@c %**start of header
@setfilename ../info/widget
@settitle The Emacs Widget Library
-@iftex
+@syncodeindex fn cp
+@syncodeindex vr cp
+@syncodeindex ky cp
@afourpaper
-@headings double
-@end iftex
@c %**end of header
-@dircategory Editors
+@copying
+Copyright @copyright{} 2000, 2002, 2003 Free Software Foundation, Inc.
+
+@quotation
+Permission is granted to copy, distribute and/or modify this document
+under the terms of the GNU Free Documentation License, Version 1.1 or
+any later version published by the Free Software Foundation; with the
+Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and
+``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU
+Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
+license is included in the section entitled ``GNU Free Documentation
+License'' in the Emacs manual.
+
+This document is part of a collection distributed under the GNU Free
+Documentation License. If you want to distribute this document
+separately from the collection, you can do so by adding a copy of the
+license to the document, as described in section 6 of the license.
+
+(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
+this GNU Manual, like GNU software. Copies published by the Free
+Software Foundation raise funds for GNU development.''
+@end quotation
+@end copying
+
+@dircategory Emacs
@direntry
-* Widget: (widget). Documenting the "widget" package used by the
- Emacs Custom facility.
+* Widget: (widget). The "widget" package used by the Emacs Customization
+ facility.
@end direntry
@node Top, Introduction, (dir), (dir)
@top The Emacs Widget Library
@menu
-* Introduction::
-* User Interface::
-* Programming Example::
-* Setting Up the Buffer::
-* Basic Types::
-* Sexp Types::
-* Widget Properties::
-* Defining New Widgets::
-* Widget Browser::
-* Widget Minor Mode::
-* Utilities::
-* Widget Wishlist::
+* Introduction::
+* User Interface::
+* Programming Example::
+* Setting Up the Buffer::
+* Basic Types::
+* Sexp Types::
+* Widget Properties::
+* Defining New Widgets::
+* Widget Browser::
+* Widget Minor Mode::
+* Utilities::
+* Widget Wishlist::
+* Index::
@end menu
@node Introduction, User Interface, Top, Top
@comment node-name, next, previous, up
@section Introduction
-Most graphical user interface toolkits, such as Motif and XView, provide
-a number of standard user interface controls (sometimes known as
-`widgets' or `gadgets'). Emacs doesn't really support anything like
-this, except for an incredible powerful text ``widget''. On the other
-hand, Emacs does provide the necessary primitives to implement many
-other widgets within a text buffer. The @code{widget} package
-simplifies this task.
+Most graphical user interface toolkits provide a number of standard
+user interface controls (sometimes known as `widgets' or `gadgets').
+Emacs doesn't really support anything like this, except for an
+incredibly powerful text ``widget.'' On the other hand, Emacs does
+provide the necessary primitives to implement many other widgets
+within a text buffer. The @code{widget} package simplifies this task.
+@cindex basic widgets
+@cindex widgets, basic types
The basic widgets are:
@table @code
@item link
Areas of text with an associated action. Intended for hypertext links
embedded in text.
-@item push-button
+@item push-button
Like link, but intended for stand-alone buttons.
@item editable-field
An editable text field. It can be either variable or fixed length.
visible in the buffer.
@item item
A simple constant widget intended to be used in the @code{menu-choice} and
-@code{radio-button-choice} widgets.
+@code{radio-button-choice} widgets.
@item choice-item
-An button item only intended for use in choices. When invoked, the user
+A button item only intended for use in choices. When invoked, the user
will be asked to select another option from the choice widget.
@item toggle
A simple @samp{on}/@samp{off} switch.
@item checkbox
-A checkbox (@samp{[ ]}/@samp{[X]}).
+A checkbox (@samp{[ ]}/@samp{[X]}).
@item editable-list
Create an editable list. The user can insert or delete items in the
list. Each list item is itself a widget.
@end table
-Now of what possible use can support for widgets be in a text editor?
+Now, of what possible use can support for widgets be in a text editor?
I'm glad you asked. The answer is that widgets are useful for
implementing forms. A @dfn{form} in Emacs is a buffer where the user is
supposed to fill out a number of fields, each of which has a specific
meaning. The user is not supposed to change or delete any of the text
between the fields. Examples of forms in Emacs are the @file{forms}
package (of course), the customize buffers, the mail and news compose
-modes, and the @sc{html} form support in the @file{w3} browser.
+modes, and the @acronym{HTML} form support in the @file{w3} browser.
+@cindex widget library, why use it
The advantages for a programmer of using the @code{widget} package to
implement forms are:
@enumerate
@item
-More complex field than just editable text are supported.
+More complex fields than just editable text are supported.
@item
-You can give the user immediate feedback if he enters invalid data in a
+You can give the users immediate feedback if they enter invalid data in a
text field, and sometimes prevent entering invalid data.
-@item
-You can have fixed sized fields, thus allowing multiple field to be
+@item
+You can have fixed sized fields, thus allowing multiple fields to be
lined up in columns.
@item
-It is simple to query or set the value of a field.
-@item
-Editing happens in buffer, not in the mini-buffer.
-@item
+It is simple to query or set the value of a field.
+@item
+Editing happens in the buffer, not in the mini-buffer.
+@item
Packages using the library get a uniform look, making them easier for
the user to learn.
-@item
-As support for embedded graphics improve, the widget library will
-extended to support it. This means that your code using the widget
-library will also use the new graphic features by automatic.
+@item
+As support for embedded graphics improve, the widget library will be
+extended to use the GUI features. This means that your code using the
+widget library will also use the new graphic features automatically.
@end enumerate
In order to minimize the code that is loaded by users who does not
create any widgets, the code has been split in two files:
+@cindex widget library, files
@table @file
@item widget.el
This will declare the user variables, define the function
-@code{widget-define}, and autoload the function @code{widget-create}.
+@code{define-widget}, and autoload the function @code{widget-create}.
@item wid-edit.el
Everything else is here, there is no reason to load it explicitly, as
it will be autoloaded when needed.
@section User Interface
A form consist of read only text for documentation and some fields,
-where each the fields contain two parts, as tag and a value. The tags
-are used to identify the fields, so the documentation can refer to the
-foo field, meaning the field tagged with @samp{Foo}. Here is an example
-form:
+where each field contains two parts, a tag and a value. The tags are
+used to identify the fields, so the documentation can refer to the
+@samp{foo field}, meaning the field tagged with @samp{Foo}. Here is an
+example form:
@example
Here is some documentation.
