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1772 lines
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Plaintext
1772 lines
54 KiB
Plaintext
\input texinfo.tex
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@c %**start of header
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@setfilename ../info/widget
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@settitle The Emacs Widget Library
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@ifnottex
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Copyright @copyright{} 2000 Free Software Foundation, Inc.
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Permission is granted to copy, distribute and/or modify this document
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under the terms of the GNU Free Documentation License, Version 1.1 or
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any later version published by the Free Software Foundation; with the
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Invariant Sections being ``The GNU Manifesto'', ``Distribution'' and
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``GNU GENERAL PUBLIC LICENSE'', with the Front-Cover texts being ``A GNU
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Manual'', and with the Back-Cover Texts as in (a) below. A copy of the
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license is included in the section entitled ``GNU Free Documentation
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License'' in the Emacs manual.
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This document is part of a collection distributed under the GNU Free
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Documentation License. If you want to distribute this document
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separately from the collection, you can do so by adding a copy of the
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license to the document, as described in section 6 of the license.
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(a) The FSF's Back-Cover Text is: ``You have freedom to copy and modify
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this GNU Manual, like GNU software. Copies published by the Free
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Software Foundation raise funds for GNU development.''
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@end ifnottex
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@iftex
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@afourpaper
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@headings double
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@end iftex
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@c %**end of header
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@syncodeindex fn cp
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@syncodeindex vr cp
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@syncodeindex ky cp
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@dircategory Emacs
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@direntry
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* Widget: (widget). Documenting the "widget" package used by the
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Emacs Custom facility.
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@end direntry
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@node Top, Introduction, (dir), (dir)
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@comment node-name, next, previous, up
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@top The Emacs Widget Library
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@menu
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* Introduction::
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* User Interface::
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* Programming Example::
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* Setting Up the Buffer::
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* Basic Types::
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* Sexp Types::
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* Widget Properties::
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* Defining New Widgets::
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* Widget Browser::
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* Widget Minor Mode::
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* Utilities::
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* Widget Wishlist::
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* Index::
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@end menu
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@node Introduction, User Interface, Top, Top
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@comment node-name, next, previous, up
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@section Introduction
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Most graphical user interface toolkits provide a number of standard
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user interface controls (sometimes known as `widgets' or `gadgets').
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Emacs doesn't really support anything like this, except for an
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incredibly powerful text ``widget.'' On the other hand, Emacs does
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provide the necessary primitives to implement many other widgets
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within a text buffer. The @code{widget} package simplifies this task.
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@cindex basic widgets
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@cindex widgets, basic types
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The basic widgets are:
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@table @code
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@item link
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Areas of text with an associated action. Intended for hypertext links
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embedded in text.
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@item push-button
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Like link, but intended for stand-alone buttons.
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@item editable-field
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An editable text field. It can be either variable or fixed length.
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@item menu-choice
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Allows the user to choose one of multiple options from a menu, each
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option is itself a widget. Only the selected option will be visible in
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the buffer.
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@item radio-button-choice
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Allows the user to choose one of multiple options by activating radio
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buttons. The options are implemented as widgets. All options will be
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visible in the buffer.
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@item item
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A simple constant widget intended to be used in the @code{menu-choice} and
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@code{radio-button-choice} widgets.
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@item choice-item
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A button item only intended for use in choices. When invoked, the user
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will be asked to select another option from the choice widget.
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@item toggle
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A simple @samp{on}/@samp{off} switch.
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@item checkbox
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A checkbox (@samp{[ ]}/@samp{[X]}).
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@item editable-list
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Create an editable list. The user can insert or delete items in the
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list. Each list item is itself a widget.
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@end table
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Now, of what possible use can support for widgets be in a text editor?
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I'm glad you asked. The answer is that widgets are useful for
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implementing forms. A @dfn{form} in Emacs is a buffer where the user is
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supposed to fill out a number of fields, each of which has a specific
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meaning. The user is not supposed to change or delete any of the text
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between the fields. Examples of forms in Emacs are the @file{forms}
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package (of course), the customize buffers, the mail and news compose
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modes, and the @sc{html} form support in the @file{w3} browser.
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@cindex widget library, why use it
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The advantages for a programmer of using the @code{widget} package to
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implement forms are:
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@enumerate
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@item
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More complex fields than just editable text are supported.
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@item
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You can give the users immediate feedback if they enter invalid data in a
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text field, and sometimes prevent entering invalid data.
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@item
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You can have fixed sized fields, thus allowing multiple fields to be
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lined up in columns.
