| 1 | \input texinfo.tex |
| 2 | |
| 3 | @c %**start of header |
| 4 | @setfilename ../info/widget |
| 5 | @settitle The Emacs Widget Library |
| 6 | @syncodeindex fn cp |
| 7 | @syncodeindex vr cp |
| 8 | @syncodeindex ky cp |
| 9 | @afourpaper |
| 10 | @c %**end of header |
| 11 | |
| 12 | @copying |
| 13 | Copyright @copyright{} 2000, 2001, 2002, 2003, 2004, 2005, |
| 14 | 2006, 2007 Free Software Foundation, Inc. |
| 15 | |
| 16 | @quotation |
| 17 | Permission is granted to copy, distribute and/or modify this document |
| 18 | under the terms of the GNU Free Documentation License, Version 1.2 or |
| 19 | any later version published by the Free Software Foundation; with the |
| 20 | Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and |
| 21 | ``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU |
| 22 | Manual'', and with the Back-Cover Texts as in (a) below. A copy of the |
| 23 | license is included in the section entitled ``GNU Free Documentation |
| 24 | License'' in the Emacs manual. |
| 25 | |
| 26 | This document is part of a collection distributed under the GNU Free |
| 27 | Documentation License. If you want to distribute this document |
| 28 | separately from the collection, you can do so by adding a copy of the |
| 29 | license to the document, as described in section 6 of the license. |
| 30 | |
| 31 | (a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify |
| 32 | this GNU Manual, like GNU software. Copies published by the Free |
| 33 | Software Foundation raise funds for GNU development.'' |
| 34 | @end quotation |
| 35 | @end copying |
| 36 | |
| 37 | @dircategory Emacs |
| 38 | @direntry |
| 39 | * Widget: (widget). The "widget" package used by the Emacs Customization |
| 40 | facility. |
| 41 | @end direntry |
| 42 | |
| 43 | @node Top, Introduction, (dir), (dir) |
| 44 | @comment node-name, next, previous, up |
| 45 | @top The Emacs Widget Library |
| 46 | |
| 47 | @menu |
| 48 | * Introduction:: |
| 49 | * User Interface:: |
| 50 | * Programming Example:: |
| 51 | * Setting Up the Buffer:: |
| 52 | * Basic Types:: |
| 53 | * Sexp Types:: |
| 54 | * Widget Properties:: |
| 55 | * Defining New Widgets:: |
| 56 | * Widget Browser:: |
| 57 | * Widget Minor Mode:: |
| 58 | * Utilities:: |
| 59 | * Widget Wishlist:: |
| 60 | * GNU Free Documentation License:: |
| 61 | * Index:: |
| 62 | @end menu |
| 63 | |
| 64 | @node Introduction, User Interface, Top, Top |
| 65 | @comment node-name, next, previous, up |
| 66 | @section Introduction |
| 67 | |
| 68 | Most graphical user interface toolkits provide a number of standard |
| 69 | user interface controls (sometimes known as `widgets' or `gadgets'). |
| 70 | Emacs doesn't really support anything like this, except for an |
| 71 | incredibly powerful text ``widget.'' On the other hand, Emacs does |
| 72 | provide the necessary primitives to implement many other widgets |
| 73 | within a text buffer. The @code{widget} package simplifies this task. |
| 74 | |
| 75 | @cindex basic widgets |
| 76 | @cindex widgets, basic types |
| 77 | The basic widgets are: |
| 78 | |
| 79 | @table @code |
| 80 | @item link |
| 81 | Areas of text with an associated action. Intended for hypertext links |
| 82 | embedded in text. |
| 83 | @item push-button |
| 84 | Like link, but intended for stand-alone buttons. |
| 85 | @item editable-field |
| 86 | An editable text field. It can be either variable or fixed length. |
| 87 | @item menu-choice |
| 88 | Allows the user to choose one of multiple options from a menu, each |
| 89 | option is itself a widget. Only the selected option will be visible in |
| 90 | the buffer. |
| 91 | @item radio-button-choice |
| 92 | Allows the user to choose one of multiple options by activating radio |
| 93 | buttons. The options are implemented as widgets. All options will be |
| 94 | visible in the buffer. |
| 95 | @item item |
| 96 | A simple constant widget intended to be used in the @code{menu-choice} and |
| 97 | @code{radio-button-choice} widgets. |
| 98 | @item choice-item |
| 99 | A button item only intended for use in choices. When invoked, the user |
| 100 | will be asked to select another option from the choice widget. |
| 101 | @item toggle |
| 102 | A simple @samp{on}/@samp{off} switch. |
| 103 | @item checkbox |
| 104 | A checkbox (@samp{[ ]}/@samp{[X]}). |
| 105 | @item editable-list |
| 106 | Create an editable list. The user can insert or delete items in the |
| 107 | list. Each list item is itself a widget. |
| 108 | @end table |
| 109 | |
| 110 | Now, of what possible use can support for widgets be in a text editor? |
| 111 | I'm glad you asked. The answer is that widgets are useful for |
| 112 | implementing forms. A @dfn{form} in Emacs is a buffer where the user is |
| 113 | supposed to fill out a number of fields, each of which has a specific |
| 114 | meaning. The user is not supposed to change or delete any of the text |
| 115 | between the fields. Examples of forms in Emacs are the @file{forms} |
| 116 | package (of course), the customize buffers, the mail and news compose |
| 117 | modes, and the @acronym{HTML} form support in the @file{w3} browser. |
| 118 | |
| 119 | @cindex widget library, why use it |
| 120 | The advantages for a programmer of using the @code{widget} package to |
| 121 | implement forms are: |
| 122 | |
| 123 | @enumerate |
| 124 | @item |
| 125 | More complex fields than just editable text are supported. |
| 126 | @item |
| 127 | You can give the users immediate feedback if they enter invalid data in a |
| 128 | text field, and sometimes prevent entering invalid data. |
| 129 | @item |
| 130 | You can have fixed sized fields, thus allowing multiple fields to be |
| 131 | lined up in columns. |
| 132 | @item |
| 133 | It is simple to query or set the value of a field. |
| 134 | @item |
| 135 | Editing happens in the buffer, not in the mini-buffer. |
| 136 | @item |
| 137 | Packages using the library get a uniform look, making them easier for |
| 138 | the user to learn. |
| 139 | @item |
| 140 | As support for embedded graphics improve, the widget library will be |
| 141 | extended to use the GUI features. This means that your code using the |
| 142 | widget library will also use the new graphic features automatically. |
| 143 | @end enumerate |
| 144 | |
| 145 | In order to minimize the code that is loaded by users who do not |
| 146 | create any widgets, the code has been split in two files: |
| 147 | |
| 148 | @cindex widget library, files |
| 149 | @table @file |
| 150 | @item widget.el |
| 151 | This will declare the user variables, define the function |
| 152 | @code{define-widget}, and autoload the function @code{widget-create}. |
| 153 | @item wid-edit.el |
| 154 | Everything else is here, there is no reason to load it explicitly, as |
| 155 | it will be autoloaded when needed. |
| 156 | @end table |
| 157 | |
| 158 | @node User Interface, Programming Example, Introduction, Top |
| 159 | @comment node-name, next, previous, up |
| 160 | @section User Interface |
| 161 | |
| 162 | A form consists of read only text for documentation and some fields, |
| 163 | where each field contains two parts, a tag and a value. The tags are |
| 164 | used to identify the fields, so the documentation can refer to the |
| 165 | @samp{foo field}, meaning the field tagged with @samp{Foo}. Here is an |
| 166 | example form: |
| 167 | |
| 168 | @example |
| 169 | Here is some documentation. |
| 170 | |
| 171 | Name: @i{My Name} @strong{Choose}: This option |
| 172 | Address: @i{Some Place |
| 173 | In some City |
| 174 | Some country.} |
| 175 | |
| 176 | See also @b{_other work_} for more information. |
| 177 | |
| 178 | Numbers: count to three below |
| 179 | @b{[INS]} @b{[DEL]} @i{One} |
| 180 | @b{[INS]} @b{[DEL]} @i{Eh, two?} |
| 181 | @b{[INS]} @b{[DEL]} @i{Five!} |
| 182 | @b{[INS]} |
| 183 | |
| 184 | Select multiple: |
| 185 | |
| 186 | @b{[X]} This |
| 187 | @b{[ ]} That |
| 188 | @b{[X]} Thus |
| 189 | |
| 190 | Select one: |
| 191 | |
| 192 | @b{(*)} One |
| 193 | @b{( )} Another One. |
| 194 | @b{( )} A Final One. |
| 195 | |
| 196 | @b{[Apply Form]} @b{[Reset Form]} |
| 197 | @end example |
| 198 | |
| 199 | The top level widgets in this example are tagged @samp{Name}, |
| 200 | @samp{Choose}, @samp{Address}, @samp{_other work_}, @samp{Numbers}, |
| 201 | @samp{Select multiple}, @samp{Select one}, @samp{[Apply Form]}, and |
| 202 | @samp{[Reset Form]}. There are basically two things the user can do |
| 203 | within a form, namely editing the editable text fields and activating |
| 204 | the buttons. |
| 205 | |
| 206 | @subsection Editable Text Fields |
| 207 | |
| 208 | In the example, the value for the @samp{Name} is most likely displayed |
| 209 | in an editable text field, and so are values for each of the members of |
| 210 | the @samp{Numbers} list. All the normal Emacs editing operations are |
| 211 | available for editing these fields. The only restriction is that each |
| 212 | change you make must be contained within a single editable text field. |
| 213 | For example, capitalizing all text from the middle of one field to the |
| 214 | middle of another field is prohibited. |
| 215 | |
| 216 | Editable text fields are created by the @code{editable-field} widget. |
| 217 | |
| 218 | @strong{Warning:} In an @code{editable-field} widget, the editable |
| 219 | field must not be adjacent to another widget---that won't work. |
| 220 | You must put some text in between. Either make this text part of |