@b{[INS]} @b{[DEL]} @i{One}
@b{[INS]} @b{[DEL]} @i{Eh, two?}
@b{[INS]} @b{[DEL]} @i{Five!}
-@b{[INS]}
+@b{[INS]}
Select multiple:
The top level widgets in is example are tagged @samp{Name},
@samp{Choose}, @samp{Address}, @samp{_other work_}, @samp{Numbers},
@samp{Select multiple}, @samp{Select one}, @samp{[Apply Form]}, and
-@samp{[Reset Form]}. There are basically two thing the user can do within
-a form, namely editing the editable text fields and activating the
-buttons.
+@samp{[Reset Form]}. There are basically two things the user can do
+within a form, namely editing the editable text fields and activating
+the buttons.
@subsection Editable Text Fields
For example, capitalizing all text from the middle of one field to the
middle of another field is prohibited.
-Editing text fields are created by the @code{editable-field} widget.
+Editable text fields are created by the @code{editable-field} widget.
+
+An editable field must be surrounded by static text on both sides, that
+is, text that does not change in the lifetime of the widget. If the
+field extends to the end of the line, the terminating line-feed character
+will count as the necessary static text on that end, but you will have
+to provide the static text before the field yourself. The
+@code{:format} keyword is useful for generating the static text; for
+instance, if you give it a value of @code{"Name: %v"}, the "Name: " part
+will count as the static text.
The editing text fields are highlighted with the
@code{widget-field-face} face, making them easy to find.
@subsection Buttons
+@cindex widget buttons
+@cindex button widgets
Some portions of the buffer have an associated @dfn{action}, which can
be @dfn{invoked} by a standard key or mouse command. These portions
are called @dfn{buttons}. The default commands for activating a button
@code{widget-global-map} (by default the global map).
@end deffn
-@item mouse-2
+@kindex Mouse-2 @r{(on button widgets})
+@item Mouse-2
@deffn Command widget-button-click @var{event}
Invoke the button at the location of the mouse pointer. If the mouse
pointer is located in an editable text field, invoke the binding in
the example:
@table @emph
-@item The Option Field Tags.
+@cindex option field tag
+@item The Option Field Tags
When you invoke one of these buttons, you will be asked to choose
between a number of different options. This is how you edit an option
field. Option fields are created by the @code{menu-choice} widget. In
the example, @samp{@b{Choose}} is an option field tag.
-@item The @samp{@b{[INS]}} and @samp{@b{[DEL]}} buttons.
-Activating these will insert or delete elements from a editable list.
-The list is created by the @code{editable-list} widget.
-@item Embedded Buttons.
+@item The @samp{@b{[INS]}} and @samp{@b{[DEL]}} buttons
+Activating these will insert or delete elements from an editable list.
+The list is created by the @code{editable-list} widget.
+@cindex embedded buttons
+@item Embedded Buttons
The @samp{@b{_other work_}} is an example of an embedded
-button. Embedded buttons are not associated with a fields, but can serve
+button. Embedded buttons are not associated with a fields, but can serve
any purpose, such as implementing hypertext references. They are
usually created by the @code{link} widget.
-@item The @samp{@b{[ ]}} and @samp{@b{[X]}} buttons.
+@item The @samp{@b{[ ]}} and @samp{@b{[X]}} buttons
Activating one of these will convert it to the other. This is useful
-for implementing multiple-choice fields. You can create it wit
-@item The @samp{@b{( )}} and @samp{@b{(*)}} buttons.
+for implementing multiple-choice fields. You can create it with the
+@code{checkbox} widget.
+@item The @samp{@b{( )}} and @samp{@b{(*)}} buttons
Only one radio button in a @code{radio-button-choice} widget can be
selected at any time. When you invoke one of the unselected radio
buttons, it will be selected and the previous selected radio button will
become unselected.
-@item The @samp{@b{[Apply Form]}} @samp{@b{[Reset Form]}} buttons.
-These are explicit buttons made with the @code{push-button} widget. The main
-difference from the @code{link} widget is that the buttons are will be
+@item The @samp{@b{[Apply Form]}} @samp{@b{[Reset Form]}} buttons
+These are explicit buttons made with the @code{push-button} widget. The
+main difference from the @code{link} widget is that the buttons will be
displayed as GUI buttons when possible.
-enough.
@end table
-To make them easier to locate, buttons are emphasized in the buffer.
+To make them easier to locate, buttons are emphasized in the buffer.
@deffn Face widget-button-face
Face used for buttons.
@end deffn
@defopt widget-mouse-face
-Face used for buttons when the mouse pointer is above it.
+Face used for highlighting a button when the mouse pointer moves across
+it.
@end defopt
@subsection Navigation
@comment node-name, next, previous, up
@section Programming Example
+@cindex widgets, programming example
+@cindex example of using widgets
Here is the code to implement the user interface example (@pxref{User
Interface}).
(make-local-variable 'widget-example-repeat)
(let ((inhibit-read-only t))
(erase-buffer))
+ (remove-overlays)
(widget-insert "Here is some documentation.\n\nName: ")
(widget-create 'editable-field
:size 13
(widget-insert "\nSee also ")
(widget-create 'link
:notify (lambda (&rest ignore)
- (widget-value-set widget-example-repeat
+ (widget-value-set widget-example-repeat
'("En" "To" "Tre"))
(widget-setup))
"other work")
- (widget-insert " for more information.\n\nNumbers: count to three below\n")
+ (widget-insert
+ " for more information.\n\nNumbers: count to three below\n")
(setq widget-example-repeat
(widget-create 'editable-list
:entry-format "%i %d %v"
'(item "One") '(item "Another One.") '(item "A Final One."))
(widget-insert "\n")
(widget-create 'push-button
- :notify (lambda (&rest ignore)
+ :notify (lambda (&rest ignore)
(if (= (length (widget-value widget-example-repeat))
3)
(message "Congratulation!")
Delete @var{widget} and remove it from the buffer.
@end defun
-@defun widget-setup
-Setup a buffer to support widgets.
+@defun widget-setup
+Set up a buffer to support widgets.
