt value unbound)
1479   ;; Prompt for a string.
1480   (let ((initial (if unbound
1481                      nil
1482                    (cons (widget-apply widget :value-to-internal
1483                                        value) 0)))
1484         (history (widget-get widget :prompt-history)))
1485     (let ((answer (widget-apply widget
1486                                 :prompt-internal prompt initial history)))
1487       (widget-apply widget :value-to-external answer))))
1488
1489 (defun widget-field-action (widget &optional event)
1490   ;; Edit the value in the minibuffer.
1491   (let ((invalid (widget-apply widget :validate)))
1492     (let ((prompt (concat (widget-apply widget :menu-tag-get) ": "))
1493           (value (unless invalid
1494                    (widget-value widget))))
1495       (let ((answer (widget-apply widget :prompt-value prompt value invalid) ))
1496         (widget-value-set widget answer)))
1497     (widget-apply widget :notify widget event)
1498     (widget-setup)))
1499
1500 (defun widget-field-validate (widget)
1501   ;; Valid if the content matches `:valid-regexp'.
1502   (save-excursion
1503     (let ((value (widget-apply widget :value-get))
1504           (regexp (widget-get widget :valid-regexp)))
1505       (if (string-match regexp value)
1506           nil
1507         widget))))
1508
1509 (defun widget-field-value-create (widget)
1510   ;; Create an editable text field.
1511   (insert " ")
1512   (let ((size (widget-get widget :size))
1513         (value (widget-get widget :value))
1514         (from (point)))
1515     (insert value)
1516     (and size
1517          (< (length value) size)
1518          (insert-char ?\  (- size (length value))))
1519     (unless (memq widget widget-field-list)
1520       (setq widget-field-new (cons widget widget-field-new)))
1521     (widget-put widget :value-to (copy-marker (point)))
1522     (set-marker-insertion-type (widget-get widget :value-to) nil)
1523     (if (null size)
1524         (insert ?\n)
1525       (insert ?\ ))
1526     (widget-put widget :value-from (copy-marker from))
1527     (set-marker-insertion-type (widget-get widget :value-from) t)))
1528
1529 (defun widget-field-value-delete (widget)
1530   ;; Remove the widget from the list of active editing fields.
1531   (setq widget-field-list (delq widget widget-field-list))
1532   ;; These are nil if the :format string doesn't contain `%v'.
1533   (when (widget-get widget :value-from)
1534     (set-marker (widget-get widget :value-from) nil))
1535   (when (widget-get widget :value-from)
1536     (set-marker (widget-get widget :value-to) nil)))
1537
1538 (defun widget-field-value-get (widget)
1539   ;; Return current text in editing field.
1540   (let ((from (widget-get widget :value-from))
1541         (to (widget-get widget :value-to))
1542         (size (widget-get widget :size))
1543         (secret (widget-get widget :secret))
1544         (old (current-buffer)))
1545     (if (and from to)
1546         (progn
1547           (set-buffer (marker-buffer from))
1548           (setq from (1+ from)
1549                 to (1- to))
1550           (while (and size
1551                       (not (zerop size))
1552                       (> to from)
1553                       (eq (char-after (1- to)) ?\ ))
1554             (setq to (1- to)))
1555           (let ((result (buffer-substring-no-properties from to)))
1556             (when (string-match "XEmacs" emacs-version)
1557               ;; XEmacs 20.1 bug: b-s-n-p doesn't clear all properties.
1558               (setq result (format "%s" result)))
1559             (when secret
1560               (let ((index 0))
1561                 (while (< (+ from index) to)
1562                   (aset result index
1563                         (get-text-property (+ from index) 'secret))
1564                   (setq index (1+ index)))))
1565             (set-buffer old)
1566             result))
1567       (widget-get widget :value))))
1568
1569 (defun widget-field-match (widget value)
1570   ;; Match any string.
1571   (stringp value))
1572
1573 ;;; The `text' Widget.
1574
1575 (define-widget 'text 'editable-field
1576   :keymap widget-text-keymap
1577   "A multiline text area.")
1578
1579 ;;; The `menu-choice' Widget.
1580
1581 (define-widget 'menu-choice 'default
1582   "A menu of options."
1583   :convert-widget  'widget-types-convert-widget
1584   :format "%[%t%]: %v"
1585   :case-fold t
1586   :tag "choice"
1587   :void '(item :format "invalid (%t)\n")
1588   :value-create 'widget-choice-value-create
1589   :value-delete 'widget-children-value-delete
1590   :value-get 'widget-choice-value-get
1591   :value-inline 'widget-choice-value-inline
1592   :mouse-down-action 'widget-choice-mouse-down-action
1593   :action 'widget-choice-action
1594   :error "Make a choice"
1595   :validate 'widget-choice-validate
1596   :match 'widget-choice-match
1597   :match-inline 'widget-choice-match-inline)
1598
1599 (defun widget-choice-value-create (widget)
1600   ;; Insert the first choice that matches the value.
1601   (let ((value (widget-get widget :value))
1602         (args (widget-get widget :args))
1603         current)
1604     (while args
1605       (setq current (car args)
1606             args (cdr args))
1607       (when (widget-apply current :match value)
1608         (widget-put widget :children (list (widget-create-child-value
1609                                             widget current value)))
1610         (widget-put widget :choice current)
1611         (setq args nil
1612               current nil)))
1613     (when current
1614       (let ((void (widget-get widget :void)))
1615         (widget-put widget :children (list (widget-create-child-and-convert
1616                                             widget void :value value)))
1617         (widget-put widget :choice void)))))
1618
1619 (defun widget-choice-value-get (widget)
1620   ;; Get value of the child widget.
1621   (widget-value (car (widget-get widget :children))))
1622
1623 (defun widget-choice-value-inline (widget)
1624   ;; Get value of the child widget.
1625   (widget-apply (car (widget-get widget :children)) :value-inline))
1626
1627 (defcustom widget-choice-toggle nil
1628   "If non-nil, a binary choice will just toggle between the values.
1629 Otherwise, the user will explicitly have to choose between the values
1630 when he activate the menu."
1631   :type 'boolean
1632   :group 'widgets)
1633
1634 (defun widget-choice-mouse-down-action (widget &optional event)
1635   ;; Return non-nil if we need a menu.
1636   (let ((args (widget-get widget :args))
1637         (old (widget-get widget :choice)))
1638     (cond ((not window-system)
1639            ;; No place to pop up a menu.
1640            nil)
1641           ((not (or (fboundp 'x-popup-menu) (fboundp 'popup-menu)))
1642            ;; No way to pop up a menu.
