Copyright © 2000–2023 Free Software Foundation, Inc.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, with the Front-Cover Texts being “A GNU Manual”,
and with the Back-Cover Texts as in (a) below. A copy of the license
is included in the section entitled “GNU Free Documentation License”.
(a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
modify this GNU manual.”
1 Introduction
Most graphical user interface toolkits provide a number of standard
user interface controls (sometimes known as “widgets” or “gadgets”).
Emacs doesn’t really support anything like this, except for an
incredibly powerful text “widget”. On the other hand, Emacs does
provide the necessary primitives to implement many other widgets
within a text buffer. The widget package simplifies this task.
The basic widgets are:
linkAreas of text with an associated action. Intended for hypertext links
embedded in text.
push-buttonLike link, but intended for stand-alone buttons.
editable-fieldAn editable text field. It can be either variable or fixed length.
menu-choiceAllows the user to choose one of multiple options from a menu, where
each option is itself a widget. Only the selected option is visible
in the buffer.
radio-button-choiceAllows the user to choose one of multiple options by activating radio
buttons. The options are implemented as widgets. All options are
visible in the buffer, with the selected one marked as chosen.
itemA simple constant widget intended to be used in the menu-choice and
radio-button-choice widgets.
choice-itemA button item only intended for use in choices. When invoked, the user
will be asked to select another option from the choice widget.
toggleA simple ‘on’/‘off’ switch.
checkboxA checkbox (‘[ ]’/‘[X]’).
editable-listCreate an editable list. The user can insert or delete items in the
list. Each list item is itself a widget.
Now, of what possible use can support for widgets be in a text editor?
I’m glad you asked. The answer is that widgets are useful for
implementing forms. A form in Emacs is a buffer where the user is
supposed to fill out a number of fields, each of which has a specific
meaning. The user is not supposed to change or delete any of the text
between the fields. Examples of forms in Emacs are the forms
package (of course), the customize buffers, the mail and news compose
modes, and the HTML form support in the w3 browser.
The advantages for a programmer of using the widget package to
implement forms are:
- More complex fields than just editable text are supported.
- You can give the users immediate feedback if they enter invalid data in a
text field, and sometimes prevent entering invalid data.
- You can have fixed sized fields, thus allowing multiple fields to be
lined up in columns.
- It is simple to query or set the value of a field.
- Editing happens in the buffer, not in the mini-buffer.
- Packages using the library get a uniform look, making them easier for
the user to learn.
- As support for embedded graphics improve, the widget library will be
extended to use the GUI features. This means that your code using the
widget library will also use the new graphic features automatically.
2 User Interface
A form consists of read only text for documentation and some fields,
where each field contains two parts, a tag and a value. The tags are
used to identify the fields, so the documentation can refer to the
‘foo field’, meaning the field tagged with ‘Foo’. Here is an
example form:
Here is some documentation.
Name: My Name Choose: This option
Address: Some Place
In some City
Some country.
See also _other work_ for more information.
Numbers: count to three below
[INS] [DEL] One
[INS] [DEL] Eh, two?
[INS] [DEL] Five!
[INS]
Select multiple:
[X] This
[ ] That
[X] Thus
Select one:
(*) One
( ) Another One.
( ) A Final One.
[Apply Form] [Reset Form]
The top level widgets in this example are tagged ‘Name’,
‘Choose’, ‘Address’, ‘_other work_’, ‘Numbers’,
‘Select multiple’, ‘Select one’, ‘[Apply Form]’, and
‘[Reset Form]’. There are basically two things the user can do
within a form, namely editing the editable text fields and activating
the buttons.
2.1 Editable Text Fields
In the example, the value for the ‘Name’ is most likely displayed
in an editable text field, and so are values for each of the members of
the ‘Numbers’ list. All the normal Emacs editing operations are
available for editing these fields. The only restriction is that each
change you make must be contained within a single editable text field.
For example, capitalizing all text from the middle of one field to the
middle of another field is prohibited.
Editable text fields are created by the editable-field widget.
The :format keyword is useful for generating the necessary
text; for instance, if you give it a value of "Name: %v ",
the ‘Name: ’ part will provide the necessary separating text
before the field and the trailing space will provide the
separating text after the field. If you don’t include the
:size keyword, the field will extend to the end of the
line, and the terminating newline will provide separation after.
