(debug): Call with-timeout-suspend and with-timeout-unsuspend.
[bpt/emacs.git] / man / widget.texi
CommitLineData
6bf7aab6
DL
1\input texinfo.tex
2
3@c %**start of header
4@setfilename ../info/widget
5@settitle The Emacs Widget Library
18f952d5
KB
6@syncodeindex fn cp
7@syncodeindex vr cp
8@syncodeindex ky cp
9@afourpaper
10@c %**end of header
11
12@copying
d3ceff91 13Copyright @copyright{} 2000, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
a159375d 14
18f952d5 15@quotation
a159375d
DL
16Permission is granted to copy, distribute and/or modify this document
17under the terms of the GNU Free Documentation License, Version 1.1 or
18any later version published by the Free Software Foundation; with the
19Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and
20``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU
21Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
22license is included in the section entitled ``GNU Free Documentation
23License'' in the Emacs manual.
24
25This document is part of a collection distributed under the GNU Free
26Documentation License. If you want to distribute this document
27separately from the collection, you can do so by adding a copy of the
28license to the document, as described in section 6 of the license.
29
30(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
31this GNU Manual, like GNU software. Copies published by the Free
32Software Foundation raise funds for GNU development.''
18f952d5
KB
33@end quotation
34@end copying
6f7f063d 35
4c2ca4f3 36@dircategory Emacs
6bf7aab6 37@direntry
a1566793
EZ
38* Widget: (widget). The "widget" package used by the Emacs Customization
39 facility.
6bf7aab6
DL
40@end direntry
41
42@node Top, Introduction, (dir), (dir)
43@comment node-name, next, previous, up
44@top The Emacs Widget Library
45
6bf7aab6 46@menu
177c0ea7
JB
47* Introduction::
48* User Interface::
49* Programming Example::
50* Setting Up the Buffer::
51* Basic Types::
52* Sexp Types::
53* Widget Properties::
54* Defining New Widgets::
55* Widget Browser::
56* Widget Minor Mode::
57* Utilities::
58* Widget Wishlist::
6f7f063d 59* Index::
6bf7aab6
DL
60@end menu
61
62@node Introduction, User Interface, Top, Top
63@comment node-name, next, previous, up
64@section Introduction
65
ce8abc78
RS
66Most graphical user interface toolkits provide a number of standard
67user interface controls (sometimes known as `widgets' or `gadgets').
68Emacs doesn't really support anything like this, except for an
69incredibly powerful text ``widget.'' On the other hand, Emacs does
70provide the necessary primitives to implement many other widgets
71within a text buffer. The @code{widget} package simplifies this task.
6bf7aab6 72
6f7f063d
EZ
73@cindex basic widgets
74@cindex widgets, basic types
6bf7aab6
DL
75The basic widgets are:
76
77@table @code
78@item link
79Areas of text with an associated action. Intended for hypertext links
80embedded in text.
177c0ea7 81@item push-button
6bf7aab6
DL
82Like link, but intended for stand-alone buttons.
83@item editable-field
84An editable text field. It can be either variable or fixed length.
85@item menu-choice
86Allows the user to choose one of multiple options from a menu, each
87option is itself a widget. Only the selected option will be visible in
88the buffer.
89@item radio-button-choice
90Allows the user to choose one of multiple options by activating radio
91buttons. The options are implemented as widgets. All options will be
92visible in the buffer.
93@item item
94A simple constant widget intended to be used in the @code{menu-choice} and
177c0ea7 95@code{radio-button-choice} widgets.
6bf7aab6 96@item choice-item
6f7f063d 97A button item only intended for use in choices. When invoked, the user
6bf7aab6
DL
98will be asked to select another option from the choice widget.
99@item toggle
100A simple @samp{on}/@samp{off} switch.
101@item checkbox
177c0ea7 102A checkbox (@samp{[ ]}/@samp{[X]}).
6bf7aab6
DL
103@item editable-list
104Create an editable list. The user can insert or delete items in the
105list. Each list item is itself a widget.
106@end table
107
6f7f063d 108Now, of what possible use can support for widgets be in a text editor?
6bf7aab6
DL
109I'm glad you asked. The answer is that widgets are useful for
110implementing forms. A @dfn{form} in Emacs is a buffer where the user is
111supposed to fill out a number of fields, each of which has a specific
112meaning. The user is not supposed to change or delete any of the text
113between the fields. Examples of forms in Emacs are the @file{forms}
114package (of course), the customize buffers, the mail and news compose
76dd3692 115modes, and the @acronym{HTML} form support in the @file{w3} browser.
6bf7aab6 116
6f7f063d 117@cindex widget library, why use it
6bf7aab6
DL
118The advantages for a programmer of using the @code{widget} package to
119implement forms are:
120
121@enumerate
122@item
177c0ea7 123More complex fields than just editable text are supported.
6bf7aab6 124@item
6f7f063d 125You can give the users immediate feedback if they enter invalid data in a
6bf7aab6 126text field, and sometimes prevent entering invalid data.
177c0ea7 127@item
6f7f063d 128You can have fixed sized fields, thus allowing multiple fields to be
6bf7aab6
DL
129lined up in columns.
130@item
177c0ea7
JB
131It is simple to query or set the value of a field.
132@item
6f7f063d 133Editing happens in the buffer, not in the mini-buffer.
177c0ea7 134@item
6bf7aab6
DL
135Packages using the library get a uniform look, making them easier for
136the user to learn.
177c0ea7 137@item
6f7f063d
EZ
138As support for embedded graphics improve, the widget library will be
139extended to use the GUI features. This means that your code using the
140widget library will also use the new graphic features automatically.
6bf7aab6
DL
141@end enumerate
142
143In order to minimize the code that is loaded by users who does not
144create any widgets, the code has been split in two files:
145
6f7f063d 146@cindex widget library, files
6bf7aab6
DL
147@table @file
148@item widget.el
149This will declare the user variables, define the function
177c0ea7 150@code{define-widget}, and autoload the function @code{widget-create}.
6bf7aab6
DL
151@item wid-edit.el
152Everything else is here, there is no reason to load it explicitly, as
153it will be autoloaded when needed.
154@end table
155
156@node User Interface, Programming Example, Introduction, Top
157@comment node-name, next, previous, up
158@section User Interface
159
160A form consist of read only text for documentation and some fields,
6f7f063d
EZ
161where each field contains two parts, a tag and a value. The tags are
162used to identify the fields, so the documentation can refer to the
163@samp{foo field}, meaning the field tagged with @samp{Foo}. Here is an
164example form:
6bf7aab6
DL
165
166@example
167Here is some documentation.
168
169Name: @i{My Name} @strong{Choose}: This option
170Address: @i{Some Place
171In some City
172Some country.}
173
174See also @b{_other work_} for more information.
175
176Numbers: count to three below
976e00f1
DL
177@b{[INS]} @b{[DEL]} @i{One}
178@b{[INS]} @b{[DEL]} @i{Eh, two?}
179@b{[INS]} @b{[DEL]} @i{Five!}
177c0ea7 180@b{[INS]}
6bf7aab6
DL
181
182Select multiple:
183
184@b{[X]} This
185@b{[ ]} That
186@b{[X]} Thus
187
188Select one:
189
190@b{(*)} One
191@b{( )} Another One.
192@b{( )} A Final One.
193
194@b{[Apply Form]} @b{[Reset Form]}
195@end example
196
197The top level widgets in is example are tagged @samp{Name},
198@samp{Choose}, @samp{Address}, @samp{_other work_}, @samp{Numbers},
199@samp{Select multiple}, @samp{Select one}, @samp{[Apply Form]}, and
6f7f063d
EZ
200@samp{[Reset Form]}. There are basically two things the user can do
201within a form, namely editing the editable text fields and activating
202the buttons.
6bf7aab6
DL
203
204@subsection Editable Text Fields
205
206In the example, the value for the @samp{Name} is most likely displayed
207in an editable text field, and so are values for each of the members of
208the @samp{Numbers} list. All the normal Emacs editing operations are
209available for editing these fields. The only restriction is that each
210change you make must be contained within a single editable text field.
211For example, capitalizing all text from the middle of one field to the
212middle of another field is prohibited.
213
4036ed83
PA
214Editable text fields are created by the @code{editable-field} widget.
215
8dbc532e
LH
216@strong{Warning:} In an @code{editable-field} widget, the editable
217field must not be adjacent to another widget---that won't work.
218You must put some text in between. Either make this text part of
219the @code{editable-field} widget itself, or insert it with
220@code{widget-insert}.
221
222The @code{:format} keyword is useful for generating the necessary
223text; for instance, if you give it a value of @code{"Name: %v "},
224the @samp{Name: } part will provide the necessary separating text
225before the field and the trailing space will provide the
226separating text after the field. If you don't include the
227@code{:size} keyword, the field will extend to the end of the
228line, and the terminating newline will provide separation after.
