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1 \input texinfo.tex
2
3 @c %**start of header
4 @setfilename custom
5 @settitle The Customization Library
6 @iftex
7 @afourpaper
8 @headings double
9 @end iftex
10 @c %**end of header
11
12 @node Top, Introduction, (dir), (dir)
13 @comment node-name, next, previous, up
14 @top The Customization Library
15
16 Version: 1.20
17
18 @menu
19 * Introduction::
20 * User Commands::
21 * The Customization Buffer::
22 * Declarations::
23 * Utilities::
24 * The Init File::
25 * Wishlist::
26 @end menu
27
28 @node Introduction, User Commands, Top, Top
29 @comment node-name, next, previous, up
30 @section Introduction
31
32 This library allows customization of @dfn{user options}. Currently two
33 types of user options are supported, namely @dfn{variables} and
34 @dfn{faces}. Each user option can have four different values
35 simultaneously:
36 @table @dfn
37 @item factory setting
38 The value specified by the programmer.
39 @item saved value
40 The value saved by the user as the default for this variable. This
41 overwrites the factory setting when starting a new emacs.
42 @item current value
43 The value used by Emacs. This will not be remembered next time you
44 run Emacs.
45 @item widget value
46 The value entered by the user in a customization buffer, but not yet
47 applied.
48 @end table
49
50 Variables also have a @dfn{type}, which specifies what kind of values
51 the variable can hold, and how the value is presented in a customization
52 buffer. By default a variable can hold any valid expression, but the
53 programmer can specify a more limited type when declaring the variable.
54
55 The user options are organized in a number of @dfn{groups}. Each group
56 can contain a number user options, as well as other groups. The groups
57 allows the user to concentrate on a specific part of emacs.
58
59 @node User Commands, The Customization Buffer, Introduction, Top
60 @comment node-name, next, previous, up
61 @section User Commands
62
63 The following commands will create a customization buffer:
64
65 @table @code
66 @item customize
67 Create a customization buffer containing a specific group, by default
68 the @code{emacs} group.
69
70 @item customize-variable
71 Create a customization buffer containing a single variable.
72
73 @item customize-face
74 Create a customization buffer containing a single face.
75
76 @item customize-apropos
77 Create a customization buffer containing all variables, faces, and
78 groups that match a user specified regular expression.
79 @end table
80
81 @node The Customization Buffer, Declarations, User Commands, Top
82 @comment node-name, next, previous, up
83 @section The Customization Buffer.
84
85 The customization buffer allows the user to make temporary or permanent
86 changes to how specific aspects of emacs works, by setting and editing
87 user options.
88
89 The customization buffer contains three types of text:
90
91 @table @dfn
92 @item informative text
93 where the normal editing commands are disabled.
94
95 @item editable fields
96 where you can edit with the usual emacs commands. Editable fields are
97 usually displayed with a grey background if your terminal supports
98 colors, or an italic font otherwise.
99
100 @item buttons
101 which can be activated by either pressing the @kbd{@key{ret}} while
102 point is located on the text, or pushing @kbd{mouse-2} while the mouse
103 pointer is above the tex. Buttons are usually displayed in a bold
104 font.
105 @end table
106
107 You can move to the next the next editable field or button by pressing
108 @kbd{@key{tab}} or the previous with @kbd{M-@key{tab}}. Some buttons
109 have a small helpful message about their purpose, which will be
110 displayed when you move to it with the @key{tab} key.
111
112 The buffer is divided into three part, an introductory text, a list of
113 customization options, and a line of customization buttons. Each part
114 will be described in the following.
115
116 @menu
117 * The Introductory Text::
118 * The Customization Options::
119 * The Variable Options::
120 * The Face Options::
121 * The Group Options::
122 * The State Button::
123 * The Customization Buttons::
124 @end menu
125
126 @node The Introductory Text, The Customization Options, The Customization Buffer, The Customization Buffer
127 @comment node-name, next, previous, up
128 @subsection The Introductory Text
129
130 The start of the buffer contains a short explanation of what it is, and
131 how to get help. It will typically look like this:
132
133 @example
134 This is a customization buffer.
135 Push RET or click mouse-2 on the word _help_ for more information.
136 @end example
137
138 Rather boring. It is mostly just informative text, but the word
139 @samp{help} is a button that will bring up this document when
140 activated.
