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1 | \input texinfo.tex |
2 | ||
3 | @c %**start of header | |
4 | @setfilename ../info/widget | |
5 | @settitle The Emacs Widget Library | |
6 | @iftex | |
7 | @afourpaper | |
8 | @headings double | |
9 | @end iftex | |
10 | @c %**end of header | |
11 | ||
12 | @dircategory Editors | |
13 | @direntry | |
14 | * Widget: (widget). Documenting the "widget" package used by the | |
15 | Emacs Custom facility. | |
16 | @end direntry | |
17 | ||
18 | @node Top, Introduction, (dir), (dir) | |
19 | @comment node-name, next, previous, up | |
20 | @top The Emacs Widget Library | |
21 | ||
6bf7aab6 DL |
22 | @menu |
23 | * Introduction:: | |
24 | * User Interface:: | |
25 | * Programming Example:: | |
26 | * Setting Up the Buffer:: | |
27 | * Basic Types:: | |
28 | * Sexp Types:: | |
29 | * Widget Properties:: | |
30 | * Defining New Widgets:: | |
31 | * Widget Browser:: | |
32 | * Widget Minor Mode:: | |
33 | * Utilities:: | |
34 | * Widget Wishlist:: | |
35 | @end menu | |
36 | ||
37 | @node Introduction, User Interface, Top, Top | |
38 | @comment node-name, next, previous, up | |
39 | @section Introduction | |
40 | ||
41 | Most graphical user interface toolkits, such as Motif and XView, provide | |
42 | a number of standard user interface controls (sometimes known as | |
43 | `widgets' or `gadgets'). Emacs doesn't really support anything like | |
44 | this, except for an incredible powerful text ``widget''. On the other | |
45 | hand, Emacs does provide the necessary primitives to implement many | |
46 | other widgets within a text buffer. The @code{widget} package | |
47 | simplifies this task. | |
48 | ||
49 | The basic widgets are: | |
50 | ||
51 | @table @code | |
52 | @item link | |
53 | Areas of text with an associated action. Intended for hypertext links | |
54 | embedded in text. | |
55 | @item push-button | |
56 | Like link, but intended for stand-alone buttons. | |
57 | @item editable-field | |
58 | An editable text field. It can be either variable or fixed length. | |
59 | @item menu-choice | |
60 | Allows the user to choose one of multiple options from a menu, each | |
61 | option is itself a widget. Only the selected option will be visible in | |
62 | the buffer. | |
63 | @item radio-button-choice | |
64 | Allows the user to choose one of multiple options by activating radio | |
65 | buttons. The options are implemented as widgets. All options will be | |
66 | visible in the buffer. | |
67 | @item item | |
68 | A simple constant widget intended to be used in the @code{menu-choice} and | |
69 | @code{radio-button-choice} widgets. | |
70 | @item choice-item | |
71 | An button item only intended for use in choices. When invoked, the user | |
72 | will be asked to select another option from the choice widget. | |
73 | @item toggle | |
74 | A simple @samp{on}/@samp{off} switch. | |
75 | @item checkbox | |
76 | A checkbox (@samp{[ ]}/@samp{[X]}). | |
77 | @item editable-list | |
78 | Create an editable list. The user can insert or delete items in the | |
79 | list. Each list item is itself a widget. | |
80 | @end table | |
81 | ||
82 | Now of what possible use can support for widgets be in a text editor? | |
83 | I'm glad you asked. The answer is that widgets are useful for | |
84 | implementing forms. A @dfn{form} in Emacs is a buffer where the user is | |
85 | supposed to fill out a number of fields, each of which has a specific | |
86 | meaning. The user is not supposed to change or delete any of the text | |
87 | between the fields. Examples of forms in Emacs are the @file{forms} | |
88 | package (of course), the customize buffers, the mail and news compose | |
89 | modes, and the @sc{html} form support in the @file{w3} browser. | |
90 | ||
91 | The advantages for a programmer of using the @code{widget} package to | |
92 | implement forms are: | |
93 | ||
94 | @enumerate | |
95 | @item | |
96 | More complex field than just editable text are supported. | |
97 | @item | |
98 | You can give the user immediate feedback if he enters invalid data in a | |
99 | text field, and sometimes prevent entering invalid data. | |
100 | @item | |
101 | You can have fixed sized fields, thus allowing multiple field to be | |
102 | lined up in columns. | |
103 | @item | |
104 | It is simple to query or set the value of a field. | |
105 | @item | |
106 | Editing happens in buffer, not in the mini-buffer. | |
107 | @item | |
108 | Packages using the library get a uniform look, making them easier for | |
109 | the user to learn. | |
110 | @item | |
111 | As support for embedded graphics improve, the widget library will | |
112 | extended to support it. This means that your code using the widget | |
113 | library will also use the new graphic features by automatic. | |
114 | @end enumerate | |
115 | ||
116 | In order to minimize the code that is loaded by users who does not | |
117 | create any widgets, the code has been split in two files: | |
118 | ||
119 | @table @file | |
120 | @item widget.el | |
121 | This will declare the user variables, define the function | |
122 | @code{widget-define}, and autoload the function @code{widget-create}. | |
123 | @item wid-edit.el | |
124 | Everything else is here, there is no reason to load it explicitly, as | |
125 | it will be autoloaded when needed. | |
126 | @end table | |
127 | ||
128 | @node User Interface, Programming Example, Introduction, Top | |
129 | @comment node-name, next, previous, up | |
130 | @section User Interface | |
131 | ||
132 | A form consist of read only text for documentation and some fields, | |
133 | where each the fields contain two parts, as tag and a value. The tags | |
134 | are used to identify the fields, so the documentation can refer to the | |
135 | foo field, meaning the field tagged with @samp{Foo}. Here is an example | |
136 | form: | |
137 | ||
138 | @example | |
139 | Here is some documentation. | |
140 | ||
141 | Name: @i{My Name} @strong{Choose}: This option | |
142 | Address: @i{Some Place | |
143 | In some City | |
144 | Some country.} | |
145 | ||
146 | See also @b{_other work_} for more information. | |
147 | ||
148 | Numbers: count to three below | |
149 | @b{[INS]} @b{[DEL]} @i{One} | |
150 | @b{[INS]} @b{[DEL]} @i{Eh, two?} | |
151 | @b{[INS]} @b{[DEL]} @i{Five!} | |
152 | @b{[INS]} | |
153 | ||
154 | Select multiple: | |
155 | ||
156 | @b{[X]} This | |
157 | @b{[ ]} That | |
158 | @b{[X]} Thus | |
159 | ||
160 | Select one: | |
161 | ||
162 | @b{(*)} One | |
163 | @b{( )} Another One. | |
164 | @b{( )} A Final One. | |
165 | ||
166 | @b{[Apply Form]} @b{[Reset Form]} | |
167 | @end example | |
168 | ||
169 | The top level widgets in is example are tagged @samp{Name}, | |
170 | @samp{Choose}, @samp{Address}, @samp{_other work_}, @samp{Numbers}, | |
171 | @samp{Select multiple}, @samp{Select one}, @samp{[Apply Form]}, and | |
172 | @samp{[Reset Form]}. There are basically two thing the user can do within | |
173 | a form, namely editing the editable text fields and activating the | |
174 | buttons. | |
175 | ||
176 | @subsection Editable Text Fields | |
177 | ||
178 | In the example, the value for the @samp{Name} is most likely displayed | |
179 | in an editable text field, and so are values for each of the members of | |
180 | the @samp{Numbers} list. All the normal Emacs editing operations are | |
181 | available for editing these fields. The only restriction is that each | |
182 | change you make must be contained within a single editable text field. | |
183 | For example, capitalizing all text from the middle of one field to the | |
184 | middle of another field is prohibited. | |
185 | ||
186 | Editing text fields are created by the @code{editable-field} widget. | |
187 | ||
188 | The editing text fields are highlighted with the | |
189 | @code{widget-field-face} face, making them easy to find. | |
190 | ||
191 | @deffn Face widget-field-face | |
192 | Face used for other editing fields. | |
193 | @end deffn | |
194 | ||
195 | @subsection Buttons | |
196 | ||
197 | Some portions of the buffer have an associated @dfn{action}, which can | |