6bf7aab6
DL
229
230The editing text fields are highlighted with the
231@code{widget-field-face} face, making them easy to find.
232
233@deffn Face widget-field-face
234Face used for other editing fields.
235@end deffn
236
237@subsection Buttons
238
6f7f063d
EZ
239@cindex widget buttons
240@cindex button widgets
6bf7aab6
DL
241Some portions of the buffer have an associated @dfn{action}, which can
242be @dfn{invoked} by a standard key or mouse command. These portions
243are called @dfn{buttons}. The default commands for activating a button
244are:
245
246@table @kbd
247@item @key{RET}
248@deffn Command widget-button-press @var{pos} &optional @var{event}
249Invoke the button at @var{pos}, defaulting to point.
250If point is not located on a button, invoke the binding in
251@code{widget-global-map} (by default the global map).
252@end deffn
253
ce8abc78
RS
254@kindex Mouse-2 @r{(on button widgets})
255@item Mouse-2
6bf7aab6
DL
256@deffn Command widget-button-click @var{event}
257Invoke the button at the location of the mouse pointer. If the mouse
258pointer is located in an editable text field, invoke the binding in
259@code{widget-global-map} (by default the global map).
260@end deffn
261@end table
262
263There are several different kind of buttons, all of which are present in
264the example:
265
266@table @emph
6f7f063d
EZ
267@cindex option field tag
268@item The Option Field Tags
6bf7aab6
DL
269When you invoke one of these buttons, you will be asked to choose
270between a number of different options. This is how you edit an option
271field. Option fields are created by the @code{menu-choice} widget. In
272the example, @samp{@b{Choose}} is an option field tag.
976e00f1 273@item The @samp{@b{[INS]}} and @samp{@b{[DEL]}} buttons
6f7f063d 274Activating these will insert or delete elements from an editable list.
177c0ea7 275The list is created by the @code{editable-list} widget.
6f7f063d
EZ
276@cindex embedded buttons
277@item Embedded Buttons
6bf7aab6 278The @samp{@b{_other work_}} is an example of an embedded
6f7f063d 279button. Embedded buttons are not associated with a fields, but can serve
6bf7aab6
DL
280any purpose, such as implementing hypertext references. They are
281usually created by the @code{link} widget.
6f7f063d 282@item The @samp{@b{[ ]}} and @samp{@b{[X]}} buttons
6bf7aab6 283Activating one of these will convert it to the other. This is useful
6f7f063d
EZ
284for implementing multiple-choice fields. You can create it with the
285@code{checkbox} widget.
286@item The @samp{@b{( )}} and @samp{@b{(*)}} buttons
6bf7aab6
DL
287Only one radio button in a @code{radio-button-choice} widget can be
288selected at any time. When you invoke one of the unselected radio
289buttons, it will be selected and the previous selected radio button will
290become unselected.
6f7f063d
EZ
291@item The @samp{@b{[Apply Form]}} @samp{@b{[Reset Form]}} buttons
292These are explicit buttons made with the @code{push-button} widget. The
293main difference from the @code{link} widget is that the buttons will be
6bf7aab6 294displayed as GUI buttons when possible.
6bf7aab6
DL
295@end table
296
177c0ea7 297To make them easier to locate, buttons are emphasized in the buffer.
6bf7aab6
DL
298
299@deffn Face widget-button-face
300Face used for buttons.
301@end deffn
302
303@defopt widget-mouse-face
6f7f063d
EZ
304Face used for highlighting a button when the mouse pointer moves across
305it.
6bf7aab6
DL
306@end defopt
307
308@subsection Navigation
309
310You can use all the normal Emacs commands to move around in a form
311buffer, plus you will have these additional commands:
312
313@table @kbd
314@item @key{TAB}
315@deffn Command widget-forward &optional count
316Move point @var{count} buttons or editing fields forward.
317@end deffn
318@item @key{M-TAB}
319@deffn Command widget-backward &optional count
320Move point @var{count} buttons or editing fields backward.
321@end deffn
322@end table
323
324@node Programming Example, Setting Up the Buffer, User Interface, Top
325@comment node-name, next, previous, up
326@section Programming Example
327
6f7f063d
EZ
328@cindex widgets, programming example
329@cindex example of using widgets
6bf7aab6
DL
330Here is the code to implement the user interface example (@pxref{User
331Interface}).
332
333@lisp
334(require 'widget)
335
336(eval-when-compile
337 (require 'wid-edit))
338
339(defvar widget-example-repeat)
340
341(defun widget-example ()
342 "Create the widgets from the Widget manual."
343 (interactive)
344 (switch-to-buffer "*Widget Example*")
345 (kill-all-local-variables)
346 (make-local-variable 'widget-example-repeat)
347 (let ((inhibit-read-only t))
348 (erase-buffer))
f24485f1 349 (remove-overlays)
6bf7aab6
DL
350 (widget-insert "Here is some documentation.\n\nName: ")
351 (widget-create 'editable-field
352 :size 13
8dbc532e 353 :format "%v " ; Text after the field!
6bf7aab6
DL
354 "My Name")
355 (widget-create 'menu-choice
356 :tag "Choose"
357 :value "This"
358 :help-echo "Choose me, please!"
359 :notify (lambda (widget &rest ignore)
360 (message "%s is a good choice!"
361 (widget-value widget)))
362 '(item :tag "This option" :value "This")
363 '(choice-item "That option")
364 '(editable-field :menu-tag "No option" "Thus option"))
365 (widget-insert "Address: ")
366 (widget-create 'editable-field
367 "Some Place\nIn some City\nSome country.")
368 (widget-insert "\nSee also ")
369 (widget-create 'link
370 :notify (lambda (&rest ignore)
177c0ea7 371 (widget-value-set widget-example-repeat
6bf7aab6
DL
372 '("En" "To" "Tre"))
373 (widget-setup))
374 "other work")
177c0ea7 375 (widget-insert
ec45fa10 376 " for more information.\n\nNumbers: count to three below\n")
6bf7aab6
DL
377 (setq widget-example-repeat
378 (widget-create 'editable-list
379 :entry-format "%i %d %v"
380 :notify (lambda (widget &rest ignore)
381 (let ((old (widget-get widget
382 ':example-length))
383 (new (length (widget-value widget))))
384 (unless (eq old new)
385 (widget-put widget ':example-length new)
386 (message "You can count to %d." new))))
387 :value '("One" "Eh, two?" "Five!")
388 '(editable-field :value "three")))
389 (widget-insert "\n\nSelect multiple:\n\n")
390 (widget-create 'checkbox t)
391 (widget-insert " This\n")
392 (widget-create 'checkbox nil)
393 (widget-insert " That\n")
394 (widget-create 'checkbox
395 :notify (lambda (&rest ignore) (message "Tickle"))
396 t)
397 (widget-insert " Thus\n\nSelect one:\n\n")
398 (widget-create 'radio-button-choice
399 :value "One"
400 :notify (lambda (widget &rest ignore)
401 (message "You selected %s"
402 (widget-value widget)))
403 '(item "One") '(item "Another One.") '(item "A Final One."))
404 (widget-insert "\n")
405 (widget-create 'push-button
177c0ea7 406 :notify (lambda (&rest ignore)
6bf7aab6
DL
407 (if (= (length (widget-value widget-example-repeat))
408 3)
409 (message "Congratulation!")
410 (error "Three was the count!")))
411 "Apply Form")
412 (widget-insert " ")
413 (widget-create 'push-button
414 :notify (lambda (&rest ignore)
415 (widget-example))
416 "Reset Form")
417 (widget-insert "\n")
418 (use-local-map widget-keymap)
419 (widget-setup))
420@end lisp
421
422@node Setting Up the Buffer, Basic Types, Programming Example, Top
423@comment node-name, next, previous, up
424@section Setting Up the Buffer
425
426Widgets are created with @code{widget-create}, which returns a
427@dfn{widget} object. This object can be queried and manipulated by
428other widget functions, until it is deleted with @code{widget-delete}.
429After the widgets have been created, @code{widget-setup} must be called
430to enable them.
431
432@defun widget-create type [ keyword argument ]@dots{}
433Create and return a widget of type @var{type}.
434The syntax for the @var{type} argument is described in @ref{Basic Types}.
435
436The keyword arguments can be used to overwrite the keyword arguments
437that are part of @var{type}.
438@end defun
439
440@defun widget-delete widget
441Delete @var{widget} and remove it from the buffer.
442@end defun
443
177c0ea7
JB
444@defun widget-setup
445Set up a buffer to support widgets.
6bf7aab6
DL
446
447This should be called after creating all the widgets and before allowing
448the user to edit them.
449@refill
450@end defun
451
452If you want to insert text outside the widgets in the form, the
453recommended way to do that is with @code{widget-insert}.
454
177c0ea7 455@defun widget-insert
6bf7aab6 456Insert the arguments, either strings or characters, at point.
6f7f063d 457The inserted text will be read-only.