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@item
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It is simple to query or set the value of a field.
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@item
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Editing happens in the buffer, not in the mini-buffer.
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@item
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Packages using the library get a uniform look, making them easier for
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the user to learn.
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@item
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As support for embedded graphics improve, the widget library will be
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extended to use the GUI features. This means that your code using the
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widget library will also use the new graphic features automatically.
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@end enumerate
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In order to minimize the code that is loaded by users who does not
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create any widgets, the code has been split in two files:
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@cindex widget library, files
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@table @file
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@item widget.el
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This will declare the user variables, define the function
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@code{define-widget}, and autoload the function @code{widget-create}.
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@item wid-edit.el
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Everything else is here, there is no reason to load it explicitly, as
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it will be autoloaded when needed.
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@end table
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@node User Interface, Programming Example, Introduction, Top
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@comment node-name, next, previous, up
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@section User Interface
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A form consist of read only text for documentation and some fields,
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where each field contains two parts, a tag and a value. The tags are
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used to identify the fields, so the documentation can refer to the
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@samp{foo field}, meaning the field tagged with @samp{Foo}. Here is an
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example form:
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@example
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Here is some documentation.
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Name: @i{My Name} @strong{Choose}: This option
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Address: @i{Some Place
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In some City
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Some country.}
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See also @b{_other work_} for more information.
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Numbers: count to three below
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@b{[INS]} @b{[DEL]} @i{One}
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@b{[INS]} @b{[DEL]} @i{Eh, two?}
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@b{[INS]} @b{[DEL]} @i{Five!}
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@b{[INS]}
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Select multiple:
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@b{[X]} This
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@b{[ ]} That
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@b{[X]} Thus
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Select one:
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@b{(*)} One
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@b{( )} Another One.
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@b{( )} A Final One.
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@b{[Apply Form]} @b{[Reset Form]}
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@end example
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The top level widgets in is example are tagged @samp{Name},
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@samp{Choose}, @samp{Address}, @samp{_other work_}, @samp{Numbers},
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@samp{Select multiple}, @samp{Select one}, @samp{[Apply Form]}, and
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@samp{[Reset Form]}. There are basically two things the user can do
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within a form, namely editing the editable text fields and activating
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the buttons.
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@subsection Editable Text Fields
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In the example, the value for the @samp{Name} is most likely displayed
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in an editable text field, and so are values for each of the members of
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the @samp{Numbers} list. All the normal Emacs editing operations are
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available for editing these fields. The only restriction is that each
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change you make must be contained within a single editable text field.
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For example, capitalizing all text from the middle of one field to the
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middle of another field is prohibited.
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Editing text fields are created by the @code{editable-field} widget.
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The editing text fields are highlighted with the
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@code{widget-field-face} face, making them easy to find.
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@deffn Face widget-field-face
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Face used for other editing fields.
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@end deffn
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@subsection Buttons
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@cindex widget buttons
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@cindex button widgets
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Some portions of the buffer have an associated @dfn{action}, which can
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be @dfn{invoked} by a standard key or mouse command. These portions
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are called @dfn{buttons}. The default commands for activating a button
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are:
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@table @kbd
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@item @key{RET}
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@deffn Command widget-button-press @var{pos} &optional @var{event}
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Invoke the button at @var{pos}, defaulting to point.
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If point is not located on a button, invoke the binding in
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@code{widget-global-map} (by default the global map).
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@end deffn
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@kindex Mouse-2 @r{(on button widgets})
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@item Mouse-2
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@deffn Command widget-button-click @var{event}
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Invoke the button at the location of the mouse pointer. If the mouse
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pointer is located in an editable text field, invoke the binding in
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@code{widget-global-map} (by default the global map).
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@end deffn
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@end table
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There are several different kind of buttons, all of which are present in
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the example:
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@table @emph
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@cindex option field tag
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@item The Option Field Tags
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When you invoke one of these buttons, you will be asked to choose
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between a number of different options. This is how you edit an option
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field. Option fields are created by the @code{menu-choice} widget. In
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the example, @samp{@b{Choose}} is an option field tag.
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@item The @samp{@b{[INS]}} and @samp{@b{[DEL]}} buttons
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Activating these will insert or delete elements from an editable list.
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The list is created by the @code{editable-list} widget.
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@cindex embedded buttons
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@item Embedded Buttons
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The @samp{@b{_other work_}} is an example of an embedded
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button. Embedded buttons are not associated with a fields, but can serve
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any purpose, such as implementing hypertext references. They are
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usually created by the @code{link} widget.