198 | be @dfn{invoked} by a standard key or mouse command. These portions | |
199 | are called @dfn{buttons}. The default commands for activating a button | |
200 | are: | |
201 | ||
202 | @table @kbd | |
203 | @item @key{RET} | |
204 | @deffn Command widget-button-press @var{pos} &optional @var{event} | |
205 | Invoke the button at @var{pos}, defaulting to point. | |
206 | If point is not located on a button, invoke the binding in | |
207 | @code{widget-global-map} (by default the global map). | |
208 | @end deffn | |
209 | ||
210 | @item mouse-2 | |
211 | @deffn Command widget-button-click @var{event} | |
212 | Invoke the button at the location of the mouse pointer. If the mouse | |
213 | pointer is located in an editable text field, invoke the binding in | |
214 | @code{widget-global-map} (by default the global map). | |
215 | @end deffn | |
216 | @end table | |
217 | ||
218 | There are several different kind of buttons, all of which are present in | |
219 | the example: | |
220 | ||
221 | @table @emph | |
222 | @item The Option Field Tags. | |
223 | When you invoke one of these buttons, you will be asked to choose | |
224 | between a number of different options. This is how you edit an option | |
225 | field. Option fields are created by the @code{menu-choice} widget. In | |
226 | the example, @samp{@b{Choose}} is an option field tag. | |
227 | @item The @samp{@b{[INS]}} and @samp{@b{[DEL]}} buttons. | |
228 | Activating these will insert or delete elements from a editable list. | |
229 | The list is created by the @code{editable-list} widget. | |
230 | @item Embedded Buttons. | |
231 | The @samp{@b{_other work_}} is an example of an embedded | |
232 | button. Embedded buttons are not associated with a fields, but can serve | |
233 | any purpose, such as implementing hypertext references. They are | |
234 | usually created by the @code{link} widget. | |
235 | @item The @samp{@b{[ ]}} and @samp{@b{[X]}} buttons. | |
236 | Activating one of these will convert it to the other. This is useful | |
237 | for implementing multiple-choice fields. You can create it wit | |
238 | @item The @samp{@b{( )}} and @samp{@b{(*)}} buttons. | |
239 | Only one radio button in a @code{radio-button-choice} widget can be | |
240 | selected at any time. When you invoke one of the unselected radio | |
241 | buttons, it will be selected and the previous selected radio button will | |
242 | become unselected. | |
243 | @item The @samp{@b{[Apply Form]}} @samp{@b{[Reset Form]}} buttons. | |
244 | These are explicit buttons made with the @code{push-button} widget. The main | |
245 | difference from the @code{link} widget is that the buttons are will be | |
246 | displayed as GUI buttons when possible. | |
247 | enough. | |
248 | @end table | |
249 | ||
250 | To make them easier to locate, buttons are emphasized in the buffer. | |
251 | ||
252 | @deffn Face widget-button-face | |
253 | Face used for buttons. | |
254 | @end deffn | |
255 | ||
256 | @defopt widget-mouse-face | |
257 | Face used for buttons when the mouse pointer is above it. | |
258 | @end defopt | |
259 | ||
260 | @subsection Navigation | |
261 | ||
262 | You can use all the normal Emacs commands to move around in a form | |
263 | buffer, plus you will have these additional commands: | |
264 | ||
265 | @table @kbd | |
266 | @item @key{TAB} | |
267 | @deffn Command widget-forward &optional count | |
268 | Move point @var{count} buttons or editing fields forward. | |
269 | @end deffn | |
270 | @item @key{M-TAB} | |
271 | @deffn Command widget-backward &optional count | |
272 | Move point @var{count} buttons or editing fields backward. | |
273 | @end deffn | |
274 | @end table | |
275 | ||
276 | @node Programming Example, Setting Up the Buffer, User Interface, Top | |
277 | @comment node-name, next, previous, up | |
278 | @section Programming Example | |
279 | ||
280 | Here is the code to implement the user interface example (@pxref{User | |
281 | Interface}). | |
282 | ||
283 | @lisp | |
284 | (require 'widget) | |
285 | ||
286 | (eval-when-compile | |
287 | (require 'wid-edit)) | |
288 | ||
289 | (defvar widget-example-repeat) | |
290 | ||
291 | (defun widget-example () | |
292 | "Create the widgets from the Widget manual." | |
293 | (interactive) | |
294 | (switch-to-buffer "*Widget Example*") | |
295 | (kill-all-local-variables) | |
296 | (make-local-variable 'widget-example-repeat) | |
297 | (let ((inhibit-read-only t)) | |
298 | (erase-buffer)) | |
299 | (widget-insert "Here is some documentation.\n\nName: ") | |
300 | (widget-create 'editable-field | |
301 | :size 13 | |
302 | "My Name") | |
303 | (widget-create 'menu-choice | |
304 | :tag "Choose" | |
305 | :value "This" | |
306 | :help-echo "Choose me, please!" | |
307 | :notify (lambda (widget &rest ignore) | |
308 | (message "%s is a good choice!" | |
309 | (widget-value widget))) | |
310 | '(item :tag "This option" :value "This") | |
311 | '(choice-item "That option") | |
312 | '(editable-field :menu-tag "No option" "Thus option")) | |
313 | (widget-insert "Address: ") | |
314 | (widget-create 'editable-field | |
315 | "Some Place\nIn some City\nSome country.") | |
316 | (widget-insert "\nSee also ") | |
317 | (widget-create 'link | |
318 | :notify (lambda (&rest ignore) | |
319 | (widget-value-set widget-example-repeat | |
320 | '("En" "To" "Tre")) | |
321 | (widget-setup)) | |
322 | "other work") | |
323 | (widget-insert " for more information.\n\nNumbers: count to three below\n") | |
324 | (setq widget-example-repeat | |
325 | (widget-create 'editable-list | |
326 | :entry-format "%i %d %v" | |
327 | :notify (lambda (widget &rest ignore) | |
328 | (let ((old (widget-get widget | |
329 | ':example-length)) | |
330 | (new (length (widget-value widget)))) | |
331 | (unless (eq old new) | |
332 | (widget-put widget ':example-length new) | |
333 | (message "You can count to %d." new)))) | |
334 | :value '("One" "Eh, two?" "Five!") | |
335 | '(editable-field :value "three"))) | |
336 | (widget-insert "\n\nSelect multiple:\n\n") | |
337 | (widget-create 'checkbox t) | |
338 | (widget-insert " This\n") | |
339 | (widget-create 'checkbox nil) | |
340 | (widget-insert " That\n") | |
341 | (widget-create 'checkbox | |
342 | :notify (lambda (&rest ignore) (message "Tickle")) | |
343 | t) | |
344 | (widget-insert " Thus\n\nSelect one:\n\n") | |
345 | (widget-create 'radio-button-choice | |
346 | :value "One" | |
347 | :notify (lambda (widget &rest ignore) | |
348 | (message "You selected %s" | |
349 | (widget-value widget))) | |
350 | '(item "One") '(item "Another One.") '(item "A Final One.")) | |
351 | (widget-insert "\n") | |
352 | (widget-create 'push-button | |
353 | :notify (lambda (&rest ignore) | |
354 | (if (= (length (widget-value widget-example-repeat)) | |
355 | 3) | |
356 | (message "Congratulation!") | |
357 | (error "Three was the count!"))) | |
358 | "Apply Form") | |
359 | (widget-insert " ") | |
360 | (widget-create 'push-button | |
361 | :notify (lambda (&rest ignore) | |
362 | (widget-example)) | |
363 | "Reset Form") | |
364 | (widget-insert "\n") | |
365 | (use-local-map widget-keymap) | |
366 | (widget-setup)) | |
367 | @end lisp | |
368 | ||
369 | @node Setting Up the Buffer, Basic Types, Programming Example, Top | |
370 | @comment node-name, next, previous, up | |
371 | @section Setting Up the Buffer | |
372 | ||
373 | Widgets are created with @code{widget-create}, which returns a | |
374 | @dfn{widget} object. This object can be queried and manipulated by | |
375 | other widget functions, until it is deleted with @code{widget-delete}. | |
376 | After the widgets have been created, @code{widget-setup} must be called | |
377 | to enable them. | |
378 | ||
379 | @defun widget-create type [ keyword argument ]@dots{} | |
380 | Create and return a widget of type @var{type}. | |
381 | The syntax for the @var{type} argument is described in @ref{Basic Types}. | |
382 | ||
383 | The keyword arguments can be used to overwrite the keyword arguments | |
384 | that are part of @var{type}. | |
385 | @end defun | |
386 | ||
387 | @defun widget-delete widget | |
388 | Delete @var{widget} and remove it from the buffer. | |