6bf7aab6
DL
458@end defun
459
460There is a standard widget keymap which you might find useful.
461
6f7f063d
EZ
462@findex widget-button-press
463@findex widget-button-click
6bf7aab6
DL
464@defvr Const widget-keymap
465A keymap with the global keymap as its parent.@*
466@key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and
ce8abc78 467@code{widget-backward}, respectively. @key{RET} and @kbd{Mouse-2}
6bf7aab6 468are bound to @code{widget-button-press} and
6f7f063d 469@code{widget-button-click}.@refill
6bf7aab6
DL
470@end defvr
471
472@defvar widget-global-map
473Keymap used by @code{widget-button-press} and @code{widget-button-click}
474when not on a button. By default this is @code{global-map}.
475@end defvar
476
477@node Basic Types, Sexp Types, Setting Up the Buffer, Top
478@comment node-name, next, previous, up
479@section Basic Types
480
481The syntax of a type specification is given below:
482
483@example
484NAME ::= (NAME [KEYWORD ARGUMENT]... ARGS)
485 | NAME
486@end example
487
488Where, @var{name} is a widget name, @var{keyword} is the name of a
489property, @var{argument} is the value of the property, and @var{args}
490are interpreted in a widget specific way.
491
6f7f063d
EZ
492@cindex keyword arguments
493The following keyword arguments that apply to all widgets:
6bf7aab6
DL
494
495@table @code
6f7f063d 496@vindex value@r{ keyword}
6bf7aab6
DL
497@item :value
498The initial value for widgets of this type.
499
6f7f063d 500@vindex format@r{ keyword}
6bf7aab6
DL
501@item :format
502This string will be inserted in the buffer when you create a widget.
503The following @samp{%} escapes are available:
504
505@table @samp
506@item %[
507@itemx %]
508The text inside will be marked as a button.
509
510By default, the text will be shown in @code{widget-button-face}, and
177c0ea7 511surrounded by brackets.
6bf7aab6
DL
512
513@defopt widget-button-prefix
514String to prefix buttons.
515@end defopt
516
517@defopt widget-button-suffix
518String to suffix buttons.
519@end defopt
520
521@item %@{
522@itemx %@}
523The text inside will be displayed with the face specified by
177c0ea7 524@code{:sample-face}.
6bf7aab6
DL
525
526@item %v
54438eb5 527This will be replaced with the buffer representation of the widget's
6bf7aab6
DL
528value. What this is depends on the widget type.
529
530@item %d
531Insert the string specified by @code{:doc} here.
532
533@item %h
534Like @samp{%d}, with the following modifications: If the documentation
535string is more than one line, it will add a button which will toggle
536between showing only the first line, and showing the full text.
537Furthermore, if there is no @code{:doc} property in the widget, it will
538instead examine the @code{:documentation-property} property. If it is a
539lambda expression, it will be called with the widget's value as an
540argument, and the result will be used as the documentation text.
541
542@item %t
543Insert the string specified by @code{:tag} here, or the @code{princ}
544representation of the value if there is no tag.
545
546@item %%
177c0ea7 547Insert a literal @samp{%}.
6bf7aab6
DL
548@end table
549
6f7f063d 550@vindex button-face@r{ keyword}
6bf7aab6
DL
551@item :button-face
552Face used to highlight text inside %[ %] in the format.
553
6f7f063d
EZ
554@vindex button-prefix@r{ keyword}
555@vindex button-suffix@r{ keyword}
6bf7aab6
DL
556@item :button-prefix
557@itemx :button-suffix
6bf7aab6
DL
558Text around %[ %] in the format.
559
560These can be
561@table @emph
562@item nil
563No text is inserted.
564
565@item a string
566The string is inserted literally.
567
568@item a symbol
569The value of the symbol is expanded according to this table.
570@end table
571
6f7f063d 572@vindex doc@r{ keyword}
6bf7aab6
DL
573@item :doc
574The string inserted by the @samp{%d} escape in the format
177c0ea7 575string.
6bf7aab6 576
6f7f063d 577@vindex tag@r{ keyword}
6bf7aab6
DL
578@item :tag
579The string inserted by the @samp{%t} escape in the format
177c0ea7 580string.
6bf7aab6 581
6f7f063d 582@vindex tag-glyph@r{ keyword}
6bf7aab6 583@item :tag-glyph
6f7f063d 584Name of image to use instead of the string specified by @code{:tag} on
6bf7aab6
DL
585Emacsen that supports it.
586
6f7f063d 587@vindex help-echo@r{ keyword}
6bf7aab6 588@item :help-echo
a159375d
DL
589Specifies how to display a message whenever you move to the widget with
590either @code{widget-forward} or @code{widget-backward} or move the mouse
56600dfa 591over it (using the standard @code{help-echo} mechanism). The argument
b0ab008b
LT
592is either a string to display, a function of one argument, the widget,
593which should return a string to display, or a form that evaluates to
594such a string.
6bf7aab6 595
d3ceff91
KS
596@vindex follow-link@r{ keyword}
597@item :follow-link
598Specifies how to interpret a @key{mouse-1} click on the widget.
1fd0f7a6 599@xref{Links and Mouse-1,,, elisp, the Emacs Lisp Reference Manual}.
d3ceff91 600
6f7f063d 601@vindex indent@r{ keyword}
6bf7aab6
DL
602@item :indent
603An integer indicating the absolute number of spaces to indent children
604of this widget.
605
6f7f063d 606@vindex offset@r{ keyword}
6bf7aab6
DL
607@item :offset
608An integer indicating how many extra spaces to add to the widget's
609grandchildren compared to this widget.
610
6f7f063d 611@vindex extra-offset@r{ keyword}
6bf7aab6
DL
612@item :extra-offset
613An integer indicating how many extra spaces to add to the widget's
614children compared to this widget.
615
6f7f063d 616@vindex notify@r{ keyword}
6bf7aab6
DL
617@item :notify
618A function called each time the widget or a nested widget is changed.
619The function is called with two or three arguments. The first argument
620is the widget itself, the second argument is the widget that was
621changed, and the third argument is the event leading to the change, if
177c0ea7 622any.
6bf7aab6 623
6f7f063d 624@vindex menu-tag@r{ keyword}
6bf7aab6
DL
625@item :menu-tag
626Tag used in the menu when the widget is used as an option in a
627@code{menu-choice} widget.
628
6f7f063d 629@vindex menu-tag-get@r{ keyword}
6bf7aab6
DL
630@item :menu-tag-get
631Function used for finding the tag when the widget is used as an option
632in a @code{menu-choice} widget. By default, the tag used will be either the
633@code{:menu-tag} or @code{:tag} property if present, or the @code{princ}
634representation of the @code{:value} property if not.
635
6f7f063d 636@vindex match@r{ keyword}
6bf7aab6
DL
637@item :match
638Should be a function called with two arguments, the widget and a value,
65247564 639and returning non-@code{nil} if the widget can represent the specified value.
6bf7aab6 640
6f7f063d 641@vindex validate@r{ keyword}
6bf7aab6 642@item :validate
6f7f063d
EZ
643A function which takes a widget as an argument, and returns @code{nil}
644if the widget's current value is valid for the widget. Otherwise it
645should return the widget containing the invalid data, and set that
646widget's @code{:error} property to a string explaining the error.
6bf7aab6
DL
647
648The following predefined function can be used:
649
650@defun widget-children-validate widget
651All the @code{:children} of @var{widget} must be valid.
652@end defun
653
6f7f063d 654@vindex tab-order@r{ keyword}
6bf7aab6
DL
655@item :tab-order
656Specify the order in which widgets are traversed with
657@code{widget-forward} or @code{widget-backward}. This is only partially
658implemented.
659
660@enumerate a
661@item
662Widgets with tabbing order @code{-1} are ignored.
663
177c0ea7 664@item
6bf7aab6
DL
665(Unimplemented) When on a widget with tabbing order @var{n}, go to the
666next widget in the buffer with tabbing order @var{n+1} or @code{nil},
667whichever comes first.
668
669@item
670When on a widget with no tabbing order specified, go to the next widget
671in the buffer with a positive tabbing order, or @code{nil}
672@end enumerate
673
6f7f063d 674@vindex parent@r{ keyword}
6bf7aab6 675@item :parent
a159375d 676The parent of a nested widget (e.g.@: a @code{menu-choice} item or an
6bf7aab6
DL
677element of a @code{editable-list} widget).
678
6f7f063d 679@vindex sibling-args@r{ keyword}
6bf7aab6
DL
680@item :sibling-args
681This keyword is only used for members of a @code{radio-button-choice} or
682@code{checklist}. The value should be a list of extra keyword
683arguments, which will be used when creating the @code{radio-button} or
684@code{checkbox} associated with this item.
685
686@end table
687
688@deffn {User Option} widget-glyph-directory
177c0ea7 689Directory where glyphs are found.
