@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::
* Widget Internals::
@end menu
@node Introduction, User Interface, Top, Top
@comment node-name, next, previous, up
-@section Introduction
+@chapter Introduction
Most graphical user interface toolkits, such as Motif and XView, provide
a number of standard user interface controls (sometimes known as
@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.
The advantages for a programmer of using the @code{widget} package to
implement forms are:
@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 user immediate feedback if he enters invalid data in a
text field, and sometimes prevent entering invalid data.
-@item
+@item
You can have fixed sized fields, thus allowing multiple field 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 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
extended to support it. This means that your code using the widget
library will also use the new graphic features by automatic.
@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.
@node User Interface, Programming Example, Introduction, Top
@comment node-name, next, previous, up
-@section User Interface
+@chapter User Interface
A form consists of read only text for documentation and some fields,
where each of the fields contains two parts, a tag and a value. The
@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:
a form, namely editing the editable text fields and activating the
buttons.
-@subsection Editable Text Fields
+@section Editable Text Fields
In the example, the value for the @samp{Name} is most likely displayed
in an editable text field, and so are values for each of the members of
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.
@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
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
displayed as GUI buttons when possible.
-enough.
+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.
@node Programming Example, Setting Up the Buffer, User Interface, Top
@comment node-name, next, previous, up
-@section Programming Example
+@chapter Programming Example
Here is the code to implement the user interface example (see @ref{User
Interface}).
(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")
'(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!")
@node Setting Up the Buffer, Basic Types, Programming Example, Top
@comment node-name, next, previous, up
-@section Setting Up the Buffer
+@chapter Setting Up the Buffer
Widgets are created with @code{widget-create}, which returns a
@dfn{widget} object. This object can be queried and manipulated by
Delete @var{widget} and remove it from the buffer.
@end defun
-@defun widget-setup
-Setup a buffer to support widgets.
+@defun widget-setup
+Setup 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
@node Basic Types, Sexp Types, Setting Up the Buffer, Top
@comment node-name, next, previous, up
-@section Basic Types
+@chapter Basic Types
The syntax of a type specification is given below:
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.
representation of the value if there is no tag.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@item :button-face
@item :doc
The string inserted by the @samp{%d} or @samp{%h} escape in the format
-string.
+string.
@item :tag
The string inserted by the @samp{%t} escape in the format
-string.
+string.
@item :tag-glyph
Name of image to use instead of the string specified by `:tag' on
@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 @samp{.xpm} (if supported) or @samp{.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
@comment node-name, next, previous, up
-@subsection The @code{link} Widget
+@section The @code{link} 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
+@section The @code{url-link} Widget
Syntax:
@end example
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
-@subsection The @code{info-link} Widget
+@section The @code{info-link} Widget
Syntax:
@end example
When this link is invoked, the built-in info browser is started on
-@var{address}.
+@var{address}.
@node push-button, editable-field, info-link, Basic Types
@comment node-name, next, previous, up
-@subsection The @code{push-button} Widget
+@section The @code{push-button} 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 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
+@section The @code{editable-field} Widget
Syntax:
@item :value-face
Face used for highlighting the editable field. Default is
-@code{widget-field-face}.
+@code{widget-field-face}.
@item :secret
Character used to display the value. You can set this to e.g. @code{?*}
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 buffer's major mode suppress some of them.
-Pressing return invokes the function specified by @code{:action}.
+Pressing return 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
+@section The @code{text} Widget
This is just like @code{editable-field}, but intended for multiline text
fields. The default @code{:keymap} is @code{widget-text-keymap}, which
@node menu-choice, radio-button-choice, text, Basic Types
@comment node-name, next, previous, up
-@subsection The @code{menu-choice} Widget
+@section The @code{menu-choice} Widget
Syntax:
arguments.
@table @code
-@item :void
+@item :void
Widget type used as a fallback when the value does not match any of the
specified @var{type} arguments.
@item :children
A list whose car is the widget representing the currently chosen type in
-the buffer.
+the buffer.
@item :choice
The current chosen type
-@item :args
-The list of types.
+@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
+@section The @code{radio-button-choice} Widget
Syntax:
@item %b
Replace with the radio button.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@item button-args
@item :choice
The current chosen type
-@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 item of type
-@var{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
+@section The @code{item} Widget
Syntax:
@node choice-item, toggle, item, Basic Types
@comment node-name, next, previous, up
-@subsection The @code{choice-item} Widget
+@section The @code{choice-item} 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
+@section The @code{toggle} Widget
Syntax:
@table @code
@item :on
String representing the `on' state. By default the string @samp{on}.