141
142 @node The Customization Options, The Variable Options, The Introductory Text, The Customization Buffer
143 @comment node-name, next, previous, up
144 @subsection The Customization Options
145
146 Each customization option looks similar to the following text:
147
148 @example
149 *** custom-background-mode: default
150 State: this item is unchanged from its factory setting.
151 [ ] [?] The brightness of the background.
152 @end example
153
154 The option contains the parts described below.
155
156 @table @samp
157 @item ***
158 The Level Button. The customization options in the buffer are organized
159 in a hierarchy, which is indicated by the number of stars in the level
160 button. The top level options will be shown as @samp{*}. When they are
161 expanded, the suboptions will be shown as @samp{**}. The example option
162 is thus a subsuboption.
163
164 Activating the level buttons will toggle between hiding and exposing the
165 content of that option. The content can either be the value of the
166 option, as in this example, or a list of suboptions.
167
168 @item custom-background-mode
169 This is the tag of the the option. The tag is a name of a variable, a
170 face, or customization group. Activating the tag has an effect that
171 depends on the exact type of the option. In this particular case,
172 activating the tag will bring up a menu that will allow you to choose
173 from the three possible values of the `custom-background-mode'
174 variable.
175
176 @item default
177 After the tag, the options value is shown. Depending on its type, you
178 may be able to edit the value directly. If an option should contain a
179 file name, it is displayed in an editable field, i.e. you can edit it
180 using the standard emacs editing commands.
181
182 @item State: this item is unchanged from its factory setting.
183 The state line. This line will explain the state of the option,
184 e.g. whether it is currently hidden, or whether it has been modified or
185 not. Activating the button will allow you to change the state, e.g. set
186 or reset the changes you have made. This is explained in detail in the
187 following sections.
188
189 @item [ ]
190 The magic button. This is an abbreviated version of the state line.
191
192 @item [?]
193 The documentation button. If the documentation is more than one line,
194 this button will be present. Activating the button will toggle whether
195 the complete documentation is shown, or only the first line.
196
197 @item The brightness of the background.
198 This is a documentation string explaining the purpose of this particular
199 customization option.
200
201 @end table
202
203 @node The Variable Options, The Face Options, The Customization Options, The Customization Buffer
204 @comment node-name, next, previous, up
205 @subsection The Variable Options
206
207 The most common customization options are emacs lisp variables. The
208 actual editing of these variables depend on what type values the
209 variable is expected to contain. For example, a lisp variable whose
210 value should be a string will typically be represented with an editable
211 text field in the buffer, where you can change the string directly. If
212 the value is a list, each item in the list will be presented in the
213 buffer buffer on a separate line, with buttons to insert new items in
214 the list, or delete existing items from the list. You may want to see
215 @ref{User Interface,,, widget, The Widget Library}, where some examples
216 of editing are discussed.
217
218 You can either choose to edit the value directly, or edit the lisp
219 value for that variable. The lisp value is a lisp expression that
220 will be evaluated when you start emacs. The result of the evaluation
221 will be used as the initial value for that variable. Editing the
222 lisp value is for experts only, but if the current value of the
223 variable is of a wrong type (i.e. a symbol where a string is expected),
224 the `edit lisp' mode will always be selected.
225
226 You can see what mode is currently selected by looking at the state
227 button. If it uses parenthesises (like @samp{( )}) it is in edit lisp
228 mode, with square brackets (like @samp{[ ]}) it is normal edit mode.
229 You can switch mode by activating the state button, and select either
230 @samp{Edit} or @samp{Edit lisp} from the menu.
231
232 You can change the state of the variable with the other menu items:
233
234 @table @samp
235 @item Set
236 When you have made your modifications in the buffer, you need to
237 activate this item to make the modifications take effect. The
238 modifications will be forgotten next time you run emacs.
239
240 @item Save
241 Unless you activate this item instead! This will mark the modification
242 as permanent, i.e. the changes will be remembered in the next emacs
243 session.
244
245 @item Reset
246 If you have made some modifications and not yet applied them, you can
247 undo the modification by activating this item.
248
249 @item Reset to Saved
250 Activating this item will reset the value of the variable to the last
251 value you marked as permanent with `Save'.
252
253 @item Reset to Factory Settings
254 Activating this item will undo all modifications you have made, and
255 reset the value to the initial value specified by the program itself.
256 @end table
257
258 By default, the value of large or complicated variables are hidden. You
259 can show the value by clicking on the level button.