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@item The @samp{@b{[ ]}} and @samp{@b{[X]}} buttons
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Activating one of these will convert it to the other. This is useful
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for implementing multiple-choice fields. You can create it with the
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@code{checkbox} widget.
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@item The @samp{@b{( )}} and @samp{@b{(*)}} buttons
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Only one radio button in a @code{radio-button-choice} widget can be
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selected at any time. When you invoke one of the unselected radio
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buttons, it will be selected and the previous selected radio button will
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become unselected.
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@item The @samp{@b{[Apply Form]}} @samp{@b{[Reset Form]}} buttons
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These are explicit buttons made with the @code{push-button} widget. The
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main difference from the @code{link} widget is that the buttons will be
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displayed as GUI buttons when possible.
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@end table
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To make them easier to locate, buttons are emphasized in the buffer.
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@deffn Face widget-button-face
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Face used for buttons.
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@end deffn
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@defopt widget-mouse-face
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Face used for highlighting a button when the mouse pointer moves across
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it.
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@end defopt
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@subsection Navigation
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You can use all the normal Emacs commands to move around in a form
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buffer, plus you will have these additional commands:
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@table @kbd
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@item @key{TAB}
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@deffn Command widget-forward &optional count
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Move point @var{count} buttons or editing fields forward.
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@end deffn
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@item @key{M-TAB}
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@deffn Command widget-backward &optional count
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Move point @var{count} buttons or editing fields backward.
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@end deffn
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@end table
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@node Programming Example, Setting Up the Buffer, User Interface, Top
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@comment node-name, next, previous, up
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@section Programming Example
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@cindex widgets, programming example
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@cindex example of using widgets
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Here is the code to implement the user interface example (@pxref{User
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Interface}).
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@lisp
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(require 'widget)
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(eval-when-compile
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(require 'wid-edit))
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(defvar widget-example-repeat)
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(defun widget-example ()
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"Create the widgets from the Widget manual."
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(interactive)
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(switch-to-buffer "*Widget Example*")
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(kill-all-local-variables)
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(make-local-variable 'widget-example-repeat)
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(let ((inhibit-read-only t))
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(erase-buffer))
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(widget-insert "Here is some documentation.\n\nName: ")
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(widget-create 'editable-field
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:size 13
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"My Name")
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(widget-create 'menu-choice
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:tag "Choose"
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:value "This"
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:help-echo "Choose me, please!"
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:notify (lambda (widget &rest ignore)
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(message "%s is a good choice!"
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(widget-value widget)))
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'(item :tag "This option" :value "This")
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'(choice-item "That option")
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'(editable-field :menu-tag "No option" "Thus option"))
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(widget-insert "Address: ")
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(widget-create 'editable-field
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"Some Place\nIn some City\nSome country.")
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(widget-insert "\nSee also ")
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(widget-create 'link
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:notify (lambda (&rest ignore)
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(widget-value-set widget-example-repeat
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'("En" "To" "Tre"))
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(widget-setup))
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"other work")
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(widget-insert
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" for more information.\n\nNumbers: count to three below\n")
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(setq widget-example-repeat
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(widget-create 'editable-list
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:entry-format "%i %d %v"
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:notify (lambda (widget &rest ignore)
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(let ((old (widget-get widget
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':example-length))
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(new (length (widget-value widget))))
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(unless (eq old new)
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(widget-put widget ':example-length new)
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(message "You can count to %d." new))))
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:value '("One" "Eh, two?" "Five!")
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'(editable-field :value "three")))
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(widget-insert "\n\nSelect multiple:\n\n")
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(widget-create 'checkbox t)
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(widget-insert " This\n")
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(widget-create 'checkbox nil)
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(widget-insert " That\n")
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(widget-create 'checkbox
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:notify (lambda (&rest ignore) (message "Tickle"))
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t)
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(widget-insert " Thus\n\nSelect one:\n\n")
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(widget-create 'radio-button-choice
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:value "One"
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:notify (lambda (widget &rest ignore)
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(message "You selected %s"
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(widget-value widget)))
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'(item "One") '(item "Another One.") '(item "A Final One."))
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(widget-insert "\n")
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(widget-create 'push-button
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:notify (lambda (&rest ignore)
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(if (= (length (widget-value widget-example-repeat))
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3)
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(message "Congratulation!")
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(error "Three was the count!")))