6bf7aab6 690Widget will look here for a file with the same name as specified for the
6f7f063d 691image, with either a @file{.xpm} (if supported) or @file{.xbm} extension.
6bf7aab6
DL
692@end deffn
693
694@deffn{User Option} widget-glyph-enable
9995b954 695If non-@code{nil}, allow glyphs to appear on displays where they are supported.
6bf7aab6
DL
696@end deffn
697
698
699@menu
177c0ea7
JB
700* link::
701* url-link::
702* info-link::
703* push-button::
704* editable-field::
705* text::
706* menu-choice::
707* radio-button-choice::
708* item::
709* choice-item::
710* toggle::
711* checkbox::
712* checklist::
713* editable-list::
714* group::
6bf7aab6
DL
715@end menu
716
717@node link, url-link, Basic Types, Basic Types
718@comment node-name, next, previous, up
719@subsection The @code{link} Widget
6f7f063d 720@findex link@r{ widget}
6bf7aab6
DL
721
722Syntax:
723
724@example
725TYPE ::= (link [KEYWORD ARGUMENT]... [ VALUE ])
726@end example
727
728The @var{value}, if present, is used to initialize the @code{:value}
729property. The value should be a string, which will be inserted in the
177c0ea7 730buffer.
6bf7aab6
DL
731
732By default the link will be shown in brackets.
733
734@defopt widget-link-prefix
735String to prefix links.
736@end defopt
737
738@defopt widget-link-suffix
739String to suffix links.
740@end defopt
741
742@node url-link, info-link, link, Basic Types
743@comment node-name, next, previous, up
744@subsection The @code{url-link} Widget
6f7f063d 745@findex url-link@r{ widget}
6bf7aab6
DL
746
747Syntax:
748
749@example
750TYPE ::= (url-link [KEYWORD ARGUMENT]... URL)
751@end example
752
6f7f063d 753@findex browse-url-browser-function@r{, and @code{url-link} widget}
76dd3692 754When this link is invoked, the @acronym{WWW} browser specified by
177c0ea7 755@code{browse-url-browser-function} will be called with @var{url}.
6bf7aab6
DL
756
757@node info-link, push-button, url-link, Basic Types
758@comment node-name, next, previous, up
759@subsection The @code{info-link} Widget
6f7f063d 760@findex info-link@r{ widget}
6bf7aab6
DL
761
762Syntax:
763
764@example
765TYPE ::= (info-link [KEYWORD ARGUMENT]... ADDRESS)
766@end example
767
6f7f063d 768When this link is invoked, the built-in Info reader is started on
177c0ea7 769@var{address}.
6bf7aab6
DL
770
771@node push-button, editable-field, info-link, Basic Types
772@comment node-name, next, previous, up
773@subsection The @code{push-button} Widget
6f7f063d 774@findex push-button@r{ widget}
6bf7aab6
DL
775
776Syntax:
777
778@example
779TYPE ::= (push-button [KEYWORD ARGUMENT]... [ VALUE ])
780@end example
781
782The @var{value}, if present, is used to initialize the @code{:value}
6f7f063d 783property. The value should be a string, which will be inserted in the
177c0ea7 784buffer.
6bf7aab6
DL
785
786By default the tag will be shown in brackets.
787
788@defopt widget-push-button-prefix
789String to prefix push buttons.
790@end defopt
791
792@defopt widget-push-button-suffix
793String to suffix push buttons.
794@end defopt
795
796@node editable-field, text, push-button, Basic Types
797@comment node-name, next, previous, up
798@subsection The @code{editable-field} Widget
6f7f063d 799@findex editable-field@r{ widget}
6bf7aab6
DL
800
801Syntax:
802
803@example
804TYPE ::= (editable-field [KEYWORD ARGUMENT]... [ VALUE ])
805@end example
806
807The @var{value}, if present, is used to initialize the @code{:value}
808property. The value should be a string, which will be inserted in
809field. This widget will match all string values.
810
6f7f063d 811The following extra properties are recognized:
6bf7aab6
DL
812
813@table @code
6f7f063d 814@vindex size@r{ keyword}
6bf7aab6
DL
815@item :size
816The width of the editable field.@*
817By default the field will reach to the end of the line.
818
6f7f063d 819@vindex value-face@r{ keyword}
6bf7aab6
DL
820@item :value-face
821Face used for highlighting the editable field. Default is
177c0ea7 822@code{widget-field-face}, see @ref{User Interface}.
6bf7aab6 823
6f7f063d 824@vindex secret@r{ keyword}
6bf7aab6 825@item :secret
a159375d 826Character used to display the value. You can set this to e.g.@: @code{?*}
6bf7aab6 827if the field contains a password or other secret information. By
9995b954 828default, this is @code{nil}, and the value is not secret.
6bf7aab6 829
6f7f063d 830@vindex valid-regexp@r{ keyword}
6bf7aab6
DL
831@item :valid-regexp
832By default the @code{:validate} function will match the content of the
833field with the value of this attribute. The default value is @code{""}
834which matches everything.
835
6f7f063d
EZ
836@vindex keymap@r{ keyword}
837@vindex widget-field-keymap
6bf7aab6
DL
838@item :keymap
839Keymap used in the editable field. The default value is
840@code{widget-field-keymap}, which allows you to use all the normal
6f7f063d
EZ
841editing commands, even if the buffer's major mode suppresses some of
842them. Pressing @key{RET} invokes the function specified by
843@code{:action}.
6bf7aab6
DL
844@end table
845
846@node text, menu-choice, editable-field, Basic Types
847@comment node-name, next, previous, up
848@subsection The @code{text} Widget
6f7f063d 849@findex text@r{ widget}
6bf7aab6 850
6f7f063d 851@vindex widget-text-keymap
6bf7aab6
DL
852This is just like @code{editable-field}, but intended for multiline text
853fields. The default @code{:keymap} is @code{widget-text-keymap}, which
6f7f063d 854does not rebind the @key{RET} key.
6bf7aab6
DL
855
856@node menu-choice, radio-button-choice, text, Basic Types
857@comment node-name, next, previous, up
858@subsection The @code{menu-choice} Widget
6f7f063d 859@findex menu-choice@r{ widget}
6bf7aab6
DL
860
861Syntax:
862
863@example
864TYPE ::= (menu-choice [KEYWORD ARGUMENT]... TYPE ... )
865@end example
866
54438eb5
DL
867The @var{type} argument represents each possible choice. The widget's
868value will be that of the chosen @var{type} argument. This widget will
869match any value matching at least one of the specified @var{type}
870arguments.
6bf7aab6
DL
871
872@table @code
6f7f063d 873@vindex void@r{ keyword}
177c0ea7 874@item :void
6bf7aab6
DL
875Widget type used as a fallback when the value does not match any of the
876specified @var{type} arguments.
877
6f7f063d 878@vindex case-fold@r{ keyword}
6bf7aab6 879@item :case-fold
9995b954 880Set this to @code{nil} if you don't want to ignore case when prompting for a
6bf7aab6
DL
881choice through the minibuffer.
882
6f7f063d 883@vindex children@r{ keyword}
6bf7aab6 884@item :children
9995b954 885A list whose @sc{car} is the widget representing the currently chosen
6f7f063d 886type in the buffer.
6bf7aab6 887
6f7f063d 888@vindex choice@r{ keyword}
6bf7aab6 889@item :choice
6f7f063d 890The current chosen type.
6bf7aab6 891
6f7f063d 892@vindex args@r{ keyword}
177c0ea7
JB
893@item :args
894The list of types.
6bf7aab6
DL
895@end table
896
897@node radio-button-choice, item, menu-choice, Basic Types
898@comment node-name, next, previous, up
899@subsection The @code{radio-button-choice} Widget
6f7f063d 900@findex radio-button-choice@r{ widget}
6bf7aab6
DL
901
902Syntax:
903
904@example
905TYPE ::= (radio-button-choice [KEYWORD ARGUMENT]... TYPE ... )
906@end example
907
54438eb5
DL
908The @var{type} argument represents each possible choice. The widget's
909value will be that of the chosen @var{type} argument. This widget will
910match any value matching at least one of the specified @var{type}
911arguments.
6bf7aab6
DL
912
913The following extra properties are recognized.
914
915@table @code
6f7f063d 916@vindex entry-format@r{ keyword}
6bf7aab6
DL
917@item :entry-format
918This string will be inserted for each entry in the list.
919The following @samp{%} escapes are available:
920@table @samp
921@item %v
6f7f063d 922Replace with the buffer representation of the @var{type} widget.
6bf7aab6
DL
923@item %b
924Replace with the radio button.
925@item %%
177c0ea7 926Insert a literal @samp{%}.
6bf7aab6
DL
927@end table
928
6f7f063d
EZ
929@vindex button-args@r{ keyword}
930@item :button-args
6bf7aab6 931A list of keywords to pass to the radio buttons. Useful for setting
a159375d 932e.g.@: the @samp{:help-echo} for each button.