This should be called after creating all the widgets and before allowing
the user to edit them.
If you want to insert text outside the widgets in the form, the
recommended way to do that is with @code{widget-insert}.
-@defun widget-insert
+@defun widget-insert
Insert the arguments, either strings or characters, at point.
-The inserted text will be read only.
+The inserted text will be read-only.
@end defun
There is a standard widget keymap which you might find useful.
+@findex widget-button-press
+@findex widget-button-click
@defvr Const widget-keymap
A keymap with the global keymap as its parent.@*
@key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and
-@code{widget-backward}, respectively. @kbd{@key{RET}} and @kbd{mouse-2}
+@code{widget-backward}, respectively. @key{RET} and @kbd{Mouse-2}
are bound to @code{widget-button-press} and
-@code{widget-button-}.@refill
+@code{widget-button-click}.@refill
@end defvr
@defvar widget-global-map
property, @var{argument} is the value of the property, and @var{args}
are interpreted in a widget specific way.
-There following keyword arguments that apply to all widgets:
+@cindex keyword arguments
+The following keyword arguments that apply to all widgets:
@table @code
+@vindex value@r{ keyword}
@item :value
The initial value for widgets of this type.
+@vindex format@r{ keyword}
@item :format
This string will be inserted in the buffer when you create a widget.
The following @samp{%} escapes are available:
The text inside will be marked as a button.
By default, the text will be shown in @code{widget-button-face}, and
-surrounded by brackets.
+surrounded by brackets.
@defopt widget-button-prefix
String to prefix buttons.
@item %@{
@itemx %@}
The text inside will be displayed with the face specified by
-@code{:sample-face}.
+@code{:sample-face}.
@item %v
This will be replaced with the buffer representation of the widget's
representation of the value if there is no tag.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
+@vindex button-face@r{ keyword}
@item :button-face
Face used to highlight text inside %[ %] in the format.
+@vindex button-prefix@r{ keyword}
+@vindex button-suffix@r{ keyword}
@item :button-prefix
@itemx :button-suffix
-
Text around %[ %] in the format.
These can be
The value of the symbol is expanded according to this table.
@end table
+@vindex doc@r{ keyword}
@item :doc
The string inserted by the @samp{%d} escape in the format
-string.
+string.
+@vindex tag@r{ keyword}
@item :tag
The string inserted by the @samp{%t} escape in the format
-string.
+string.
+@vindex tag-glyph@r{ keyword}
@item :tag-glyph
-Name of image to use instead of the string specified by `:tag' on
+Name of image to use instead of the string specified by @code{:tag} on
Emacsen that supports it.
+@vindex help-echo@r{ keyword}
@item :help-echo
-Message displayed whenever you move to the widget with either
-@code{widget-forward} or @code{widget-backward}.
-
+Specifies how to display a message whenever you move to the widget with
+either @code{widget-forward} or @code{widget-backward} or move the mouse
+over it (using the standard @code{help-echo} mechanism). The argument
+is either a string to display, a function of one argument, the widget,
+which should return a string to display, or a form that evaluates to
+such a string.
+
+@vindex indent@r{ keyword}
@item :indent
An integer indicating the absolute number of spaces to indent children
of this widget.
+@vindex offset@r{ keyword}
@item :offset
An integer indicating how many extra spaces to add to the widget's
grandchildren compared to this widget.
+@vindex extra-offset@r{ keyword}
@item :extra-offset
An integer indicating how many extra spaces to add to the widget's
children compared to this widget.
+@vindex notify@r{ keyword}
@item :notify
A function called each time the widget or a nested widget is changed.
The function is called with two or three arguments. The first argument
is the widget itself, the second argument is the widget that was
changed, and the third argument is the event leading to the change, if
-any.
+any.
+@vindex menu-tag@r{ keyword}
@item :menu-tag
Tag used in the menu when the widget is used as an option in a
@code{menu-choice} widget.
+@vindex menu-tag-get@r{ keyword}
@item :menu-tag-get
Function used for finding the tag when the widget is used as an option
in a @code{menu-choice} widget. By default, the tag used will be either the
@code{:menu-tag} or @code{:tag} property if present, or the @code{princ}
representation of the @code{:value} property if not.
+@vindex match@r{ keyword}
@item :match
Should be a function called with two arguments, the widget and a value,
-and returning non-nil if the widget can represent the specified value.
+and returning non-@code{nil} if the widget can represent the specified value.
+@vindex validate@r{ keyword}
@item :validate
-A function which takes a widget as an argument, and return nil if the
-widget's current value is valid for the widget. Otherwise it should
-return the widget containing the invalid data, and set that widget's
-@code{:error} property to a string explaining the error.
+A function which takes a widget as an argument, and returns @code{nil}
+if the widget's current value is valid for the widget. Otherwise it
+should return the widget containing the invalid data, and set that
+widget's @code{:error} property to a string explaining the error.
The following predefined function can be used:
All the @code{:children} of @var{widget} must be valid.
@end defun
+@vindex tab-order@r{ keyword}
@item :tab-order
Specify the order in which widgets are traversed with
@code{widget-forward} or @code{widget-backward}. This is only partially
@item
Widgets with tabbing order @code{-1} are ignored.
-@item
+@item
(Unimplemented) When on a widget with tabbing order @var{n}, go to the
next widget in the buffer with tabbing order @var{n+1} or @code{nil},
whichever comes first.
in the buffer with a positive tabbing order, or @code{nil}
@end enumerate
+@vindex parent@r{ keyword}
@item :parent
-The parent of a nested widget (e.g. a @code{menu-choice} item or an
+The parent of a nested widget (e.g.@: a @code{menu-choice} item or an
element of a @code{editable-list} widget).
+@vindex sibling-args@r{ keyword}
@item :sibling-args
This keyword is only used for members of a @code{radio-button-choice} or
@code{checklist}. The value should be a list of extra keyword
@end table
@deffn {User Option} widget-glyph-directory
-Directory where glyphs are found.
+Directory where glyphs are found.
Widget will look here for a file with the same name as specified for the
-image, with either a @samp{.xpm} (if supported) or @samp{.xbm} extension.
+image, with either a @file{.xpm} (if supported) or @file{.xbm} extension.
@end deffn
@deffn{User Option} widget-glyph-enable
-If non-nil, allow glyphs to appear on displays where they are supported.