1643            nil)
1644           ((< (length args) 2)
1645            ;; Empty or singleton list, just return the value.
1646            nil)
1647           ((> (length args) widget-menu-max-size)
1648            ;; Too long, prompt.
1649            nil)
1650           ((> (length args) 2)
1651            ;; Reasonable sized list, use menu.
1652            t)
1653           ((and widget-choice-toggle (memq old args))
1654            ;; We toggle.
1655            nil)
1656           (t
1657            ;; Ask which of the two.
1658            t))))
1659
1660 (defun widget-choice-action (widget &optional event)
1661   ;; Make a choice.
1662   (let ((args (widget-get widget :args))
1663         (old (widget-get widget :choice))
1664         (tag (widget-apply widget :menu-tag-get))
1665         (completion-ignore-case (widget-get widget :case-fold))
1666         current choices)
1667     ;; Remember old value.
1668     (if (and old (not (widget-apply widget :validate)))
1669         (let* ((external (widget-value widget))
1670                (internal (widget-apply old :value-to-internal external)))
1671           (widget-put old :value internal)))
1672     ;; Find new choice.
1673     (setq current
1674           (cond ((= (length args) 0)
1675                  nil)
1676                 ((= (length args) 1)
1677                  (nth 0 args))
1678                 ((and widget-choice-toggle
1679                       (= (length args) 2)
1680                       (memq old args))
1681                  (if (eq old (nth 0 args))
1682                      (nth 1 args)
1683                    (nth 0 args)))
1684                 (t
1685                  (while args
1686                    (setq current (car args)
1687                          args (cdr args))
1688                    (setq choices
1689                          (cons (cons (widget-apply current :menu-tag-get)
1690                                      current)
1691                                choices)))
1692                  (widget-choose tag (reverse choices) event))))
1693     (when current
1694       (widget-value-set widget
1695                         (widget-apply current :value-to-external
1696                                       (widget-get current :value)))
1697       (widget-apply widget :notify widget event)
1698       (widget-setup))))
1699
1700 (defun widget-choice-validate (widget)
1701   ;; Valid if we have made a valid choice.
1702   (let ((void (widget-get widget :void))
1703         (choice (widget-get widget :choice))
1704         (child (car (widget-get widget :children))))
1705     (if (eq void choice)
1706         widget
1707       (widget-apply child :validate))))
1708
1709 (defun widget-choice-match (widget value)
1710   ;; Matches if one of the choices matches.
1711   (let ((args (widget-get widget :args))
1712         current found)
1713     (while (and args (not found))
1714       (setq current (car args)
1715             args (cdr args)
1716             found (widget-apply current :match value)))
1717     found))
1718
1719 (defun widget-choice-match-inline (widget values)
1720   ;; Matches if one of the choices matches.
1721   (let ((args (widget-get widget :args))
1722         current found)
1723     (while (and args (null found))
1724       (setq current (car args)
1725             args (cdr args)
1726             found (widget-match-inline current values)))
1727     found))
1728
1729 ;;; The `toggle' Widget.
1730
1731 (define-widget 'toggle 'item
1732   "Toggle between two states."
1733   :format "%[%v%]\n"
1734   :value-create 'widget-toggle-value-create
1735   :action 'widget-toggle-action
1736   :match (lambda (widget value) t)
1737   :on "on"
1738   :off "off")
1739
1740 (defun widget-toggle-value-create (widget)
1741   ;; Insert text representing the `on' and `off' states.
1742   (if (widget-value widget)
1743       (widget-glyph-insert widget
1744                            (widget-get widget :on)
1745                            (widget-get widget :on-glyph))
1746     (widget-glyph-insert widget
1747                          (widget-get widget :off)
1748                          (widget-get widget :off-glyph))))
1749
1750 (defun widget-toggle-action (widget &optional event)
1751   ;; Toggle value.
1752   (widget-value-set widget (not (widget-value widget)))
1753   (widget-apply widget :notify widget event))
1754
1755 ;;; The `checkbox' Widget.
1756
1757 (define-widget 'checkbox 'toggle
1758   "A checkbox toggle."
1759   :format "%[%v%]"
1760   :on "[X]"
1761   :on-glyph "check1"
1762   :off "[ ]"
1763   :off-glyph "check0"
1764   :action 'widget-checkbox-action)
1765
1766 (defun widget-checkbox-action (widget &optional event)
1767   "Toggle checkbox, notify parent, and set active state of sibling."
1768   (widget-toggle-action widget event)
1769   (let ((sibling (widget-get-sibling widget)))
1770     (when sibling
1771       (if (widget-value widget)
1772           (widget-apply sibling :activate)
1773         (widget-apply sibling :deactivate)))))
1774
1775 ;;; The `checklist' Widget.
1776
1777 (define-widget 'checklist 'default
1778   "A multiple choice widget."
1779   :convert-widget 'widget-types-convert-widget
1780   :format "%v"
1781   :offset 4
1782   :entry-format "%b %v"
1783   :menu-tag "checklist"
1784   :greedy nil
1785   :value-create 'widget-checklist-value-create
1786   :value-delete 'widget-children-value-delete
1787   :value-get 'widget-checklist-value-get
1788   :validate 'widget-checklist-validate
1789   :match 'widget-checklist-match
1790   :match-inline 'widget-checklist-match-inline)
1791
1792 (defun widget-checklist-value-create (widget)
1793   ;; Insert all values
1794   (let ((alist (widget-checklist-match-find widget (widget-get widget :value)))
1795         (args (widget-get widget :args)))
1796     (while args
1797       (widget-checklist-add-item widget (car args) (assq (car args) alist))
1798       (setq args (cdr args)))
1799     (widget-put widget :children (nreverse (widget-get widget :children)))))
1800
1801 (defun widget-checklist-add-item (widget type chosen)
1802   ;; Create checklist item in WIDGET of type TYPE.
1803   ;; If the item is checked, CHOSEN is a cons whose cdr is the value.
1804   (and (eq (preceding-char) ?\n)
1805        (widget-get widget :indent)
1806        (insert-char ?  (widget-get widget :indent)))
1807   (widget-specify-insert
1808    (let* ((children (widget-get widget :children))
1809           (buttons (widget-get widget :buttons))
1810           (button-args (or (widget-get type :sibling-args)
1811                            (widget-get widget :button-args)))
1812           (from (point))
1813           child button)
1814      (insert (widget-get widget :entry-format))
1815      (goto-char from)
1816      ;; Parse % escapes in format.