260
261 @node The Face Options, The Group Options, The Variable Options, The Customization Buffer
262 @comment node-name, next, previous, up
263 @subsection The Face Options
264
265 A face is an object that controls the appearance of some buffer text.
266 The face has a number of possible attributes, such as boldness,
267 foreground color, and more. For each attribute you can specify whether
268 this attribute is controlled by the face, and if so, what the value is.
269 For example, if the attribute bold is not controlled by a face, using
270 that face on some buffer text will not affect its boldness. If the bold
271 attribute is controlled by the face, it can be turned either on or of.
272
273 It is possible to specify that a face should have different attributes
274 on different device types. For example, a face may make text red on a
275 color device, and bold on a monochrome device.
276
277 The way this is presented in the customization buffer is to have a list
278 of display specifications, and for each display specification a list of
279 face attributes. For each face attribute, there is a checkbox
280 specifying whether this attribute has effect and what the value is.
281 Here is an example:
282
283 @example
284 *** custom-invalid-face: (sample)
285 [ ] Face used when the customize item is invalid.
286 [INS] [DEL] Display: [ ] Type: [ ] X [ ] TTY
287 [X] Class: [X] Color [ ] Grayscale [ ] Monochrome
288 [ ] Background: [ ] Light [ ] Dark
289 Attributes: [ ] Bold: off
290 [ ] Italic: off
291 [ ] Underline: off
292 [X] Foreground: yellow (sample)
293 [X] Background: red (sample)
294 [ ] Stipple:
295 [INS] [DEL] Display: all
296 Attributes: [X] Bold: on
297 [X] Italic: on
298 [X] Underline: on
299 [ ] Foreground: default (sample)
300 [ ] Background: default (sample)
301 [ ] Stipple:
302 [INS]
303 @end example
304
305 This has two display specifications. The first will match all color
306 displays, independently on whether the device is X11 or a tty, and
307 whether background color is dark or light. For devices matching this
308 specification, @samp{custom-invalid-face} will force text to be
309 displayed in yellow on red, but leave all other attributes alone.
310
311 The second display will simply match everything. Since the list is
312 prioritised, this means that it will match all non-color displays. For
313 these, the face will not affect the foreground or background color, but
314 force the font to be both bold, italic, and underline.
315
316 You can add or delete display specifications by activating the
317 @samp{[INS]} and @samp{[DEL]} buttons, and modify them by clicking on
318 the check boxes. The first checkbox in each line in the display
319 specification is special. It specify whether this particular property
320 will even be relevant. By not checking the box in the first display, we
321 match all device types, also device types other than X11 and tty, for
322 example ms-windows, nextstep, and mac os.
323
324 After modifying the face, you can activate the state button to make the
325 changes take effect. The menu items in the state button menu is similar
326 to the state menu items for variables described in the previous section.
327
328 @node The Group Options, The State Button, The Face Options, The Customization Buffer
329 @comment node-name, next, previous, up
330 @subsection The Group Options
331
332 Since Emacs has approximately a zillion configuration options, they have
333 been organized in groups. Each group can contain other groups, thus
334 creating a customization hierarchy. The nesting of the customization
335 within the visible part of this hierarchy is indicated by the number of
336 stars in the level button.
337
338 Since there is really no customization needed for the group itself, the
339 menu items in the groups state button will affect all modified group
340 members recursively. Thus, if you activate the @samp{Set} menu item,
341 all variables and faces that have been modified and belong to that group
342 will be applied. For those members that themselves are groups, it will
343 work as if you had activated the @samp{Set} menu item on them as well.
344
345 @node The State Button, The Customization Buttons, The Group Options, The Customization Buffer
346 @comment node-name, next, previous, up
347 @subsection The State Line and The Magic Button
348
349 The state line has two purposes. The first is to hold the state menu,
350 as described in the previous sections. The second is to indicate the
351 state of each customization item.
352
353 For the magic button, this is done by the character inside the brackets.
354 The following states have been defined, the first that applies to the
355 current item will be used:
356
357 @table @samp
358 @item -
359 The option is currently hidden. For group options that means the
360 members are not shown, for variables and faces that the value is not
361 shown. You cannot perform any of the state change operations on a
362 hidden customization option.
363
364 @item *
365 The value if this option has been modified in the buffer, but not yet
366 applied.
367
368 @item +
369 The item has has been set by the user.
370
371 @item :
372 The current value of this option is different from the saved value.
373
374 @item !
375 The saved value of this option is different from the factory setting.
376
377 @item @@
378 The factory setting of this option is not known. This occurs when you
379 try to customize variables or faces that have not been explicitly
380 declared as customizable.