+If non-@code{nil}, allow glyphs to appear on displays where they are supported.
@end deffn
@menu
-* link::
-* url-link::
-* info-link::
-* push-button::
-* editable-field::
-* text::
-* menu-choice::
-* radio-button-choice::
-* item::
-* choice-item::
-* toggle::
-* checkbox::
-* checklist::
-* editable-list::
-* group::
+* link::
+* url-link::
+* info-link::
+* push-button::
+* editable-field::
+* text::
+* menu-choice::
+* radio-button-choice::
+* item::
+* choice-item::
+* toggle::
+* checkbox::
+* checklist::
+* editable-list::
+* group::
@end menu
@node link, url-link, Basic Types, Basic Types
@comment node-name, next, previous, up
@subsection The @code{link} Widget
+@findex link@r{ widget}
Syntax:
The @var{value}, if present, is used to initialize the @code{:value}
property. The value should be a string, which will be inserted in the
-buffer.
+buffer.
By default the link will be shown in brackets.
@node url-link, info-link, link, Basic Types
@comment node-name, next, previous, up
@subsection The @code{url-link} Widget
+@findex url-link@r{ widget}
Syntax:
TYPE ::= (url-link [KEYWORD ARGUMENT]... URL)
@end example
-When this link is invoked, the @sc{www} browser specified by
-@code{browse-url-browser-function} will be called with @var{url}.
+@findex browse-url-browser-function@r{, and @code{url-link} widget}
+When this link is invoked, the @acronym{WWW} browser specified by
+@code{browse-url-browser-function} will be called with @var{url}.
@node info-link, push-button, url-link, Basic Types
@comment node-name, next, previous, up
@subsection The @code{info-link} Widget
+@findex info-link@r{ widget}
Syntax:
TYPE ::= (info-link [KEYWORD ARGUMENT]... ADDRESS)
@end example
-When this link is invoked, the built-in info browser is started on
-@var{address}.
+When this link is invoked, the built-in Info reader is started on
+@var{address}.
@node push-button, editable-field, info-link, Basic Types
@comment node-name, next, previous, up
@subsection The @code{push-button} Widget
+@findex push-button@r{ widget}
Syntax:
@end example
The @var{value}, if present, is used to initialize the @code{:value}
-property. The value should be a string, which will be inserted in the
-buffer.
+property. The value should be a string, which will be inserted in the
+buffer.
By default the tag will be shown in brackets.
@node editable-field, text, push-button, Basic Types
@comment node-name, next, previous, up
@subsection The @code{editable-field} Widget
+@findex editable-field@r{ widget}
Syntax:
property. The value should be a string, which will be inserted in
field. This widget will match all string values.
-The following extra properties are recognized.
+The following extra properties are recognized:
@table @code
+@vindex size@r{ keyword}
@item :size
The width of the editable field.@*
By default the field will reach to the end of the line.
+@vindex value-face@r{ keyword}
@item :value-face
Face used for highlighting the editable field. Default is
-@code{widget-field-face}.
+@code{widget-field-face}, see @ref{User Interface}.
+@vindex secret@r{ keyword}
@item :secret
-Character used to display the value. You can set this to e.g. @code{?*}
+Character used to display the value. You can set this to e.g.@: @code{?*}
if the field contains a password or other secret information. By
-default, the value is not secret.
+default, this is @code{nil}, and the value is not secret.
+@vindex valid-regexp@r{ keyword}
@item :valid-regexp
By default the @code{:validate} function will match the content of the
field with the value of this attribute. The default value is @code{""}
which matches everything.
+@vindex keymap@r{ keyword}
+@vindex widget-field-keymap
@item :keymap
Keymap used in the editable field. The default value is
@code{widget-field-keymap}, which allows you to use all the normal
-editing commands, even if the buffers major mode suppress some of them.
-Pressing return invokes the function specified by @code{:action}.
+editing commands, even if the buffer's major mode suppresses some of
+them. Pressing @key{RET} invokes the function specified by
+@code{:action}.
@end table
@node text, menu-choice, editable-field, Basic Types
@comment node-name, next, previous, up
@subsection The @code{text} Widget
+@findex text@r{ widget}
+@vindex widget-text-keymap
This is just like @code{editable-field}, but intended for multiline text
fields. The default @code{:keymap} is @code{widget-text-keymap}, which
-does not rebind the return key.
+does not rebind the @key{RET} key.
@node menu-choice, radio-button-choice, text, Basic Types
@comment node-name, next, previous, up
@subsection The @code{menu-choice} Widget
+@findex menu-choice@r{ widget}
Syntax:
arguments.
@table @code
-@item :void
+@vindex void@r{ keyword}
+@item :void
Widget type used as a fallback when the value does not match any of the
specified @var{type} arguments.
+@vindex case-fold@r{ keyword}
@item :case-fold
-Set this to nil if you don't want to ignore case when prompting for a
+Set this to @code{nil} if you don't want to ignore case when prompting for a
choice through the minibuffer.
+@vindex children@r{ keyword}
@item :children
-A list whose car is the widget representing the currently chosen type in
-the buffer.
+A list whose @sc{car} is the widget representing the currently chosen
+type in the buffer.
+@vindex choice@r{ keyword}
@item :choice
-The current chosen type
+The current chosen type.
-@item :args
-The list of types.
+@vindex args@r{ keyword}
+@item :args
+The list of types.
@end table
@node radio-button-choice, item, menu-choice, Basic Types
@comment node-name, next, previous, up
@subsection The @code{radio-button-choice} Widget
+@findex radio-button-choice@r{ widget}
Syntax:
The following extra properties are recognized.
@table @code
+@vindex entry-format@r{ keyword}
@item :entry-format
This string will be inserted for each entry in the list.
The following @samp{%} escapes are available:
@table @samp
@item %v
-Replaced with the buffer representation of the @var{type} widget.
+Replace with the buffer representation of the @var{type} widget.
@item %b
Replace with the radio button.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
-@item button-args
+@vindex button-args@r{ keyword}
+@item :button-args
A list of keywords to pass to the radio buttons. Useful for setting
-e.g. the @samp{:help-echo} for each button.
+e.g.@: the @samp{:help-echo} for each button.