1817      (while (re-search-forward "%\\([bv%]\\)" nil t)
1818        (let ((escape (aref (match-string 1) 0)))
1819          (replace-match "" t t)
1820          (cond ((eq escape ?%)
1821                 (insert "%"))
1822                ((eq escape ?b)
1823                 (setq button (apply 'widget-create-child-and-convert
1824                                     widget 'checkbox
1825                                     :value (not (null chosen))
1826                                     button-args)))
1827                ((eq escape ?v)
1828                 (setq child
1829                       (cond ((not chosen)
1830                              (let ((child (widget-create-child widget type)))
1831                                (widget-apply child :deactivate)
1832                                child))
1833                             ((widget-get type :inline)
1834                              (widget-create-child-value
1835                               widget type (cdr chosen)))
1836                             (t
1837                              (widget-create-child-value
1838                               widget type (car (cdr chosen)))))))
1839                (t
1840                 (error "Unknown escape `%c'" escape)))))
1841      ;; Update properties.
1842      (and button child (widget-put child :button button))
1843      (and button (widget-put widget :buttons (cons button buttons)))
1844      (and child (widget-put widget :children (cons child children))))))
1845
1846 (defun widget-checklist-match (widget values)
1847   ;; All values must match a type in the checklist.
1848   (and (listp values)
1849        (null (cdr (widget-checklist-match-inline widget values)))))
1850
1851 (defun widget-checklist-match-inline (widget values)
1852   ;; Find the values which match a type in the checklist.
1853   (let ((greedy (widget-get widget :greedy))
1854         (args (copy-sequence (widget-get widget :args)))
1855         found rest)
1856     (while values
1857       (let ((answer (widget-checklist-match-up args values)))
1858         (cond (answer
1859                (let ((vals (widget-match-inline answer values)))
1860                  (setq found (append found (car vals))
1861                        values (cdr vals)
1862                        args (delq answer args))))
1863               (greedy
1864                (setq rest (append rest (list (car values)))
1865                      values (cdr values)))
1866               (t
1867                (setq rest (append rest values)
1868                      values nil)))))
1869     (cons found rest)))
1870
1871 (defun widget-checklist-match-find (widget vals)
1872   ;; Find the vals which match a type in the checklist.
1873   ;; Return an alist of (TYPE MATCH).
1874   (let ((greedy (widget-get widget :greedy))
1875         (args (copy-sequence (widget-get widget :args)))
1876         found)
1877     (while vals
1878       (let ((answer (widget-checklist-match-up args vals)))
1879         (cond (answer
1880                (let ((match (widget-match-inline answer vals)))
1881                  (setq found (cons (cons answer (car match)) found)
1882                        vals (cdr match)
1883                        args (delq answer args))))
1884               (greedy
1885                (setq vals (cdr vals)))
1886               (t
1887                (setq vals nil)))))
1888     found))
1889
1890 (defun widget-checklist-match-up (args vals)
1891   ;; Rerturn the first type from ARGS that matches VALS.
1892   (let (current found)
1893     (while (and args (null found))
1894       (setq current (car args)
1895             args (cdr args)
1896             found (widget-match-inline current vals)))
1897     (if found
1898         current
1899       nil)))
1900
1901 (defun widget-checklist-value-get (widget)
1902   ;; The values of all selected items.
1903   (let ((children (widget-get widget :children))
1904         child result)
1905     (while children
1906       (setq child (car children)
1907             children (cdr children))
1908       (if (widget-value (widget-get child :button))
1909           (setq result (append result (widget-apply child :value-inline)))))
1910     result))
1911
1912 (defun widget-checklist-validate (widget)
1913   ;; Ticked chilren must be valid.
1914   (let ((children (widget-get widget :children))
1915         child button found)
1916     (while (and children (not found))
1917       (setq child (car children)
1918             children (cdr children)
1919             button (widget-get child :button)
1920             found (and (widget-value button)
1921                        (widget-apply child :validate))))
1922     found))
1923
1924 ;;; The `option' Widget
1925
1926 (define-widget 'option 'checklist
1927   "An widget with an optional item."
1928   :inline t)
1929
1930 ;;; The `choice-item' Widget.
1931
1932 (define-widget 'choice-item 'item
1933   "Button items that delegate action events to their parents."
1934   :action 'widget-parent-action
1935   :format "%[%t%] \n")
1936
1937 ;;; The `radio-button' Widget.
1938
1939 (define-widget 'radio-button 'toggle
1940   "A radio button for use in the `radio' widget."
1941   :notify 'widget-radio-button-notify
1942   :format "%[%v%]"
1943   :on "(*)"
1944   :on-glyph "radio1"
1945   :off "( )"
1946   :off-glyph "radio0")
1947
1948 (defun widget-radio-button-notify (widget child &optional event)
1949   ;; Tell daddy.
1950   (widget-apply (widget-get widget :parent) :action widget event))
1951
1952 ;;; The `radio-button-choice' Widget.
1953
1954 (define-widget 'radio-button-choice 'default
1955   "Select one of multiple options."
1956   :convert-widget 'widget-types-convert-widget
1957   :offset 4
1958   :format "%v"
1959   :entry-format "%b %v"
1960   :menu-tag "radio"
1961   :value-create 'widget-radio-value-create
1962   :value-delete 'widget-children-value-delete
1963   :value-get 'widget-radio-value-get
1964   :value-inline 'widget-radio-value-inline
1965   :value-set 'widget-radio-value-set
1966   :error "You must push one of the buttons"
1967   :validate 'widget-radio-validate
1968   :match 'widget-choice-match
1969   :match-inline 'widget-choice-match-inline
1970   :action 'widget-radio-action)
1971
1972 (defun widget-radio-value-create (widget)
1973   ;; Insert all values
1974   (let ((args (widget-get widget :args))
1975         arg)
1976     (while args
1977       (setq arg (car args)
1978             args (cdr args))
1979       (widget-radio-add-item widget arg))))
1980
1981 (defun widget-radio-add-item (widget type)
1982   "Add to radio widget WIDGET a new radio button item of type TYPE."
1983   ;; (setq type (widget-convert type))
1984   (and (eq (preceding-char) ?\n)
1985        (widget-get widget :indent)
1986        (insert-char ?  (widget-get widget :indent)))
1987   (widget-specify-insert
1988    (let* ((value (widget-get widget :value))
1989           (children (widget-get widget :children))
1990           (buttons (widget-get widget :buttons))
1991           (button-args (or (widget-get type :sibling-args)
1992                            (widget-get widget :button-args)))
1993           (from (point))
1994           (chosen (and (null (widget-get widget :choice))
1995                        (widget-apply type :match value)))
1996           child button)
1997      (insert (widget-get widget :entry-format))
1998      (goto-char from)
1999      ;; Parse % escapes in format.