6bf7aab6 933
6f7f063d 934@vindex buttons@r{ keyword}
6bf7aab6
DL
935@item :buttons
936The widgets representing the radio buttons.
937
6f7f063d 938@vindex children@r{ keyword}
6bf7aab6
DL
939@item :children
940The widgets representing each type.
941
6f7f063d 942@vindex choice@r{ keyword}
6bf7aab6
DL
943@item :choice
944The current chosen type
945
6f7f063d 946@vindex args@r{ keyword}
177c0ea7
JB
947@item :args
948The list of types.
6bf7aab6
DL
949@end table
950
951You can add extra radio button items to a @code{radio-button-choice}
952widget after it has been created with the function
177c0ea7 953@code{widget-radio-add-item}.
6bf7aab6
DL
954
955@defun widget-radio-add-item widget type
6f7f063d
EZ
956Add to @code{radio-button-choice} widget @var{widget} a new radio button
957item of type @var{type}.
6bf7aab6
DL
958@end defun
959
960Please note that such items added after the @code{radio-button-choice}
961widget has been created will @strong{not} be properly destructed when
962you call @code{widget-delete}.
963
964@node item, choice-item, radio-button-choice, Basic Types
965@comment node-name, next, previous, up
966@subsection The @code{item} Widget
6f7f063d 967@findex item@r{ widget}
6bf7aab6
DL
968
969Syntax:
970
971@example
972ITEM ::= (item [KEYWORD ARGUMENT]... VALUE)
973@end example
974
975The @var{value}, if present, is used to initialize the @code{:value}
976property. The value should be a string, which will be inserted in the
977buffer. This widget will only match the specified value.
978
979@node choice-item, toggle, item, Basic Types
980@comment node-name, next, previous, up
981@subsection The @code{choice-item} Widget
6f7f063d 982@findex choice-item@r{ widget}
6bf7aab6
DL
983
984Syntax:
985
986@example
987ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE)
988@end example
989
990The @var{value}, if present, is used to initialize the @code{:value}
991property. The value should be a string, which will be inserted in the
992buffer as a button. Activating the button of a @code{choice-item} is
993equivalent to activating the parent widget. This widget will only match
177c0ea7 994the specified value.
6bf7aab6
DL
995
996@node toggle, checkbox, choice-item, Basic Types
997@comment node-name, next, previous, up
998@subsection The @code{toggle} Widget
6f7f063d 999@findex toggle@r{ widget}
6bf7aab6
DL
1000
1001Syntax:
1002
1003@example
1004TYPE ::= (toggle [KEYWORD ARGUMENT]...)
1005@end example
1006
6f7f063d
EZ
1007The widget has two possible states, @samp{on} and @samp{off}, which
1008correspond to a @code{t} or @code{nil} value, respectively.
6bf7aab6 1009
6f7f063d 1010The following extra properties are recognized:
6bf7aab6
DL
1011
1012@table @code
1013@item :on
6f7f063d
EZ
1014A string representing the @samp{on} state. By default the string
1015@samp{on}.
177c0ea7 1016@item :off
6f7f063d
EZ
1017A string representing the @samp{off} state. By default the string
1018@samp{off}.
1019@vindex on-glyph@r{ keyword}
6bf7aab6 1020@item :on-glyph
6f7f063d
EZ
1021Name of a glyph to be used instead of the @samp{:on} text string, on
1022emacsen that supports this.
1023@vindex off-glyph@r{ keyword}
6bf7aab6 1024@item :off-glyph
6f7f063d
EZ
1025Name of a glyph to be used instead of the @samp{:off} text string, on
1026emacsen that supports this.
6bf7aab6
DL
1027@end table
1028
1029@node checkbox, checklist, toggle, Basic Types
1030@comment node-name, next, previous, up
1031@subsection The @code{checkbox} Widget
6f7f063d 1032@findex checkbox@r{ widget}
6bf7aab6 1033
6f7f063d
EZ
1034This widget has two possible states, @samp{selected} and
1035@samp{unselected}, which corresponds to a @code{t} or @code{nil} value.
6bf7aab6
DL
1036
1037Syntax:
1038
1039@example
1040TYPE ::= (checkbox [KEYWORD ARGUMENT]...)
1041@end example
1042
1043@node checklist, editable-list, checkbox, Basic Types
1044@comment node-name, next, previous, up
1045@subsection The @code{checklist} Widget
6f7f063d 1046@findex checklist@r{ widget}
6bf7aab6
DL
1047
1048Syntax:
1049
1050@example
1051TYPE ::= (checklist [KEYWORD ARGUMENT]... TYPE ... )
1052@end example
1053
6f7f063d
EZ
1054The @var{type} arguments represent each checklist item. The widget's
1055value will be a list containing the values of all checked @var{type}
54438eb5
DL
1056arguments. The checklist widget will match a list whose elements all
1057match at least one of the specified @var{type} arguments.
6bf7aab6 1058
6f7f063d 1059The following extra properties are recognized:
6bf7aab6
DL
1060
1061@table @code
6f7f063d 1062@vindex entry-format@r{ keyword}
6bf7aab6
DL
1063@item :entry-format
1064This string will be inserted for each entry in the list.
1065The following @samp{%} escapes are available:
1066@table @samp
1067@item %v
1068Replaced with the buffer representation of the @var{type} widget.
1069@item %b
1070Replace with the checkbox.
1071@item %%
177c0ea7 1072Insert a literal @samp{%}.
6bf7aab6
DL
1073@end table
1074
6f7f063d 1075@vindex greedy@r{ keyword}
6bf7aab6 1076@item :greedy
54438eb5 1077Usually a checklist will only match if the items are in the exact
6bf7aab6 1078sequence given in the specification. By setting @code{:greedy} to
9995b954
JH
1079non-@code{nil}, it will allow the items to come in any sequence.
1080However, if you extract the value they will be in the sequence given
1081in the checklist, i.e.@: the original sequence is forgotten.
6bf7aab6 1082
6f7f063d 1083@vindex button-args@r{ keyword}
a159375d 1084@item :button-args
6bf7aab6 1085A list of keywords to pass to the checkboxes. Useful for setting
a159375d 1086e.g.@: the @samp{:help-echo} for each checkbox.
6bf7aab6 1087
6f7f063d 1088@vindex buttons@r{ keyword}
6bf7aab6
DL
1089@item :buttons
1090The widgets representing the checkboxes.
1091
6f7f063d 1092@vindex children@r{ keyword}
6bf7aab6
DL
1093@item :children
1094The widgets representing each type.
1095
6f7f063d 1096@vindex args@r{ keyword}
177c0ea7
JB
1097@item :args
1098The list of types.
6bf7aab6
DL
1099@end table
1100
1101@node editable-list, group, checklist, Basic Types
1102@comment node-name, next, previous, up
1103@subsection The @code{editable-list} Widget
6f7f063d 1104@findex editable-list@r{ widget}
6bf7aab6
DL
1105
1106Syntax:
1107
1108@example
1109TYPE ::= (editable-list [KEYWORD ARGUMENT]... TYPE)
1110@end example
1111
1112The value is a list, where each member represents one widget of type
177c0ea7 1113@var{type}.
6bf7aab6 1114
6f7f063d 1115The following extra properties are recognized:
6bf7aab6
DL
1116
1117@table @code
6f7f063d 1118@vindex entry-format@r{ keyword}
6bf7aab6
DL
1119@item :entry-format
1120This string will be inserted for each entry in the list.
1121The following @samp{%} escapes are available:
1122@table @samp
1123@item %v
1124This will be replaced with the buffer representation of the @var{type}
1125widget.
1126@item %i
976e00f1 1127Insert the @b{[INS]} button.
6bf7aab6
DL
1128@item %d
1129Insert the @b{[DEL]} button.
1130@item %%
177c0ea7 1131Insert a literal @samp{%}.
6bf7aab6
DL
1132@end table
1133
976e00f1
DL
1134@vindex insert-button-args@r{ keyword}
1135@item :insert-button-args
6bf7aab6
DL
1136A list of keyword arguments to pass to the insert buttons.
1137
6f7f063d 1138@vindex delete-button-args@r{ keyword}
6bf7aab6
DL
1139@item :delete-button-args
1140A list of keyword arguments to pass to the delete buttons.
1141
6f7f063d 1142@vindex append-button-args@r{ keyword}
6bf7aab6
DL
1143@item :append-button-args
1144A list of keyword arguments to pass to the trailing insert button.
1145
6f7f063d 1146@vindex buttons@r{ keyword}
6bf7aab6
DL
1147@item :buttons
1148The widgets representing the insert and delete buttons.
1149
6f7f063d 1150@vindex children@r{ keyword}
6bf7aab6
DL
1151@item :children
1152The widgets representing the elements of the list.
1153
6f7f063d 1154@vindex args@r{ keyword}
6bf7aab6 1155@item :args
9995b954 1156List whose @sc{car} is the type of the list elements.