+@vindex buttons@r{ keyword}
@item :buttons
The widgets representing the radio buttons.
+@vindex children@r{ keyword}
@item :children
The widgets representing each type.
+@vindex choice@r{ keyword}
@item :choice
The current chosen type
-@item :args
-The list of types.
+@vindex args@r{ keyword}
+@item :args
+The list of types.
@end table
You can add extra radio button items to a @code{radio-button-choice}
widget after it has been created with the function
-@code{widget-radio-add-item}.
+@code{widget-radio-add-item}.
@defun widget-radio-add-item widget type
-Add to @code{radio-button-choice} widget @var{widget} a new radio button item of type
-@var{type}.
+Add to @code{radio-button-choice} widget @var{widget} a new radio button
+item of type @var{type}.
@end defun
Please note that such items added after the @code{radio-button-choice}
@node item, choice-item, radio-button-choice, Basic Types
@comment node-name, next, previous, up
@subsection The @code{item} Widget
+@findex item@r{ widget}
Syntax:
@node choice-item, toggle, item, Basic Types
@comment node-name, next, previous, up
@subsection The @code{choice-item} Widget
+@findex choice-item@r{ widget}
Syntax:
property. The value should be a string, which will be inserted in the
buffer as a button. Activating the button of a @code{choice-item} is
equivalent to activating the parent widget. This widget will only match
-the specified value.
+the specified value.
@node toggle, checkbox, choice-item, Basic Types
@comment node-name, next, previous, up
@subsection The @code{toggle} Widget
+@findex toggle@r{ widget}
Syntax:
TYPE ::= (toggle [KEYWORD ARGUMENT]...)
@end example
-The widget has two possible states, `on' and `off', which correspond to
-a @code{t} or @code{nil} value respectively.
+The widget has two possible states, @samp{on} and @samp{off}, which
+correspond to a @code{t} or @code{nil} value, respectively.
-The following extra properties are recognized.
+The following extra properties are recognized:
@table @code
@item :on
-String representing the `on' state. By default the string @samp{on}.
-@item :off
-String representing the `off' state. By default the string @samp{off}.
+A string representing the @samp{on} state. By default the string
+@samp{on}.
+@item :off
+A string representing the @samp{off} state. By default the string
+@samp{off}.
+@vindex on-glyph@r{ keyword}
@item :on-glyph
-Name of a glyph to be used instead of the `:on' text string, on emacsen
-that supports it.
+Name of a glyph to be used instead of the @samp{:on} text string, on
+emacsen that supports this.
+@vindex off-glyph@r{ keyword}
@item :off-glyph
-Name of a glyph to be used instead of the `:off' text string, on emacsen
-that supports it.
+Name of a glyph to be used instead of the @samp{:off} text string, on
+emacsen that supports this.
@end table
@node checkbox, checklist, toggle, Basic Types
@comment node-name, next, previous, up
@subsection The @code{checkbox} Widget
+@findex checkbox@r{ widget}
-The widget has two possible states, `selected' and `unselected', which
-corresponds to a @code{t} or @code{nil} value.
+This widget has two possible states, @samp{selected} and
+@samp{unselected}, which corresponds to a @code{t} or @code{nil} value.
Syntax:
@node checklist, editable-list, checkbox, Basic Types
@comment node-name, next, previous, up
@subsection The @code{checklist} Widget
+@findex checklist@r{ widget}
Syntax:
TYPE ::= (checklist [KEYWORD ARGUMENT]... TYPE ... )
@end example
-The @var{type} arguments represents each checklist item. The widget's
-value will be a list containing the values of all ticked @var{type}
+The @var{type} arguments represent each checklist item. The widget's
+value will be a list containing the values of all checked @var{type}
arguments. The checklist widget will match a list whose elements all
match at least one of the specified @var{type} arguments.
-The following extra properties are recognized.
+The following extra properties are recognized:
@table @code
+@vindex entry-format@r{ keyword}
@item :entry-format
This string will be inserted for each entry in the list.
The following @samp{%} escapes are available:
@item %b
Replace with the checkbox.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
+@vindex greedy@r{ keyword}
@item :greedy
Usually a checklist will only match if the items are in the exact
sequence given in the specification. By setting @code{:greedy} to
-non-nil, it will allow the items to come in any sequence. However, if
-you extract the value they will be in the sequence given in the
-checklist. I.e. the original sequence is forgotten.
+non-@code{nil}, it will allow the items to come in any sequence.
+However, if you extract the value they will be in the sequence given
+in the checklist, i.e.@: the original sequence is forgotten.
-@item button-args
+@vindex button-args@r{ keyword}
+@item :button-args
A list of keywords to pass to the checkboxes. Useful for setting
-e.g. the @samp{:help-echo} for each checkbox.
+e.g.@: the @samp{:help-echo} for each checkbox.
+@vindex buttons@r{ keyword}
@item :buttons
The widgets representing the checkboxes.
+@vindex children@r{ keyword}
@item :children
The widgets representing each type.
-@item :args
-The list of types.
+@vindex args@r{ keyword}
+@item :args
+The list of types.
@end table
@node editable-list, group, checklist, Basic Types
@comment node-name, next, previous, up
@subsection The @code{editable-list} Widget
+@findex editable-list@r{ widget}
Syntax:
@end example
The value is a list, where each member represents one widget of type
-@var{type}.
+@var{type}.
-The following extra properties are recognized.
+The following extra properties are recognized:
@table @code
+@vindex entry-format@r{ keyword}
@item :entry-format
This string will be inserted for each entry in the list.
The following @samp{%} escapes are available:
@item %d
Insert the @b{[DEL]} button.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
+@vindex insert-button-args@r{ keyword}
@item :insert-button-args
A list of keyword arguments to pass to the insert buttons.
+@vindex delete-button-args@r{ keyword}
@item :delete-button-args
A list of keyword arguments to pass to the delete buttons.
+@vindex append-button-args@r{ keyword}
@item :append-button-args
A list of keyword arguments to pass to the trailing insert button.
-
+@vindex buttons@r{ keyword}
@item :buttons
The widgets representing the insert and delete buttons.
+@vindex children@r{ keyword}
@item :children
The widgets representing the elements of the list.
+@vindex args@r{ keyword}
@item :args
-List whose car is the type of the list elements.
-
+List whose @sc{car} is the type of the list elements.