389 | @end defun | |
390 | ||
391 | @defun widget-setup | |
392 | Setup a buffer to support widgets. | |
393 | ||
394 | This should be called after creating all the widgets and before allowing | |
395 | the user to edit them. | |
396 | @refill | |
397 | @end defun | |
398 | ||
399 | If you want to insert text outside the widgets in the form, the | |
400 | recommended way to do that is with @code{widget-insert}. | |
401 | ||
402 | @defun widget-insert | |
403 | Insert the arguments, either strings or characters, at point. | |
404 | The inserted text will be read only. | |
405 | @end defun | |
406 | ||
407 | There is a standard widget keymap which you might find useful. | |
408 | ||
409 | @defvr Const widget-keymap | |
410 | A keymap with the global keymap as its parent.@* | |
411 | @key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and | |
412 | @code{widget-backward}, respectively. @kbd{@key{RET}} and @kbd{mouse-2} | |
413 | are bound to @code{widget-button-press} and | |
414 | @code{widget-button-}.@refill | |
415 | @end defvr | |
416 | ||
417 | @defvar widget-global-map | |
418 | Keymap used by @code{widget-button-press} and @code{widget-button-click} | |
419 | when not on a button. By default this is @code{global-map}. | |
420 | @end defvar | |
421 | ||
422 | @node Basic Types, Sexp Types, Setting Up the Buffer, Top | |
423 | @comment node-name, next, previous, up | |
424 | @section Basic Types | |
425 | ||
426 | The syntax of a type specification is given below: | |
427 | ||
428 | @example | |
429 | NAME ::= (NAME [KEYWORD ARGUMENT]... ARGS) | |
430 | | NAME | |
431 | @end example | |
432 | ||
433 | Where, @var{name} is a widget name, @var{keyword} is the name of a | |
434 | property, @var{argument} is the value of the property, and @var{args} | |
435 | are interpreted in a widget specific way. | |
436 | ||
437 | There following keyword arguments that apply to all widgets: | |
438 | ||
439 | @table @code | |
440 | @item :value | |
441 | The initial value for widgets of this type. | |
442 | ||
443 | @item :format | |
444 | This string will be inserted in the buffer when you create a widget. | |
445 | The following @samp{%} escapes are available: | |
446 | ||
447 | @table @samp | |
448 | @item %[ | |
449 | @itemx %] | |
450 | The text inside will be marked as a button. | |
451 | ||
452 | By default, the text will be shown in @code{widget-button-face}, and | |
453 | surrounded by brackets. | |
454 | ||
455 | @defopt widget-button-prefix | |
456 | String to prefix buttons. | |
457 | @end defopt | |
458 | ||
459 | @defopt widget-button-suffix | |
460 | String to suffix buttons. | |
461 | @end defopt | |
462 | ||
463 | @item %@{ | |
464 | @itemx %@} | |
465 | The text inside will be displayed with the face specified by | |
466 | @code{:sample-face}. | |
467 | ||
468 | @item %v | |
54438eb5 | 469 | This will be replaced with the buffer representation of the widget's |
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470 | value. What this is depends on the widget type. |
471 | ||
472 | @item %d | |
473 | Insert the string specified by @code{:doc} here. | |
474 | ||
475 | @item %h | |
476 | Like @samp{%d}, with the following modifications: If the documentation | |
477 | string is more than one line, it will add a button which will toggle | |
478 | between showing only the first line, and showing the full text. | |
479 | Furthermore, if there is no @code{:doc} property in the widget, it will | |
480 | instead examine the @code{:documentation-property} property. If it is a | |
481 | lambda expression, it will be called with the widget's value as an | |
482 | argument, and the result will be used as the documentation text. | |
483 | ||
484 | @item %t | |
485 | Insert the string specified by @code{:tag} here, or the @code{princ} | |
486 | representation of the value if there is no tag. | |
487 | ||
488 | @item %% | |
489 | Insert a literal @samp{%}. | |
490 | @end table | |
491 | ||
492 | @item :button-face | |
493 | Face used to highlight text inside %[ %] in the format. | |
494 | ||
495 | @item :button-prefix | |
496 | @itemx :button-suffix | |
497 | ||
498 | Text around %[ %] in the format. | |
499 | ||
500 | These can be | |
501 | @table @emph | |
502 | @item nil | |
503 | No text is inserted. | |
504 | ||
505 | @item a string | |
506 | The string is inserted literally. | |
507 | ||
508 | @item a symbol | |
509 | The value of the symbol is expanded according to this table. | |
510 | @end table | |
511 | ||
512 | @item :doc | |
513 | The string inserted by the @samp{%d} escape in the format | |
514 | string. | |
515 | ||
516 | @item :tag | |
517 | The string inserted by the @samp{%t} escape in the format | |
518 | string. | |
519 | ||
520 | @item :tag-glyph | |
521 | Name of image to use instead of the string specified by `:tag' on | |
522 | Emacsen that supports it. | |
523 | ||
524 | @item :help-echo | |
525 | Message displayed whenever you move to the widget with either | |
526 | @code{widget-forward} or @code{widget-backward}. | |
527 | ||
528 | @item :indent | |
529 | An integer indicating the absolute number of spaces to indent children | |
530 | of this widget. | |
531 | ||
532 | @item :offset | |
533 | An integer indicating how many extra spaces to add to the widget's | |
534 | grandchildren compared to this widget. | |
535 | ||
536 | @item :extra-offset | |
537 | An integer indicating how many extra spaces to add to the widget's | |
538 | children compared to this widget. | |
539 | ||
540 | @item :notify | |
541 | A function called each time the widget or a nested widget is changed. | |
542 | The function is called with two or three arguments. The first argument | |
543 | is the widget itself, the second argument is the widget that was | |
544 | changed, and the third argument is the event leading to the change, if | |
545 | any. | |
546 | ||
547 | @item :menu-tag | |
548 | Tag used in the menu when the widget is used as an option in a | |
549 | @code{menu-choice} widget. | |
550 | ||
551 | @item :menu-tag-get | |
552 | Function used for finding the tag when the widget is used as an option | |
553 | in a @code{menu-choice} widget. By default, the tag used will be either the | |
554 | @code{:menu-tag} or @code{:tag} property if present, or the @code{princ} | |
555 | representation of the @code{:value} property if not. | |
556 | ||
557 | @item :match | |
558 | Should be a function called with two arguments, the widget and a value, | |
559 | and returning non-nil if the widget can represent the specified value. | |
560 | ||
561 | @item :validate | |
562 | A function which takes a widget as an argument, and return nil if the | |
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563 | widget's current value is valid for the widget. Otherwise it should |
564 | return the widget containing the invalid data, and set that widget's | |
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565 | @code{:error} property to a string explaining the error. |
566 | ||
567 | The following predefined function can be used: | |
568 | ||
569 | @defun widget-children-validate widget | |
570 | All the @code{:children} of @var{widget} must be valid. | |
571 | @end defun | |
572 | ||
573 | @item :tab-order | |
574 | Specify the order in which widgets are traversed with | |
575 | @code{widget-forward} or @code{widget-backward}. This is only partially | |
576 | implemented. | |
577 | ||
578 | @enumerate a | |
579 | @item | |
580 | Widgets with tabbing order @code{-1} are ignored. | |
581 | ||
582 | @item | |
583 | (Unimplemented) When on a widget with tabbing order @var{n}, go to the | |
584 | next widget in the buffer with tabbing order @var{n+1} or @code{nil}, | |
585 | whichever comes first. | |
586 | ||
587 | @item | |
588 | When on a widget with no tabbing order specified, go to the next widget | |
589 | in the buffer with a positive tabbing order, or @code{nil} | |
590 | @end enumerate | |
591 | ||
592 | @item :parent | |
593 | The parent of a nested widget (e.g. a @code{menu-choice} item or an | |
594 | element of a @code{editable-list} widget). | |
595 | ||