6bf7aab6
DL
1157@end table
1158
1159@node group, , editable-list, Basic Types
1160@comment node-name, next, previous, up
1161@subsection The @code{group} Widget
6f7f063d 1162@findex group@r{ widget}
6bf7aab6 1163
6f7f063d 1164This widget simply group other widgets together.
6bf7aab6
DL
1165
1166Syntax:
1167
1168@example
1169TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...)
1170@end example
1171
177c0ea7 1172The value is a list, with one member for each @var{type}.
6bf7aab6
DL
1173
1174@node Sexp Types, Widget Properties, Basic Types, Top
1175@comment
1176@section Sexp Types
6f7f063d 1177@cindex sexp types
6bf7aab6 1178
9995b954 1179A number of widgets for editing @dfn{s-expressions} (Lisp types), sexp
6f7f063d
EZ
1180for short, are also available. These basically fall in several
1181categories described in this section.
6bf7aab6
DL
1182
1183@menu
177c0ea7
JB
1184* constants::
1185* generic::
1186* atoms::
1187* composite::
6bf7aab6
DL
1188@end menu
1189
1190@node constants, generic, Sexp Types, Sexp Types
1191@comment node-name, next, previous, up
6f7f063d
EZ
1192@subsection The Constant Widgets
1193@cindex constant widgets
6bf7aab6 1194
9995b954 1195The @code{const} widget can contain any Lisp expression, but the user is
6f7f063d
EZ
1196prohibited from editing it, which is mainly useful as a component of one
1197of the composite widgets.
6bf7aab6 1198
6f7f063d 1199The syntax for the @code{const} widget is:
6bf7aab6
DL
1200
1201@example
1202TYPE ::= (const [KEYWORD ARGUMENT]... [ VALUE ])
1203@end example
1204
1205The @var{value}, if present, is used to initialize the @code{:value}
1206property and can be any s-expression.
1207
1208@deffn Widget const
1209This will display any valid s-expression in an immutable part of the
177c0ea7 1210buffer.
6bf7aab6
DL
1211@end deffn
1212
1213There are two variations of the @code{const} widget, namely
1214@code{variable-item} and @code{function-item}. These should contain a
1215symbol with a variable or function binding. The major difference from
1216the @code{const} widget is that they will allow the user to see the
1217variable or function documentation for the symbol.
1218
1219@deffn Widget variable-item
1220An immutable symbol that is bound as a variable.
1221@end deffn
1222
1223@deffn Widget function-item
1224An immutable symbol that is bound as a function.
1225@end deffn
1226
1227@node generic, atoms, constants, Sexp Types
1228@comment node-name, next, previous, up
6f7f063d
EZ
1229@subsection Generic Sexp Widget
1230@cindex generic sexp widget
6bf7aab6 1231
9995b954 1232The @code{sexp} widget can contain any Lisp expression, and allows the
6bf7aab6
DL
1233user to edit it inline in the buffer.
1234
6f7f063d 1235The syntax for the @code{sexp} widget is:
6bf7aab6
DL
1236
1237@example
1238TYPE ::= (sexp [KEYWORD ARGUMENT]... [ VALUE ])
1239@end example
1240
1241@deffn Widget sexp
1242This will allow you to edit any valid s-expression in an editable buffer
177c0ea7 1243field.
6bf7aab6
DL
1244
1245The @code{sexp} widget takes the same keyword arguments as the
6f7f063d 1246@code{editable-field} widget. @xref{editable-field}.
6bf7aab6
DL
1247@end deffn
1248
1249@node atoms, composite, generic, Sexp Types
1250@comment node-name, next, previous, up
6f7f063d
EZ
1251@subsection Atomic Sexp Widgets
1252@cindex atomic sexp widget
6bf7aab6 1253
6f7f063d
EZ
1254The atoms are s-expressions that do not consist of other s-expressions.
1255For example, a string, a file name, or a symbol are atoms, while a list
1256is a composite type. You can edit the value of an atom with the
1257following widgets.
6bf7aab6 1258
6f7f063d 1259The syntax for all the atoms are:
6bf7aab6
DL
1260
1261@example
1262TYPE ::= (NAME [KEYWORD ARGUMENT]... [ VALUE ])
1263@end example
1264
1265The @var{value}, if present, is used to initialize the @code{:value}
1266property and must be an expression of the same type as the widget.
6f7f063d 1267That is, the string widget can only be initialized with a string.
6bf7aab6
DL
1268
1269All the atom widgets take the same keyword arguments as the
6f7f063d 1270@code{editable-field} widget. @xref{editable-field}.
6bf7aab6
DL
1271
1272@deffn Widget string
1273Allows you to edit a string in an editable field.
1274@end deffn
1275
1276@deffn Widget regexp
1277Allows you to edit a regular expression in an editable field.
1278@end deffn
1279
1280@deffn Widget character
1281Allows you to enter a character in an editable field.
1282@end deffn
1283
1284@deffn Widget file
1285Allows you to edit a file name in an editable field. If you invoke
1286the tag button, you can edit the file name in the mini-buffer with
177c0ea7 1287completion.
6bf7aab6
DL
1288
1289Keywords:
1290@table @code
6f7f063d 1291@vindex must-match@r{ keyword}
6bf7aab6 1292@item :must-match
9995b954
JH
1293If this is set to non-@code{nil}, only existing file names will be
1294allowed in the minibuffer.
6bf7aab6
DL
1295@end table
1296@end deffn
1297
1298@deffn Widget directory
1299Allows you to edit a directory name in an editable field.
1300Similar to the @code{file} widget.
1301@end deffn
1302
1303@deffn Widget symbol
9995b954 1304Allows you to edit a Lisp symbol in an editable field.
6bf7aab6
DL
1305@end deffn
1306
1307@deffn Widget function
1308Allows you to edit a lambda expression, or a function name with completion.
1309@end deffn
1310
1311@deffn Widget variable
1312Allows you to edit a variable name, with completion.
1313@end deffn
1314
1315@deffn Widget integer
1316Allows you to edit an integer in an editable field.
1317@end deffn
1318
1319@deffn Widget number
1320Allows you to edit a number in an editable field.
1321@end deffn
1322
1323@deffn Widget boolean
9995b954
JH
1324Allows you to edit a boolean. In Lisp this means a variable which is
1325either @code{nil} meaning false, or non-@code{nil} meaning true.
6bf7aab6
DL
1326@end deffn
1327
1328
1329@node composite, , atoms, Sexp Types
1330@comment node-name, next, previous, up
6f7f063d
EZ
1331@subsection Composite Sexp Widgets
1332@cindex composite sexp widgets
6bf7aab6 1333
6f7f063d 1334The syntax for the composite widget is:
6bf7aab6
DL
1335
1336@example
1337TYPE ::= (NAME [KEYWORD ARGUMENT]... COMPONENT...)
1338@end example
1339
6f7f063d
EZ
1340@noindent
1341where each @var{component} must be a widget type. Each component widget
1342will be displayed in the buffer, and will be editable by the user.
6bf7aab6
DL
1343
1344@deffn Widget cons
9995b954
JH
1345The value of a @code{cons} widget is a cons-cell where the @sc{car} is
1346the value of the first component and the @sc{cdr} is the value of the
6f7f063d 1347second component. There must be exactly two components.
6bf7aab6
DL
1348@end deffn
1349
1350@deffn Widget list
1351The value of a @code{list} widget is a list containing the value of
1352each of its component.
1353@end deffn
1354
1355@deffn Widget vector
1356The value of a @code{vector} widget is a vector containing the value of
1357each of its component.
1358@end deffn
1359
1360The above suffice for specifying fixed size lists and vectors. To get
1361variable length lists and vectors, you can use a @code{choice},
6f7f063d 1362@code{set}, or @code{repeat} widgets together with the @code{:inline}
6bf7aab6
DL
1363keywords. If any component of a composite widget has the @code{:inline}
1364keyword set, its value must be a list which will then be spliced into
1365the composite. For example, to specify a list whose first element must
1366be a file name, and whose remaining arguments should either by the
1367symbol @code{t} or two files, you can use the following widget
1368specification:
1369
1370@example
1371(list file
1372 (choice (const t)
1373 (list :inline t
1374 :value ("foo" "bar")
1375 string string)))
1376@end example
1377
177c0ea7 1378The value of a widget of this type will either have the form
6f7f063d 1379@code{(file t)} or @code{(file string string)}.
6bf7aab6
DL
1380
1381This concept of inline is probably hard to understand. It was certainly
6f7f063d 1382hard to implement, so instead of confusing you more by trying to explain
54438eb5 1383it here, I'll just suggest you meditate over it for a while.
6bf7aab6
DL
1384
1385@deffn Widget choice
54438eb5
DL
1386Allows you to edit a sexp which may have one of a fixed set of types.
1387It is currently implemented with the @code{choice-menu} basic widget,
1388and has a similar syntax.