| 221 | the @code{editable-field} widget itself, or insert it with |
| 222 | @code{widget-insert}. |
| 223 | |
| 224 | The @code{:format} keyword is useful for generating the necessary |
| 225 | text; for instance, if you give it a value of @code{"Name: %v "}, |
| 226 | the @samp{Name: } part will provide the necessary separating text |
| 227 | before the field and the trailing space will provide the |
| 228 | separating text after the field. If you don't include the |
| 229 | @code{:size} keyword, the field will extend to the end of the |
| 230 | line, and the terminating newline will provide separation after. |
| 231 | |
| 232 | @strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape |
| 233 | must be preceded by some other text in the @code{:format} string |
| 234 | (if specified). |
| 235 | |
| 236 | The editing text fields are highlighted with the |
| 237 | @code{widget-field-face} face, making them easy to find. |
| 238 | |
| 239 | @deffn Face widget-field-face |
| 240 | Face used for other editing fields. |
| 241 | @end deffn |
| 242 | |
| 243 | @subsection Buttons |
| 244 | |
| 245 | @cindex widget buttons |
| 246 | @cindex button widgets |
| 247 | Some portions of the buffer have an associated @dfn{action}, which can |
| 248 | be @dfn{invoked} by a standard key or mouse command. These portions |
| 249 | are called @dfn{buttons}. The default commands for activating a button |
| 250 | are: |
| 251 | |
| 252 | @table @kbd |
| 253 | @item @key{RET} |
| 254 | @deffn Command widget-button-press @var{pos} &optional @var{event} |
| 255 | Invoke the button at @var{pos}, defaulting to point. |
| 256 | If point is not located on a button, invoke the binding in |
| 257 | @code{widget-global-map} (by default the global map). |
| 258 | @end deffn |
| 259 | |
| 260 | @kindex Mouse-2 @r{(on button widgets}) |
| 261 | @item Mouse-2 |
| 262 | @deffn Command widget-button-click @var{event} |
| 263 | Invoke the button at the location of the mouse pointer. If the mouse |
| 264 | pointer is located in an editable text field, invoke the binding in |
| 265 | @code{widget-global-map} (by default the global map). |
| 266 | @end deffn |
| 267 | @end table |
| 268 | |
| 269 | There are several different kind of buttons, all of which are present in |
| 270 | the example: |
| 271 | |
| 272 | @table @emph |
| 273 | @cindex option field tag |
| 274 | @item The Option Field Tags |
| 275 | When you invoke one of these buttons, you will be asked to choose |
| 276 | between a number of different options. This is how you edit an option |
| 277 | field. Option fields are created by the @code{menu-choice} widget. In |
| 278 | the example, @samp{@b{Choose}} is an option field tag. |
| 279 | @item The @samp{@b{[INS]}} and @samp{@b{[DEL]}} buttons |
| 280 | Activating these will insert or delete elements from an editable list. |
| 281 | The list is created by the @code{editable-list} widget. |
| 282 | @cindex embedded buttons |
| 283 | @item Embedded Buttons |
| 284 | The @samp{@b{_other work_}} is an example of an embedded |
| 285 | button. Embedded buttons are not associated with any fields, but can serve |
| 286 | any purpose, such as implementing hypertext references. They are |
| 287 | usually created by the @code{link} widget. |
| 288 | @item The @samp{@b{[ ]}} and @samp{@b{[X]}} buttons |
| 289 | Activating one of these will convert it to the other. This is useful |
| 290 | for implementing multiple-choice fields. You can create them with the |
| 291 | @code{checkbox} widget. |
| 292 | @item The @samp{@b{( )}} and @samp{@b{(*)}} buttons |
| 293 | Only one radio button in a @code{radio-button-choice} widget can be |
| 294 | selected at any time. When you invoke one of the unselected radio |
| 295 | buttons, it will be selected and the previous selected radio button will |
| 296 | become unselected. |
| 297 | @item The @samp{@b{[Apply Form]}} and @samp{@b{[Reset Form]}} buttons |
| 298 | These are explicit buttons made with the @code{push-button} widget. The |
| 299 | main difference from the @code{link} widget is that the buttons will be |
| 300 | displayed as GUI buttons when possible. |
| 301 | @end table |
| 302 | |
| 303 | To make them easier to locate, buttons are emphasized in the buffer. |
| 304 | |
| 305 | @deffn Face widget-button-face |
| 306 | Face used for buttons. |
| 307 | @end deffn |
| 308 | |
| 309 | @defopt widget-mouse-face |
| 310 | Face used for highlighting a button when the mouse pointer moves across |
| 311 | it. |
| 312 | @end defopt |
| 313 | |
| 314 | @subsection Navigation |
| 315 | |
| 316 | You can use all the normal Emacs commands to move around in a form |
| 317 | buffer, plus you will have these additional commands: |
| 318 | |
| 319 | @table @kbd |
| 320 | @item @key{TAB} |
| 321 | @deffn Command widget-forward &optional count |
| 322 | Move point @var{count} buttons or editing fields forward. |
| 323 | @end deffn |
| 324 | @item @kbd{M-@key{TAB}} |
| 325 | @itemx @kbd{S-@key{TAB}} |
| 326 | @deffn Command widget-backward &optional count |
| 327 | Move point @var{count} buttons or editing fields backward. |
| 328 | @end deffn |
| 329 | @end table |
| 330 | |
| 331 | @node Programming Example, Setting Up the Buffer, User Interface, Top |
| 332 | @comment node-name, next, previous, up |
| 333 | @section Programming Example |
| 334 | |
| 335 | @cindex widgets, programming example |
| 336 | @cindex example of using widgets |
| 337 | Here is the code to implement the user interface example (@pxref{User |
| 338 | Interface}). |
| 339 | |
| 340 | @lisp |
| 341 | (require 'widget) |
| 342 | |
| 343 | (eval-when-compile |
| 344 | (require 'wid-edit)) |
| 345 | |
| 346 | (defvar widget-example-repeat) |
| 347 | |
| 348 | (defun widget-example () |
| 349 | "Create the widgets from the Widget manual." |
| 350 | (interactive) |
| 351 | (switch-to-buffer "*Widget Example*") |
| 352 | (kill-all-local-variables) |
| 353 | (make-local-variable 'widget-example-repeat) |
| 354 | (let ((inhibit-read-only t)) |
| 355 | (erase-buffer)) |
| 356 | (remove-overlays) |
| 357 | (widget-insert "Here is some documentation.\n\n") |
| 358 | (widget-create 'editable-field |
| 359 | :size 13 |
| 360 | :format "Name: %v " ; Text after the field! |
| 361 | "My Name") |
| 362 | (widget-create 'menu-choice |
| 363 | :tag "Choose" |
| 364 | :value "This" |
| 365 | :help-echo "Choose me, please!" |
| 366 | :notify (lambda (widget &rest ignore) |
| 367 | (message "%s is a good choice!" |
| 368 | (widget-value widget))) |
| 369 | '(item :tag "This option" :value "This") |
| 370 | '(choice-item "That option") |
| 371 | '(editable-field :menu-tag "No option" "Thus option")) |
| 372 | (widget-create 'editable-field |
| 373 | :format "Address: %v" |
| 374 | "Some Place\nIn some City\nSome country.") |
| 375 | (widget-insert "\nSee also ") |
| 376 | (widget-create 'link |
| 377 | :notify (lambda (&rest ignore) |
| 378 | (widget-value-set widget-example-repeat |
| 379 | '("En" "To" "Tre")) |
| 380 | (widget-setup)) |
| 381 | "other work") |
| 382 | (widget-insert |
| 383 | " for more information.\n\nNumbers: count to three below\n") |
| 384 | (setq widget-example-repeat |
| 385 | (widget-create 'editable-list |
| 386 | :entry-format "%i %d %v" |
| 387 | :notify (lambda (widget &rest ignore) |
| 388 | (let ((old (widget-get widget |
| 389 | ':example-length)) |
| 390 | (new (length (widget-value widget)))) |
| 391 | (unless (eq old new) |
| 392 | (widget-put widget ':example-length new) |
| 393 | (message "You can count to %d." new)))) |
| 394 | :value '("One" "Eh, two?" "Five!") |
| 395 | '(editable-field :value "three"))) |
| 396 | (widget-insert "\n\nSelect multiple:\n\n") |
| 397 | (widget-create 'checkbox t) |
| 398 | (widget-insert " This\n") |
| 399 | (widget-create 'checkbox nil) |
| 400 | (widget-insert " That\n") |
| 401 | (widget-create 'checkbox |
| 402 | :notify (lambda (&rest ignore) (message "Tickle")) |
| 403 | t) |
| 404 | (widget-insert " Thus\n\nSelect one:\n\n") |
| 405 | (widget-create 'radio-button-choice |
| 406 | :value "One" |
| 407 | :notify (lambda (widget &rest ignore) |
| 408 | (message "You selected %s" |
| 409 | (widget-value widget))) |
| 410 | '(item "One") '(item "Another One.") '(item "A Final One.")) |
| 411 | (widget-insert "\n") |
| 412 | (widget-create 'push-button |
| 413 | :notify (lambda (&rest ignore) |
| 414 | (if (= (length (widget-value widget-example-repeat)) |
| 415 | 3) |
| 416 | (message "Congratulation!") |
| 417 | (error "Three was the count!"))) |
| 418 | "Apply Form") |
| 419 | (widget-insert " ") |
| 420 | (widget-create 'push-button |
| 421 | :notify (lambda (&rest ignore) |
| 422 | (widget-example)) |
| 423 | "Reset Form") |
| 424 | (widget-insert "\n") |
| 425 | (use-local-map widget-keymap) |
| 426 | (widget-setup)) |
| 427 | @end lisp |
| 428 | |
| 429 | @node Setting Up the Buffer, Basic Types, Programming Example, Top |
| 430 | @comment node-name, next, previous, up |
| 431 | @section Setting Up the Buffer |
| 432 | |
| 433 | Widgets are created with @code{widget-create}, which returns a |
| 434 | @dfn{widget} object. This object can be queried and manipulated by |
| 435 | other widget functions, until it is deleted with @code{widget-delete}. |
| 436 | After the widgets have been created, @code{widget-setup} must be called |
| 437 | to enable them. |
| 438 | |
| 439 | @defun widget-create type [ keyword argument ]@dots{} |
| 440 | Create and return a widget of type @var{type}. |