596 | @item :sibling-args | |
597 | This keyword is only used for members of a @code{radio-button-choice} or | |
598 | @code{checklist}. The value should be a list of extra keyword | |
599 | arguments, which will be used when creating the @code{radio-button} or | |
600 | @code{checkbox} associated with this item. | |
601 | ||
602 | @end table | |
603 | ||
604 | @deffn {User Option} widget-glyph-directory | |
605 | Directory where glyphs are found. | |
606 | Widget will look here for a file with the same name as specified for the | |
607 | image, with either a @samp{.xpm} (if supported) or @samp{.xbm} extension. | |
608 | @end deffn | |
609 | ||
610 | @deffn{User Option} widget-glyph-enable | |
611 | If non-nil, allow glyphs to appear on displays where they are supported. | |
612 | @end deffn | |
613 | ||
614 | ||
615 | @menu | |
616 | * link:: | |
617 | * url-link:: | |
618 | * info-link:: | |
619 | * push-button:: | |
620 | * editable-field:: | |
621 | * text:: | |
622 | * menu-choice:: | |
623 | * radio-button-choice:: | |
624 | * item:: | |
625 | * choice-item:: | |
626 | * toggle:: | |
627 | * checkbox:: | |
628 | * checklist:: | |
629 | * editable-list:: | |
630 | * group:: | |
631 | @end menu | |
632 | ||
633 | @node link, url-link, Basic Types, Basic Types | |
634 | @comment node-name, next, previous, up | |
635 | @subsection The @code{link} Widget | |
636 | ||
637 | Syntax: | |
638 | ||
639 | @example | |
640 | TYPE ::= (link [KEYWORD ARGUMENT]... [ VALUE ]) | |
641 | @end example | |
642 | ||
643 | The @var{value}, if present, is used to initialize the @code{:value} | |
644 | property. The value should be a string, which will be inserted in the | |
645 | buffer. | |
646 | ||
647 | By default the link will be shown in brackets. | |
648 | ||
649 | @defopt widget-link-prefix | |
650 | String to prefix links. | |
651 | @end defopt | |
652 | ||
653 | @defopt widget-link-suffix | |
654 | String to suffix links. | |
655 | @end defopt | |
656 | ||
657 | @node url-link, info-link, link, Basic Types | |
658 | @comment node-name, next, previous, up | |
659 | @subsection The @code{url-link} Widget | |
660 | ||
661 | Syntax: | |
662 | ||
663 | @example | |
664 | TYPE ::= (url-link [KEYWORD ARGUMENT]... URL) | |
665 | @end example | |
666 | ||
667 | When this link is invoked, the @sc{www} browser specified by | |
668 | @code{browse-url-browser-function} will be called with @var{url}. | |
669 | ||
670 | @node info-link, push-button, url-link, Basic Types | |
671 | @comment node-name, next, previous, up | |
672 | @subsection The @code{info-link} Widget | |
673 | ||
674 | Syntax: | |
675 | ||
676 | @example | |
677 | TYPE ::= (info-link [KEYWORD ARGUMENT]... ADDRESS) | |
678 | @end example | |
679 | ||
54438eb5 | 680 | When this link is invoked, the built-in info browser is started on |
6bf7aab6 DL |
681 | @var{address}. |
682 | ||
683 | @node push-button, editable-field, info-link, Basic Types | |
684 | @comment node-name, next, previous, up | |
685 | @subsection The @code{push-button} Widget | |
686 | ||
687 | Syntax: | |
688 | ||
689 | @example | |
690 | TYPE ::= (push-button [KEYWORD ARGUMENT]... [ VALUE ]) | |
691 | @end example | |
692 | ||
693 | The @var{value}, if present, is used to initialize the @code{:value} | |
694 | property. The value should be a string, which will be inserted in the | |
695 | buffer. | |
696 | ||
697 | By default the tag will be shown in brackets. | |
698 | ||
699 | @defopt widget-push-button-prefix | |
700 | String to prefix push buttons. | |
701 | @end defopt | |
702 | ||
703 | @defopt widget-push-button-suffix | |
704 | String to suffix push buttons. | |
705 | @end defopt | |
706 | ||
707 | @node editable-field, text, push-button, Basic Types | |
708 | @comment node-name, next, previous, up | |
709 | @subsection The @code{editable-field} Widget | |
710 | ||
711 | Syntax: | |
712 | ||
713 | @example | |
714 | TYPE ::= (editable-field [KEYWORD ARGUMENT]... [ VALUE ]) | |
715 | @end example | |
716 | ||
717 | The @var{value}, if present, is used to initialize the @code{:value} | |
718 | property. The value should be a string, which will be inserted in | |
719 | field. This widget will match all string values. | |
720 | ||
721 | The following extra properties are recognized. | |
722 | ||
723 | @table @code | |
724 | @item :size | |
725 | The width of the editable field.@* | |
726 | By default the field will reach to the end of the line. | |
727 | ||
728 | @item :value-face | |
729 | Face used for highlighting the editable field. Default is | |
730 | @code{widget-field-face}. | |
731 | ||
732 | @item :secret | |
733 | Character used to display the value. You can set this to e.g. @code{?*} | |
734 | if the field contains a password or other secret information. By | |
735 | default, the value is not secret. | |
736 | ||
737 | @item :valid-regexp | |
738 | By default the @code{:validate} function will match the content of the | |
739 | field with the value of this attribute. The default value is @code{""} | |
740 | which matches everything. | |
741 | ||
742 | @item :keymap | |
743 | Keymap used in the editable field. The default value is | |
744 | @code{widget-field-keymap}, which allows you to use all the normal | |
745 | editing commands, even if the buffers major mode suppress some of them. | |
746 | Pressing return invokes the function specified by @code{:action}. | |
747 | @end table | |
748 | ||
749 | @node text, menu-choice, editable-field, Basic Types | |
750 | @comment node-name, next, previous, up | |
751 | @subsection The @code{text} Widget | |
752 | ||
753 | This is just like @code{editable-field}, but intended for multiline text | |
754 | fields. The default @code{:keymap} is @code{widget-text-keymap}, which | |
755 | does not rebind the return key. | |
756 | ||
757 | @node menu-choice, radio-button-choice, text, Basic Types | |
758 | @comment node-name, next, previous, up | |
759 | @subsection The @code{menu-choice} Widget | |
760 | ||
761 | Syntax: | |
762 | ||
763 | @example | |
764 | TYPE ::= (menu-choice [KEYWORD ARGUMENT]... TYPE ... ) | |
765 | @end example | |
766 | ||
54438eb5 DL |
767 | The @var{type} argument represents each possible choice. The widget's |
768 | value will be that of the chosen @var{type} argument. This widget will | |
769 | match any value matching at least one of the specified @var{type} | |
770 | arguments. | |
6bf7aab6 DL |
771 | |
772 | @table @code | |
773 | @item :void | |
774 | Widget type used as a fallback when the value does not match any of the | |
775 | specified @var{type} arguments. | |
776 | ||
777 | @item :case-fold | |
778 | Set this to nil if you don't want to ignore case when prompting for a | |
779 | choice through the minibuffer. | |
780 | ||
781 | @item :children | |
782 | A list whose car is the widget representing the currently chosen type in | |
783 | the buffer. | |
784 | ||
785 | @item :choice | |
786 | The current chosen type | |
787 | ||
788 | @item :args | |
789 | The list of types. | |
790 | @end table | |
791 | ||
792 | @node radio-button-choice, item, menu-choice, Basic Types | |
793 | @comment node-name, next, previous, up | |
794 | @subsection The @code{radio-button-choice} Widget | |
795 | ||
796 | Syntax: | |
797 | ||
798 | @example | |
799 | TYPE ::= (radio-button-choice [KEYWORD ARGUMENT]... TYPE ... ) | |
800 | @end example | |
801 | ||
54438eb5 DL |
802 | The @var{type} argument represents each possible choice. The widget's |
803 | value will be that of the chosen @var{type} argument. This widget will | |
804 | match any value matching at least one of the specified @var{type} | |
805 | arguments. | |
6bf7aab6 DL |
806 | |
807 | The following extra properties are recognized. | |
808 | ||
809 | @table @code | |
810 | @item :entry-format | |
811 | This string will be inserted for each entry in the list. | |
812 | The following @samp{%} escapes are available: | |
813 | @table @samp | |
814 | @item %v | |
815 | Replaced with the buffer representation of the @var{type} widget. | |
816 | @item %b | |
817 | Replace with the radio button. | |
818 | @item %% | |
819 | Insert a literal @samp{%}. | |