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"Apply Form")
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(widget-insert " ")
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(widget-create 'push-button
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:notify (lambda (&rest ignore)
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(widget-example))
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"Reset Form")
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(widget-insert "\n")
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(use-local-map widget-keymap)
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(widget-setup))
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@end lisp
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@node Setting Up the Buffer, Basic Types, Programming Example, Top
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@comment node-name, next, previous, up
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@section Setting Up the Buffer
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Widgets are created with @code{widget-create}, which returns a
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@dfn{widget} object. This object can be queried and manipulated by
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other widget functions, until it is deleted with @code{widget-delete}.
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After the widgets have been created, @code{widget-setup} must be called
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to enable them.
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@defun widget-create type [ keyword argument ]@dots{}
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Create and return a widget of type @var{type}.
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The syntax for the @var{type} argument is described in @ref{Basic Types}.
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The keyword arguments can be used to overwrite the keyword arguments
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that are part of @var{type}.
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@end defun
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@defun widget-delete widget
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Delete @var{widget} and remove it from the buffer.
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@end defun
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@defun widget-setup
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Set up a buffer to support widgets.
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This should be called after creating all the widgets and before allowing
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the user to edit them.
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@refill
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@end defun
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If you want to insert text outside the widgets in the form, the
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recommended way to do that is with @code{widget-insert}.
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@defun widget-insert
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Insert the arguments, either strings or characters, at point.
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The inserted text will be read-only.
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@end defun
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There is a standard widget keymap which you might find useful.
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@findex widget-button-press
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@findex widget-button-click
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@defvr Const widget-keymap
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A keymap with the global keymap as its parent.@*
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@key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and
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@code{widget-backward}, respectively. @key{RET} and @kbd{Mouse-2}
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are bound to @code{widget-button-press} and
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@code{widget-button-click}.@refill
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@end defvr
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@defvar widget-global-map
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Keymap used by @code{widget-button-press} and @code{widget-button-click}
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when not on a button. By default this is @code{global-map}.
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@end defvar
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@node Basic Types, Sexp Types, Setting Up the Buffer, Top
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@comment node-name, next, previous, up
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@section Basic Types
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The syntax of a type specification is given below:
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@example
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NAME ::= (NAME [KEYWORD ARGUMENT]... ARGS)
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| NAME
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@end example
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Where, @var{name} is a widget name, @var{keyword} is the name of a
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property, @var{argument} is the value of the property, and @var{args}
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are interpreted in a widget specific way.
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@cindex keyword arguments
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The following keyword arguments that apply to all widgets:
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@table @code
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@vindex value@r{ keyword}
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@item :value
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The initial value for widgets of this type.
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@vindex format@r{ keyword}
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@item :format
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This string will be inserted in the buffer when you create a widget.
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The following @samp{%} escapes are available:
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@table @samp
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@item %[
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@itemx %]
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The text inside will be marked as a button.
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By default, the text will be shown in @code{widget-button-face}, and
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surrounded by brackets.
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@defopt widget-button-prefix
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String to prefix buttons.
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@end defopt
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@defopt widget-button-suffix
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String to suffix buttons.
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@end defopt
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@item %@{
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@itemx %@}
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The text inside will be displayed with the face specified by
|
|
@code{:sample-face}.
|
|
|
|
@item %v
|
|
This will be replaced with the buffer representation of the widget's
|
|
value. What this is depends on the widget type.
|
|
|
|
@item %d
|
|
Insert the string specified by @code{:doc} here.
|
|
|
|
@item %h
|
|
Like @samp{%d}, with the following modifications: If the documentation
|
|
string is more than one line, it will add a button which will toggle
|
|
between showing only the first line, and showing the full text.
|
|
Furthermore, if there is no @code{:doc} property in the widget, it will
|
|
instead examine the @code{:documentation-property} property. If it is a
|
|
lambda expression, it will be called with the widget's value as an
|
|
argument, and the result will be used as the documentation text.
|
|
|
|
@item %t
|
|
Insert the string specified by @code{:tag} here, or the @code{princ}
|
|
representation of the value if there is no tag.
|
|
|
|
@item %%
|
|
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
|
|
@table @emph
|
|
@item nil
|
|
No text is inserted.
|
|
|
|
@item a string
|
|
The string is inserted literally.
|
|
|
|
@item a symbol
|
|
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.
|
|
|
|
@vindex tag@r{ keyword}
|
|
@item :tag
|
|
The string inserted by the @samp{%t} escape in the format
|
|
string.
|
|
|
|
@vindex tag-glyph@r{ keyword}
|
|
@item :tag-glyph
|
|
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
|
|
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 or a function of one argument, the widget,
|
|
which should return a string to display.