| 441 | The syntax for the @var{type} argument is described in @ref{Basic Types}. |
| 442 | |
| 443 | The keyword arguments can be used to overwrite the keyword arguments |
| 444 | that are part of @var{type}. |
| 445 | @end defun |
| 446 | |
| 447 | @defun widget-delete widget |
| 448 | Delete @var{widget} and remove it from the buffer. |
| 449 | @end defun |
| 450 | |
| 451 | @defun widget-setup |
| 452 | Set up a buffer to support widgets. |
| 453 | |
| 454 | This should be called after creating all the widgets and before allowing |
| 455 | the user to edit them. |
| 456 | @refill |
| 457 | @end defun |
| 458 | |
| 459 | If you want to insert text outside the widgets in the form, the |
| 460 | recommended way to do that is with @code{widget-insert}. |
| 461 | |
| 462 | @defun widget-insert |
| 463 | Insert the arguments, either strings or characters, at point. |
| 464 | The inserted text will be read-only. |
| 465 | @end defun |
| 466 | |
| 467 | There is a standard widget keymap which you might find useful. |
| 468 | |
| 469 | @findex widget-button-press |
| 470 | @findex widget-button-click |
| 471 | @defvr Const widget-keymap |
| 472 | A keymap with the global keymap as its parent.@* |
| 473 | @key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and |
| 474 | @code{widget-backward}, respectively. @key{RET} and @kbd{Mouse-2} |
| 475 | are bound to @code{widget-button-press} and |
| 476 | @code{widget-button-click}.@refill |
| 477 | @end defvr |
| 478 | |
| 479 | @defvar widget-global-map |
| 480 | Keymap used by @code{widget-button-press} and @code{widget-button-click} |
| 481 | when not on a button. By default this is @code{global-map}. |
| 482 | @end defvar |
| 483 | |
| 484 | @node Basic Types, Sexp Types, Setting Up the Buffer, Top |
| 485 | @comment node-name, next, previous, up |
| 486 | @section Basic Types |
| 487 | |
| 488 | This is the general syntax of a type specification: |
| 489 | |
| 490 | @example |
| 491 | @var{name} ::= (@var{name} [@var{keyword} @var{argument}]... @var{args}) |
| 492 | | @var{name} |
| 493 | @end example |
| 494 | |
| 495 | Where, @var{name} is a widget name, @var{keyword} is the name of a |
| 496 | property, @var{argument} is the value of the property, and @var{args} |
| 497 | are interpreted in a widget specific way. |
| 498 | |
| 499 | @cindex keyword arguments |
| 500 | The following keyword arguments apply to all widgets: |
| 501 | |
| 502 | @table @code |
| 503 | @vindex value@r{ keyword} |
| 504 | @item :value |
| 505 | The initial value for widgets of this type. |
| 506 | |
| 507 | @vindex format@r{ keyword} |
| 508 | @item :format |
| 509 | This string will be inserted in the buffer when you create a widget. |
| 510 | The following @samp{%} escapes are available: |
| 511 | |
| 512 | @table @samp |
| 513 | @item %[ |
| 514 | @itemx %] |
| 515 | The text inside will be marked as a button. |
| 516 | |
| 517 | By default, the text will be shown in @code{widget-button-face}, and |
| 518 | surrounded by brackets. |
| 519 | |
| 520 | @defopt widget-button-prefix |
| 521 | String to prefix buttons. |
| 522 | @end defopt |
| 523 | |
| 524 | @defopt widget-button-suffix |
| 525 | String to suffix buttons. |
| 526 | @end defopt |
| 527 | |
| 528 | @item %@{ |
| 529 | @itemx %@} |
| 530 | The text inside will be displayed with the face specified by |
| 531 | @code{:sample-face}. |
| 532 | |
| 533 | @item %v |
| 534 | This will be replaced with the buffer representation of the widget's |
| 535 | value. What this is depends on the widget type. |
| 536 | |
| 537 | @strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape |
| 538 | must be preceded by some other text in the format string (if specified). |
| 539 | |
| 540 | @item %d |
| 541 | Insert the string specified by @code{:doc} here. |
| 542 | |
| 543 | @item %h |
| 544 | Like @samp{%d}, with the following modifications: If the documentation |
| 545 | string is more than one line, it will add a button which will toggle |
| 546 | between showing only the first line, and showing the full text. |
| 547 | Furthermore, if there is no @code{:doc} property in the widget, it will |
| 548 | instead examine the @code{:documentation-property} property. If it is a |
| 549 | lambda expression, it will be called with the widget's value as an |
| 550 | argument, and the result will be used as the documentation text. |
| 551 | |
| 552 | @item %t |
| 553 | Insert the string specified by @code{:tag} here, or the @code{princ} |
| 554 | representation of the value if there is no tag. |
| 555 | |
| 556 | @item %% |
| 557 | Insert a literal @samp{%}. |
| 558 | @end table |
| 559 | |
| 560 | @vindex button-face@r{ keyword} |
| 561 | @item :button-face |
| 562 | Face used to highlight text inside %[ %] in the format. |
| 563 | |
| 564 | @vindex button-prefix@r{ keyword} |
| 565 | @vindex button-suffix@r{ keyword} |
| 566 | @item :button-prefix |
| 567 | @itemx :button-suffix |
| 568 | Text around %[ %] in the format. |
| 569 | |
| 570 | These can be |
| 571 | @table @emph |
| 572 | @item nil |
| 573 | No text is inserted. |
| 574 | |
| 575 | @item a string |
| 576 | The string is inserted literally. |
| 577 | |
| 578 | @item a symbol |
| 579 | The value of the symbol is expanded according to this table. |
| 580 | @end table |
| 581 | |
| 582 | @vindex doc@r{ keyword} |
| 583 | @item :doc |
| 584 | The string inserted by the @samp{%d} escape in the format |
| 585 | string. |
| 586 | |
| 587 | @vindex tag@r{ keyword} |
| 588 | @item :tag |
| 589 | The string inserted by the @samp{%t} escape in the format |
| 590 | string. |
| 591 | |
| 592 | @vindex tag-glyph@r{ keyword} |
| 593 | @item :tag-glyph |
| 594 | Name of image to use instead of the string specified by @code{:tag} on |
| 595 | Emacsen that supports it. |
| 596 | |
| 597 | @vindex help-echo@r{ keyword} |
| 598 | @item :help-echo |
| 599 | Specifies how to display a message whenever you move to the widget with |
| 600 | either @code{widget-forward} or @code{widget-backward} or move the mouse |
| 601 | over it (using the standard @code{help-echo} mechanism). The argument |
| 602 | is either a string to display, a function of one argument, the widget, |
| 603 | which should return a string to display, or a form that evaluates to |
| 604 | such a string. |
| 605 | |
| 606 | @vindex follow-link@r{ keyword} |
| 607 | @item :follow-link |
| 608 | Specifies how to interpret a @key{mouse-1} click on the widget. |
| 609 | @xref{Links and Mouse-1,,, elisp, the Emacs Lisp Reference Manual}. |
| 610 | |
| 611 | @vindex indent@r{ keyword} |
| 612 | @item :indent |
| 613 | An integer indicating the absolute number of spaces to indent children |
| 614 | of this widget. |
| 615 | |
| 616 | @vindex offset@r{ keyword} |
| 617 | @item :offset |
| 618 | An integer indicating how many extra spaces to add to the widget's |
| 619 | grandchildren compared to this widget. |
| 620 | |
| 621 | @vindex extra-offset@r{ keyword} |
| 622 | @item :extra-offset |
| 623 | An integer indicating how many extra spaces to add to the widget's |
| 624 | children compared to this widget. |
| 625 | |
| 626 | @vindex notify@r{ keyword} |
| 627 | @item :notify |
| 628 | A function called each time the widget or a nested widget is changed. |
| 629 | The function is called with two or three arguments. The first argument |
| 630 | is the widget itself, the second argument is the widget that was |
| 631 | changed, and the third argument is the event leading to the change, if |
| 632 | any. |
| 633 | |
| 634 | @vindex menu-tag@r{ keyword} |
| 635 | @item :menu-tag |
| 636 | Tag used in the menu when the widget is used as an option in a |
| 637 | @code{menu-choice} widget. |
| 638 | |
| 639 | @vindex menu-tag-get@r{ keyword} |
| 640 | @item :menu-tag-get |
| 641 | Function used for finding the tag when the widget is used as an option |
| 642 | in a @code{menu-choice} widget. By default, the tag used will be either the |
| 643 | @code{:menu-tag} or @code{:tag} property if present, or the @code{princ} |
| 644 | representation of the @code{:value} property if not. |
| 645 | |
| 646 | @vindex match@r{ keyword} |
| 647 | @item :match |
| 648 | Should be a function called with two arguments, the widget and a value, |
| 649 | and returning non-@code{nil} if the widget can represent the specified value. |
| 650 | |
| 651 | @vindex validate@r{ keyword} |
| 652 | @item :validate |
| 653 | A function which takes a widget as an argument, and returns @code{nil} |
| 654 | if the widget's current value is valid for the widget. Otherwise it |
| 655 | should return the widget containing the invalid data, and set that |
| 656 | widget's @code{:error} property to a string explaining the error. |
| 657 | |
| 658 | The following predefined function can be used: |
| 659 | |
| 660 | @defun widget-children-validate widget |
| 661 | All the @code{:children} of @var{widget} must be valid. |
| 662 | @end defun |
| 663 | |
| 664 | @vindex tab-order@r{ keyword} |
| 665 | @item :tab-order |
| 666 | Specify the order in which widgets are traversed with |
| 667 | @code{widget-forward} or @code{widget-backward}. This is only partially |
| 668 | implemented. |
| 669 | |
| 670 | @enumerate a |
| 671 | @item |
| 672 | Widgets with tabbing order @code{-1} are ignored. |
| 673 | |
| 674 | @item |
| 675 | (Unimplemented) When on a widget with tabbing order @var{n}, go to the |
| 676 | next widget in the buffer with tabbing order @var{n+1} or @code{nil}, |
| 677 | whichever comes first. |
| 678 | |
| 679 | @item |