2000      (while (re-search-forward "%\\([bv%]\\)" nil t)
2001        (let ((escape (aref (match-string 1) 0)))
2002          (replace-match "" t t)
2003          (cond ((eq escape ?%)
2004                 (insert "%"))
2005                ((eq escape ?b)
2006                 (setq button (apply 'widget-create-child-and-convert
2007                                     widget 'radio-button
2008                                     :value (not (null chosen))
2009                                     button-args)))
2010                ((eq escape ?v)
2011                 (setq child (if chosen
2012                                 (widget-create-child-value
2013                                  widget type value)
2014                               (widget-create-child widget type)))
2015                 (unless chosen
2016                   (widget-apply child :deactivate)))
2017                (t
2018                 (error "Unknown escape `%c'" escape)))))
2019      ;; Update properties.
2020      (when chosen
2021        (widget-put widget :choice type))
2022      (when button
2023        (widget-put child :button button)
2024        (widget-put widget :buttons (nconc buttons (list button))))
2025      (when child
2026        (widget-put widget :children (nconc children (list child))))
2027      child)))
2028
2029 (defun widget-radio-value-get (widget)
2030   ;; Get value of the child widget.
2031   (let ((chosen (widget-radio-chosen widget)))
2032     (and chosen (widget-value chosen))))
2033
2034 (defun widget-radio-chosen (widget)
2035   "Return the widget representing the chosen radio button."
2036   (let ((children (widget-get widget :children))
2037         current found)
2038     (while children
2039       (setq current (car children)
2040             children (cdr children))
2041       (let* ((button (widget-get current :button))
2042              (value (widget-apply button :value-get)))
2043         (when value
2044           (setq found current
2045                 children nil))))
2046     found))
2047
2048 (defun widget-radio-value-inline (widget)
2049   ;; Get value of the child widget.
2050   (let ((children (widget-get widget :children))
2051         current found)
2052     (while children
2053       (setq current (car children)
2054             children (cdr children))
2055       (let* ((button (widget-get current :button))
2056              (value (widget-apply button :value-get)))
2057         (when value
2058           (setq found (widget-apply current :value-inline)
2059                 children nil))))
2060     found))
2061
2062 (defun widget-radio-value-set (widget value)
2063   ;; We can't just delete and recreate a radio widget, since children
2064   ;; can be added after the original creation and won't be recreated
2065   ;; by `:create'.
2066   (let ((children (widget-get widget :children))
2067         current found)
2068     (while children
2069       (setq current (car children)
2070             children (cdr children))
2071       (let* ((button (widget-get current :button))
2072              (match (and (not found)
2073                          (widget-apply current :match value))))
2074         (widget-value-set button match)
2075         (if match
2076             (progn
2077               (widget-value-set current value)
2078               (widget-apply current :activate))
2079           (widget-apply current :deactivate))
2080         (setq found (or found match))))))
2081
2082 (defun widget-radio-validate (widget)
2083   ;; Valid if we have made a valid choice.
2084   (let ((children (widget-get widget :children))
2085         current found button)
2086     (while (and children (not found))
2087       (setq current (car children)
2088             children (cdr children)
2089             button (widget-get current :button)
2090             found (widget-apply button :value-get)))
2091     (if found
2092         (widget-apply current :validate)
2093       widget)))
2094
2095 (defun widget-radio-action (widget child event)
2096   ;; Check if a radio button was pressed.
2097   (let ((children (widget-get widget :children))
2098         (buttons (widget-get widget :buttons))
2099         current)
2100     (when (memq child buttons)
2101       (while children
2102         (setq current (car children)
2103               children (cdr children))
2104         (let* ((button (widget-get current :button)))
2105           (cond ((eq child button)
2106                  (widget-value-set button t)
2107                  (widget-apply current :activate))
2108                 ((widget-value button)
2109                  (widget-value-set button nil)
2110                  (widget-apply current :deactivate)))))))
2111   ;; Pass notification to parent.
2112   (widget-apply widget :notify child event))
2113
2114 ;;; The `insert-button' Widget.
2115
2116 (define-widget 'insert-button 'push-button
2117   "An insert button for the `editable-list' widget."
2118   :tag "INS"
2119   :help-echo "Insert a new item into the list at this position."
2120   :action 'widget-insert-button-action)
2121
2122 (defun widget-insert-button-action (widget &optional event)
2123   ;; Ask the parent to insert a new item.
2124   (widget-apply (widget-get widget :parent)
2125                 :insert-before (widget-get widget :widget)))
2126
2127 ;;; The `delete-button' Widget.
2128
2129 (define-widget 'delete-button 'push-button
2130   "A delete button for the `editable-list' widget."
2131   :tag "DEL"
2132   :help-echo "Delete this item from the list."
2133   :action 'widget-delete-button-action)
2134
2135 (defun widget-delete-button-action (widget &optional event)
2136   ;; Ask the parent to insert a new item.
2137   (widget-apply (widget-get widget :parent)
2138                 :delete-at (widget-get widget :widget)))
2139
2140 ;;; The `editable-list' Widget.
2141
2142 (defcustom widget-editable-list-gui nil
2143   "If non nil, use GUI push-buttons in editable list when available."
2144   :type 'boolean
2145   :group 'widgets)
2146
2147 (define-widget 'editable-list 'default
2148   "A variable list of widgets of the same type."
2149   :convert-widget 'widget-types-convert-widget
2150   :offset 12
2151   :format "%v%i\n"
2152   :format-handler 'widget-editable-list-format-handler
2153   :entry-format "%i %d %v"
2154   :menu-tag "editable-list"
2155   :value-create 'widget-editable-list-value-create
2156   :value-delete 'widget-children-value-delete
2157   :value-get 'widget-editable-list-value-get
2158   :validate 'widget-children-validate
2159   :match 'widget-editable-list-match
2160   :match-inline 'widget-editable-list-match-inline
2161   :insert-before 'widget-editable-list-insert-before
2162   :delete-at 'widget-editable-list-delete-at)
2163
2164 (defun widget-editable-list-format-handler (widget escape)
2165   ;; We recognize the insert button.