@end table
@node group, , editable-list, Basic Types
@comment node-name, next, previous, up
@subsection The @code{group} Widget
+@findex group@r{ widget}
-This widget simply group other widget together.
+This widget simply group other widgets together.
Syntax:
TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...)
@end example
-The value is a list, with one member for each @var{type}.
+The value is a list, with one member for each @var{type}.
@node Sexp Types, Widget Properties, Basic Types, Top
@comment
@section Sexp Types
+@cindex sexp types
-A number of widgets for editing s-expressions (lisp types) are also
-available. These basically fall in the following categories.
+A number of widgets for editing @dfn{s-expressions} (Lisp types), sexp
+for short, are also available. These basically fall in several
+categories described in this section.
@menu
-* constants::
-* generic::
-* atoms::
-* composite::
+* constants::
+* generic::
+* atoms::
+* composite::
@end menu
@node constants, generic, Sexp Types, Sexp Types
@comment node-name, next, previous, up
-@subsection The Constant Widgets.
+@subsection The Constant Widgets
+@cindex constant widgets
-The @code{const} widget can contain any lisp expression, but the user is
-prohibited from editing edit it, which is mainly useful as a component
-of one of the composite widgets.
+The @code{const} widget can contain any Lisp expression, but the user is
+prohibited from editing it, which is mainly useful as a component of one
+of the composite widgets.
-The syntax for the @code{const} widget is
+The syntax for the @code{const} widget is:
@example
TYPE ::= (const [KEYWORD ARGUMENT]... [ VALUE ])
@deffn Widget const
This will display any valid s-expression in an immutable part of the
-buffer.
+buffer.
@end deffn
There are two variations of the @code{const} widget, namely
@node generic, atoms, constants, Sexp Types
@comment node-name, next, previous, up
-@subsection Generic Sexp Widget.
+@subsection Generic Sexp Widget
+@cindex generic sexp widget
-The @code{sexp} widget can contain any lisp expression, and allows the
+The @code{sexp} widget can contain any Lisp expression, and allows the
user to edit it inline in the buffer.
-The syntax for the @code{sexp} widget is
+The syntax for the @code{sexp} widget is:
@example
TYPE ::= (sexp [KEYWORD ARGUMENT]... [ VALUE ])
@deffn Widget sexp
This will allow you to edit any valid s-expression in an editable buffer
-field.
+field.
The @code{sexp} widget takes the same keyword arguments as the
-@code{editable-field} widget.
+@code{editable-field} widget. @xref{editable-field}.
@end deffn
@node atoms, composite, generic, Sexp Types
@comment node-name, next, previous, up
-@subsection Atomic Sexp Widgets.
+@subsection Atomic Sexp Widgets
+@cindex atomic sexp widget
-The atoms are s-expressions that does not consist of other
-s-expressions. A string is an atom, while a list is a composite type.
-You can edit the value of an atom with the following widgets.
+The atoms are s-expressions that do not consist of other s-expressions.
+For example, a string, a file name, or a symbol are atoms, while a list
+is a composite type. You can edit the value of an atom with the
+following widgets.
-The syntax for all the atoms are
+The syntax for all the atoms are:
@example
TYPE ::= (NAME [KEYWORD ARGUMENT]... [ VALUE ])
The @var{value}, if present, is used to initialize the @code{:value}
property and must be an expression of the same type as the widget.
-I.e. the string widget can only be initialized with a string.
+That is, the string widget can only be initialized with a string.
All the atom widgets take the same keyword arguments as the
-@code{editable-field} widget.
+@code{editable-field} widget. @xref{editable-field}.
@deffn Widget string
Allows you to edit a string in an editable field.
@deffn Widget file
Allows you to edit a file name in an editable field. If you invoke
the tag button, you can edit the file name in the mini-buffer with
-completion.
+completion.
Keywords:
@table @code
+@vindex must-match@r{ keyword}
@item :must-match
-If this is set to non-nil, only existing file names will be allowed in
-the minibuffer.
+If this is set to non-@code{nil}, only existing file names will be
+allowed in the minibuffer.
@end table
@end deffn
@end deffn
@deffn Widget symbol
-Allows you to edit a lisp symbol in an editable field.
+Allows you to edit a Lisp symbol in an editable field.
@end deffn
@deffn Widget function
@end deffn
@deffn Widget boolean
-Allows you to edit a boolean. In lisp this means a variable which is
-either nil meaning false, or non-nil meaning true.
+Allows you to edit a boolean. In Lisp this means a variable which is
+either @code{nil} meaning false, or non-@code{nil} meaning true.
@end deffn
@node composite, , atoms, Sexp Types
@comment node-name, next, previous, up
-@subsection Composite Sexp Widgets.
+@subsection Composite Sexp Widgets
+@cindex composite sexp widgets
-The syntax for the composite are
+The syntax for the composite widget is:
@example
TYPE ::= (NAME [KEYWORD ARGUMENT]... COMPONENT...)
@end example
-Where each @var{component} must be a widget type. Each component widget
-will be displayed in the buffer, and be editable to the user.
+@noindent
+where each @var{component} must be a widget type. Each component widget
+will be displayed in the buffer, and will be editable by the user.
@deffn Widget cons
-The value of a @code{cons} widget is a cons-cell where the car is the
-value of the first component and the cdr is the value of the second
-component. There must be exactly two components.
+The value of a @code{cons} widget is a cons-cell where the @sc{car} is
+the value of the first component and the @sc{cdr} is the value of the
+second component. There must be exactly two components.
@end deffn
@deffn Widget list
The above suffice for specifying fixed size lists and vectors. To get
variable length lists and vectors, you can use a @code{choice},
-@code{set} or @code{repeat} widgets together with the @code{:inline}
+@code{set}, or @code{repeat} widgets together with the @code{:inline}
keywords. If any component of a composite widget has the @code{:inline}
keyword set, its value must be a list which will then be spliced into
the composite. For example, to specify a list whose first element must
string string)))
@end example
-The value of a widget of this type will either have the form
-@samp{(file t)} or @code{(file string string)}.
+The value of a widget of this type will either have the form
+@code{(file t)} or @code{(file string string)}.