|
|
|
|
@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.
|
|
|
|
@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.
|
|
|
|
@vindex validate@r{ keyword}
|
|
@item :validate
|
|
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:
|
|
|
|
@defun widget-children-validate widget
|
|
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
|
|
implemented.
|
|
|
|
@enumerate a
|
|
@item
|
|
Widgets with tabbing order @code{-1} are ignored.
|
|
|
|
@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.
|
|
|
|
@item
|
|
When on a widget with no tabbing order specified, go to the next widget
|
|
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
|
|
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
|
|
arguments, which will be used when creating the @code{radio-button} or
|
|
@code{checkbox} associated with this item.
|
|
|
|
@end table
|
|
|
|
@deffn {User Option} widget-glyph-directory
|
|
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
|
|
|
|
@deffn{User Option} widget-glyph-enable
|
|
If non-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::
|
|
@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:
|
|
|
|
@example
|
|
TYPE ::= (link [KEYWORD ARGUMENT]... [ VALUE ])
|
|
@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.
|
|
|
|
By default the link will be shown in brackets.
|
|
|
|
@defopt widget-link-prefix
|
|
String to prefix links.
|
|
@end defopt
|
|
|
|
@defopt widget-link-suffix
|
|
String to suffix links.
|
|
@end defopt
|
|
|
|
@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:
|
|
|
|
@example
|
|
TYPE ::= (url-link [KEYWORD ARGUMENT]... URL)
|
|
@end example
|
|
|
|
@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}.
|
|
|
|
@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:
|
|
|
|
@example
|
|
TYPE ::= (info-link [KEYWORD ARGUMENT]... ADDRESS)
|
|
@end example
|
|
|
|
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:
|
|
|
|
@example
|
|
TYPE ::= (push-button [KEYWORD ARGUMENT]... [ VALUE ])
|
|
@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.
|
|
|
|
By default the tag will be shown in brackets.
|
|
|
|
@defopt widget-push-button-prefix
|
|
String to prefix push buttons.
|
|
@end defopt
|
|
|
|
@defopt widget-push-button-suffix
|
|
String to suffix push buttons.
|
|
@end defopt
|
|
|
|
@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:
|
|
|
|
@example
|
|
TYPE ::= (editable-field [KEYWORD ARGUMENT]... [ VALUE ])
|
|
@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
|
|
field. This widget will match all string values.
|
|
|
|
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}, see @ref{User Interface}.
|
|
|
|
@vindex secret@r{ keyword}
|
|
@item :secret
|
|
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, this is 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 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 @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:
|
|
|
|
@example
|
|
TYPE ::= (menu-choice [KEYWORD ARGUMENT]... TYPE ... )
|
|
@end example
|
|
|
|
The @var{type} argument represents each possible choice. The widget's
|
|
value will be that of the chosen @var{type} argument. This widget will
|
|
match any value matching at least one of the specified @var{type}
|
|
arguments.
|
|
|
|
@table @code
|
|
@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
|
|
choice through the minibuffer.
|
|
|
|
@vindex children@r{ keyword}
|
|
@item :children
|
|
A list whose @code{car} is the widget representing the currently chosen
|
|
type in the buffer.
|
|
|
|
@vindex choice@r{ keyword}
|
|
@item :choice
|
|
The current chosen type.
|
|
|
|
@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:
|
|
|
|
@example
|
|
TYPE ::= (radio-button-choice [KEYWORD ARGUMENT]... TYPE ... )
|
|
@end example
|
|
|
|
The @var{type} argument represents each possible choice. The widget's
|
|
value will be that of the chosen @var{type} argument. This widget will
|
|
match any value matching at least one of the specified @var{type}
|
|
arguments.
|
|
|
|
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
|
|
Replace with the buffer representation of the @var{type} widget.
|
|
@item %b
|
|
Replace with the radio button.
|
|
@item %%
|
|
Insert a literal @samp{%}.
|
|
@end table
|
|
|
|
@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.
|
|
|
|
@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
|
|
|
|
@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}.
|
|
|
|
@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}.
|
|
@end defun
|
|
|
|
Please note that such items added after the @code{radio-button-choice}
|
|
widget has been created will @strong{not} be properly destructed when
|
|
you call @code{widget-delete}.
|
|
|
|
@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:
|
|
|
|
@example
|
|
ITEM ::= (item [KEYWORD ARGUMENT]... VALUE)
|
|
@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. This widget will only match the specified value.