2166   (let ((widget-push-button-gui widget-editable-list-gui))
2167     (cond ((eq escape ?i)
2168            (and (widget-get widget :indent)
2169                 (insert-char ?  (widget-get widget :indent)))
2170            (apply 'widget-create-child-and-convert
2171                   widget 'insert-button
2172                   (widget-get widget :append-button-args)))
2173           (t
2174            (widget-default-format-handler widget escape)))))
2175
2176 (defun widget-editable-list-value-create (widget)
2177   ;; Insert all values
2178   (let* ((value (widget-get widget :value))
2179          (type (nth 0 (widget-get widget :args)))
2180          (inlinep (widget-get type :inline))
2181          children)
2182     (widget-put widget :value-pos (copy-marker (point)))
2183     (set-marker-insertion-type (widget-get widget :value-pos) t)
2184     (while value
2185       (let ((answer (widget-match-inline type value)))
2186         (if answer
2187             (setq children (cons (widget-editable-list-entry-create
2188                                   widget
2189                                   (if inlinep
2190                                       (car answer)
2191                                     (car (car answer)))
2192                                   t)
2193                                  children)
2194                   value (cdr answer))
2195           (setq value nil))))
2196     (widget-put widget :children (nreverse children))))
2197
2198 (defun widget-editable-list-value-get (widget)
2199   ;; Get value of the child widget.
2200   (apply 'append (mapcar (lambda (child) (widget-apply child :value-inline))
2201                          (widget-get widget :children))))
2202
2203 (defun widget-editable-list-match (widget value)
2204   ;; Value must be a list and all the members must match the type.
2205   (and (listp value)
2206        (null (cdr (widget-editable-list-match-inline widget value)))))
2207
2208 (defun widget-editable-list-match-inline (widget value)
2209   (let ((type (nth 0 (widget-get widget :args)))
2210         (ok t)
2211         found)
2212     (while (and value ok)
2213       (let ((answer (widget-match-inline type value)))
2214         (if answer
2215             (setq found (append found (car answer))
2216                   value (cdr answer))
2217           (setq ok nil))))
2218     (cons found value)))
2219
2220 (defun widget-editable-list-insert-before (widget before)
2221   ;; Insert a new child in the list of children.
2222   (save-excursion
2223     (let ((children (widget-get widget :children))
2224           (inhibit-read-only t)
2225           after-change-functions)
2226       (cond (before
2227              (goto-char (widget-get before :entry-from)))
2228             (t
2229              (goto-char (widget-get widget :value-pos))))
2230       (let ((child (widget-editable-list-entry-create
2231                     widget nil nil)))
2232         (when (< (widget-get child :entry-from) (widget-get widget :from))
2233           (set-marker (widget-get widget :from)
2234                       (widget-get child :entry-from)))
2235         (widget-specify-text (widget-get child :entry-from)
2236                              (widget-get child :entry-to))
2237         (if (eq (car children) before)
2238             (widget-put widget :children (cons child children))
2239           (while (not (eq (car (cdr children)) before))
2240             (setq children (cdr children)))
2241           (setcdr children (cons child (cdr children)))))))
2242   (widget-setup)
2243  widget (widget-apply widget :notify widget))
2244
2245 (defun widget-editable-list-delete-at (widget child)
2246   ;; Delete child from list of children.
2247   (save-excursion
2248     (let ((buttons (copy-sequence (widget-get widget :buttons)))
2249           button
2250           (inhibit-read-only t)
2251           after-change-functions)
2252       (while buttons
2253         (setq button (car buttons)
2254               buttons (cdr buttons))
2255         (when (eq (widget-get button :widget) child)
2256           (widget-put widget
2257                       :buttons (delq button (widget-get widget :buttons)))
2258           (widget-delete button))))
2259     (let ((entry-from (widget-get child :entry-from))
2260           (entry-to (widget-get child :entry-to))
2261           (inhibit-read-only t)
2262           after-change-functions)
2263       (widget-delete child)
2264       (delete-region entry-from entry-to)
2265       (set-marker entry-from nil)
2266       (set-marker entry-to nil))
2267     (widget-put widget :children (delq child (widget-get widget :children))))
2268   (widget-setup)
2269   (widget-apply widget :notify widget))
2270
2271 (defun widget-editable-list-entry-create (widget value conv)
2272   ;; Create a new entry to the list.
2273   (let ((type (nth 0 (widget-get widget :args)))
2274         (widget-push-button-gui widget-editable-list-gui)
2275         child delete insert)
2276     (widget-specify-insert
2277      (save-excursion
2278        (and (widget-get widget :indent)
2279             (insert-char ?  (widget-get widget :indent)))
2280        (insert (widget-get widget :entry-format)))
2281      ;; Parse % escapes in format.
2282      (while (re-search-forward "%\\(.\\)" nil t)
2283        (let ((escape (aref (match-string 1) 0)))
2284          (replace-match "" t t)
2285          (cond ((eq escape ?%)
2286                 (insert "%"))
2287                ((eq escape ?i)
2288                 (setq insert (apply 'widget-create-child-and-convert
2289                                     widget 'insert-button
2290                                     (widget-get widget :insert-button-args))))
2291                ((eq escape ?d)
2292                 (setq delete (apply 'widget-create-child-and-convert
2293                                     widget 'delete-button
2294                                     (widget-get widget :delete-button-args))))
2295                ((eq escape ?v)
2296                 (if conv
2297                     (setq child (widget-create-child-value
2298                                  widget type value))
2299                   (setq child (widget-create-child widget type))))
2300                (t
2301                 (error "Unknown escape `%c'" escape)))))
2302      (widget-put widget
2303                  :buttons (cons delete
2304                                 (cons insert
2305                                       (widget-get widget :buttons))))
2306      (let ((entry-from (copy-marker (point-min)))
2307            (entry-to (copy-marker (point-max))))
2308        (widget-specify-text entry-from entry-to)
2309        (set-marker-insertion-type entry-from t)
2310        (set-marker-insertion-type entry-to nil)
2311        (widget-put child :entry-from entry-from)
2312        (widget-put child :entry-to entry-to)))
2313     (widget-put insert :widget child)
2314     (widget-put delete :widget child)
2315     child))
2316
2317 ;;; The `group' Widget.
2318
2319 (define-widget 'group 'default
2320   "A widget which group other widgets inside."
2321   :convert-widget 'widget-types-convert-widget
2322   :format "%v"
2323   :value-create 'widget-group-value-create
2324   :value-delete 'widget-children-value-delete
2325   :value-get 'widget-editable-list-value-get
2326   :validate 'widget-children-validate
2327   :match 'widget-group-match
2328   :match-inline 'widget-group-match-inline)
2329
2330 (defun widget-group-value-create (widget)
2331   ;; Create each component.
2332   (let ((args (widget-get widget :args))
2333         (value (widget-get widget :value))
2334         arg answer children)
2335     (while args
2336       (setq arg (car args)
2337             args (cdr args)
2338             answer (widget-match-inline arg value)
2339             value (cdr answer))
2340       (and (eq (preceding-char) ?\n)
2341            (widget-get widget :indent)
2342            (insert-char ?  (widget-get widget :indent)))
2343       (push (cond ((null answer)
2344                    (widget-create-child widget arg))
2345                   ((widget-get arg :inline)
2346                    (widget-create-child-value widget arg  (car answer)))
2347                   (t
2348                    (widget-create-child-value widget arg  (car (car answer)))))
2349             children))
2350     (widget-put widget :children (nreverse children))))
2351
2352 (defun widget-group-match (widget values)
2353   ;; Match if the components match.