-@item :off
+@item :off
String representing the `off' state. By default the string @samp{off}.
@item :on-glyph
Name of a glyph to be used instead of the `:on' text string, on emacsen
@node checkbox, checklist, toggle, Basic Types
@comment node-name, next, previous, up
-@subsection The @code{checkbox} Widget
+@section The @code{checkbox} Widget
The widget has two possible states, `selected' and `unselected', which
corresponds to a @code{t} or @code{nil} value.
@node checklist, editable-list, checkbox, Basic Types
@comment node-name, next, previous, up
-@subsection The @code{checklist} Widget
+@section The @code{checklist} Widget
Syntax:
@item %b
Replace with the checkbox.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@item :greedy
@item :children
The widgets representing each type.
-@item :args
-The list of types.
+@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
+@section The @code{editable-list} 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.
@item %d
Insert the @b{[DEL]} button.
@item %%
-Insert a literal @samp{%}.
+Insert a literal @samp{%}.
@end table
@item :insert-button-args
@node group, , editable-list, Basic Types
@comment node-name, next, previous, up
-@subsection The @code{group} Widget
+@section The @code{group} Widget
This widget simply groups other widgets together.
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
+@chapter Sexp Types
A number of widgets for editing s-expressions (lisp types) are also
available. These basically fall in the following categories.
@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.
+@section The Constant 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
@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.
+@section Generic Sexp Widget.
The @code{sexp} widget can contain any lisp expression, and allows the
user to edit it inline in the buffer.
@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.
@node atoms, composite, generic, Sexp Types
@comment node-name, next, previous, up
-@subsection Atomic Sexp Widgets.
+@section Atomic Sexp Widgets.
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.
+You can edit the value of an atom with the following widgets.
The syntax for all the atoms are
@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
@node composite, , atoms, Sexp Types
@comment node-name, next, previous, up
-@subsection Composite Sexp Widgets.
+@section Composite Sexp Widgets.
The syntax for the composite are
@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.
+component. There must be exactly two components.
@end deffn
@deffn Widget list
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
@samp{(file t)} or @code{(file string string)}.
This concept of inline is probably hard to understand. It was certainly
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.
+similar syntax.
@end deffn
@deffn Widget repeat
@node Widget Properties, Defining New Widgets, Sexp Types, Top
@comment node-name, next, previous, up
-@section Properties
+@chapter 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
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
@node Defining New Widgets, Widget Browser, Widget Properties, Top
@comment node-name, next, previous, up
-@section Defining New Widgets
+@chapter Defining New Widgets
You can define specialized widgets with @code{define-widget}. It allows
you to create a shorthand for more complex widgets. This includes
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.
function.
The following additional keyword arguments are useful when defining new
-widgets:
+widgets:
@table @code
@item :convert-widget
Method to convert type-specific components of a widget type before
Delete all @code{:children} and @code{:buttons} in @var{widget}.
@end defun
-@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:
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
In implementing complex hierarchical widgets (@emph{e.g.}, using the
@node Widget Browser, Widget Minor Mode, Defining New Widgets, Top
@comment node-name, next, previous, up
-@section Widget Browser
+@chapter 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
@node Widget Minor Mode, Utilities, Widget Browser, Top
@comment node-name, next, previous, up
-@section Widget Minor Mode
+@chapter 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.
+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.
+@chapter Utilities.
@defun widget-prompt-value widget prompt [ value unbound ]
Prompt for a value matching @var{widget}, using @var{prompt}.@*
@node Widget Wishlist, Widget Internals, Utilities, Top
@comment node-name, next, previous, up
-@section Wishlist
+@chapter Wishlist
@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
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
A mailto widget.
-@item
+@item
@kbd{C-e e} in a fixed size field should go to the end of the text in
-the field, not the end of the field itself.
+the field, not the end of the field itself.
@item
Use an overlay instead of markers to delimit the widget. Create
@end itemize
@node Widget Internals, , Widget Wishlist, Top
-@section Internals
+@chapter Internals
This (very brief!) section provides a few notes on the internal
structure and implementation of Emacs widgets. Avoid relying on this
To the extent that it actually describes APIs, the information will be
moved to appropriate sections of the manual in due course.
-@subsection The @dfn{Widget} and @dfn{Type} Structures
+@section The @dfn{Widget} and @dfn{Type} Structures
Widgets and types are currently both implemented as lists.
projects / sxemacs / blobdiff