This concept of inline is probably hard to understand. It was certainly
-hard to implement so instead of confusing you more by trying to explain
+hard to implement, so instead of confusing you more by trying to explain
it here, I'll just suggest you meditate over it for a while.
@deffn Widget choice
@deffn Widget set
Allows you to specify a type which must be a list whose elements all
-belong to given set. The elements of the list is not significant. This
-is implemented on top of the @code{checklist} basic widget, and has a
-similar syntax.
+belong to given set. The elements of the list are not significant.
+This is implemented on top of the @code{checklist} basic widget, and has
+a similar syntax.
@end deffn
@deffn Widget repeat
Allows you to specify a variable length list whose members are all of
-the same type. Implemented on top of the `editable-list' basic widget,
-and has a similar syntax.
+the same type. Implemented on top of the @code{editable-list} basic
+widget, and has a similar syntax.
@end deffn
@node Widget Properties, Defining New Widgets, Sexp Types, Top
@comment node-name, next, previous, up
@section Properties
+@cindex properties of widgets
+@cindex widget properties
You can examine or set the value of a widget by using the widget object
that was returned by @code{widget-create}.
widget again. It is enough to call @code{widget-setup} once if you
modify multiple widgets. This is currently only necessary if the widget
contains an editing field, but may be necessary for other widgets in the
-future.
+future.
If your application needs to associate some information with the widget
objects, for example a reference to the item being edited, it can be
@end defun
@defun widget-member widget property
-Non-nil if @var{widget} has a value (even nil) for property @var{property}.
+Non-@code{nil} if @var{widget} has a value (even @code{nil}) for
+property @var{property}.
@end defun
Occasionally it can be useful to know which kind of widget you have,
-i.e. the name of the widget type you gave when the widget was created.
+i.e.@: the name of the widget type you gave when the widget was created.
@defun widget-type widget
Return the name of @var{widget}, a symbol.
@end defun
+@cindex active widget
+@cindex inactive widget
+@cindex activate a widget
+@cindex deactivate a widget
Widgets can be in two states: active, which means they are modifiable by
the user, or inactive, which means they cannot be modified by the user.
You can query or set the state with the following code:
all its ancestors.
@lisp
-(while widget
+(while widget
(widget-apply widget :activate)
(setq widget (widget-get widget :parent)))
@end lisp
You can check if a widget has been made inactive by examining the value
-of the @code{:inactive} keyword. If this is non-nil, the widget itself
+of the @code{:inactive} keyword. If this is non-@code{nil}, the widget itself
has been deactivated. This is different from using the @code{:active}
keyword, in that the latter tells you if the widget @strong{or} any of
its ancestors have been deactivated. Do not attempt to set the
@node Defining New Widgets, Widget Browser, Widget Properties, Top
@comment node-name, next, previous, up
@section Defining New Widgets
+@cindex new widgets
+@cindex defining new widgets
You can define specialized widgets with @code{define-widget}. It allows
you to create a shorthand for more complex widgets, including specifying
component widgets and new default values for the keyword
-arguments.
+arguments.
-@defun widget-define name class doc &rest args
+@defun define-widget name class doc &rest args
Define a new widget type named @var{name} from @code{class}.
@var{name} and class should both be symbols, @code{class} should be one
-of the existing widget types.
+of the existing widget types.
-The third argument @var{DOC} is a documentation string for the widget.
+The third argument @var{doc} is a documentation string for the widget.
After the new widget has been defined, the following two calls will
create identical widgets:
@end defun
-Using @code{widget-define} just stores the definition of the widget type
+Using @code{define-widget} just stores the definition of the widget type
in the @code{widget-type} property of @var{name}, which is what
@code{widget-create} uses.
-If you just want to specify defaults for keywords with no complex
+If you only want to specify defaults for keywords with no complex
conversions, you can use @code{identity} as your conversion function.
The following additional keyword arguments are useful when defining new
-widgets:
+widgets:
@table @code
+@vindex convert-widget@r{ keyword}
@item :convert-widget
Function to convert a widget type before creating a widget of that
type. It takes a widget type as an argument, and returns the converted
widget type. When a widget is created, this function is called for the
-widget type and all the widget's parent types, most derived first.
+widget type and all the widget's parent types, most derived first.
The following predefined functions can be used here:
Initialize @code{:value} from @code{:args} in @var{widget}.
@end defun
+@vindex copy@r{ keyword}
+@item :copy
+Function to deep copy a widget type. It takes a shallow copy of the
+widget type as an argument (made by @code{copy-sequence}), and returns a
+deep copy. The purpose of this is to avoid having different instances
+of combined widgets share nested attributes.
+
+The following predefined functions can be used here:
+
+@defun widget-types-copy widget
+Copy @code{:args} as widget types in @var{widget}.
+@end defun
+
+@vindex value-to-internal@r{ keyword}
@item :value-to-internal
Function to convert the value to the internal format. The function
takes two arguments, a widget and an external value, and returns the
when the widget is created, and on any value set later with
@code{widget-value-set}.
+@vindex value-to-external@r{ keyword}
@item :value-to-external
Function to convert the value to the external format. The function
takes two arguments, a widget and an internal value, and returns the
-internal value. The function is called on the present @code{:value}
+external value. The function is called on the present @code{:value}
when the widget is created, and on any value set later with
@code{widget-value-set}.
+@vindex create@r{ keyword}
@item :create
Function to create a widget from scratch. The function takes one
argument, a widget type, and creates a widget of that type, inserts it
in the buffer, and returns a widget object.
+@vindex delete@r{ keyword}
@item :delete
Function to delete a widget. The function takes one argument, a widget,
and should remove all traces of the widget from the buffer.
+The default value is:
+
+@defun widget-default-delete widget
+Remove @var{widget} from the buffer.
+Delete all @code{:children} and @code{:buttons} in @var{widget}.
+@end defun
+
+In most cases you should not change this value, but instead use
+@code{:value-delete} to make any additional cleanup.
+
+@vindex value-create@r{ keyword}
@item :value-create
Function to expand the @samp{%v} escape in the format string. It will
be called with the widget as its argument and should insert a
representation of the widget's value in the buffer.
+Nested widgets should be listed in @code{:children} or @code{:buttons}
+to make sure they are automatically deleted.
+
+@vindex value-delete@r{ keyword}
@item :value-delete
Should remove the representation of the widget's value from the buffer.