820 | @end table | |
821 | ||
822 | @item button-args | |
823 | A list of keywords to pass to the radio buttons. Useful for setting | |
824 | e.g. the @samp{:help-echo} for each button. | |
825 | ||
826 | @item :buttons | |
827 | The widgets representing the radio buttons. | |
828 | ||
829 | @item :children | |
830 | The widgets representing each type. | |
831 | ||
832 | @item :choice | |
833 | The current chosen type | |
834 | ||
835 | @item :args | |
836 | The list of types. | |
837 | @end table | |
838 | ||
839 | You can add extra radio button items to a @code{radio-button-choice} | |
840 | widget after it has been created with the function | |
841 | @code{widget-radio-add-item}. | |
842 | ||
843 | @defun widget-radio-add-item widget type | |
844 | Add to @code{radio-button-choice} widget @var{widget} a new radio button item of type | |
845 | @var{type}. | |
846 | @end defun | |
847 | ||
848 | Please note that such items added after the @code{radio-button-choice} | |
849 | widget has been created will @strong{not} be properly destructed when | |
850 | you call @code{widget-delete}. | |
851 | ||
852 | @node item, choice-item, radio-button-choice, Basic Types | |
853 | @comment node-name, next, previous, up | |
854 | @subsection The @code{item} Widget | |
855 | ||
856 | Syntax: | |
857 | ||
858 | @example | |
859 | ITEM ::= (item [KEYWORD ARGUMENT]... VALUE) | |
860 | @end example | |
861 | ||
862 | The @var{value}, if present, is used to initialize the @code{:value} | |
863 | property. The value should be a string, which will be inserted in the | |
864 | buffer. This widget will only match the specified value. | |
865 | ||
866 | @node choice-item, toggle, item, Basic Types | |
867 | @comment node-name, next, previous, up | |
868 | @subsection The @code{choice-item} Widget | |
869 | ||
870 | Syntax: | |
871 | ||
872 | @example | |
873 | ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE) | |
874 | @end example | |
875 | ||
876 | The @var{value}, if present, is used to initialize the @code{:value} | |
877 | property. The value should be a string, which will be inserted in the | |
878 | buffer as a button. Activating the button of a @code{choice-item} is | |
879 | equivalent to activating the parent widget. This widget will only match | |
880 | the specified value. | |
881 | ||
882 | @node toggle, checkbox, choice-item, Basic Types | |
883 | @comment node-name, next, previous, up | |
884 | @subsection The @code{toggle} Widget | |
885 | ||
886 | Syntax: | |
887 | ||
888 | @example | |
889 | TYPE ::= (toggle [KEYWORD ARGUMENT]...) | |
890 | @end example | |
891 | ||
54438eb5 DL |
892 | The widget has two possible states, `on' and `off', which correspond to |
893 | a @code{t} or @code{nil} value respectively. | |
6bf7aab6 DL |
894 | |
895 | The following extra properties are recognized. | |
896 | ||
897 | @table @code | |
898 | @item :on | |
899 | String representing the `on' state. By default the string @samp{on}. | |
900 | @item :off | |
901 | String representing the `off' state. By default the string @samp{off}. | |
902 | @item :on-glyph | |
903 | Name of a glyph to be used instead of the `:on' text string, on emacsen | |
904 | that supports it. | |
905 | @item :off-glyph | |
906 | Name of a glyph to be used instead of the `:off' text string, on emacsen | |
907 | that supports it. | |
908 | @end table | |
909 | ||
910 | @node checkbox, checklist, toggle, Basic Types | |
911 | @comment node-name, next, previous, up | |
912 | @subsection The @code{checkbox} Widget | |
913 | ||
914 | The widget has two possible states, `selected' and `unselected', which | |
915 | corresponds to a @code{t} or @code{nil} value. | |
916 | ||
917 | Syntax: | |
918 | ||
919 | @example | |
920 | TYPE ::= (checkbox [KEYWORD ARGUMENT]...) | |
921 | @end example | |
922 | ||
923 | @node checklist, editable-list, checkbox, Basic Types | |
924 | @comment node-name, next, previous, up | |
925 | @subsection The @code{checklist} Widget | |
926 | ||
927 | Syntax: | |
928 | ||
929 | @example | |
930 | TYPE ::= (checklist [KEYWORD ARGUMENT]... TYPE ... ) | |
931 | @end example | |
932 | ||
54438eb5 DL |
933 | The @var{type} arguments represents each checklist item. The widget's |
934 | value will be a list containing the values of all ticked @var{type} | |
935 | arguments. The checklist widget will match a list whose elements all | |
936 | match at least one of the specified @var{type} arguments. | |
6bf7aab6 DL |
937 | |
938 | The following extra properties are recognized. | |
939 | ||
940 | @table @code | |
941 | @item :entry-format | |
942 | This string will be inserted for each entry in the list. | |
943 | The following @samp{%} escapes are available: | |
944 | @table @samp | |
945 | @item %v | |
946 | Replaced with the buffer representation of the @var{type} widget. | |
947 | @item %b | |
948 | Replace with the checkbox. | |
949 | @item %% | |
950 | Insert a literal @samp{%}. | |
951 | @end table | |
952 | ||
953 | @item :greedy | |
54438eb5 | 954 | Usually a checklist will only match if the items are in the exact |
6bf7aab6 DL |
955 | sequence given in the specification. By setting @code{:greedy} to |
956 | non-nil, it will allow the items to come in any sequence. However, if | |
957 | you extract the value they will be in the sequence given in the | |
54438eb5 | 958 | checklist. I.e. the original sequence is forgotten. |
6bf7aab6 DL |
959 | |
960 | @item button-args | |
961 | A list of keywords to pass to the checkboxes. Useful for setting | |
962 | e.g. the @samp{:help-echo} for each checkbox. | |
963 | ||
964 | @item :buttons | |
965 | The widgets representing the checkboxes. | |
966 | ||
967 | @item :children | |
968 | The widgets representing each type. | |
969 | ||
970 | @item :args | |
971 | The list of types. | |
972 | @end table | |
973 | ||
974 | @node editable-list, group, checklist, Basic Types | |
975 | @comment node-name, next, previous, up | |
976 | @subsection The @code{editable-list} Widget | |
977 | ||
978 | Syntax: | |
979 | ||
980 | @example | |
981 | TYPE ::= (editable-list [KEYWORD ARGUMENT]... TYPE) | |
982 | @end example | |
983 | ||
984 | The value is a list, where each member represents one widget of type | |
985 | @var{type}. | |
986 | ||
987 | The following extra properties are recognized. | |
988 | ||
989 | @table @code | |
990 | @item :entry-format | |
991 | This string will be inserted for each entry in the list. | |
992 | The following @samp{%} escapes are available: | |
993 | @table @samp | |
994 | @item %v | |
995 | This will be replaced with the buffer representation of the @var{type} | |
996 | widget. | |
997 | @item %i | |
998 | Insert the @b{[INS]} button. | |
999 | @item %d | |
1000 | Insert the @b{[DEL]} button. | |
1001 | @item %% | |
1002 | Insert a literal @samp{%}. | |
1003 | @end table | |
1004 | ||
1005 | @item :insert-button-args | |
1006 | A list of keyword arguments to pass to the insert buttons. | |
1007 | ||
1008 | @item :delete-button-args | |
1009 | A list of keyword arguments to pass to the delete buttons. | |
1010 | ||
1011 | @item :append-button-args | |
1012 | A list of keyword arguments to pass to the trailing insert button. | |
1013 | ||
1014 | ||
1015 | @item :buttons | |
1016 | The widgets representing the insert and delete buttons. | |
1017 | ||
1018 | @item :children | |
1019 | The widgets representing the elements of the list. | |
1020 | ||
1021 | @item :args | |
1022 | List whose car is the type of the list elements. | |
1023 | ||
1024 | @end table | |
1025 | ||
1026 | @node group, , editable-list, Basic Types | |
1027 | @comment node-name, next, previous, up | |
1028 | @subsection The @code{group} Widget | |
1029 | ||
1030 | This widget simply group other widget together. | |
1031 | ||
1032 | Syntax: | |
1033 | ||
1034 | @example | |
1035 | TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...) | |
1036 | @end example | |
1037 | ||
1038 | The value is a list, with one member for each @var{type}. | |
1039 | ||
1040 | @node Sexp Types, Widget Properties, Basic Types, Top | |
1041 | @comment | |
1042 | @section Sexp Types | |
1043 | ||