2354   (and (listp values)
2355        (let ((match (widget-group-match-inline widget values)))
2356          (and match (null (cdr match))))))
2357
2358 (defun widget-group-match-inline (widget vals)
2359   ;; Match if the components match.
2360   (let ((args (widget-get widget :args))
2361         argument answer found)
2362     (while args
2363       (setq argument (car args)
2364             args (cdr args)
2365             answer (widget-match-inline argument vals))
2366       (if answer
2367           (setq vals (cdr answer)
2368                 found (append found (car answer)))
2369         (setq vals nil
2370               args nil)))
2371     (if answer
2372         (cons found vals)
2373       nil)))
2374
2375 ;;; The `widget-help' Widget.
2376
2377 (define-widget 'widget-help 'push-button
2378   "The widget documentation button."
2379   :format "%[[%t]%] %d"
2380   :help-echo "Toggle display of documentation."
2381   :action 'widget-help-action)
2382
2383 (defun widget-help-action (widget &optional event)
2384   "Toggle documentation for WIDGET."
2385   (let ((old (widget-get widget :doc))
2386         (new (widget-get widget :widget-doc)))
2387     (widget-put widget :doc new)
2388     (widget-put widget :widget-doc old))
2389   (widget-value-set widget (widget-value widget)))
2390
2391 ;;; The Sexp Widgets.
2392
2393 (define-widget 'const 'item
2394   "An immutable sexp."
2395   :prompt-value 'widget-const-prompt-value
2396   :format "%t\n%d")
2397
2398 (defun widget-const-prompt-value (widget prompt value unbound)
2399   ;; Return the value of the const.
2400   (widget-value widget))
2401
2402 (define-widget 'function-item 'const
2403   "An immutable function name."
2404   :format "%v\n%h"
2405   :documentation-property (lambda (symbol)
2406                             (condition-case nil
2407                                 (documentation symbol t)
2408                               (error nil))))
2409
2410 (define-widget 'variable-item 'const
2411   "An immutable variable name."
2412   :format "%v\n%h"
2413   :documentation-property 'variable-documentation)
2414
2415 (defvar widget-string-prompt-value-history nil
2416   "History of input to `widget-string-prompt-value'.")
2417
2418 (define-widget 'string 'editable-field
2419   "A string"
2420   :tag "String"
2421   :format "%{%t%}: %v"
2422   :prompt-history 'widget-string-prompt-value-history)
2423
2424 (define-widget 'regexp 'string
2425   "A regular expression."
2426   :match 'widget-regexp-match
2427   :validate 'widget-regexp-validate
2428   :tag "Regexp")
2429
2430 (defun widget-regexp-match (widget value)
2431   ;; Match valid regexps.
2432   (and (stringp value)
2433        (condition-case nil
2434            (prog1 t
2435              (string-match value ""))
2436          (error nil))))
2437
2438 (defun widget-regexp-validate (widget)
2439   "Check that the value of WIDGET is a valid regexp."
2440   (let ((val (widget-value widget)))
2441     (condition-case data
2442         (prog1 nil
2443           (string-match val ""))
2444       (error (widget-put widget :error (error-message-string data))
2445              widget))))
2446
2447 (define-widget 'file 'string
2448   "A file widget.
2449 It will read a file name from the minibuffer when activated."
2450   :prompt-value 'widget-file-prompt-value
2451   :format "%{%t%}: %v"
2452   :tag "File"
2453   :action 'widget-file-action)
2454
2455 (defun widget-file-prompt-value (widget prompt value unbound)
2456   ;; Read file from minibuffer.
2457   (abbreviate-file-name
2458    (if unbound
2459        (read-file-name prompt)
2460      (let ((prompt2 (format "%s (default %s) " prompt value))
2461            (dir (file-name-directory value))
2462            (file (file-name-nondirectory value))
2463            (must-match (widget-get widget :must-match)))
2464        (read-file-name prompt2 dir nil must-match file)))))
2465
2466 (defun widget-file-action (widget &optional event)
2467   ;; Read a file name from the minibuffer.
2468   (let* ((value (widget-value widget))
2469          (dir (file-name-directory value))
2470          (file (file-name-nondirectory value))
2471          (menu-tag (widget-apply widget :menu-tag-get))
2472          (must-match (widget-get widget :must-match))
2473          (answer (read-file-name (concat menu-tag ": (default `" value "') ")
2474                                  dir nil must-match file)))
2475     (widget-value-set widget (abbreviate-file-name answer))
2476     (widget-apply widget :notify widget event)
2477     (widget-setup)))
2478
2479 (define-widget 'directory 'file
2480   "A directory widget.
2481 It will read a directory name from the minibuffer when activated."
2482   :tag "Directory")
2483
2484 (defvar widget-symbol-prompt-value-history nil
2485   "History of input to `widget-symbol-prompt-value'.")
2486
2487 (define-widget 'symbol 'editable-field
2488   "A lisp symbol."
2489   :value nil
2490   :tag "Symbol"
2491   :format "%{%t%}: %v"
2492   :match (lambda (widget value) (symbolp value))
2493   :prompt-internal 'widget-symbol-prompt-internal
2494   :prompt-match 'symbolp
2495   :prompt-history 'widget-symbol-prompt-value-history
2496   :value-to-internal (lambda (widget value)
2497                        (if (symbolp value)
2498                            (symbol-name value)
2499                          value))
2500   :value-to-external (lambda (widget value)
2501                        (if (stringp value)
2502                            (intern value)
2503                          value)))
2504
2505 (defun widget-symbol-prompt-internal (widget prompt initial history)
2506   ;; Read file from minibuffer.
2507   (let ((answer (completing-read prompt obarray
2508                                  (widget-get widget :prompt-match)
2509                                  nil initial history)))
2510     (if (and (stringp answer)
2511              (not (zerop (length answer))))
2512         answer
2513       (error "No value"))))
2514
2515 (defvar widget-function-prompt-value-history nil
2516   "History of input to `widget-function-prompt-value'.")
2517
2518 (define-widget 'function 'sexp
2519   "A lisp function."