It will be called with the widget as its argument. It doesn't have to
remove the text, but it should release markers and delete nested widgets
-if such have been used.
+if these are not listed in @code{:children} or @code{:buttons}.
-The following predefined function can be used here:
-
-@defun widget-children-value-delete widget
-Delete all @code{:children} and @code{:buttons} in @var{widget}.
-@end defun
-
-@item :value-get
+@vindex value-get@r{ keyword}
+@item :value-get
Function to extract the value of a widget, as it is displayed in the
-buffer.
+buffer.
The following predefined function can be used here:
Return the @code{:value} property of @var{widget}.
@end defun
+@vindex format-handler@r{ keyword}
@item :format-handler
Function to handle unknown @samp{%} escapes in the format string. It
-will be called with the widget and the escape character as arguments.
-You can set this to allow your widget to handle non-standard escapes.
+will be called with the widget and the character that follows the
+@samp{%} as arguments. You can set this to allow your widget to handle
+non-standard escapes.
+@findex widget-default-format-handler
You should end up calling @code{widget-default-format-handler} to handle
unknown escape sequences, which will handle the @samp{%h} and any future
escape sequences, as well as give an error for unknown escapes.
+@vindex action@r{ keyword}
@item :action
Function to handle user initiated events. By default, @code{:notify}
-the parent.
+the parent.
The following predefined function can be used here:
Optional @var{event} is the event that triggered the action.
@end defun
+@vindex prompt-value@r{ keyword}
@item :prompt-value
Function to prompt for a value in the minibuffer. The function should
take four arguments, @var{widget}, @var{prompt}, @var{value}, and
@var{unbound} and should return a value for widget entered by the user.
@var{prompt} is the prompt to use. @var{value} is the default value to
-use, unless @var{unbound} is non-nil, in which case there is no default
+use, unless @var{unbound} is non-@code{nil}, in which case there is no default
value. The function should read the value using the method most natural
for this widget, and does not have to check that it matches.
@end table
If you want to define a new widget from scratch, use the @code{default}
widget as its base.
-@deffn Widget default
-Widget used as a base for other widgets.
+@deffn Widget default
+Widget used as a base for other widgets.
It provides most of the functionality that is referred to as ``by
-default'' in this text.
+default'' in this text.
@end deffn
@node Widget Browser, Widget Minor Mode, Defining New Widgets, Top
@comment node-name, next, previous, up
@section Widget Browser
+@cindex widget browser
There is a separate package to browse widgets. This is intended to help
programmers who want to examine the content of a widget. The browser
shows the value of each keyword, but uses links for certain keywords
-such as `:parent', which avoids printing cyclic structures.
+such as @samp{:parent}, which avoids printing cyclic structures.
-@deffn Command widget-browse WIDGET
-Create a widget browser for WIDGET.
-When called interactively, prompt for WIDGET.
+@deffn Command widget-browse @var{widget}
+Create a widget browser for @var{widget}.
+When called interactively, prompt for @var{widget}.
@end deffn
-@deffn Command widget-browse-other-window WIDGET
-Create a widget browser for WIDGET and show it in another window.
-When called interactively, prompt for WIDGET.
+@deffn Command widget-browse-other-window @var{widget}
+Create a widget browser for @var{widget} and show it in another window.
+When called interactively, prompt for @var{widget}.
@end deffn
-@deffn Command widget-browse-at POS
-Create a widget browser for the widget at POS.
+@deffn Command widget-browse-at @var{pos}
+Create a widget browser for the widget at @var{pos}.
When called interactively, use the position of point.
@end deffn
@node Widget Minor Mode, Utilities, Widget Browser, Top
@comment node-name, next, previous, up
@section Widget Minor Mode
+@cindex widget minor mode
There is a minor mode for manipulating widgets in major modes that
-doesn't provide any support for widgets themselves. This is mostly
-intended to be useful for programmers doing experiments.
+don't provide any support for widgets themselves. This is mostly
+intended to be useful for programmers doing experiments.
@deffn Command widget-minor-mode
Toggle minor mode for traversing widgets.
@node Utilities, Widget Wishlist, Widget Minor Mode, Top
@comment node-name, next, previous, up
@section Utilities.
+@cindex utility functions for widgets
@defun widget-prompt-value widget prompt [ value unbound ]
Prompt for a value matching @var{widget}, using @var{prompt}.
The current value is assumed to be @var{value}, unless @var{unbound} is
-non-nil.@refill
+non-@code{nil}.@refill
@end defun
@defun widget-get-sibling widget
-Get the item @var{widget} is assumed to toggle.
+Get the item which @var{widget} is assumed to toggle.
This is only meaningful for radio buttons or checkboxes in a list.
@end defun
-@node Widget Wishlist, , Utilities, Top
+@node Widget Wishlist, Index, Utilities, Top
@comment node-name, next, previous, up
@section Wishlist
+@cindex todo
@itemize @bullet
-@item
+@item
It should be possible to add or remove items from a list with @kbd{C-k}
and @kbd{C-o} (suggested by @sc{rms}).
-@item
+@item
The @samp{[INS]} and @samp{[DEL]} buttons should be replaced by a single
-dash (@samp{-}). The dash should be a button that, when invoked, ask
+dash (@samp{-}). The dash should be a button that, when invoked, asks
whether you want to add or delete an item (@sc{rms} wanted to git rid of
the ugly buttons, the dash is my idea).
@item
Add commands to show overview of object and class hierarchies to the
-browser.
+browser.
-@item
+@item
Find a way to disable mouse highlight for inactive widgets.
@item
Find clean way to implement variable length list.
See @code{TeX-printer-list} for an explanation.
-@item
+@item
@kbd{C-h} in @code{widget-prompt-value} should give type specific help.
-@item
-A mailto widget.
-
+@item
+Add a @code{mailto} widget.
@end itemize
+@node Index, , Widget Wishlist, Top
+@comment node-name, next, previous, up
+@unnumbered Index
+
+This is an alphabetical listing of all concepts, functions, commands,
+variables, and widgets described in this manual.
+@printindex cp
+
@setchapternewpage odd
@contents
@bye
+
+@ignore
+ arch-tag: 2b427731-4c61-4e72-85de-5ccec9c623f0
+@end ignore
HCoop / bpt / emacs.git / blobdiff