381
382 @item SPC
383 The factory setting is still in effect.
384
385 @end table
386
387 For non-hidden group options, the state shown is the most severe state
388 of its members, where more severe means that it appears earlier in the
389 list above (except hidden members, which are ignored).
390
391 @node The Customization Buttons, , The State Button, The Customization Buffer
392 @comment node-name, next, previous, up
393 @subsection The Customization Buttons
394
395 The last part of the customization buffer looks like this:
396
397 @example
398 [Set] [Save] [Reset]
399 @end example
400
401 Activating the @samp{[Set]}, @samp{[Save]}, or @samp{[Reset]}
402 button will affect all modified customization items that are visible in
403 the buffer.
404
405 @node Declarations, Utilities, The Customization Buffer, Top
406 @comment node-name, next, previous, up
407 @section Declarations
408
409 @menu
410 * Declaring Groups::
411 * Declaring Variables::
412 * Declaring Faces::
413 @end menu
414
415 All the customization declarations can be changes by keyword arguments.
416 Groups, variables, and faces all share these common keywords:
417
418 @table @code
419 @item :group
420 @var{value} should be a customization group.
421 Add @var{symbol} to that group.
422 @item :link
423 @var{value} should be a widget type.
424 Add @var{value} to the extrenal links for this customization option.
425 Useful widget types include @code{custom-manual}, @code{info-link}, and
426 @code{url-link}.
427 @item :load
428 Add @var{value} to the files that should be loaded nefore displaying
429 this customization option. The value should be iether a string, which
430 should be a string which will be loaded with @code{load-library} unless
431 present in @code{load-history}, or a symbol which will be loaded with
432 @code{require}.
433 @item :tag
434 @var{Value} should be a short string used for identifying the option in
435 customization menus and buffers. By default the tag will be
436 automatically created from the options name.
437 @end table
438
439 @node Declaring Groups, Declaring Variables, Declarations, Declarations
440 @comment node-name, next, previous, up
441 @subsection Declaring Groups
442
443 Use @code{defgroup} to declare new customization groups.
444
445 @defun defgroup symbol members doc [keyword value]...
446 Declare @var{symbol} as a customization group containing @var{members}.
447 @var{symbol} does not need to be quoted.
448
449 @var{doc} is the group documentation.
450
451 @var{members} should be an alist of the form ((@var{name}
452 @var{widget})...) where @var{name} is a symbol and @var{widget} is a
453 widget for editing that symbol. Useful widgets are
454 @code{custom-variable} for editing variables, @code{custom-face} for
455 editing faces, and @code{custom-group} for editing groups.@refill
456
457 Internally, custom uses the symbol property @code{custom-group} to keep
458 track of the group members, and @code{group-documentation} for the
459 documentation string.
460
461 The following additional @var{keyword}'s are defined:
462
463 @table @code
464 @item :prefix
465 @var{value} should be a string. If the string is a prefix for the name
466 of a member of the group, that prefix will be ignored when creating a
467 tag for that member.
468 @end table
469 @end defun
470
471 @node Declaring Variables, Declaring Faces, Declaring Groups, Declarations
472 @comment node-name, next, previous, up
473 @subsection Declaring Variables
474
475 Use @code{defcustom} to declare user editable variables.
476
477 @defun defcustom symbol value doc [keyword value]...
478 Declare @var{symbol} as a customizable variable that defaults to @var{value}.
479 Neither @var{symbol} nor @var{value} needs to be quoted.
480 If @var{symbol} is not already bound, initialize it to @var{value}.
481
482 @var{doc} is the variable documentation.
483
484 The following additional @var{keyword}'s are defined:
485
486 @table @code
487 @item :type
488 @var{value} should be a widget type.
489 @item :options
490 @var{value} should be a list of possible members of the specified type.
491 For hooks, this is a list of function names.
492 @end table
493
494 @xref{Sexp Types,,,widget,The Widget Library}, for information about
495 widgets to use together with the @code{:type} keyword.
496 @end defun
497
498 Internally, custom uses the symbol property @code{custom-type} to keep
499 track of the variables type, @code{factory-value} for the program
500 specified default value, @code{saved-value} for a value saved by the
501 user, and @code{variable-documentation} for the documentation string.
502
503 Use @code{custom-add-option} to specify that a specific function is
504 useful as an meber of a hook.
505
506 @defun custom-add-option symbol option
507 To the variable @var{symbol} add @var{option}.
508
509 If @var{symbol} is a hook variable, @var{option} should be a hook
510 member. For other types variables, the effect is undefined."