| 680 | When on a widget with no tabbing order specified, go to the next widget |
| 681 | in the buffer with a positive tabbing order, or @code{nil} |
| 682 | @end enumerate |
| 683 | |
| 684 | @vindex parent@r{ keyword} |
| 685 | @item :parent |
| 686 | The parent of a nested widget (e.g.@: a @code{menu-choice} item or an |
| 687 | element of a @code{editable-list} widget). |
| 688 | |
| 689 | @vindex sibling-args@r{ keyword} |
| 690 | @item :sibling-args |
| 691 | This keyword is only used for members of a @code{radio-button-choice} or |
| 692 | @code{checklist}. The value should be a list of extra keyword |
| 693 | arguments, which will be used when creating the @code{radio-button} or |
| 694 | @code{checkbox} associated with this item. |
| 695 | |
| 696 | @end table |
| 697 | |
| 698 | @deffn {User Option} widget-glyph-directory |
| 699 | Directory where glyphs are found. |
| 700 | Widget will look here for a file with the same name as specified for the |
| 701 | image, with either a @file{.xpm} (if supported) or @file{.xbm} extension. |
| 702 | @end deffn |
| 703 | |
| 704 | @deffn{User Option} widget-glyph-enable |
| 705 | If non-@code{nil}, allow glyphs to appear on displays where they are supported. |
| 706 | @end deffn |
| 707 | |
| 708 | |
| 709 | @menu |
| 710 | * link:: |
| 711 | * url-link:: |
| 712 | * info-link:: |
| 713 | * push-button:: |
| 714 | * editable-field:: |
| 715 | * text:: |
| 716 | * menu-choice:: |
| 717 | * radio-button-choice:: |
| 718 | * item:: |
| 719 | * choice-item:: |
| 720 | * toggle:: |
| 721 | * checkbox:: |
| 722 | * checklist:: |
| 723 | * editable-list:: |
| 724 | * group:: |
| 725 | @end menu |
| 726 | |
| 727 | @node link, url-link, Basic Types, Basic Types |
| 728 | @comment node-name, next, previous, up |
| 729 | @subsection The @code{link} Widget |
| 730 | @findex link@r{ widget} |
| 731 | |
| 732 | Syntax: |
| 733 | |
| 734 | @example |
| 735 | @var{type} ::= (link [@var{keyword} @var{argument}]... [ @var{value} ]) |
| 736 | @end example |
| 737 | |
| 738 | The @var{value}, if present, is used to initialize the @code{:value} |
| 739 | property. The value should be a string, which will be inserted in the |
| 740 | buffer. |
| 741 | |
| 742 | By default the link will be shown in brackets. |
| 743 | |
| 744 | @defopt widget-link-prefix |
| 745 | String to prefix links. |
| 746 | @end defopt |
| 747 | |
| 748 | @defopt widget-link-suffix |
| 749 | String to suffix links. |
| 750 | @end defopt |
| 751 | |
| 752 | @node url-link, info-link, link, Basic Types |
| 753 | @comment node-name, next, previous, up |
| 754 | @subsection The @code{url-link} Widget |
| 755 | @findex url-link@r{ widget} |
| 756 | |
| 757 | Syntax: |
| 758 | |
| 759 | @example |
| 760 | @var{type} ::= (url-link [@var{keyword} @var{argument}]... @var{url}) |
| 761 | @end example |
| 762 | |
| 763 | @findex browse-url-browser-function@r{, and @code{url-link} widget} |
| 764 | When this link is invoked, the @acronym{WWW} browser specified by |
| 765 | @code{browse-url-browser-function} will be called with @var{url}. |
| 766 | |
| 767 | @node info-link, push-button, url-link, Basic Types |
| 768 | @comment node-name, next, previous, up |
| 769 | @subsection The @code{info-link} Widget |
| 770 | @findex info-link@r{ widget} |
| 771 | |
| 772 | Syntax: |
| 773 | |
| 774 | @example |
| 775 | @var{type} ::= (info-link [@var{keyword} @var{argument}]... @var{address}) |
| 776 | @end example |
| 777 | |
| 778 | When this link is invoked, the built-in Info reader is started on |
| 779 | @var{address}. |
| 780 | |
| 781 | @node push-button, editable-field, info-link, Basic Types |
| 782 | @comment node-name, next, previous, up |
| 783 | @subsection The @code{push-button} Widget |
| 784 | @findex push-button@r{ widget} |
| 785 | |
| 786 | Syntax: |
| 787 | |
| 788 | @example |
| 789 | @var{type} ::= (push-button [@var{keyword} @var{argument}]... [ @var{value} ]) |
| 790 | @end example |
| 791 | |
| 792 | The @var{value}, if present, is used to initialize the @code{:value} |
| 793 | property. The value should be a string, which will be inserted in the |
| 794 | buffer. |
| 795 | |
| 796 | By default the tag will be shown in brackets. |
| 797 | |
| 798 | @defopt widget-push-button-prefix |
| 799 | String to prefix push buttons. |
| 800 | @end defopt |
| 801 | |
| 802 | @defopt widget-push-button-suffix |
| 803 | String to suffix push buttons. |
| 804 | @end defopt |
| 805 | |
| 806 | @node editable-field, text, push-button, Basic Types |
| 807 | @comment node-name, next, previous, up |
| 808 | @subsection The @code{editable-field} Widget |
| 809 | @findex editable-field@r{ widget} |
| 810 | |
| 811 | Syntax: |
| 812 | |
| 813 | @example |
| 814 | @var{type} ::= (editable-field [@var{keyword} @var{argument}]... [ @var{value} ]) |
| 815 | @end example |
| 816 | |
| 817 | The @var{value}, if present, is used to initialize the @code{:value} |
| 818 | property. The value should be a string, which will be inserted in the |
| 819 | field. This widget will match all string values. |
| 820 | |
| 821 | The following extra properties are recognized: |
| 822 | |
| 823 | @table @code |
| 824 | @vindex size@r{ keyword} |
| 825 | @item :size |
| 826 | The width of the editable field.@* |
| 827 | By default the field will reach to the end of the line. |
| 828 | |
| 829 | @vindex value-face@r{ keyword} |
| 830 | @item :value-face |
| 831 | Face used for highlighting the editable field. Default is |
| 832 | @code{widget-field-face}, see @ref{User Interface}. |
| 833 | |
| 834 | @vindex secret@r{ keyword} |
| 835 | @item :secret |
| 836 | Character used to display the value. You can set this to e.g.@: @code{?*} |
| 837 | if the field contains a password or other secret information. By |
| 838 | default, this is @code{nil}, and the value is not secret. |
| 839 | |
| 840 | @vindex valid-regexp@r{ keyword} |
| 841 | @item :valid-regexp |
| 842 | By default the @code{:validate} function will match the content of the |
| 843 | field with the value of this attribute. The default value is @code{""} |
| 844 | which matches everything. |
| 845 | |
| 846 | @vindex keymap@r{ keyword} |
| 847 | @vindex widget-field-keymap |
| 848 | @item :keymap |
| 849 | Keymap used in the editable field. The default value is |
| 850 | @code{widget-field-keymap}, which allows you to use all the normal |
| 851 | editing commands, even if the buffer's major mode suppresses some of |
| 852 | them. Pressing @key{RET} invokes the function specified by |
| 853 | @code{:action}. |
| 854 | @end table |
| 855 | |
| 856 | @node text, menu-choice, editable-field, Basic Types |
| 857 | @comment node-name, next, previous, up |
| 858 | @subsection The @code{text} Widget |
| 859 | @findex text@r{ widget} |
| 860 | |
| 861 | @vindex widget-text-keymap |
| 862 | This is just like @code{editable-field}, but intended for multiline text |
| 863 | fields. The default @code{:keymap} is @code{widget-text-keymap}, which |
| 864 | does not rebind the @key{RET} key. |
| 865 | |
| 866 | @node menu-choice, radio-button-choice, text, Basic Types |
| 867 | @comment node-name, next, previous, up |
| 868 | @subsection The @code{menu-choice} Widget |
| 869 | @findex menu-choice@r{ widget} |
| 870 | |
| 871 | Syntax: |
| 872 | |
| 873 | @example |
| 874 | @var{type} ::= (menu-choice [@var{keyword} @var{argument}]... @var{type} ... ) |
| 875 | @end example |
| 876 | |
| 877 | The @var{type} argument represents each possible choice. The widget's |
| 878 | value will be that of the chosen @var{type} argument. This widget will |
| 879 | match any value matching at least one of the specified @var{type} |
| 880 | arguments. |
| 881 | |
| 882 | @table @code |
| 883 | @vindex void@r{ keyword} |
| 884 | @item :void |
| 885 | Widget type used as a fallback when the value does not match any of the |
| 886 | specified @var{type} arguments. |
| 887 | |
| 888 | @vindex case-fold@r{ keyword} |
| 889 | @item :case-fold |
| 890 | Set this to @code{nil} if you don't want to ignore case when prompting for a |
| 891 | choice through the minibuffer. |
| 892 | |
| 893 | @vindex children@r{ keyword} |
| 894 | @item :children |
| 895 | A list whose @sc{car} is the widget representing the currently chosen |
| 896 | type in the buffer. |
| 897 | |
| 898 | @vindex choice@r{ keyword} |
| 899 | @item :choice |
| 900 | The current chosen type. |
| 901 | |
| 902 | @vindex args@r{ keyword} |
| 903 | @item :args |
| 904 | The list of types. |
| 905 | @end table |
| 906 | |
| 907 | @node radio-button-choice, item, menu-choice, Basic Types |
| 908 | @comment node-name, next, previous, up |
| 909 | @subsection The @code{radio-button-choice} Widget |
| 910 | @findex radio-button-choice@r{ widget} |
| 911 | |
| 912 | Syntax: |
| 913 | |
| 914 | @example |
| 915 | @var{type} ::= (radio-button-choice [@var{keyword} @var{argument}]... @var{type} ... ) |
| 916 | @end example |
| 917 | |
| 918 | The component types specify the choices, with one radio button for |
| 919 | each. The widget's value will be that of the chosen @var{type} |
| 920 | argument. This widget matches any value that matches at least one of |
| 921 | the specified @var{type} arguments. |
| 922 | |
| 923 | The following extra properties are recognized. |
| 924 | |
| 925 | @table @code |
| 926 | @vindex entry-format@r{ keyword} |
| 927 | @item :entry-format |
| 928 | This string will be inserted for each entry in the list. |
| 929 | The following @samp{%} escapes are available: |
| 930 | @table @samp |