2520   :prompt-value 'widget-field-prompt-value
2521   :prompt-internal 'widget-symbol-prompt-internal
2522   :prompt-match 'fboundp
2523   :prompt-history 'widget-function-prompt-value-history
2524   :action 'widget-field-action
2525   :tag "Function")
2526
2527 (defvar widget-variable-prompt-value-history nil
2528   "History of input to `widget-variable-prompt-value'.")
2529
2530 (define-widget 'variable 'symbol
2531   ;; Should complete on variables.
2532   "A lisp variable."
2533   :prompt-match 'boundp
2534   :prompt-history 'widget-variable-prompt-value-history
2535   :tag "Variable")
2536
2537 (define-widget 'sexp 'editable-field
2538   "An arbitrary lisp expression."
2539   :tag "Lisp expression"
2540   :format "%{%t%}: %v"
2541   :value nil
2542   :validate 'widget-sexp-validate
2543   :match (lambda (widget value) t)
2544   :value-to-internal 'widget-sexp-value-to-internal
2545   :value-to-external (lambda (widget value) (read value))
2546   :prompt-history 'widget-sexp-prompt-value-history
2547   :prompt-value 'widget-sexp-prompt-value)
2548
2549 (defun widget-sexp-value-to-internal (widget value)
2550   ;; Use pp for printer representation.
2551   (let ((pp (pp-to-string value)))
2552     (while (string-match "\n\\'" pp)
2553       (setq pp (substring pp 0 -1)))
2554     (if (or (string-match "\n\\'" pp)
2555             (> (length pp) 40))
2556         (concat "\n" pp)
2557       pp)))
2558
2559 (defun widget-sexp-validate (widget)
2560   ;; Valid if we can read the string and there is no junk left after it.
2561   (save-excursion
2562     (let ((buffer (set-buffer (get-buffer-create " *Widget Scratch*"))))
2563       (erase-buffer)
2564       (insert (widget-apply widget :value-get))
2565       (goto-char (point-min))
2566       (condition-case data
2567           (let ((value (read buffer)))
2568             (if (eobp)
2569                 (if (widget-apply widget :match value)
2570                     nil
2571                   (widget-put widget :error (widget-get widget :type-error))
2572                   widget)
2573               (widget-put widget
2574                           :error (format "Junk at end of expression: %s"
2575                                          (buffer-substring (point)
2576                                                            (point-max))))
2577               widget))
2578         (error (widget-put widget :error (error-message-string data))
2579                widget)))))
2580
2581 (defvar widget-sexp-prompt-value-history nil
2582   "History of input to `widget-sexp-prompt-value'.")
2583
2584 (defun widget-sexp-prompt-value (widget prompt value unbound)
2585   ;; Read an arbitrary sexp.
2586   (let ((found (read-string prompt
2587                             (if unbound nil (cons (prin1-to-string value) 0))
2588                             (widget-get widget :prompt-history))))
2589     (save-excursion
2590       (let ((buffer (set-buffer (get-buffer-create " *Widget Scratch*"))))
2591         (erase-buffer)
2592         (insert found)
2593         (goto-char (point-min))
2594         (let ((answer (read buffer)))
2595           (unless (eobp)
2596             (error "Junk at end of expression: %s"
2597                    (buffer-substring (point) (point-max))))
2598           answer)))))
2599
2600 (define-widget 'integer 'sexp
2601   "An integer."
2602   :tag "Integer"
2603   :value 0
2604   :type-error "This field should contain an integer"
2605   :value-to-internal (lambda (widget value)
2606                        (if (integerp value)
2607                            (prin1-to-string value)
2608                          value))
2609   :match (lambda (widget value) (integerp value)))
2610
2611 (define-widget 'character 'editable-field
2612   "An character."
2613   :tag "Character"
2614   :value 0
2615   :size 1
2616   :format "%{%t%}: %v\n"
2617   :valid-regexp "\\`.\\'"
2618   :error "This field should contain a single character"
2619   :value-to-internal (lambda (widget value)
2620                        (if (stringp value)
2621                            value
2622                          (char-to-string value)))
2623   :value-to-external (lambda (widget value)
2624                        (if (stringp value)
2625                            (aref value 0)
2626                          value))
2627   :match (lambda (widget value)
2628            (if (fboundp 'characterp)
2629                (characterp value)
2630              (integerp value))))
2631
2632 (define-widget 'number 'sexp
2633   "A floating point number."
2634   :tag "Number"
2635   :value 0.0
2636   :type-error "This field should contain a number"
2637   :value-to-internal (lambda (widget value)
2638                        (if (numberp value)
2639                            (prin1-to-string value)
2640                          value))
2641   :match (lambda (widget value) (numberp value)))
2642
2643 (define-widget 'list 'group
2644   "A lisp list."
2645   :tag "List"
2646   :format "%{%t%}:\n%v")
2647
2648 (define-widget 'vector 'group
2649   "A lisp vector."
2650   :tag "Vector"
2651   :format "%{%t%}:\n%v"
2652   :match 'widget-vector-match
2653   :value-to-internal (lambda (widget value) (append value nil))
2654   :value-to-external (lambda (widget value) (apply 'vector value)))
2655
2656 (defun widget-vector-match (widget value)
2657   (and (vectorp value)
2658        (widget-group-match widget
2659                            (widget-apply widget :value-to-internal value))))
2660
2661 (define-widget 'cons 'group
2662   "A cons-cell."
2663   :tag "Cons-cell"
2664   :format "%{%t%}:\n%v"
2665   :match 'widget-cons-match
2666   :value-to-internal (lambda (widget value)
2667                        (list (car value) (cdr value)))
2668   :value-to-external (lambda (widget value)
2669                        (cons (nth 0 value) (nth 1 value))))
2670
2671 (defun widget-cons-match (widget value)
2672   (and (consp value)
2673        (widget-group-match widget
2674                            (widget-apply widget :value-to-internal value))))
2675
2676 (define-widget 'choice 'menu-choice
2677   "A union of several sexp types."
2678   :tag "Choice"
2679   :format "%[%t%]: %v"
2680   :prompt-value 'widget-choice-prompt-value)
2681
2682 (defun widget-choice-prompt-value (widget prompt value unbound)
2683   "Make a choice."
2684   (let ((args (widget-get widget :args))
2685         (completion-ignore-case (widget-get widget :case-fold))
2686         current choices old)
2687     ;; Find the first arg that match VALUE.
2688     (let ((look args))
2689       (while look
2690         (if (widget-apply (car look) :match value)
2691             (setq old (car look)
2692                   look nil)
2693           (setq look (cdr look)))))
2694     ;; Find new choice.