6bf7aab6
DL
1389@end deffn
1390
1391@deffn Widget set
1392Allows you to specify a type which must be a list whose elements all
6f7f063d
EZ
1393belong to given set. The elements of the list are not significant.
1394This is implemented on top of the @code{checklist} basic widget, and has
1395a similar syntax.
6bf7aab6
DL
1396@end deffn
1397
1398@deffn Widget repeat
1399Allows you to specify a variable length list whose members are all of
6f7f063d
EZ
1400the same type. Implemented on top of the @code{editable-list} basic
1401widget, and has a similar syntax.
6bf7aab6
DL
1402@end deffn
1403
1404@node Widget Properties, Defining New Widgets, Sexp Types, Top
1405@comment node-name, next, previous, up
1406@section Properties
6f7f063d
EZ
1407@cindex properties of widgets
1408@cindex widget properties
6bf7aab6
DL
1409
1410You can examine or set the value of a widget by using the widget object
1411that was returned by @code{widget-create}.
1412
1413@defun widget-value widget
1414Return the current value contained in @var{widget}.
1415It is an error to call this function on an uninitialized widget.
1416@end defun
1417
1418@defun widget-value-set widget value
1419Set the value contained in @var{widget} to @var{value}.
1420It is an error to call this function with an invalid @var{value}.
1421@end defun
1422
1423@strong{Important:} You @emph{must} call @code{widget-setup} after
1424modifying the value of a widget before the user is allowed to edit the
1425widget again. It is enough to call @code{widget-setup} once if you
1426modify multiple widgets. This is currently only necessary if the widget
1427contains an editing field, but may be necessary for other widgets in the
177c0ea7 1428future.
6bf7aab6
DL
1429
1430If your application needs to associate some information with the widget
1431objects, for example a reference to the item being edited, it can be
1432done with @code{widget-put} and @code{widget-get}. The property names
1433must begin with a @samp{:}.
1434
1435@defun widget-put widget property value
1436In @var{widget} set @var{property} to @var{value}.
1437@var{property} should be a symbol, while @var{value} can be anything.
1438@end defun
1439
1440@defun widget-get widget property
1441In @var{widget} return the value for @var{property}.
1442@var{property} should be a symbol, the value is what was last set by
1443@code{widget-put} for @var{property}.
1444@end defun
1445
1446@defun widget-member widget property
9995b954
JH
1447Non-@code{nil} if @var{widget} has a value (even @code{nil}) for
1448property @var{property}.
6bf7aab6
DL
1449@end defun
1450
1451Occasionally it can be useful to know which kind of widget you have,
177c0ea7 1452i.e.@: the name of the widget type you gave when the widget was created.
6bf7aab6
DL
1453
1454@defun widget-type widget
1455Return the name of @var{widget}, a symbol.
1456@end defun
1457
6f7f063d
EZ
1458@cindex active widget
1459@cindex inactive widget
1460@cindex activate a widget
1461@cindex deactivate a widget
6bf7aab6
DL
1462Widgets can be in two states: active, which means they are modifiable by
1463the user, or inactive, which means they cannot be modified by the user.
1464You can query or set the state with the following code:
1465
1466@lisp
1467;; Examine if @var{widget} is active or not.
1468(if (widget-apply @var{widget} :active)
1469 (message "Widget is active.")
1470 (message "Widget is inactive.")
1471
1472;; Make @var{widget} inactive.
1473(widget-apply @var{widget} :deactivate)
1474
1475;; Make @var{widget} active.
1476(widget-apply @var{widget} :activate)
1477@end lisp
1478
54438eb5
DL
1479A widget is inactive if it, or any of its ancestors (found by
1480following the @code{:parent} link), have been deactivated. To make sure
1481a widget is really active, you must therefore activate both it and
6bf7aab6
DL
1482all its ancestors.
1483
1484@lisp
177c0ea7 1485(while widget
6bf7aab6
DL
1486 (widget-apply widget :activate)
1487 (setq widget (widget-get widget :parent)))
1488@end lisp
1489
1490You can check if a widget has been made inactive by examining the value
9995b954 1491of the @code{:inactive} keyword. If this is non-@code{nil}, the widget itself
54438eb5
DL
1492has been deactivated. This is different from using the @code{:active}
1493keyword, in that the latter tells you if the widget @strong{or} any of
1494its ancestors have been deactivated. Do not attempt to set the
6bf7aab6 1495@code{:inactive} keyword directly. Use the @code{:activate}
54438eb5 1496@code{:deactivate} keywords instead.
6bf7aab6
DL
1497
1498
1499@node Defining New Widgets, Widget Browser, Widget Properties, Top
1500@comment node-name, next, previous, up
1501@section Defining New Widgets
6f7f063d
EZ
1502@cindex new widgets
1503@cindex defining new widgets
6bf7aab6 1504
75ba82a9 1505You can define specialized widgets with @code{define-widget}. It allows
6bf7aab6 1506you to create a shorthand for more complex widgets, including specifying
54438eb5 1507component widgets and new default values for the keyword
177c0ea7 1508arguments.
6bf7aab6 1509
75ba82a9 1510@defun define-widget name class doc &rest args
6bf7aab6
DL
1511Define a new widget type named @var{name} from @code{class}.
1512
1513@var{name} and class should both be symbols, @code{class} should be one
177c0ea7 1514of the existing widget types.
6bf7aab6 1515
9995b954 1516The third argument @var{doc} is a documentation string for the widget.
6bf7aab6
DL
1517
1518After the new widget has been defined, the following two calls will
1519create identical widgets:
1520
1521@itemize @bullet
1522@item
1523@lisp
1524(widget-create @var{name})
1525@end lisp
1526
1527@item
1528@lisp
1529(apply widget-create @var{class} @var{args})
1530@end lisp
1531@end itemize
1532
1533@end defun
1534
75ba82a9 1535Using @code{define-widget} just stores the definition of the widget type
54438eb5 1536in the @code{widget-type} property of @var{name}, which is what
6bf7aab6
DL
1537@code{widget-create} uses.
1538
6f7f063d 1539If you only want to specify defaults for keywords with no complex
6bf7aab6
DL
1540conversions, you can use @code{identity} as your conversion function.
1541
1542The following additional keyword arguments are useful when defining new
177c0ea7 1543widgets:
6bf7aab6 1544@table @code
6f7f063d 1545@vindex convert-widget@r{ keyword}
6bf7aab6
DL
1546@item :convert-widget
1547Function to convert a widget type before creating a widget of that
1548type. It takes a widget type as an argument, and returns the converted
1549widget type. When a widget is created, this function is called for the
177c0ea7 1550widget type and all the widget's parent types, most derived first.
6bf7aab6
DL
1551
1552The following predefined functions can be used here:
1553
1554@defun widget-types-convert-widget widget
1555Convert @code{:args} as widget types in @var{widget}.
1556@end defun
1557
1558@defun widget-value-convert-widget widget
1559Initialize @code{:value} from @code{:args} in @var{widget}.
1560@end defun
1561
4c2f559e
PA
1562@vindex copy@r{ keyword}
1563@item :copy
1564Function to deep copy a widget type. It takes a shallow copy of the
1565widget type as an argument (made by @code{copy-sequence}), and returns a
1566deep copy. The purpose of this is to avoid having different instances
1567of combined widgets share nested attributes.
1568
1569The following predefined functions can be used here:
1570
1571@defun widget-types-copy widget
1572Copy @code{:args} as widget types in @var{widget}.
1573@end defun
1574
6f7f063d 1575@vindex value-to-internal@r{ keyword}
6bf7aab6
DL
1576@item :value-to-internal
1577Function to convert the value to the internal format. The function
1578takes two arguments, a widget and an external value, and returns the
1579internal value. The function is called on the present @code{:value}
1580when the widget is created, and on any value set later with
1581@code{widget-value-set}.
1582
6f7f063d 1583@vindex value-to-external@r{ keyword}
6bf7aab6
DL
1584@item :value-to-external
1585Function to convert the value to the external format. The function
1586takes two arguments, a widget and an internal value, and returns the
6f7f063d 1587external value. The function is called on the present @code{:value}
6bf7aab6
DL
1588when the widget is created, and on any value set later with
1589@code{widget-value-set}.
1590
6f7f063d 1591@vindex create@r{ keyword}
6bf7aab6
DL
1592@item :create
1593Function to create a widget from scratch. The function takes one
54438eb5
DL
1594argument, a widget type, and creates a widget of that type, inserts it
1595in the buffer, and returns a widget object.
6bf7aab6 1596
6f7f063d 1597@vindex delete@r{ keyword}
6bf7aab6
DL
1598@item :delete
1599Function to delete a widget. The function takes one argument, a widget,
1600and should remove all traces of the widget from the buffer.
1601
1ded3d46
PA
1602The default value is:
1603
1604@defun widget-default-delete widget
1605Remove @var{widget} from the buffer.
1606Delete all @code{:children} and @code{:buttons} in @var{widget}.