1044 | A number of widgets for editing s-expressions (lisp types) are also | |
1045 | available. These basically fall in the following categories. | |
1046 | ||
1047 | @menu | |
1048 | * constants:: | |
1049 | * generic:: | |
1050 | * atoms:: | |
1051 | * composite:: | |
1052 | @end menu | |
1053 | ||
1054 | @node constants, generic, Sexp Types, Sexp Types | |
1055 | @comment node-name, next, previous, up | |
1056 | @subsection The Constant Widgets. | |
1057 | ||
1058 | The @code{const} widget can contain any lisp expression, but the user is | |
1059 | prohibited from editing edit it, which is mainly useful as a component | |
1060 | of one of the composite widgets. | |
1061 | ||
1062 | The syntax for the @code{const} widget is | |
1063 | ||
1064 | @example | |
1065 | TYPE ::= (const [KEYWORD ARGUMENT]... [ VALUE ]) | |
1066 | @end example | |
1067 | ||
1068 | The @var{value}, if present, is used to initialize the @code{:value} | |
1069 | property and can be any s-expression. | |
1070 | ||
1071 | @deffn Widget const | |
1072 | This will display any valid s-expression in an immutable part of the | |
1073 | buffer. | |
1074 | @end deffn | |
1075 | ||
1076 | There are two variations of the @code{const} widget, namely | |
1077 | @code{variable-item} and @code{function-item}. These should contain a | |
1078 | symbol with a variable or function binding. The major difference from | |
1079 | the @code{const} widget is that they will allow the user to see the | |
1080 | variable or function documentation for the symbol. | |
1081 | ||
1082 | @deffn Widget variable-item | |
1083 | An immutable symbol that is bound as a variable. | |
1084 | @end deffn | |
1085 | ||
1086 | @deffn Widget function-item | |
1087 | An immutable symbol that is bound as a function. | |
1088 | @end deffn | |
1089 | ||
1090 | @node generic, atoms, constants, Sexp Types | |
1091 | @comment node-name, next, previous, up | |
1092 | @subsection Generic Sexp Widget. | |
1093 | ||
1094 | The @code{sexp} widget can contain any lisp expression, and allows the | |
1095 | user to edit it inline in the buffer. | |
1096 | ||
1097 | The syntax for the @code{sexp} widget is | |
1098 | ||
1099 | @example | |
1100 | TYPE ::= (sexp [KEYWORD ARGUMENT]... [ VALUE ]) | |
1101 | @end example | |
1102 | ||
1103 | @deffn Widget sexp | |
1104 | This will allow you to edit any valid s-expression in an editable buffer | |
1105 | field. | |
1106 | ||
1107 | The @code{sexp} widget takes the same keyword arguments as the | |
1108 | @code{editable-field} widget. | |
1109 | @end deffn | |
1110 | ||
1111 | @node atoms, composite, generic, Sexp Types | |
1112 | @comment node-name, next, previous, up | |
1113 | @subsection Atomic Sexp Widgets. | |
1114 | ||
1115 | The atoms are s-expressions that does not consist of other | |
1116 | s-expressions. A string is an atom, while a list is a composite type. | |
1117 | You can edit the value of an atom with the following widgets. | |
1118 | ||
1119 | The syntax for all the atoms are | |
1120 | ||
1121 | @example | |
1122 | TYPE ::= (NAME [KEYWORD ARGUMENT]... [ VALUE ]) | |
1123 | @end example | |
1124 | ||
1125 | The @var{value}, if present, is used to initialize the @code{:value} | |
1126 | property and must be an expression of the same type as the widget. | |
1127 | I.e. the string widget can only be initialized with a string. | |
1128 | ||
1129 | All the atom widgets take the same keyword arguments as the | |
1130 | @code{editable-field} widget. | |
1131 | ||
1132 | @deffn Widget string | |
1133 | Allows you to edit a string in an editable field. | |
1134 | @end deffn | |
1135 | ||
1136 | @deffn Widget regexp | |
1137 | Allows you to edit a regular expression in an editable field. | |
1138 | @end deffn | |
1139 | ||
1140 | @deffn Widget character | |
1141 | Allows you to enter a character in an editable field. | |
1142 | @end deffn | |
1143 | ||
1144 | @deffn Widget file | |
1145 | Allows you to edit a file name in an editable field. If you invoke | |
1146 | the tag button, you can edit the file name in the mini-buffer with | |
1147 | completion. | |
1148 | ||
1149 | Keywords: | |
1150 | @table @code | |
1151 | @item :must-match | |
1152 | If this is set to non-nil, only existing file names will be allowed in | |
1153 | the minibuffer. | |
1154 | @end table | |
1155 | @end deffn | |
1156 | ||
1157 | @deffn Widget directory | |
1158 | Allows you to edit a directory name in an editable field. | |
1159 | Similar to the @code{file} widget. | |
1160 | @end deffn | |
1161 | ||
1162 | @deffn Widget symbol | |
1163 | Allows you to edit a lisp symbol in an editable field. | |
1164 | @end deffn | |
1165 | ||
1166 | @deffn Widget function | |
1167 | Allows you to edit a lambda expression, or a function name with completion. | |
1168 | @end deffn | |
1169 | ||
1170 | @deffn Widget variable | |
1171 | Allows you to edit a variable name, with completion. | |
1172 | @end deffn | |
1173 | ||
1174 | @deffn Widget integer | |
1175 | Allows you to edit an integer in an editable field. | |
1176 | @end deffn | |
1177 | ||
1178 | @deffn Widget number | |
1179 | Allows you to edit a number in an editable field. | |
1180 | @end deffn | |
1181 | ||
1182 | @deffn Widget boolean | |
1183 | Allows you to edit a boolean. In lisp this means a variable which is | |
1184 | either nil meaning false, or non-nil meaning true. | |
1185 | @end deffn | |
1186 | ||
1187 | ||
1188 | @node composite, , atoms, Sexp Types | |
1189 | @comment node-name, next, previous, up | |
1190 | @subsection Composite Sexp Widgets. | |
1191 | ||
1192 | The syntax for the composite are | |
1193 | ||
1194 | @example | |
1195 | TYPE ::= (NAME [KEYWORD ARGUMENT]... COMPONENT...) | |
1196 | @end example | |
1197 | ||
1198 | Where each @var{component} must be a widget type. Each component widget | |
1199 | will be displayed in the buffer, and be editable to the user. | |
1200 | ||
1201 | @deffn Widget cons | |
1202 | The value of a @code{cons} widget is a cons-cell where the car is the | |
1203 | value of the first component and the cdr is the value of the second | |
1204 | component. There must be exactly two components. | |
1205 | @end deffn | |
1206 | ||
1207 | @deffn Widget list | |
1208 | The value of a @code{list} widget is a list containing the value of | |
1209 | each of its component. | |
1210 | @end deffn | |
1211 | ||
1212 | @deffn Widget vector | |
1213 | The value of a @code{vector} widget is a vector containing the value of | |
1214 | each of its component. | |
1215 | @end deffn | |
1216 | ||
1217 | The above suffice for specifying fixed size lists and vectors. To get | |
1218 | variable length lists and vectors, you can use a @code{choice}, | |
1219 | @code{set} or @code{repeat} widgets together with the @code{:inline} | |
1220 | keywords. If any component of a composite widget has the @code{:inline} | |
1221 | keyword set, its value must be a list which will then be spliced into | |
1222 | the composite. For example, to specify a list whose first element must | |
1223 | be a file name, and whose remaining arguments should either by the | |
1224 | symbol @code{t} or two files, you can use the following widget | |
1225 | specification: | |
1226 | ||
1227 | @example | |
1228 | (list file | |
1229 | (choice (const t) | |
1230 | (list :inline t | |
1231 | :value ("foo" "bar") | |
1232 | string string))) | |
1233 | @end example | |
1234 | ||
1235 | The value of a widget of this type will either have the form | |
1236 | @samp{(file t)} or @code{(file string string)}. | |
1237 | ||
1238 | This concept of inline is probably hard to understand. It was certainly | |
54438eb5 DL |
1239 | hard to implement so instead of confusing you more by trying to explain |
1240 | it here, I'll just suggest you meditate over it for a while. | |
6bf7aab6 DL |
1241 | |
1242 | @deffn Widget choice | |
54438eb5 DL |
1243 | Allows you to edit a sexp which may have one of a fixed set of types. |
1244 | It is currently implemented with the @code{choice-menu} basic widget, | |
1245 | and has a similar syntax. | |
6bf7aab6 DL |
1246 | @end deffn |
1247 | ||
1248 | @deffn Widget set | |