| 931 | @item %v |
| 932 | Replace with the buffer representation of the @var{type} widget. |
| 933 | @item %b |
| 934 | Replace with the radio button. |
| 935 | @item %% |
| 936 | Insert a literal @samp{%}. |
| 937 | @end table |
| 938 | |
| 939 | @vindex button-args@r{ keyword} |
| 940 | @item :button-args |
| 941 | A list of keywords to pass to the radio buttons. Useful for setting |
| 942 | e.g.@: the @samp{:help-echo} for each button. |
| 943 | |
| 944 | @vindex buttons@r{ keyword} |
| 945 | @item :buttons |
| 946 | The widgets representing the radio buttons. |
| 947 | |
| 948 | @vindex children@r{ keyword} |
| 949 | @item :children |
| 950 | The widgets representing each type. |
| 951 | |
| 952 | @vindex choice@r{ keyword} |
| 953 | @item :choice |
| 954 | The current chosen type |
| 955 | |
| 956 | @vindex args@r{ keyword} |
| 957 | @item :args |
| 958 | The list of types. |
| 959 | @end table |
| 960 | |
| 961 | You can add extra radio button items to a @code{radio-button-choice} |
| 962 | widget after it has been created with the function |
| 963 | @code{widget-radio-add-item}. |
| 964 | |
| 965 | @defun widget-radio-add-item widget type |
| 966 | Add to @code{radio-button-choice} widget @var{widget} a new radio button |
| 967 | item of type @var{type}. |
| 968 | @end defun |
| 969 | |
| 970 | Please note that such items added after the @code{radio-button-choice} |
| 971 | widget has been created will @strong{not} be properly destructed when |
| 972 | you call @code{widget-delete}. |
| 973 | |
| 974 | @node item, choice-item, radio-button-choice, Basic Types |
| 975 | @comment node-name, next, previous, up |
| 976 | @subsection The @code{item} Widget |
| 977 | @findex item@r{ widget} |
| 978 | |
| 979 | Syntax: |
| 980 | |
| 981 | @example |
| 982 | @var{item} ::= (item [@var{keyword} @var{argument}]... @var{value}) |
| 983 | @end example |
| 984 | |
| 985 | The @var{value}, if present, is used to initialize the @code{:value} |
| 986 | property. The value should be a string, which will be inserted in the |
| 987 | buffer. This widget will only match the specified value. |
| 988 | |
| 989 | @node choice-item, toggle, item, Basic Types |
| 990 | @comment node-name, next, previous, up |
| 991 | @subsection The @code{choice-item} Widget |
| 992 | @findex choice-item@r{ widget} |
| 993 | |
| 994 | Syntax: |
| 995 | |
| 996 | @example |
| 997 | @var{item} ::= (choice-item [@var{keyword} @var{argument}]... @var{value}) |
| 998 | @end example |
| 999 | |
| 1000 | The @var{value}, if present, is used to initialize the @code{:value} |
| 1001 | property. The value should be a string, which will be inserted in the |
| 1002 | buffer as a button. Activating the button of a @code{choice-item} is |
| 1003 | equivalent to activating the parent widget. This widget will only match |
| 1004 | the specified value. |
| 1005 | |
| 1006 | @node toggle, checkbox, choice-item, Basic Types |
| 1007 | @comment node-name, next, previous, up |
| 1008 | @subsection The @code{toggle} Widget |
| 1009 | @findex toggle@r{ widget} |
| 1010 | |
| 1011 | Syntax: |
| 1012 | |
| 1013 | @example |
| 1014 | @var{type} ::= (toggle [@var{keyword} @var{argument}]...) |
| 1015 | @end example |
| 1016 | |
| 1017 | The widget has two possible states, @samp{on} and @samp{off}, which |
| 1018 | correspond to a @code{t} or @code{nil} value, respectively. |
| 1019 | |
| 1020 | The following extra properties are recognized: |
| 1021 | |
| 1022 | @table @code |
| 1023 | @item :on |
| 1024 | A string representing the @samp{on} state. By default the string |
| 1025 | @samp{on}. |
| 1026 | @item :off |
| 1027 | A string representing the @samp{off} state. By default the string |
| 1028 | @samp{off}. |
| 1029 | @vindex on-glyph@r{ keyword} |
| 1030 | @item :on-glyph |
| 1031 | Name of a glyph to be used instead of the @samp{:on} text string, on |
| 1032 | emacsen that supports this. |
| 1033 | @vindex off-glyph@r{ keyword} |
| 1034 | @item :off-glyph |
| 1035 | Name of a glyph to be used instead of the @samp{:off} text string, on |
| 1036 | emacsen that supports this. |
| 1037 | @end table |
| 1038 | |
| 1039 | @node checkbox, checklist, toggle, Basic Types |
| 1040 | @comment node-name, next, previous, up |
| 1041 | @subsection The @code{checkbox} Widget |
| 1042 | @findex checkbox@r{ widget} |
| 1043 | |
| 1044 | This widget has two possible states, @samp{selected} and |
| 1045 | @samp{unselected}, which corresponds to a @code{t} or @code{nil} value. |
| 1046 | |
| 1047 | Syntax: |
| 1048 | |
| 1049 | @example |
| 1050 | @var{type} ::= (checkbox [@var{keyword} @var{argument}]...) |
| 1051 | @end example |
| 1052 | |
| 1053 | @node checklist, editable-list, checkbox, Basic Types |
| 1054 | @comment node-name, next, previous, up |
| 1055 | @subsection The @code{checklist} Widget |
| 1056 | @findex checklist@r{ widget} |
| 1057 | |
| 1058 | Syntax: |
| 1059 | |
| 1060 | @example |
| 1061 | @var{type} ::= (checklist [@var{keyword} @var{argument}]... @var{type} ... ) |
| 1062 | @end example |
| 1063 | |
| 1064 | The @var{type} arguments represent each checklist item. The widget's |
| 1065 | value will be a list containing the values of all checked @var{type} |
| 1066 | arguments. The checklist widget will match a list whose elements all |
| 1067 | match at least one of the specified @var{type} arguments. |
| 1068 | |
| 1069 | The following extra properties are recognized: |
| 1070 | |
| 1071 | @table @code |
| 1072 | @vindex entry-format@r{ keyword} |
| 1073 | @item :entry-format |
| 1074 | This string will be inserted for each entry in the list. |
| 1075 | The following @samp{%} escapes are available: |
| 1076 | @table @samp |
| 1077 | @item %v |
| 1078 | Replaced with the buffer representation of the @var{type} widget. |
| 1079 | @item %b |
| 1080 | Replace with the checkbox. |
| 1081 | @item %% |
| 1082 | Insert a literal @samp{%}. |
| 1083 | @end table |
| 1084 | |
| 1085 | @vindex greedy@r{ keyword} |
| 1086 | @item :greedy |
| 1087 | Usually a checklist will only match if the items are in the exact |
| 1088 | sequence given in the specification. By setting @code{:greedy} to |
| 1089 | non-@code{nil}, it will allow the items to come in any sequence. |
| 1090 | However, if you extract the value they will be in the sequence given |
| 1091 | in the checklist, i.e.@: the original sequence is forgotten. |
| 1092 | |
| 1093 | @vindex button-args@r{ keyword} |
| 1094 | @item :button-args |
| 1095 | A list of keywords to pass to the checkboxes. Useful for setting |
| 1096 | e.g.@: the @samp{:help-echo} for each checkbox. |
| 1097 | |
| 1098 | @vindex buttons@r{ keyword} |
| 1099 | @item :buttons |
| 1100 | The widgets representing the checkboxes. |
| 1101 | |
| 1102 | @vindex children@r{ keyword} |
| 1103 | @item :children |
| 1104 | The widgets representing each type. |
| 1105 | |
| 1106 | @vindex args@r{ keyword} |
| 1107 | @item :args |
| 1108 | The list of types. |
| 1109 | @end table |
| 1110 | |
| 1111 | @node editable-list, group, checklist, Basic Types |
| 1112 | @comment node-name, next, previous, up |
| 1113 | @subsection The @code{editable-list} Widget |
| 1114 | @findex editable-list@r{ widget} |
| 1115 | |
| 1116 | Syntax: |
| 1117 | |
| 1118 | @example |
| 1119 | @var{type} ::= (editable-list [@var{keyword} @var{argument}]... @var{type}) |
| 1120 | @end example |
| 1121 | |
| 1122 | The value is a list, where each member represents one widget of type |
| 1123 | @var{type}. |
| 1124 | |
| 1125 | The following extra properties are recognized: |
| 1126 | |
| 1127 | @table @code |
| 1128 | @vindex entry-format@r{ keyword} |
| 1129 | @item :entry-format |
| 1130 | This string will be inserted for each entry in the list. |
| 1131 | The following @samp{%} escapes are available: |
| 1132 | @table @samp |
| 1133 | @item %v |
| 1134 | This will be replaced with the buffer representation of the @var{type} |
| 1135 | widget. |
| 1136 | @item %i |
| 1137 | Insert the @b{[INS]} button. |
| 1138 | @item %d |
| 1139 | Insert the @b{[DEL]} button. |
| 1140 | @item %% |
| 1141 | Insert a literal @samp{%}. |
| 1142 | @end table |
| 1143 | |
| 1144 | @vindex insert-button-args@r{ keyword} |
| 1145 | @item :insert-button-args |
| 1146 | A list of keyword arguments to pass to the insert buttons. |
| 1147 | |
| 1148 | @vindex delete-button-args@r{ keyword} |
| 1149 | @item :delete-button-args |
| 1150 | A list of keyword arguments to pass to the delete buttons. |
| 1151 | |
| 1152 | @vindex append-button-args@r{ keyword} |
| 1153 | @item :append-button-args |
| 1154 | A list of keyword arguments to pass to the trailing insert button. |
| 1155 | |
| 1156 | @vindex buttons@r{ keyword} |
| 1157 | @item :buttons |
| 1158 | The widgets representing the insert and delete buttons. |
| 1159 | |
| 1160 | @vindex children@r{ keyword} |
| 1161 | @item :children |
| 1162 | The widgets representing the elements of the list. |
| 1163 | |
| 1164 | @vindex args@r{ keyword} |
| 1165 | @item :args |
| 1166 | List whose @sc{car} is the type of the list elements. |
| 1167 | @end table |
| 1168 | |
| 1169 | @node group, , editable-list, Basic Types |
| 1170 | @comment node-name, next, previous, up |
| 1171 | @subsection The @code{group} Widget |
| 1172 | @findex group@r{ widget} |
| 1173 | |
| 1174 | This widget simply group other widgets together. |
| 1175 | |
| 1176 | Syntax: |
| 1177 | |
| 1178 | @example |
| 1179 | @var{type} ::= (group [@var{keyword} @var{argument}]... @var{type}...) |
| 1180 | @end example |
| 1181 | |