|
|
|
|
@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:
|
|
|
|
@example
|
|
ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE)
|
|
@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 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.
|
|
|
|
@node toggle, checkbox, choice-item, Basic Types
|
|
@comment node-name, next, previous, up
|
|
@subsection The @code{toggle} Widget
|
|
@findex toggle@r{ widget}
|
|
|
|
Syntax:
|
|
|
|
@example
|
|
TYPE ::= (toggle [KEYWORD ARGUMENT]...)
|
|
@end example
|
|
|
|
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:
|
|
|
|
@table @code
|
|
@item :on
|
|
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 @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 @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}
|
|
|
|
This widget has two possible states, @samp{selected} and
|
|
@samp{unselected}, which corresponds to a @code{t} or @code{nil} value.
|
|
|
|
Syntax:
|
|
|
|
@example
|
|
TYPE ::= (checkbox [KEYWORD ARGUMENT]...)
|
|
@end example
|
|
|
|
@node checklist, editable-list, checkbox, Basic Types
|
|
@comment node-name, next, previous, up
|
|
@subsection The @code{checklist} Widget
|
|
@findex checklist@r{ widget}
|
|
|
|
Syntax:
|
|
|
|
@example
|
|
TYPE ::= (checklist [KEYWORD ARGUMENT]... TYPE ... )
|
|
@end example
|
|
|
|
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:
|
|
|
|
@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.
|
|
@item %b
|
|
Replace with the checkbox.
|
|
@item %%
|
|
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.
|
|
|
|
@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.
|
|
|
|
@vindex buttons@r{ keyword}
|
|
@item :buttons
|
|
The widgets representing the checkboxes.
|
|
|
|
@vindex children@r{ keyword}
|
|
@item :children
|
|
The widgets representing each type.
|
|
|
|
@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:
|
|
|
|
@example
|
|
TYPE ::= (editable-list [KEYWORD ARGUMENT]... TYPE)
|
|
@end example
|
|
|
|
The value is a list, where each member represents one widget of type
|
|
@var{type}.
|
|
|
|
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
|
|
This will be replaced with the buffer representation of the @var{type}
|
|
widget.
|
|
@item %i
|
|
Insert the @b{[INS]} button.
|
|
@item %d
|
|
Insert the @b{[DEL]} button.
|
|
@item %%
|
|
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 @code{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 widgets together.
|
|
|
|
Syntax:
|
|
|
|
@example
|
|
TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...)
|
|
@end example
|
|
|
|
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 @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::
|
|
@end menu
|
|
|
|
@node constants, generic, Sexp Types, Sexp Types
|
|
@comment node-name, next, previous, up
|
|
@subsection The Constant Widgets
|
|
@cindex 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
|
|
of the composite widgets.
|
|
|
|
The syntax for the @code{const} widget is:
|
|
|
|
@example
|
|
TYPE ::= (const [KEYWORD ARGUMENT]... [ VALUE ])
|
|
@end example
|
|
|
|
The @var{value}, if present, is used to initialize the @code{:value}
|
|
property and can be any s-expression.
|
|
|
|
@deffn Widget const
|
|
This will display any valid s-expression in an immutable part of the
|
|
buffer.
|
|
@end deffn
|
|
|
|
There are two variations of the @code{const} widget, namely
|
|
@code{variable-item} and @code{function-item}. These should contain a
|
|
symbol with a variable or function binding. The major difference from
|
|
the @code{const} widget is that they will allow the user to see the
|
|
variable or function documentation for the symbol.
|
|
|
|
@deffn Widget variable-item
|
|
An immutable symbol that is bound as a variable.
|
|
@end deffn
|
|
|
|
@deffn Widget function-item
|
|
An immutable symbol that is bound as a function.
|
|
@end deffn
|
|
|
|
@node generic, atoms, constants, Sexp Types
|
|
@comment node-name, next, previous, up
|
|
@subsection Generic Sexp Widget
|
|
@cindex generic sexp widget
|
|
|
|
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:
|
|
|
|
@example
|
|
TYPE ::= (sexp [KEYWORD ARGUMENT]... [ VALUE ])
|
|
@end example
|
|
|
|
@deffn Widget sexp
|
|
This will allow you to edit any valid s-expression in an editable buffer
|
|
field.
|
|
|
|
The @code{sexp} widget takes the same keyword arguments as the
|
|
@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
|
|
@cindex atomic sexp widget
|
|
|
|
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:
|
|
|
|
@example
|
|
TYPE ::= (NAME [KEYWORD ARGUMENT]... [ VALUE ])
|
|
@end example
|
|
|
|
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.