The editing text fields are highlighted with the
widget-field-face face, making them easy to find.
2.3 Navigation
You can use all the normal Emacs commands to move around in a form
buffer, plus you will have these additional commands to navigate from
widget to widget: widget-forward and widget-backward.
3 Programming Example
Here is the code to implement the user interface example (see User Interface).
(require 'widget)
(eval-when-compile
(require 'wid-edit))
(defvar widget-example-repeat)
(defun widget-example ()
"Create the widgets from the Widget manual."
(interactive)
(switch-to-buffer "*Widget Example*")
(kill-all-local-variables)
(make-local-variable 'widget-example-repeat)
(let ((inhibit-read-only t))
(erase-buffer))
(remove-overlays)
(widget-insert "Here is some documentation.\n\n")
(widget-create 'editable-field
:size 13
:format "Name: %v " ; Text after the field!
"My Name")
(widget-create 'menu-choice
:tag "Choose"
:value "This"
:help-echo "Choose me, please!"
:notify (lambda (widget &rest ignore)
(message "%s is a good choice!"
(widget-value widget)))
'(item :tag "This option" :value "This")
'(choice-item "That option")
'(editable-field :menu-tag "No option" "Thus option"))
(widget-create 'editable-field
:format "Address: %v"
"Some Place\nIn some City\nSome country.")
(widget-insert "\nSee also ")
(widget-create 'link
:notify (lambda (&rest ignore)
(widget-value-set widget-example-repeat
'("En" "To" "Tre"))
(widget-setup))
"other work")
(widget-insert
" for more information.\n\nNumbers: count to three below\n")
(setq widget-example-repeat
(widget-create 'editable-list
:entry-format "%i %d %v"
:notify
(lambda (widget &rest ignore)
(let ((old (widget-get widget
':example-length))
(new (length (widget-value widget))))
(unless (eq old new)
(widget-put widget ':example-length new)
(message "You can count to %d." new))))
:value '("One" "Eh, two?" "Five!")
'(editable-field :value "three")))
(widget-insert "\n\nSelect multiple:\n\n")
(widget-create 'checkbox t)
(widget-insert " This\n")
(widget-create 'checkbox nil)
(widget-insert " That\n")
(widget-create 'checkbox
:notify (lambda (&rest ignore) (message "Tickle"))
t)
(widget-insert " Thus\n\nSelect one:\n\n")
(widget-create 'radio-button-choice
:value "One"
:notify (lambda (widget &rest ignore)
(message "You selected %s"
(widget-value widget)))
'(item "One") '(item "Another One.")
'(item "A Final One."))
(widget-insert "\n")
(widget-create 'push-button
:notify (lambda (&rest ignore)
(if (= (length
(widget-value widget-example-repeat))
3)
(message "Congratulation!")
(error "Three was the count!")))
"Apply Form")
(widget-insert " ")
(widget-create 'push-button
:notify (lambda (&rest ignore)
(widget-example))
"Reset Form")
(widget-insert "\n")
(use-local-map widget-keymap)
(widget-setup))
The Widget Library deals with widgets objects. A widget object has
properties whose value may be anything, be it numbers, strings,
symbols, functions, etc. Those properties are referred to as keywords
and are responsible for the way a widget is represented in a buffer,
and control the way a user or a program can interact with it.
The library defines several widget types, and gives you a way to
define new types as well. In addition, widgets can derive from other
types, creating a sort of widget inheritance. In fact, all widgets
defined in the Widget Library share a common parent, the default
widget. In this manual, when we talk about a default behavior, we
usually mean the behavior as defined by this default widget.
See Widget Gallery, for a description of each defined widget.
Defining a new type that derives from a previous one is not mandatory
to create widgets that work very different from a specified type.
When creating a widget, you can override any default property,
including functions, that control the widget. That is, you can
specialize a widget on creation, without having to define it as a new
type of widget.
In addition to the function for defining a widget, this library
provides functions to create widgets, query and change its properties,
respond to user events and destroy them. The following sections
describe them.
One important property of a widget is its value. All widgets
may have a value, which is stored in a so-called internal format.
For the rest of Emacs, the widget presents its value in a so-called
external format. Both formats can be equal or different, and
each widget is responsible for defining how the conversion between
each format should happen.