| 1182 | The value is a list, with one member for each @var{type}. |
| 1183 | |
| 1184 | @node Sexp Types, Widget Properties, Basic Types, Top |
| 1185 | @comment |
| 1186 | @section Sexp Types |
| 1187 | @cindex sexp types |
| 1188 | |
| 1189 | A number of widgets for editing @dfn{s-expressions} (Lisp types), sexp |
| 1190 | for short, are also available. These basically fall in several |
| 1191 | categories described in this section. |
| 1192 | |
| 1193 | @menu |
| 1194 | * constants:: |
| 1195 | * generic:: |
| 1196 | * atoms:: |
| 1197 | * composite:: |
| 1198 | @end menu |
| 1199 | |
| 1200 | @node constants, generic, Sexp Types, Sexp Types |
| 1201 | @comment node-name, next, previous, up |
| 1202 | @subsection The Constant Widgets |
| 1203 | @cindex constant widgets |
| 1204 | |
| 1205 | The @code{const} widget can contain any Lisp expression, but the user is |
| 1206 | prohibited from editing it, which is mainly useful as a component of one |
| 1207 | of the composite widgets. |
| 1208 | |
| 1209 | The syntax for the @code{const} widget is: |
| 1210 | |
| 1211 | @example |
| 1212 | @var{type} ::= (const [@var{keyword} @var{argument}]... [ @var{value} ]) |
| 1213 | @end example |
| 1214 | |
| 1215 | The @var{value}, if present, is used to initialize the @code{:value} |
| 1216 | property and can be any s-expression. |
| 1217 | |
| 1218 | @deffn Widget const |
| 1219 | This will display any valid s-expression in an immutable part of the |
| 1220 | buffer. |
| 1221 | @end deffn |
| 1222 | |
| 1223 | There are two variations of the @code{const} widget, namely |
| 1224 | @code{variable-item} and @code{function-item}. These should contain a |
| 1225 | symbol with a variable or function binding. The major difference from |
| 1226 | the @code{const} widget is that they will allow the user to see the |
| 1227 | variable or function documentation for the symbol. |
| 1228 | |
| 1229 | @deffn Widget variable-item |
| 1230 | An immutable symbol that is bound as a variable. |
| 1231 | @end deffn |
| 1232 | |
| 1233 | @deffn Widget function-item |
| 1234 | An immutable symbol that is bound as a function. |
| 1235 | @end deffn |
| 1236 | |
| 1237 | @node generic, atoms, constants, Sexp Types |
| 1238 | @comment node-name, next, previous, up |
| 1239 | @subsection Generic Sexp Widget |
| 1240 | @cindex generic sexp widget |
| 1241 | |
| 1242 | The @code{sexp} widget can contain any Lisp expression, and allows the |
| 1243 | user to edit it inline in the buffer. |
| 1244 | |
| 1245 | The syntax for the @code{sexp} widget is: |
| 1246 | |
| 1247 | @example |
| 1248 | @var{type} ::= (sexp [@var{keyword} @var{argument}]... [ @var{value} ]) |
| 1249 | @end example |
| 1250 | |
| 1251 | @deffn Widget sexp |
| 1252 | This will allow you to edit any valid s-expression in an editable buffer |
| 1253 | field. |
| 1254 | |
| 1255 | The @code{sexp} widget takes the same keyword arguments as the |
| 1256 | @code{editable-field} widget. @xref{editable-field}. |
| 1257 | @end deffn |
| 1258 | |
| 1259 | @node atoms, composite, generic, Sexp Types |
| 1260 | @comment node-name, next, previous, up |
| 1261 | @subsection Atomic Sexp Widgets |
| 1262 | @cindex atomic sexp widget |
| 1263 | |
| 1264 | The atoms are s-expressions that do not consist of other s-expressions. |
| 1265 | For example, a string, a file name, or a symbol are atoms, while a list |
| 1266 | is a composite type. You can edit the value of an atom with the |
| 1267 | following widgets. |
| 1268 | |
| 1269 | The syntax for all the atoms are: |
| 1270 | |
| 1271 | @example |
| 1272 | @var{type} ::= (@var{construct} [@var{keyword} @var{argument}]... [ @var{value} ]) |
| 1273 | @end example |
| 1274 | |
| 1275 | The @var{value}, if present, is used to initialize the @code{:value} |
| 1276 | property and must be an expression of the same type as the widget. |
| 1277 | That is, the string widget can only be initialized with a string. |
| 1278 | |
| 1279 | All the atom widgets take the same keyword arguments as the |
| 1280 | @code{editable-field} widget. @xref{editable-field}. |
| 1281 | |
| 1282 | @deffn Widget string |
| 1283 | Allows you to edit a string in an editable field. |
| 1284 | @end deffn |
| 1285 | |
| 1286 | @deffn Widget regexp |
| 1287 | Allows you to edit a regular expression in an editable field. |
| 1288 | @end deffn |
| 1289 | |
| 1290 | @deffn Widget character |
| 1291 | Allows you to enter a character in an editable field. |
| 1292 | @end deffn |
| 1293 | |
| 1294 | @deffn Widget file |
| 1295 | Allows you to edit a file name in an editable field. |
| 1296 | |
| 1297 | Keywords: |
| 1298 | @table @code |
| 1299 | @vindex must-match@r{ keyword} |
| 1300 | @item :must-match |
| 1301 | If this is set to non-@code{nil}, only existing file names will be |
| 1302 | allowed in the minibuffer. |
| 1303 | @end table |
| 1304 | @end deffn |
| 1305 | |
| 1306 | @deffn Widget directory |
| 1307 | Allows you to edit a directory name in an editable field. |
| 1308 | Similar to the @code{file} widget. |
| 1309 | @end deffn |
| 1310 | |
| 1311 | @deffn Widget symbol |
| 1312 | Allows you to edit a Lisp symbol in an editable field. |
| 1313 | @end deffn |
| 1314 | |
| 1315 | @deffn Widget function |
| 1316 | Allows you to edit a lambda expression, or a function name with completion. |
| 1317 | @end deffn |
| 1318 | |
| 1319 | @deffn Widget variable |
| 1320 | Allows you to edit a variable name, with completion. |
| 1321 | @end deffn |
| 1322 | |
| 1323 | @deffn Widget integer |
| 1324 | Allows you to edit an integer in an editable field. |
| 1325 | @end deffn |
| 1326 | |
| 1327 | @deffn Widget number |
| 1328 | Allows you to edit a number in an editable field. |
| 1329 | @end deffn |
| 1330 | |
| 1331 | @deffn Widget boolean |
| 1332 | Allows you to edit a boolean. In Lisp this means a variable which is |
| 1333 | either @code{nil} meaning false, or non-@code{nil} meaning true. |
| 1334 | @end deffn |
| 1335 | |
| 1336 | |
| 1337 | @node composite, , atoms, Sexp Types |
| 1338 | @comment node-name, next, previous, up |
| 1339 | @subsection Composite Sexp Widgets |
| 1340 | @cindex composite sexp widgets |
| 1341 | |
| 1342 | The syntax for the composite widget construct is: |
| 1343 | |
| 1344 | @example |
| 1345 | @var{type} ::= (@var{construct} [@var{keyword} @var{argument}]... @var{component}...) |
| 1346 | @end example |
| 1347 | |
| 1348 | @noindent |
| 1349 | where each @var{component} must be a widget type. Each component widget |
| 1350 | will be displayed in the buffer, and will be editable by the user. |
| 1351 | |
| 1352 | @deffn Widget cons |
| 1353 | The value of a @code{cons} widget must be a cons-cell whose @sc{car} |
| 1354 | and @sc{cdr} have two specified types. It uses this syntax: |
| 1355 | |
| 1356 | @example |
| 1357 | @var{type} ::= (cons [@var{keyword} @var{argument}]... @var{car-type} @var{cdr-type}) |
| 1358 | @end example |
| 1359 | @end deffn |
| 1360 | |
| 1361 | @deffn Widget choice |
| 1362 | The value matched by a @code{choice} widget must have one of a fixed |
| 1363 | set of types. The widget's syntax is as follows: |
| 1364 | |
| 1365 | @example |
| 1366 | @var{type} ::= (choice [@var{keyword} @var{argument}]... @var{type} ... ) |
| 1367 | @end example |
| 1368 | |
| 1369 | The value of a @code{choice} widget can be anything that matches any of the |
| 1370 | @var{types}. |
| 1371 | @end deffn |
| 1372 | |
| 1373 | @deffn Widget list |
| 1374 | The value of a @code{list} widget must be a list whose element types |
| 1375 | match the specified component types: |
| 1376 | |
| 1377 | @example |
| 1378 | @var{type} ::= (list [@var{keyword} @var{argument}]... @var{component-type}...) |
| 1379 | @end example |
| 1380 | |
| 1381 | Thus, @code{(list string number)} matches lists of two elements, |
| 1382 | the first being a string and the second being a number. |
| 1383 | @end deffn |
| 1384 | |
| 1385 | @deffn Widget vector |
| 1386 | The @code{vector} widget is like the @code{list} widget but matches |
| 1387 | vectors instead of lists. Thus, @code{(vector string number)} matches |
| 1388 | vectors of two elements, the first being a string and the second being |
| 1389 | a number. |
| 1390 | @end deffn |
| 1391 | |
| 1392 | The above suffice for specifying fixed size lists and vectors. To get |
| 1393 | variable length lists and vectors, you can use a @code{choice}, |
| 1394 | @code{set}, or @code{repeat} widget together with the @code{:inline} |
| 1395 | keyword. If any component of a composite widget has the |
| 1396 | @code{:inline} keyword set, its value must be a list which will then |
| 1397 | be spliced into the composite. For example, to specify a list whose |
| 1398 | first element must be a file name, and whose remaining elements should |
| 1399 | either be the symbol @code{t} or two strings (file names), you can use |
| 1400 | the following widget specification: |
| 1401 | |
| 1402 | @example |
| 1403 | (list file |
| 1404 | (choice (const t) |
| 1405 | (list :inline t |
| 1406 | :value ("foo" "bar") |
| 1407 | string string))) |
| 1408 | @end example |
| 1409 | |
| 1410 | The value of a widget of this type will either have the form |
| 1411 | @code{(file t)} or @code{(file @var{string} @var{string})}. |
| 1412 | |
| 1413 | This concept of @code{:inline} may be hard to understand. It was |
| 1414 | certainly hard to implement, so instead of confusing you more by |
| 1415 | trying to explain it here, I'll just suggest you meditate over it for |
| 1416 | a while. |