|
|
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. @xref{editable-field}.
|
|
|
|
@deffn Widget string
|
|
Allows you to edit a string in an editable field.
|
|
@end deffn
|
|
|
|
@deffn Widget regexp
|
|
Allows you to edit a regular expression in an editable field.
|
|
@end deffn
|
|
|
|
@deffn Widget character
|
|
Allows you to enter a character in an editable field.
|
|
@end deffn
|
|
|
|
@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.
|
|
|
|
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.
|
|
@end table
|
|
@end deffn
|
|
|
|
@deffn Widget directory
|
|
Allows you to edit a directory name in an editable field.
|
|
Similar to the @code{file} widget.
|
|
@end deffn
|
|
|
|
@deffn Widget symbol
|
|
Allows you to edit a lisp symbol in an editable field.
|
|
@end deffn
|
|
|
|
@deffn Widget function
|
|
Allows you to edit a lambda expression, or a function name with completion.
|
|
@end deffn
|
|
|
|
@deffn Widget variable
|
|
Allows you to edit a variable name, with completion.
|
|
@end deffn
|
|
|
|
@deffn Widget integer
|
|
Allows you to edit an integer in an editable field.
|
|
@end deffn
|
|
|
|
@deffn Widget number
|
|
Allows you to edit a number in an editable field.
|
|
@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.
|
|
@end deffn
|
|
|
|
|
|
@node composite, , atoms, Sexp Types
|
|
@comment node-name, next, previous, up
|
|
@subsection Composite Sexp Widgets
|
|
@cindex composite sexp widgets
|
|
|
|
The syntax for the composite widget is:
|
|
|
|
@example
|
|
TYPE ::= (NAME [KEYWORD ARGUMENT]... COMPONENT...)
|
|
@end example
|
|
|
|
@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 @code{car} is
|
|
the value of the first component and the @code{cdr} is the value of the
|
|
second component. There must be exactly two components.
|
|
@end deffn
|
|
|
|
@deffn Widget list
|
|
The value of a @code{list} widget is a list containing the value of
|
|
each of its component.
|
|
@end deffn
|
|
|
|
@deffn Widget vector
|
|
The value of a @code{vector} widget is a vector containing the value of
|
|
each of its component.
|
|
@end deffn
|
|
|
|
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}
|
|
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
|
|
be a file name, and whose remaining arguments should either by the
|
|
symbol @code{t} or two files, you can use the following widget
|
|
specification:
|
|
|
|
@example
|
|
(list file
|
|
(choice (const t)
|
|
(list :inline t
|
|
:value ("foo" "bar")
|
|
string string)))
|
|
@end example
|
|
|
|
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
|
|
it here, I'll just suggest you meditate over it for a while.
|
|
|
|
@deffn Widget choice
|
|
Allows you to edit a sexp which may have one of a fixed set of types.
|
|
It is currently implemented with the @code{choice-menu} basic widget,
|
|
and has a similar syntax.
|
|
@end deffn
|
|
|
|
@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 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 @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}.
|
|
|
|
@defun widget-value widget
|
|
Return the current value contained in @var{widget}.
|
|
It is an error to call this function on an uninitialized widget.
|
|
@end defun
|
|
|
|
@defun widget-value-set widget value
|
|
Set the value contained in @var{widget} to @var{value}.
|
|
It is an error to call this function with an invalid @var{value}.
|
|
@end defun
|
|
|
|
@strong{Important:} You @emph{must} call @code{widget-setup} after
|
|
modifying the value of a widget before the user is allowed to edit the
|
|
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.
|
|
|
|
If your application needs to associate some information with the widget
|
|
objects, for example a reference to the item being edited, it can be
|
|
done with @code{widget-put} and @code{widget-get}. The property names
|
|
must begin with a @samp{:}.
|
|
|
|
@defun widget-put widget property value
|
|
In @var{widget} set @var{property} to @var{value}.
|
|
@var{property} should be a symbol, while @var{value} can be anything.
|
|
@end defun
|
|
|
|
@defun widget-get widget property
|
|
In @var{widget} return the value for @var{property}.
|
|
@var{property} should be a symbol, the value is what was last set by
|
|
@code{widget-put} for @var{property}.
|
|
@end defun
|
|
|
|
@defun widget-member widget property
|
|
Non-nil if @var{widget} has a value (even 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.
|
|
|
|
@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:
|
|
|
|
@lisp
|
|
;; Examine if @var{widget} is active or not.