1249 | Allows you to specify a type which must be a list whose elements all | |
1250 | belong to given set. The elements of the list is not significant. This | |
1251 | is implemented on top of the @code{checklist} basic widget, and has a | |
1252 | similar syntax. | |
1253 | @end deffn | |
1254 | ||
1255 | @deffn Widget repeat | |
1256 | Allows you to specify a variable length list whose members are all of | |
1257 | the same type. Implemented on top of the `editable-list' basic widget, | |
1258 | and has a similar syntax. | |
1259 | @end deffn | |
1260 | ||
1261 | @node Widget Properties, Defining New Widgets, Sexp Types, Top | |
1262 | @comment node-name, next, previous, up | |
1263 | @section Properties | |
1264 | ||
1265 | You can examine or set the value of a widget by using the widget object | |
1266 | that was returned by @code{widget-create}. | |
1267 | ||
1268 | @defun widget-value widget | |
1269 | Return the current value contained in @var{widget}. | |
1270 | It is an error to call this function on an uninitialized widget. | |
1271 | @end defun | |
1272 | ||
1273 | @defun widget-value-set widget value | |
1274 | Set the value contained in @var{widget} to @var{value}. | |
1275 | It is an error to call this function with an invalid @var{value}. | |
1276 | @end defun | |
1277 | ||
1278 | @strong{Important:} You @emph{must} call @code{widget-setup} after | |
1279 | modifying the value of a widget before the user is allowed to edit the | |
1280 | widget again. It is enough to call @code{widget-setup} once if you | |
1281 | modify multiple widgets. This is currently only necessary if the widget | |
1282 | contains an editing field, but may be necessary for other widgets in the | |
1283 | future. | |
1284 | ||
1285 | If your application needs to associate some information with the widget | |
1286 | objects, for example a reference to the item being edited, it can be | |
1287 | done with @code{widget-put} and @code{widget-get}. The property names | |
1288 | must begin with a @samp{:}. | |
1289 | ||
1290 | @defun widget-put widget property value | |
1291 | In @var{widget} set @var{property} to @var{value}. | |
1292 | @var{property} should be a symbol, while @var{value} can be anything. | |
1293 | @end defun | |
1294 | ||
1295 | @defun widget-get widget property | |
1296 | In @var{widget} return the value for @var{property}. | |
1297 | @var{property} should be a symbol, the value is what was last set by | |
1298 | @code{widget-put} for @var{property}. | |
1299 | @end defun | |
1300 | ||
1301 | @defun widget-member widget property | |
1302 | Non-nil if @var{widget} has a value (even nil) for property @var{property}. | |
1303 | @end defun | |
1304 | ||
1305 | Occasionally it can be useful to know which kind of widget you have, | |
1306 | i.e. the name of the widget type you gave when the widget was created. | |
1307 | ||
1308 | @defun widget-type widget | |
1309 | Return the name of @var{widget}, a symbol. | |
1310 | @end defun | |
1311 | ||
1312 | Widgets can be in two states: active, which means they are modifiable by | |
1313 | the user, or inactive, which means they cannot be modified by the user. | |
1314 | You can query or set the state with the following code: | |
1315 | ||
1316 | @lisp | |
1317 | ;; Examine if @var{widget} is active or not. | |
1318 | (if (widget-apply @var{widget} :active) | |
1319 | (message "Widget is active.") | |
1320 | (message "Widget is inactive.") | |
1321 | ||
1322 | ;; Make @var{widget} inactive. | |
1323 | (widget-apply @var{widget} :deactivate) | |
1324 | ||
1325 | ;; Make @var{widget} active. | |
1326 | (widget-apply @var{widget} :activate) | |
1327 | @end lisp | |
1328 | ||
54438eb5 DL |
1329 | A widget is inactive if it, or any of its ancestors (found by |
1330 | following the @code{:parent} link), have been deactivated. To make sure | |
1331 | a widget is really active, you must therefore activate both it and | |
6bf7aab6 DL |
1332 | all its ancestors. |
1333 | ||
1334 | @lisp | |
1335 | (while widget | |
1336 | (widget-apply widget :activate) | |
1337 | (setq widget (widget-get widget :parent))) | |
1338 | @end lisp | |
1339 | ||
1340 | You can check if a widget has been made inactive by examining the value | |
54438eb5 DL |
1341 | of the @code{:inactive} keyword. If this is non-nil, the widget itself |
1342 | has been deactivated. This is different from using the @code{:active} | |
1343 | keyword, in that the latter tells you if the widget @strong{or} any of | |
1344 | its ancestors have been deactivated. Do not attempt to set the | |
6bf7aab6 | 1345 | @code{:inactive} keyword directly. Use the @code{:activate} |
54438eb5 | 1346 | @code{:deactivate} keywords instead. |
6bf7aab6 DL |
1347 | |
1348 | ||
1349 | @node Defining New Widgets, Widget Browser, Widget Properties, Top | |
1350 | @comment node-name, next, previous, up | |
1351 | @section Defining New Widgets | |
1352 | ||
1353 | You can define specialized widgets with @code{define-widget}. It allows | |
1354 | you to create a shorthand for more complex widgets, including specifying | |
54438eb5 | 1355 | component widgets and new default values for the keyword |
6bf7aab6 DL |
1356 | arguments. |
1357 | ||
1358 | @defun widget-define name class doc &rest args | |
1359 | Define a new widget type named @var{name} from @code{class}. | |
1360 | ||
1361 | @var{name} and class should both be symbols, @code{class} should be one | |
1362 | of the existing widget types. | |
1363 | ||
1364 | The third argument @var{DOC} is a documentation string for the widget. | |
1365 | ||
1366 | After the new widget has been defined, the following two calls will | |
1367 | create identical widgets: | |
1368 | ||
1369 | @itemize @bullet | |
1370 | @item | |
1371 | @lisp | |
1372 | (widget-create @var{name}) | |
1373 | @end lisp | |
1374 | ||
1375 | @item | |
1376 | @lisp | |
1377 | (apply widget-create @var{class} @var{args}) | |
1378 | @end lisp | |
1379 | @end itemize | |
1380 | ||
1381 | @end defun | |
1382 | ||
54438eb5 DL |
1383 | Using @code{widget-define} just stores the definition of the widget type |
1384 | in the @code{widget-type} property of @var{name}, which is what | |
6bf7aab6 DL |
1385 | @code{widget-create} uses. |
1386 | ||
1387 | If you just want to specify defaults for keywords with no complex | |
1388 | conversions, you can use @code{identity} as your conversion function. | |
1389 | ||
1390 | The following additional keyword arguments are useful when defining new | |
1391 | widgets: | |
1392 | @table @code | |
1393 | @item :convert-widget | |
1394 | Function to convert a widget type before creating a widget of that | |
1395 | type. It takes a widget type as an argument, and returns the converted | |
1396 | widget type. When a widget is created, this function is called for the | |
54438eb5 | 1397 | widget type and all the widget's parent types, most derived first. |
6bf7aab6 DL |
1398 | |
1399 | The following predefined functions can be used here: | |
1400 | ||
1401 | @defun widget-types-convert-widget widget | |
1402 | Convert @code{:args} as widget types in @var{widget}. | |
1403 | @end defun | |
1404 | ||
1405 | @defun widget-value-convert-widget widget | |
1406 | Initialize @code{:value} from @code{:args} in @var{widget}. | |
1407 | @end defun | |
1408 | ||
1409 | @item :value-to-internal | |
1410 | Function to convert the value to the internal format. The function | |
1411 | takes two arguments, a widget and an external value, and returns the | |
1412 | internal value. The function is called on the present @code{:value} | |
1413 | when the widget is created, and on any value set later with | |
1414 | @code{widget-value-set}. | |
1415 | ||
1416 | @item :value-to-external | |
1417 | Function to convert the value to the external format. The function | |
1418 | takes two arguments, a widget and an internal value, and returns the | |
1419 | internal value. The function is called on the present @code{:value} | |
1420 | when the widget is created, and on any value set later with | |
1421 | @code{widget-value-set}. | |
1422 | ||
1423 | @item :create | |
1424 | Function to create a widget from scratch. The function takes one | |