The value property is an important property for almost all widgets,
and perhaps more important for editable-field widgets. This
type of widgets allow the user to edit them via the usual editing
commands in Emacs. They can also be edited programmatically.
Important: You must call widget-setup after
modifying the value of a widget before the user is allowed to edit the
widget again. It is enough to call 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 the widget-put and widget-get functions. The
property names, as shown, are keywords, so they must begin with a
‘:’.
5 Setting Up the Buffer
To show the widgets in a buffer, you have to create them. Widget
creation is actually a two-step process: conversion and creation per
se. With simple projects, usually the conversion step isn’t really
important, and you only care about widget creation, so feel free to
skip the conversion description until you really need to know it.
Widget conversion is the process that involves taking a widget
specification and transforming it into a widget object, suitable
to be created, queried and manipulated with other widget functions.
Widget creation is the process that takes a widget object and actually
inserts it in the buffer.
The simplest function to create a widget is widget-create, which
gets a widget specification and returns a widget object.
- Function: widget-create type [ keyword argument ]… args ¶
Create and return a widget of type type, converting it.
type is a symbol that specifies a widget type. keyword
may be one of the properties supported by the widget type, and
argument specify the value for that property. These keyword
arguments can be used to overwrite the keyword arguments that are part
of type by default, as well as to provide other properties not
present in type by default. args holds additional
information for the creation of type and each widget type is
responsible for handling that information in a specific way.
The syntax for the type argument is described in Widget Gallery, and in more detail in every widget where it’s relevant.
There are other functions for creating widgets, useful when you work
with composite widgets. That is, widgets that are part of other
widgets.
- Function: widget-create-child-and-convert parent type &rest args ¶
Create a widget of type type as a child of parent.
Before creating it, converts type using the keyword arguments
provided in args.
Adds the :indent property, unless it is already present, and
sets it to the sum of the values of: :indent and :offset
from parent and :extra-offset from type.
Returns a widget object, with the property :parent set to
PARENT.
- Function: widget-create-child parent type ¶
Create a widget of type type as a child of parent.
This function is like widget-create-child-and-convert but it
doesn’t convert type, so it expects an already converted widget.
- Function: widget-create-child-value parent type value ¶
Create a widget of type type as a child of parent with
value value.
This function is like widget-create-child, but it lets you
specify a value for the widget.
Converts value to the internal format, as specified by
type, and stores it into the :value property of type.
That means, value should be in the external format, as
specified by type.
All these creating functions described here use the function stored in
the :create property. So, to modify the creation logic for a
widget, you can provide a different :create function.
When you’re done creating widgets and you’re ready for the user to
interact with the buffer, use the function widget-setup.
- Function: widget-setup ¶
Setup the current buffer, so that editable widgets can be edited.
This should be called after creating all the widgets and before allowing
the user to edit them.
As mentioned, all these functions return a widget object. That widget
object can be queried and manipulated with widget functions that
take widgets as arguments, until deleting it with the widgets
functions available to delete widgets. Even if you don’t save the
returned widget object, you still can interact programmatically with
the widget. See Working with Widgets.
- Function: widget-delete widget ¶
Delete the widget widget and remove it from the buffer.
- Function: widget-children-value-delete widget ¶
Delete all children and buttons in widget widget.
This function does not delete widget itself, only the widgets
stored in the :children and :buttons properties. It
also sets those properties to nil.
As with the creation mechanism, the function stored in :delete
controls the deletion mechanism for a widget.
Additionally, the library provides a way to make a copy of a widget.
- Function: widget-copy widget ¶
Makes a copy of widget widget and returns it.
It uses the function stored in the :copy property of widget
and returns the widget that that function returns.
As discussed, there is a conversion step when creating a widget. To
do the conversion without actually creating the widget, you can use
the widget-convert function.
- Function: widget-convert type &rest args ¶
Convert type to a widget object, using keyword arguments args.
Returns a widget object, suitable for creation. It calls the function
stored in the :convert-widget property, after putting into the
:args property the arguments that the widget in question needs.
If type has a :value property, either originally or after
doing the conversion, this function converts the value stored in
:value to the internal format, and stores it into :value.