1607@end defun
1608
1609In most cases you should not change this value, but instead use
1610@code{:value-delete} to make any additional cleanup.
1611
6f7f063d 1612@vindex value-create@r{ keyword}
6bf7aab6
DL
1613@item :value-create
1614Function to expand the @samp{%v} escape in the format string. It will
54438eb5
DL
1615be called with the widget as its argument and should insert a
1616representation of the widget's value in the buffer.
6bf7aab6 1617
1ded3d46
PA
1618Nested widgets should be listed in @code{:children} or @code{:buttons}
1619to make sure they are automatically deleted.
1620
6f7f063d 1621@vindex value-delete@r{ keyword}
6bf7aab6 1622@item :value-delete
54438eb5 1623Should remove the representation of the widget's value from the buffer.
6bf7aab6
DL
1624It will be called with the widget as its argument. It doesn't have to
1625remove the text, but it should release markers and delete nested widgets
1ded3d46 1626if these are not listed in @code{:children} or @code{:buttons}.
6bf7aab6 1627
6f7f063d 1628@vindex value-get@r{ keyword}
177c0ea7 1629@item :value-get
6bf7aab6 1630Function to extract the value of a widget, as it is displayed in the
177c0ea7 1631buffer.
6bf7aab6
DL
1632
1633The following predefined function can be used here:
1634
1635@defun widget-value-value-get widget
1636Return the @code{:value} property of @var{widget}.
1637@end defun
1638
6f7f063d 1639@vindex format-handler@r{ keyword}
6bf7aab6
DL
1640@item :format-handler
1641Function to handle unknown @samp{%} escapes in the format string. It
6f7f063d
EZ
1642will be called with the widget and the character that follows the
1643@samp{%} as arguments. You can set this to allow your widget to handle
1644non-standard escapes.
6bf7aab6 1645
6f7f063d 1646@findex widget-default-format-handler
6bf7aab6
DL
1647You should end up calling @code{widget-default-format-handler} to handle
1648unknown escape sequences, which will handle the @samp{%h} and any future
1649escape sequences, as well as give an error for unknown escapes.
1650
6f7f063d 1651@vindex action@r{ keyword}
6bf7aab6
DL
1652@item :action
1653Function to handle user initiated events. By default, @code{:notify}
177c0ea7 1654the parent.
6bf7aab6
DL
1655
1656The following predefined function can be used here:
1657
1658@defun widget-parent-action widget &optional event
1659Tell @code{:parent} of @var{widget} to handle the @code{:action}.
1660Optional @var{event} is the event that triggered the action.
1661@end defun
1662
6f7f063d 1663@vindex prompt-value@r{ keyword}
6bf7aab6
DL
1664@item :prompt-value
1665Function to prompt for a value in the minibuffer. The function should
1666take four arguments, @var{widget}, @var{prompt}, @var{value}, and
1667@var{unbound} and should return a value for widget entered by the user.
1668@var{prompt} is the prompt to use. @var{value} is the default value to
9995b954 1669use, unless @var{unbound} is non-@code{nil}, in which case there is no default
6bf7aab6
DL
1670value. The function should read the value using the method most natural
1671for this widget, and does not have to check that it matches.
1672@end table
1673
1674If you want to define a new widget from scratch, use the @code{default}
1675widget as its base.
1676
177c0ea7
JB
1677@deffn Widget default
1678Widget used as a base for other widgets.
6bf7aab6
DL
1679
1680It provides most of the functionality that is referred to as ``by
177c0ea7 1681default'' in this text.
6bf7aab6
DL
1682@end deffn
1683
1684@node Widget Browser, Widget Minor Mode, Defining New Widgets, Top
1685@comment node-name, next, previous, up
1686@section Widget Browser
6f7f063d 1687@cindex widget browser
6bf7aab6
DL
1688
1689There is a separate package to browse widgets. This is intended to help
1690programmers who want to examine the content of a widget. The browser
1691shows the value of each keyword, but uses links for certain keywords
6f7f063d 1692such as @samp{:parent}, which avoids printing cyclic structures.
6bf7aab6 1693
49c24f48
RS
1694@deffn Command widget-browse @var{widget}
1695Create a widget browser for @var{widget}.
1696When called interactively, prompt for @var{widget}.
6bf7aab6
DL
1697@end deffn
1698
49c24f48
RS
1699@deffn Command widget-browse-other-window @var{widget}
1700Create a widget browser for @var{widget} and show it in another window.
1701When called interactively, prompt for @var{widget}.
6bf7aab6
DL
1702@end deffn
1703
49c24f48
RS
1704@deffn Command widget-browse-at @var{pos}
1705Create a widget browser for the widget at @var{pos}.
6bf7aab6
DL
1706When called interactively, use the position of point.
1707@end deffn
1708
1709@node Widget Minor Mode, Utilities, Widget Browser, Top
1710@comment node-name, next, previous, up
1711@section Widget Minor Mode
6f7f063d 1712@cindex widget minor mode
6bf7aab6
DL
1713
1714There is a minor mode for manipulating widgets in major modes that
6f7f063d 1715don't provide any support for widgets themselves. This is mostly
177c0ea7 1716intended to be useful for programmers doing experiments.
6bf7aab6
DL
1717
1718@deffn Command widget-minor-mode
1719Toggle minor mode for traversing widgets.
1720With arg, turn widget mode on if and only if arg is positive.
1721@end deffn
1722
1723@defvar widget-minor-mode-keymap
1724Keymap used in @code{widget-minor-mode}.
1725@end defvar
1726
1727@node Utilities, Widget Wishlist, Widget Minor Mode, Top
1728@comment node-name, next, previous, up
1729@section Utilities.
6f7f063d 1730@cindex utility functions for widgets
6bf7aab6
DL
1731
1732@defun widget-prompt-value widget prompt [ value unbound ]
1733Prompt for a value matching @var{widget}, using @var{prompt}.
1734The current value is assumed to be @var{value}, unless @var{unbound} is
9995b954 1735non-@code{nil}.@refill
6bf7aab6
DL
1736@end defun
1737
1738@defun widget-get-sibling widget
6f7f063d 1739Get the item which @var{widget} is assumed to toggle.
6bf7aab6
DL
1740This is only meaningful for radio buttons or checkboxes in a list.
1741@end defun
1742
6f7f063d 1743@node Widget Wishlist, Index, Utilities, Top
6bf7aab6
DL
1744@comment node-name, next, previous, up
1745@section Wishlist
6f7f063d 1746@cindex todo
6bf7aab6
DL
1747
1748@itemize @bullet
177c0ea7 1749@item
6bf7aab6
DL
1750It should be possible to add or remove items from a list with @kbd{C-k}
1751and @kbd{C-o} (suggested by @sc{rms}).
1752
177c0ea7 1753@item
976e00f1
DL
1754The @samp{[INS]} and @samp{[DEL]} buttons should be replaced by a single
1755dash (@samp{-}). The dash should be a button that, when invoked, asks
1756whether you want to add or delete an item (@sc{rms} wanted to git rid of
1757the ugly buttons, the dash is my idea).
1758
6bf7aab6
DL
1759@item
1760The @code{menu-choice} tag should be prettier, something like the abbreviated
1761menus in Open Look.
1762
1763@item
1764Finish @code{:tab-order}.
1765
1766@item
1767Make indentation work with glyphs and proportional fonts.
1768
1769@item
1770Add commands to show overview of object and class hierarchies to the
177c0ea7 1771browser.
6bf7aab6 1772
177c0ea7 1773@item
6bf7aab6
DL
1774Find a way to disable mouse highlight for inactive widgets.
1775
1776@item
1777Find a way to make glyphs look inactive.
1778
976e00f1
DL
1779@item
1780Add @code{property-list} widget.
1781
1782@item
1783Add @code{association-list} widget.
1784
6bf7aab6
DL
1785@item
1786Add @code{key-binding} widget.
1787
1788@item
1789Add @code{widget} widget for editing widget specifications.
1790
1791@item
1792Find clean way to implement variable length list.
1793See @code{TeX-printer-list} for an explanation.
1794
177c0ea7 1795@item
6bf7aab6
DL
1796@kbd{C-h} in @code{widget-prompt-value} should give type specific help.
1797
177c0ea7 1798@item
6f7f063d 1799Add a @code{mailto} widget.
6bf7aab6
DL
1800@end itemize
1801
6f7f063d
EZ
1802@node Index, , Widget Wishlist, Top
1803@comment node-name, next, previous, up
1804@unnumbered Index
1805
1806This is an alphabetical listing of all concepts, functions, commands,
1807variables, and widgets described in this manual.
1808@printindex cp
1809
56f7c94a 1810@setchapternewpage odd
6bf7aab6
DL
1811@contents
1812@bye
ab5796a9
MB
1813
1814@ignore
1815 arch-tag: 2b427731-4c61-4e72-85de-5ccec9c623f0
1816@end ignore