54438eb5 DL |
1425 | argument, a widget type, and creates a widget of that type, inserts it |
1426 | in the buffer, and returns a widget object. | |
6bf7aab6 DL |
1427 | |
1428 | @item :delete | |
1429 | Function to delete a widget. The function takes one argument, a widget, | |
1430 | and should remove all traces of the widget from the buffer. | |
1431 | ||
1432 | @item :value-create | |
1433 | Function to expand the @samp{%v} escape in the format string. It will | |
54438eb5 DL |
1434 | be called with the widget as its argument and should insert a |
1435 | representation of the widget's value in the buffer. | |
6bf7aab6 DL |
1436 | |
1437 | @item :value-delete | |
54438eb5 | 1438 | Should remove the representation of the widget's value from the buffer. |
6bf7aab6 DL |
1439 | It will be called with the widget as its argument. It doesn't have to |
1440 | remove the text, but it should release markers and delete nested widgets | |
54438eb5 | 1441 | if such have been used. |
6bf7aab6 DL |
1442 | |
1443 | The following predefined function can be used here: | |
1444 | ||
1445 | @defun widget-children-value-delete widget | |
1446 | Delete all @code{:children} and @code{:buttons} in @var{widget}. | |
1447 | @end defun | |
1448 | ||
1449 | @item :value-get | |
1450 | Function to extract the value of a widget, as it is displayed in the | |
1451 | buffer. | |
1452 | ||
1453 | The following predefined function can be used here: | |
1454 | ||
1455 | @defun widget-value-value-get widget | |
1456 | Return the @code{:value} property of @var{widget}. | |
1457 | @end defun | |
1458 | ||
1459 | @item :format-handler | |
1460 | Function to handle unknown @samp{%} escapes in the format string. It | |
1461 | will be called with the widget and the escape character as arguments. | |
1462 | You can set this to allow your widget to handle non-standard escapes. | |
1463 | ||
1464 | You should end up calling @code{widget-default-format-handler} to handle | |
1465 | unknown escape sequences, which will handle the @samp{%h} and any future | |
1466 | escape sequences, as well as give an error for unknown escapes. | |
1467 | ||
1468 | @item :action | |
1469 | Function to handle user initiated events. By default, @code{:notify} | |
1470 | the parent. | |
1471 | ||
1472 | The following predefined function can be used here: | |
1473 | ||
1474 | @defun widget-parent-action widget &optional event | |
1475 | Tell @code{:parent} of @var{widget} to handle the @code{:action}. | |
1476 | Optional @var{event} is the event that triggered the action. | |
1477 | @end defun | |
1478 | ||
1479 | @item :prompt-value | |
1480 | Function to prompt for a value in the minibuffer. The function should | |
1481 | take four arguments, @var{widget}, @var{prompt}, @var{value}, and | |
1482 | @var{unbound} and should return a value for widget entered by the user. | |
1483 | @var{prompt} is the prompt to use. @var{value} is the default value to | |
54438eb5 | 1484 | use, unless @var{unbound} is non-nil, in which case there is no default |
6bf7aab6 DL |
1485 | value. The function should read the value using the method most natural |
1486 | for this widget, and does not have to check that it matches. | |
1487 | @end table | |
1488 | ||
1489 | If you want to define a new widget from scratch, use the @code{default} | |
1490 | widget as its base. | |
1491 | ||
1492 | @deffn Widget default | |
1493 | Widget used as a base for other widgets. | |
1494 | ||
1495 | It provides most of the functionality that is referred to as ``by | |
1496 | default'' in this text. | |
1497 | @end deffn | |
1498 | ||
1499 | @node Widget Browser, Widget Minor Mode, Defining New Widgets, Top | |
1500 | @comment node-name, next, previous, up | |
1501 | @section Widget Browser | |
1502 | ||
1503 | There is a separate package to browse widgets. This is intended to help | |
1504 | programmers who want to examine the content of a widget. The browser | |
1505 | shows the value of each keyword, but uses links for certain keywords | |
1506 | such as `:parent', which avoids printing cyclic structures. | |
1507 | ||
1508 | @deffn Command widget-browse WIDGET | |
1509 | Create a widget browser for WIDGET. | |
1510 | When called interactively, prompt for WIDGET. | |
1511 | @end deffn | |
1512 | ||
1513 | @deffn Command widget-browse-other-window WIDGET | |
1514 | Create a widget browser for WIDGET and show it in another window. | |
1515 | When called interactively, prompt for WIDGET. | |
1516 | @end deffn | |
1517 | ||
1518 | @deffn Command widget-browse-at POS | |
1519 | Create a widget browser for the widget at POS. | |
1520 | When called interactively, use the position of point. | |
1521 | @end deffn | |
1522 | ||
1523 | @node Widget Minor Mode, Utilities, Widget Browser, Top | |
1524 | @comment node-name, next, previous, up | |
1525 | @section Widget Minor Mode | |
1526 | ||
1527 | There is a minor mode for manipulating widgets in major modes that | |
1528 | doesn't provide any support for widgets themselves. This is mostly | |
1529 | intended to be useful for programmers doing experiments. | |
1530 | ||
1531 | @deffn Command widget-minor-mode | |
1532 | Toggle minor mode for traversing widgets. | |
1533 | With arg, turn widget mode on if and only if arg is positive. | |
1534 | @end deffn | |
1535 | ||
1536 | @defvar widget-minor-mode-keymap | |
1537 | Keymap used in @code{widget-minor-mode}. | |
1538 | @end defvar | |
1539 | ||
1540 | @node Utilities, Widget Wishlist, Widget Minor Mode, Top | |
1541 | @comment node-name, next, previous, up | |
1542 | @section Utilities. | |
1543 | ||
1544 | @defun widget-prompt-value widget prompt [ value unbound ] | |
1545 | Prompt for a value matching @var{widget}, using @var{prompt}. | |
1546 | The current value is assumed to be @var{value}, unless @var{unbound} is | |
1547 | non-nil.@refill | |
1548 | @end defun | |
1549 | ||
1550 | @defun widget-get-sibling widget | |
1551 | Get the item @var{widget} is assumed to toggle. | |
1552 | This is only meaningful for radio buttons or checkboxes in a list. | |
1553 | @end defun | |
1554 | ||
1555 | @node Widget Wishlist, , Utilities, Top | |
1556 | @comment node-name, next, previous, up | |
1557 | @section Wishlist | |
1558 | ||
1559 | @itemize @bullet | |
1560 | @item | |
1561 | It should be possible to add or remove items from a list with @kbd{C-k} | |
1562 | and @kbd{C-o} (suggested by @sc{rms}). | |
1563 | ||
1564 | @item | |
1565 | The @samp{[INS]} and @samp{[DEL]} buttons should be replaced by a single | |
1566 | dash (@samp{-}). The dash should be a button that, when invoked, ask | |
1567 | whether you want to add or delete an item (@sc{rms} wanted to git rid of | |
1568 | the ugly buttons, the dash is my idea). | |
1569 | ||
1570 | @item | |
1571 | The @code{menu-choice} tag should be prettier, something like the abbreviated | |
1572 | menus in Open Look. | |
1573 | ||
1574 | @item | |
1575 | Finish @code{:tab-order}. | |
1576 | ||
1577 | @item | |
1578 | Make indentation work with glyphs and proportional fonts. | |
1579 | ||
1580 | @item | |
1581 | Add commands to show overview of object and class hierarchies to the | |
1582 | browser. | |
1583 | ||
1584 | @item | |
1585 | Find a way to disable mouse highlight for inactive widgets. | |
1586 | ||
1587 | @item | |
1588 | Find a way to make glyphs look inactive. | |
1589 | ||
1590 | @item | |
1591 | Add @code{property-list} widget. | |
1592 | ||
1593 | @item | |
1594 | Add @code{association-list} widget. | |
1595 | ||
1596 | @item | |
1597 | Add @code{key-binding} widget. | |
1598 | ||
1599 | @item | |
1600 | Add @code{widget} widget for editing widget specifications. | |
1601 | ||
1602 | @item | |
1603 | Find clean way to implement variable length list. | |
1604 | See @code{TeX-printer-list} for an explanation. | |
1605 | ||
1606 | @item | |
1607 | @kbd{C-h} in @code{widget-prompt-value} should give type specific help. | |
1608 | ||
1609 | @item | |
1610 | A mailto widget. | |
1611 | ||
1612 | @end itemize | |
1613 | ||
56f7c94a | 1614 | @setchapternewpage odd |
6bf7aab6 DL |
1615 | @contents |
1616 | @bye |