|
|
(if (widget-apply @var{widget} :active)
|
|
(message "Widget is active.")
|
|
(message "Widget is inactive.")
|
|
|
|
;; Make @var{widget} inactive.
|
|
(widget-apply @var{widget} :deactivate)
|
|
|
|
;; Make @var{widget} active.
|
|
(widget-apply @var{widget} :activate)
|
|
@end lisp
|
|
|
|
A widget is inactive if it, or any of its ancestors (found by
|
|
following the @code{:parent} link), have been deactivated. To make sure
|
|
a widget is really active, you must therefore activate both it and
|
|
all its ancestors.
|
|
|
|
@lisp
|
|
(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
|
|
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
|
|
@code{:inactive} keyword directly. Use the @code{:activate}
|
|
@code{:deactivate} keywords instead.
|
|
|
|
|
|
@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.
|
|
|
|
@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.
|
|
|
|
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:
|
|
|
|
@itemize @bullet
|
|
@item
|
|
@lisp
|
|
(widget-create @var{name})
|
|
@end lisp
|
|
|
|
@item
|
|
@lisp
|
|
(apply widget-create @var{class} @var{args})
|
|
@end lisp
|
|
@end itemize
|
|
|
|
@end defun
|
|
|
|
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 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:
|
|
@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.
|
|
|
|
The following predefined functions can be used here:
|
|
|
|
@defun widget-types-convert-widget widget
|
|
Convert @code{:args} as widget types in @var{widget}.
|
|
@end defun
|
|
|
|
@defun widget-value-convert-widget widget
|
|
Initialize @code{:value} from @code{:args} 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
|
|
internal 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 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
|
|
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.
|
|
|
|
@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.
|
|
|
|
@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.
|
|
|
|
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
|
|
|
|
@vindex value-get@r{ keyword}
|
|
@item :value-get
|
|
Function to extract the value of a widget, as it is displayed in the
|
|
buffer.
|
|
|
|
The following predefined function can be used here:
|
|
|
|
@defun widget-value-value-get widget
|
|
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 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 following predefined function can be used here:
|
|
|
|
@defun widget-parent-action widget &optional event
|
|
Tell @code{:parent} of @var{widget} to handle the @code{:action}.
|
|
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
|
|
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.
|
|
|
|
It provides most of the functionality that is referred to as ``by
|
|
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 @samp{:parent}, which avoids printing cyclic structures.
|
|
|
|
@deffn Command widget-browse WIDGET
|
|
Create a widget browser for WIDGET.
|
|
When called interactively, prompt for 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.
|
|
@end deffn
|
|
|
|
@deffn Command widget-browse-at POS
|
|
Create a widget browser for the widget at 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
|
|
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.
|
|
With arg, turn widget mode on if and only if arg is positive.
|
|
@end deffn
|
|
|
|
@defvar widget-minor-mode-keymap
|
|
Keymap used in @code{widget-minor-mode}.
|
|
@end defvar
|
|
|
|
@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
|
|
@end defun
|
|
|
|
@defun widget-get-sibling widget
|
|
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, Index, Utilities, Top
|
|
@comment node-name, next, previous, up
|
|
@section Wishlist
|
|
@cindex todo
|
|
|
|
@itemize @bullet
|
|
@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
|
|
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
|
|
the ugly buttons, the dash is my idea).
|
|
|
|
@item
|
|
The @code{menu-choice} tag should be prettier, something like the abbreviated
|
|
menus in Open Look.
|
|
|
|
@item
|
|
Finish @code{:tab-order}.
|
|
|
|
@item
|
|
Make indentation work with glyphs and proportional fonts.
|
|
|
|
@item
|
|
Add commands to show overview of object and class hierarchies to the
|
|
browser.
|
|
|
|
@item
|
|
Find a way to disable mouse highlight for inactive widgets.
|
|
|
|
@item
|
|
Find a way to make glyphs look inactive.
|
|
|
|
@item
|
|
Add @code{property-list} widget.
|
|
|
|
@item
|
|
Add @code{association-list} widget.
|
|
|
|
@item
|
|
Add @code{key-binding} widget.
|
|
|
|
@item
|
|
Add @code{widget} widget for editing widget specifications.
|
|
|
|
@item
|
|
Find clean way to implement variable length list.
|
|
See @code{TeX-printer-list} for an explanation.
|
|
|
|
@item
|
|
@kbd{C-h} in @code{widget-prompt-value} should give type specific help.
|
|
|
|
@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
|