2695     (setq current
2696           (cond ((= (length args) 0)
2697                  nil)
2698                 ((= (length args) 1)
2699                  (nth 0 args))
2700                 ((and (= (length args) 2)
2701                       (memq old args))
2702                  (if (eq old (nth 0 args))
2703                      (nth 1 args)
2704                    (nth 0 args)))
2705                 (t
2706                  (while args
2707                    (setq current (car args)
2708                          args (cdr args))
2709                    (setq choices
2710                          (cons (cons (widget-apply current :menu-tag-get)
2711                                      current)
2712                                choices)))
2713                  (let ((val (completing-read prompt choices nil t)))
2714                    (if (stringp val)
2715                        (let ((try (try-completion val choices)))
2716                          (when (stringp try)
2717                            (setq val try))
2718                          (cdr (assoc val choices)))
2719                      nil)))))
2720     (if current
2721         (widget-prompt-value current prompt nil t)
2722       value)))
2723
2724 (define-widget 'radio 'radio-button-choice
2725   "A union of several sexp types."
2726   :tag "Choice"
2727   :format "%{%t%}:\n%v"
2728   :prompt-value 'widget-choice-prompt-value)
2729
2730 (define-widget 'repeat 'editable-list
2731   "A variable length homogeneous list."
2732   :tag "Repeat"
2733   :format "%{%t%}:\n%v%i\n")
2734
2735 (define-widget 'set 'checklist
2736   "A list of members from a fixed set."
2737   :tag "Set"
2738   :format "%{%t%}:\n%v")
2739
2740 (define-widget 'boolean 'toggle
2741   "To be nil or non-nil, that is the question."
2742   :tag "Boolean"
2743   :prompt-value 'widget-boolean-prompt-value
2744   :format "%[%t%]: %v\n")
2745
2746 (defun widget-boolean-prompt-value (widget prompt value unbound)
2747   ;; Toggle a boolean.
2748   (y-or-n-p prompt))
2749
2750 ;;; The `color' Widget.
2751
2752 (define-widget 'color-item 'choice-item
2753   "A color name (with sample)."
2754   :format "%v (%{sample%})\n"
2755   :sample-face-get 'widget-color-item-button-face-get)
2756
2757 (defun widget-color-item-button-face-get (widget)
2758   ;; We create a face from the value.
2759   (require 'facemenu)
2760   (condition-case nil
2761       (facemenu-get-face (intern (concat "fg:" (widget-value widget))))
2762     (error 'default)))
2763
2764 (define-widget 'color 'push-button
2765   "Choose a color name (with sample)."
2766   :format "%[%t%]: %v"
2767   :tag "Color"
2768   :value "black"
2769   :value-create 'widget-color-value-create
2770   :value-delete 'widget-children-value-delete
2771   :value-get 'widget-color-value-get
2772   :value-set 'widget-color-value-set
2773   :action 'widget-color-action
2774   :match 'widget-field-match
2775   :tag "Color")
2776
2777 (defvar widget-color-choice-list nil)
2778 ;; Variable holding the possible colors.
2779
2780 (defun widget-color-choice-list ()
2781   (unless widget-color-choice-list
2782     (setq widget-color-choice-list
2783           (mapcar '(lambda (color) (list color))
2784                   (x-defined-colors))))
2785   widget-color-choice-list)
2786
2787 (defun widget-color-value-create (widget)
2788   (let ((child (widget-create-child-and-convert
2789                 widget 'color-item (widget-get widget :value))))
2790     (widget-put widget :children (list child))))
2791
2792 (defun widget-color-value-get (widget)
2793   ;; Pass command to first child.
2794   (widget-apply (car (widget-get widget :children)) :value-get))
2795
2796 (defun widget-color-value-set (widget value)
2797   ;; Pass command to first child.
2798   (widget-apply (car (widget-get widget :children)) :value-set value))
2799
2800 (defvar widget-color-history nil
2801   "History of entered colors")
2802
2803 (defun widget-color-action (widget &optional event)
2804   ;; Prompt for a color.
2805   (let* ((tag (widget-apply widget :menu-tag-get))
2806          (prompt (concat tag ": "))
2807          (answer (cond ((string-match "XEmacs" emacs-version)
2808                         (read-color prompt))
2809                        ((fboundp 'x-defined-colors)
2810                         (completing-read (concat tag ": ")
2811                                          (widget-color-choice-list)
2812                                          nil nil nil 'widget-color-history))
2813                        (t
2814                         (read-string prompt (widget-value widget))))))
2815     (unless (zerop (length answer))
2816       (widget-value-set widget answer)
2817       (widget-apply widget :notify widget event)
2818       (widget-setup))))
2819
2820 ;;; The Help Echo
2821
2822 (defun widget-echo-help-mouse ()
2823   "Display the help message for the widget under the mouse.
2824 Enable with (run-with-idle-timer 1 t 'widget-echo-help-mouse)"
2825   (let* ((pos (mouse-position))
2826          (frame (car pos))
2827          (x (car (cdr pos)))
2828          (y (cdr (cdr pos)))
2829          (win (window-at x y frame))
2830          (where (coordinates-in-window-p (cons x y) win)))
2831     (when (consp where)
2832       (save-window-excursion
2833         (progn ; save-excursion
2834           (select-window win)
2835           (let* ((result (compute-motion (window-start win)
2836                                          '(0 . 0)
2837                                          (window-end win)
2838                                          where
2839                                          (window-width win)
2840                                          (cons (window-hscroll) 0)
2841                                          win)))
2842             (when (and (eq (nth 1 result) x)
2843                        (eq (nth 2 result) y))
2844               (widget-echo-help (nth 0 result))))))))
2845   (unless track-mouse
2846     (setq track-mouse t)
2847     (add-hook 'post-command-hook 'widget-stop-mouse-tracking)))
2848
2849 (defun widget-stop-mouse-tracking (&rest args)
2850   "Stop the mouse tracking done while idle."
2851   (remove-hook 'post-command-hook 'widget-stop-mouse-tracking)
2852   (setq track-mouse nil))
2853
2854 (defun widget-at (pos)
2855   "The button or field at POS."
2856   (or (get-text-property pos 'button)
2857       (get-text-property pos 'field)))
2858
2859 (defun widget-echo-help (pos)
2860   "Display the help echo for widget at POS."
2861   (let* ((widget (widget-at pos))
2862          (help-echo (and widget (widget-get widget :help-echo))))
2863     (cond ((stringp help-echo)
2864            (message "%s" help-echo))
2865           ((and (symbolp help-echo) (fboundp help-echo)
2866                 (stringp (setq help-echo (funcall help-echo widget))))
2867            (message "%s" help-echo)))))
2868
2869 ;;; The End:
2870
2871 (provide 'wid-edit)
2872
2873 ;; wid-edit.el ends here