| 1417 | |
| 1418 | @deffn Widget set |
| 1419 | Specifies a type whose values are the lists whose elements all belong |
| 1420 | to a given set. The order of elements of the list is not significant. |
| 1421 | Here's the syntax: |
| 1422 | |
| 1423 | @example |
| 1424 | @var{type} ::= (set [@var{keyword} @var{argument}]... @var{permitted-element} ... ) |
| 1425 | @end example |
| 1426 | |
| 1427 | Use @code{const} to specify each permitted element, like this: |
| 1428 | @code{(set (const a) (const b))}. |
| 1429 | @end deffn |
| 1430 | |
| 1431 | @deffn Widget repeat |
| 1432 | Specifies a list of any number of elements that fit a certain type. |
| 1433 | |
| 1434 | @example |
| 1435 | @var{type} ::= (repeat [@var{keyword} @var{argument}]... @var{type}) |
| 1436 | @end example |
| 1437 | @end deffn |
| 1438 | |
| 1439 | @node Widget Properties, Defining New Widgets, Sexp Types, Top |
| 1440 | @comment node-name, next, previous, up |
| 1441 | @section Properties |
| 1442 | @cindex properties of widgets |
| 1443 | @cindex widget properties |
| 1444 | |
| 1445 | You can examine or set the value of a widget by using the widget object |
| 1446 | that was returned by @code{widget-create}. |
| 1447 | |
| 1448 | @defun widget-value widget |
| 1449 | Return the current value contained in @var{widget}. |
| 1450 | It is an error to call this function on an uninitialized widget. |
| 1451 | @end defun |
| 1452 | |
| 1453 | @defun widget-value-set widget value |
| 1454 | Set the value contained in @var{widget} to @var{value}. |
| 1455 | It is an error to call this function with an invalid @var{value}. |
| 1456 | @end defun |
| 1457 | |
| 1458 | @strong{Important:} You @emph{must} call @code{widget-setup} after |
| 1459 | modifying the value of a widget before the user is allowed to edit the |
| 1460 | widget again. It is enough to call @code{widget-setup} once if you |
| 1461 | modify multiple widgets. This is currently only necessary if the widget |
| 1462 | contains an editing field, but may be necessary for other widgets in the |
| 1463 | future. |
| 1464 | |
| 1465 | If your application needs to associate some information with the widget |
| 1466 | objects, for example a reference to the item being edited, it can be |
| 1467 | done with @code{widget-put} and @code{widget-get}. The property names |
| 1468 | must begin with a @samp{:}. |
| 1469 | |
| 1470 | @defun widget-put widget property value |
| 1471 | In @var{widget} set @var{property} to @var{value}. |
| 1472 | @var{property} should be a symbol, while @var{value} can be anything. |
| 1473 | @end defun |
| 1474 | |
| 1475 | @defun widget-get widget property |
| 1476 | In @var{widget} return the value for @var{property}. |
| 1477 | @var{property} should be a symbol, the value is what was last set by |
| 1478 | @code{widget-put} for @var{property}. |
| 1479 | @end defun |
| 1480 | |
| 1481 | @defun widget-member widget property |
| 1482 | Non-@code{nil} if @var{widget} has a value (even @code{nil}) for |
| 1483 | property @var{property}. |
| 1484 | @end defun |
| 1485 | |
| 1486 | Occasionally it can be useful to know which kind of widget you have, |
| 1487 | i.e.@: the name of the widget type you gave when the widget was created. |
| 1488 | |
| 1489 | @defun widget-type widget |
| 1490 | Return the name of @var{widget}, a symbol. |
| 1491 | @end defun |
| 1492 | |
| 1493 | @cindex active widget |
| 1494 | @cindex inactive widget |
| 1495 | @cindex activate a widget |
| 1496 | @cindex deactivate a widget |
| 1497 | Widgets can be in two states: active, which means they are modifiable by |
| 1498 | the user, or inactive, which means they cannot be modified by the user. |
| 1499 | You can query or set the state with the following code: |
| 1500 | |
| 1501 | @lisp |
| 1502 | ;; Examine if @var{widget} is active or not. |
| 1503 | (if (widget-apply @var{widget} :active) |
| 1504 | (message "Widget is active.") |
| 1505 | (message "Widget is inactive.") |
| 1506 | |
| 1507 | ;; Make @var{widget} inactive. |
| 1508 | (widget-apply @var{widget} :deactivate) |
| 1509 | |
| 1510 | ;; Make @var{widget} active. |
| 1511 | (widget-apply @var{widget} :activate) |
| 1512 | @end lisp |
| 1513 | |
| 1514 | A widget is inactive if it, or any of its ancestors (found by |
| 1515 | following the @code{:parent} link), have been deactivated. To make sure |
| 1516 | a widget is really active, you must therefore activate both it and |
| 1517 | all its ancestors. |
| 1518 | |
| 1519 | @lisp |
| 1520 | (while widget |
| 1521 | (widget-apply widget :activate) |
| 1522 | (setq widget (widget-get widget :parent))) |
| 1523 | @end lisp |
| 1524 | |
| 1525 | You can check if a widget has been made inactive by examining the value |
| 1526 | of the @code{:inactive} keyword. If this is non-@code{nil}, the widget itself |
| 1527 | has been deactivated. This is different from using the @code{:active} |
| 1528 | keyword, in that the latter tells you if the widget @strong{or} any of |
| 1529 | its ancestors have been deactivated. Do not attempt to set the |
| 1530 | @code{:inactive} keyword directly. Use the @code{:activate} |
| 1531 | @code{:deactivate} keywords instead. |
| 1532 | |
| 1533 | |
| 1534 | @node Defining New Widgets, Widget Browser, Widget Properties, Top |
| 1535 | @comment node-name, next, previous, up |
| 1536 | @section Defining New Widgets |
| 1537 | @cindex new widgets |
| 1538 | @cindex defining new widgets |
| 1539 | |
| 1540 | You can define specialized widgets with @code{define-widget}. It allows |
| 1541 | you to create a shorthand for more complex widgets, including specifying |
| 1542 | component widgets and new default values for the keyword |
| 1543 | arguments. |
| 1544 | |
| 1545 | @defun define-widget name class doc &rest args |
| 1546 | Define a new widget type named @var{name} from @code{class}. |
| 1547 | |
| 1548 | @var{name} and class should both be symbols, @code{class} should be one |
| 1549 | of the existing widget types. |
| 1550 | |
| 1551 | The third argument @var{doc} is a documentation string for the widget. |
| 1552 | |
| 1553 | After the new widget has been defined, the following two calls will |
| 1554 | create identical widgets: |
| 1555 | |
| 1556 | @itemize @bullet |
| 1557 | @item |
| 1558 | @lisp |
| 1559 | (widget-create @var{name}) |
| 1560 | @end lisp |
| 1561 | |
| 1562 | @item |
| 1563 | @lisp |
| 1564 | (apply widget-create @var{class} @var{args}) |
| 1565 | @end lisp |
| 1566 | @end itemize |
| 1567 | |
| 1568 | @end defun |
| 1569 | |
| 1570 | Using @code{define-widget} just stores the definition of the widget type |
| 1571 | in the @code{widget-type} property of @var{name}, which is what |
| 1572 | @code{widget-create} uses. |
| 1573 | |
| 1574 | If you only want to specify defaults for keywords with no complex |
| 1575 | conversions, you can use @code{identity} as your conversion function. |
| 1576 | |
| 1577 | The following additional keyword arguments are useful when defining new |
| 1578 | widgets: |
| 1579 | @table @code |
| 1580 | @vindex convert-widget@r{ keyword} |
| 1581 | @item :convert-widget |
| 1582 | Function to convert a widget type before creating a widget of that |
| 1583 | type. It takes a widget type as an argument, and returns the converted |
| 1584 | widget type. When a widget is created, this function is called for the |
| 1585 | widget type and all the widget's parent types, most derived first. |
| 1586 | |
| 1587 | The following predefined functions can be used here: |
| 1588 | |
| 1589 | @defun widget-types-convert-widget widget |
| 1590 | Convert @code{:args} as widget types in @var{widget}. |
| 1591 | @end defun |
| 1592 | |
| 1593 | @defun widget-value-convert-widget widget |
| 1594 | Initialize @code{:value} from @code{:args} in @var{widget}. |
| 1595 | @end defun |
| 1596 | |
| 1597 | @vindex copy@r{ keyword} |
| 1598 | @item :copy |
| 1599 | Function to deep copy a widget type. It takes a shallow copy of the |
| 1600 | widget type as an argument (made by @code{copy-sequence}), and returns a |
| 1601 | deep copy. The purpose of this is to avoid having different instances |
| 1602 | of combined widgets share nested attributes. |
| 1603 | |
| 1604 | The following predefined functions can be used here: |
| 1605 | |
| 1606 | @defun widget-types-copy widget |
| 1607 | Copy @code{:args} as widget types in @var{widget}. |
| 1608 | @end defun |
| 1609 | |
| 1610 | @vindex value-to-internal@r{ keyword} |
| 1611 | @item :value-to-internal |
| 1612 | Function to convert the value to the internal format. The function |
| 1613 | takes two arguments, a widget and an external value, and returns the |
| 1614 | internal value. The function is called on the present @code{:value} |
| 1615 | when the widget is created, and on any value set later with |
| 1616 | @code{widget-value-set}. |
| 1617 | |
| 1618 | @vindex value-to-external@r{ keyword} |
| 1619 | @item :value-to-external |
| 1620 | Function to convert the value to the external format. The function |
| 1621 | takes two arguments, a widget and an internal value, and returns the |
| 1622 | external value. The function is called on the present @code{:value} |
| 1623 | when the widget is created, and on any value set later with |
| 1624 | @code{widget-value-set}. |
| 1625 | |
| 1626 | @vindex create@r{ keyword} |
| 1627 | @item :create |
| 1628 | Function to create a widget from scratch. The function takes one |
| 1629 | argument, a widget type, and creates a widget of that type, inserts it |
