@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
@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
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.
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 @sc{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
@enumerate
@item
-More complex fields than just editable text are supported.
+More complex fields than just editable text are supported.
@item
You can give the users immediate feedback if they enter invalid data in a
text field, and sometimes prevent entering invalid data.
-@item
+@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
+It is simple to query or set the value of a field.
+@item
Editing happens in the buffer, not in the mini-buffer.
-@item
+@item
Packages using the library get a uniform look, making them easier for
the user to learn.
-@item
+@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.
@table @file
@item widget.el
This will declare the user variables, define the function
-@code{define-widget}, 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.
@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 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 an editable list.
-The list is created by the @code{editable-list} widget.
+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
displayed as GUI buttons when possible.
@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.
(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
+ (widget-insert
" for more information.\n\nNumbers: count to three below\n")
(setq widget-example-repeat
(widget-create 'editable-list
'(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
-Set up 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.
@end defun
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}
@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
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
@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.
@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 @file{.xpm} (if supported) or @file{.xbm} extension.
@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
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.
@findex browse-url-browser-function@r{, and @code{url-link} widget}
When this link is invoked, the @sc{www} browser specified by
-@code{browse-url-browser-function} will be called with @var{url}.
+@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
@end example
When this link is invoked, the built-in Info reader is started on
-@var{address}.
+@var{address}.
@node push-button, editable-field, info-link, Basic Types
@comment node-name, next, previous, up
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 tag will be shown in brackets.
@vindex value-face@r{ keyword}
@item :value-face
Face used for highlighting the editable field. Default is
-@code{widget-field-face}, see @ref{User Interface}.
+@code{widget-field-face}, see @ref{User Interface}.
@vindex secret@r{ keyword}
@item :secret
@table @code
@vindex void@r{ keyword}
-@item :void
+@item :void
Widget type used as a fallback when the value does not match any of the
specified @var{type} arguments.
The current chosen type.
@vindex args@r{ keyword}
-@item :args
-The list of types.
+@item :args
+The list of types.
@end table
@node radio-button-choice, item, menu-choice, Basic Types
@item %b
Replace with the radio button.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@vindex button-args@r{ keyword}
The current chosen type
@vindex args@r{ keyword}
-@item :args
-The list of types.
+@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
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
@item :on
A string representing the @samp{on} state. By default the string
@samp{on}.
-@item :off
+@item :off
A string representing the @samp{off} state. By default the string
@samp{off}.
@vindex on-glyph@r{ keyword}
@item %b
Replace with the checkbox.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@vindex greedy@r{ keyword}
The widgets representing each type.
@vindex args@r{ keyword}
-@item :args
-The list of types.
+@item :args
+The list of types.
@end table
@node editable-list, group, checklist, Basic Types
@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:
@item %d
Insert the @b{[DEL]} button.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@vindex insert-button-args@r{ keyword}
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
categories described in this section.
@menu
-* constants::
-* generic::
-* atoms::
-* composite::
+* constants::
+* generic::
+* atoms::
+* composite::
@end menu
@node constants, generic, Sexp Types, Sexp Types
@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
@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. @xref{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
string string)))
@end example
-The value of a widget of this type will either have the form
+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
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
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.
all its ancestors.
@lisp
-(while widget
+(while widget
(widget-apply widget :activate)
(setq widget (widget-get widget :parent)))
@end lisp
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 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.
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:
@end defun
@vindex value-get@r{ keyword}
-@item :value-get
+@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:
@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:
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
There is a minor mode for manipulating widgets in major modes that
don't provide any support for widgets themselves. This is mostly
-intended to be useful for programmers doing experiments.
+intended to be useful for programmers doing experiments.
@deffn Command widget-minor-mode
Toggle minor mode for traversing widgets.
@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, asks
whether you want to add or delete an item (@sc{rms} wanted to git rid of
@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
+@item
Add a @code{mailto} widget.
@end itemize