511 @end defun
512
513 @node Declaring Faces, , Declaring Variables, Declarations
514 @comment node-name, next, previous, up
515 @subsection Declaring Faces
516
517 Faces are declared with @code{defface}.
518
519 @defun defface face spec doc [keyword value]...
520
521 Declare @var{face} as a customizable face that defaults to @var{spec}.
522 @var{face} does not need to be quoted.
523
524 If @var{face} has been set with `custom-set-face', set the face attributes
525 as specified by that function, otherwise set the face attributes
526 according to @var{spec}.
527
528 @var{doc} is the face documentation.
529
530 @var{spec} should be an alist of the form @samp{((@var{display} @var{atts})...)}.
531
532 @var{atts} is a list of face attributes and their values. The possible
533 attributes are defined in the variable `custom-face-attributes'.
534 Alternatively, @var{atts} can be a face in which case the attributes of
535 that face is used.
536
537 The @var{atts} of the first entry in @var{spec} where the @var{display}
538 matches the frame should take effect in that frame. @var{display} can
539 either be the symbol `t', which will match all frames, or an alist of
540 the form @samp{((@var{req} @var{item}...)...)}@refill
541
542 For the @var{display} to match a FRAME, the @var{req} property of the
543 frame must match one of the @var{item}. The following @var{req} are
544 defined:@refill
545
546 @table @code
547 @item type
548 (the value of (window-system))@br
549 Should be one of @code{x} or @code{tty}.
550
551 @item class
552 (the frame's color support)@br
553 Should be one of @code{color}, @code{grayscale}, or @code{mono}.
554
555 @item background
556 (what color is used for the background text)@br
557 Should be one of @code{light} or @code{dark}.
558 @end table
559
560 Internally, custom uses the symbol property @code{factory-face} for the
561 program specified default face properties, @code{saved-face} for
562 properties saved by the user, and @code{face-documentation} for the
563 documentation string.@refill
564
565 @end defun
566
567 @node Utilities, The Init File, Declarations, Top
568 @comment node-name, next, previous, up
569 @section Utilities
570
571 These utilities can come in handy when adding customization support.
572
573 @deffn Widget custom-manual
574 Widget type for specifying the info manual entry for a customization
575 option. It takes one argument, an info address.
576 @end deffn
577
578 @defun custom-add-to-group group member widget
579 To existing @var{group} add a new @var{member} of type @var{widget},
580 If there already is an entry for that member, overwrite it.
581 @end defun
582
583 @defun custom-add-link symbol widget
584 To the custom option @var{symbol} add the link @var{widget}.
585 @end defun
586
587 @defun custom-add-load symbol load
588 To the custom option @var{symbol} add the dependency @var{load}.
589 @var{load} should be either a library file name, or a feature name.
590 @end defun
591
592 @defun custom-menu-create symbol &optional name
593 Create menu for customization group @var{symbol}.
594 If optional @var{name} is given, use that as the name of the menu.
595 Otherwise make up a name from @var{symbol}.
596 The menu is in a format applicable to @code{easy-menu-define}.
597 @end defun
598
599 @node The Init File, Wishlist, Utilities, Top
600 @comment node-name, next, previous, up
601 @section The Init File
602
603 When you save the customizations, call to @code{custom-set-variables},
604 @code{custom-set-faces} are inserted into the file specified by
605 @code{custom-file}. By default @code{custom-file} is your @file{.emacs}
606 file. The two functions will initialize variables and faces as you have
607 specified.
608
609 @node Wishlist, , The Init File, Top
610 @comment node-name, next, previous, up
611 @section Wishlist
612
613 @itemize @bullet
614 @item
615 The menu items should be grayed out when the information is
616 missing. I.e. if a variable doesn't have a factory setting, the user
617 should not be allowed to select the @samp{Factory} menu item.
618
619 @item
620 We need @strong{much} better support for keyboard operations in the
621 customize buffer.
622
623 @item
624 Support real specifiers under XEmacs.
625
626 @item
627 Integrate with @file{w3} so you can customization buffers with much
628 better formatting. I'm thinking about adding a <custom>name</custom>
629 tag.
630
631 @item
632 Add an `examples' section, with explained examples of custom type
633 definitions.
634
635 @item
636 Support undo using lmi's @file{gnus-undo.el}.
637
638 @item
639 Make it possible to append to `choice', `radio', and `set' options.
640
641 @end itemize
642
643 @contents
644 @bye