| 1630 | in the buffer, and returns a widget object. |
| 1631 | |
| 1632 | @vindex delete@r{ keyword} |
| 1633 | @item :delete |
| 1634 | Function to delete a widget. The function takes one argument, a widget, |
| 1635 | and should remove all traces of the widget from the buffer. |
| 1636 | |
| 1637 | The default value is: |
| 1638 | |
| 1639 | @defun widget-default-delete widget |
| 1640 | Remove @var{widget} from the buffer. |
| 1641 | Delete all @code{:children} and @code{:buttons} in @var{widget}. |
| 1642 | @end defun |
| 1643 | |
| 1644 | In most cases you should not change this value, but instead use |
| 1645 | @code{:value-delete} to make any additional cleanup. |
| 1646 | |
| 1647 | @vindex value-create@r{ keyword} |
| 1648 | @item :value-create |
| 1649 | Function to expand the @samp{%v} escape in the format string. It will |
| 1650 | be called with the widget as its argument and should insert a |
| 1651 | representation of the widget's value in the buffer. |
| 1652 | |
| 1653 | Nested widgets should be listed in @code{:children} or @code{:buttons} |
| 1654 | to make sure they are automatically deleted. |
| 1655 | |
| 1656 | @vindex value-delete@r{ keyword} |
| 1657 | @item :value-delete |
| 1658 | Should remove the representation of the widget's value from the buffer. |
| 1659 | It will be called with the widget as its argument. It doesn't have to |
| 1660 | remove the text, but it should release markers and delete nested widgets |
| 1661 | if these are not listed in @code{:children} or @code{:buttons}. |
| 1662 | |
| 1663 | @vindex value-get@r{ keyword} |
| 1664 | @item :value-get |
| 1665 | Function to extract the value of a widget, as it is displayed in the |
| 1666 | buffer. |
| 1667 | |
| 1668 | The following predefined function can be used here: |
| 1669 | |
| 1670 | @defun widget-value-value-get widget |
| 1671 | Return the @code{:value} property of @var{widget}. |
| 1672 | @end defun |
| 1673 | |
| 1674 | @vindex format-handler@r{ keyword} |
| 1675 | @item :format-handler |
| 1676 | Function to handle unknown @samp{%} escapes in the format string. It |
| 1677 | will be called with the widget and the character that follows the |
| 1678 | @samp{%} as arguments. You can set this to allow your widget to handle |
| 1679 | non-standard escapes. |
| 1680 | |
| 1681 | @findex widget-default-format-handler |
| 1682 | You should end up calling @code{widget-default-format-handler} to handle |
| 1683 | unknown escape sequences, which will handle the @samp{%h} and any future |
| 1684 | escape sequences, as well as give an error for unknown escapes. |
| 1685 | |
| 1686 | @vindex action@r{ keyword} |
| 1687 | @item :action |
| 1688 | Function to handle user initiated events. By default, @code{:notify} |
| 1689 | the parent. |
| 1690 | |
| 1691 | The following predefined function can be used here: |
| 1692 | |
| 1693 | @defun widget-parent-action widget &optional event |
| 1694 | Tell @code{:parent} of @var{widget} to handle the @code{:action}. |
| 1695 | Optional @var{event} is the event that triggered the action. |
| 1696 | @end defun |
| 1697 | |
| 1698 | @vindex prompt-value@r{ keyword} |
| 1699 | @item :prompt-value |
| 1700 | Function to prompt for a value in the minibuffer. The function should |
| 1701 | take four arguments, @var{widget}, @var{prompt}, @var{value}, and |
| 1702 | @var{unbound} and should return a value for widget entered by the user. |
| 1703 | @var{prompt} is the prompt to use. @var{value} is the default value to |
| 1704 | use, unless @var{unbound} is non-@code{nil}, in which case there is no default |
| 1705 | value. The function should read the value using the method most natural |
| 1706 | for this widget, and does not have to check that it matches. |
| 1707 | @end table |
| 1708 | |
| 1709 | If you want to define a new widget from scratch, use the @code{default} |
| 1710 | widget as its base. |
| 1711 | |
| 1712 | @deffn Widget default |
| 1713 | Widget used as a base for other widgets. |
| 1714 | |
| 1715 | It provides most of the functionality that is referred to as ``by |
| 1716 | default'' in this text. |
| 1717 | @end deffn |
| 1718 | |
| 1719 | @node Widget Browser, Widget Minor Mode, Defining New Widgets, Top |
| 1720 | @comment node-name, next, previous, up |
| 1721 | @section Widget Browser |
| 1722 | @cindex widget browser |
| 1723 | |
| 1724 | There is a separate package to browse widgets. This is intended to help |
| 1725 | programmers who want to examine the content of a widget. The browser |
| 1726 | shows the value of each keyword, but uses links for certain keywords |
| 1727 | such as @samp{:parent}, which avoids printing cyclic structures. |
| 1728 | |
| 1729 | @deffn Command widget-browse @var{widget} |
| 1730 | Create a widget browser for @var{widget}. |
| 1731 | When called interactively, prompt for @var{widget}. |
| 1732 | @end deffn |
| 1733 | |
| 1734 | @deffn Command widget-browse-other-window @var{widget} |
| 1735 | Create a widget browser for @var{widget} and show it in another window. |
| 1736 | When called interactively, prompt for @var{widget}. |
| 1737 | @end deffn |
| 1738 | |
| 1739 | @deffn Command widget-browse-at @var{pos} |
| 1740 | Create a widget browser for the widget at @var{pos}. |
| 1741 | When called interactively, use the position of point. |
| 1742 | @end deffn |
| 1743 | |
| 1744 | @node Widget Minor Mode, Utilities, Widget Browser, Top |
| 1745 | @comment node-name, next, previous, up |
| 1746 | @section Widget Minor Mode |
| 1747 | @cindex widget minor mode |
| 1748 | |
| 1749 | There is a minor mode for manipulating widgets in major modes that |
| 1750 | don't provide any support for widgets themselves. This is mostly |
| 1751 | intended to be useful for programmers doing experiments. |
| 1752 | |
| 1753 | @deffn Command widget-minor-mode |
| 1754 | Toggle minor mode for traversing widgets. |
| 1755 | With arg, turn widget mode on if and only if arg is positive. |
| 1756 | @end deffn |
| 1757 | |
| 1758 | @defvar widget-minor-mode-keymap |
| 1759 | Keymap used in @code{widget-minor-mode}. |
| 1760 | @end defvar |
| 1761 | |
| 1762 | @node Utilities, Widget Wishlist, Widget Minor Mode, Top |
| 1763 | @comment node-name, next, previous, up |
| 1764 | @section Utilities. |
| 1765 | @cindex utility functions for widgets |
| 1766 | |
| 1767 | @defun widget-prompt-value widget prompt [ value unbound ] |
| 1768 | Prompt for a value matching @var{widget}, using @var{prompt}. |
| 1769 | The current value is assumed to be @var{value}, unless @var{unbound} is |
| 1770 | non-@code{nil}.@refill |
| 1771 | @end defun |
| 1772 | |
| 1773 | @defun widget-get-sibling widget |
| 1774 | Get the item which @var{widget} is assumed to toggle. |
| 1775 | This is only meaningful for radio buttons or checkboxes in a list. |
| 1776 | @end defun |
| 1777 | |
| 1778 | @node Widget Wishlist, GNU Free Documentation License, Utilities, Top |
| 1779 | @comment node-name, next, previous, up |
| 1780 | @section Wishlist |
| 1781 | @cindex todo |
| 1782 | |
| 1783 | @itemize @bullet |
| 1784 | @item |
| 1785 | It should be possible to add or remove items from a list with @kbd{C-k} |
| 1786 | and @kbd{C-o} (suggested by @sc{rms}). |
| 1787 | |
| 1788 | @item |
| 1789 | The @samp{[INS]} and @samp{[DEL]} buttons should be replaced by a single |
| 1790 | dash (@samp{-}). The dash should be a button that, when invoked, asks |
| 1791 | whether you want to add or delete an item (@sc{rms} wanted to git rid of |
| 1792 | the ugly buttons, the dash is my idea). |
| 1793 | |
| 1794 | @item |
| 1795 | The @code{menu-choice} tag should be prettier, something like the abbreviated |
| 1796 | menus in Open Look. |
| 1797 | |
| 1798 | @item |
| 1799 | Finish @code{:tab-order}. |
| 1800 | |
| 1801 | @item |
| 1802 | Make indentation work with glyphs and proportional fonts. |
| 1803 | |
| 1804 | @item |
| 1805 | Add commands to show overview of object and class hierarchies to the |
| 1806 | browser. |
| 1807 | |
| 1808 | @item |
| 1809 | Find a way to disable mouse highlight for inactive widgets. |
| 1810 | |
| 1811 | @item |
| 1812 | Find a way to make glyphs look inactive. |
| 1813 | |
| 1814 | @item |
| 1815 | Add @code{property-list} widget. |
| 1816 | |
| 1817 | @item |
| 1818 | Add @code{association-list} widget. |
| 1819 | |
| 1820 | @item |
| 1821 | Add @code{key-binding} widget. |
| 1822 | |
| 1823 | @item |
| 1824 | Add @code{widget} widget for editing widget specifications. |
| 1825 | |
| 1826 | @item |
| 1827 | Find clean way to implement variable length list. |
| 1828 | See @code{TeX-printer-list} for an explanation. |
| 1829 | |
| 1830 | @item |
| 1831 | @kbd{C-h} in @code{widget-prompt-value} should give type specific help. |
| 1832 | |
| 1833 | @item |
| 1834 | Add a @code{mailto} widget. |
| 1835 | @end itemize |
| 1836 | |
| 1837 | @node GNU Free Documentation License, Index, Widget Wishlist, Top |
| 1838 | @appendix GNU Free Documentation License |
| 1839 | @include doclicense.texi |
| 1840 | |
| 1841 | @node Index, , GNU Free Documentation License, Top |
| 1842 | @comment node-name, next, previous, up |
| 1843 | @unnumbered Index |
| 1844 | |
| 1845 | This is an alphabetical listing of all concepts, functions, commands, |
| 1846 | variables, and widgets described in this manual. |
| 1847 | @printindex cp |
| 1848 | |
| 1849 | @setchapternewpage odd |
| 1850 | @contents |
| 1851 | @bye |
| 1852 | |
| 1853 | @ignore |
| 1854 | arch-tag: 2b427731-4c61-4e72-85de-5ccec9c623f0 |
| 1855 | @end ignore |