Apart from only creating widgets in the buffer, It’s useful to have
plain text. For inserting text, the recommended way is with the
widget-insert function.
- Function: widget-insert &rest args ¶
Insert args, either strings or characters, at point.
Uses insert to perform the insertion, passing args as
argument. See Insertion in the Emacs Lisp Reference Manual,
for more information about args.
The resulting text will be read-only.
12 Utilities
Here we describe some utility functions that don’t really have a place
earlier in this manual.
- Function: widget-prompt-value widget prompt [ value unbound ] ¶
Prompt for a value matching widget, using prompt.
The current value is assumed to be value, unless unbound is
non-nil.
Converts widget before prompting, and for prompting it uses the
:prompt-value function. This function returns the user
“answer”, and it’s an error if that answer doesn’t match the widget,
as with the :match function.
If the answer matches the widget, returns the answer.
- Function: widget-get-sibling widget ¶
Get the item which widget should toggle.
This is only meaningful for radio buttons or checkboxes in a list.
- Function: widget-choose title items &optional event ¶
Prompt the user to choose an item from a list of options.
title is the name of the list of options. items should be
a menu, with its items in the simple format or in the extended format.
See Defining Menus in the Emacs Lisp Reference
Manual. Independently of the format, you don’t have to provide a
title for the menu, just pass the desired title in title. The
optional event is an input event. If event is a mouse
event and the number of elements in items is less than the user
option widget-menu-max-size, then widget-choose uses a
popup menu to prompt the user. Otherwise, widget-choose uses
the minibuffer.
When items is a keymap menu, the returned value is the symbol in
the key vector, as in the argument of define-key
(see Changing Key Bindings in the Emacs Lisp Reference
Manual). When items is a list whose selectable items are of
the form (name . value) (i.e., the simplified format),
then the return value is the value of the chosen element.
- Function: widget-image-find image ¶
Create a graphical button from image, an image or a file name
sans extension.
If image is a file name, the file should be in
widget-image-directory, or in a place where find-image
will find it.
- Function: widget-image-insert widget tag image ¶
As part of widget, insert the text tag or, if supported,
the image image.
image should be as described in widget-image-find.
- Function: widget-echo-help pos ¶
Display help-echo text for the widget at pos.
Uses the value of :help-echo. If it is a function, it calls it
to get a string. Otherwise, it evals it.
13 Customization
This chapter is about the customization options for the Widget
library, for the end user.
- Face: widget-field-face ¶
Face used for other editing fields.
- Face: widget-button-face ¶
Face used for buttons.
- User Option: widget-mouse-face ¶
Face used for highlighting a button when the mouse pointer moves
across it.
The default value is highlight.
- User Option: widget-image-directory ¶
Directory where Widget should look for images.
Widget will look here for a file with the same name as specified for the
image, with either a .xpm (if supported) or .xbm extension.
- User Option: widget-image-enable ¶
If non-nil, allow images to appear on displays where they are supported.
- User Option: widget-image-conversion ¶
An alist to convert symbols from image formats to file name suffixes.
Each element is a cons cell (format . suffix), where
format is a symbol that represents an image format and
suffix is its correspondent suffix.
- User Option: widget-button-prefix ¶
String to prefix buttons.
- User Option: widget-button-suffix ¶
String to suffix buttons.
- User Option: widget-push-button-prefix ¶
String to prefix push buttons.
- User Option: widget-push-button-suffix ¶
String to suffix push buttons.
- User Option: widget-link-prefix ¶
String to prefix links.
- User Option: widget-link-suffix ¶
String to suffix links.
- User Option: widget-choice-toggle ¶
If non-nil, toggle when there are just two options.
By default, its value is nil.
- User Option: widget-documentation-links ¶
If non-nil, add hyperlinks to documentation strings.
- User Option: widget-documentation-link-regexp ¶
A regexp that matches potential links in documentation strings. The
link itself should match to the first group.
- User Option: widget-documentation-link-p ¶
A predicate function to test if a string is useful as a link. The
function is called with one argument, a string, and should return
non-nil if there should be a link for that string.
By default, the value is intern-soft.
- User Option: widget-documentation-link-type ¶
A symbol that represents a widget type to use for links in
documentation strings.
By default, the value is documentation-link.
Maximum size for a popup menu. By default, its value is 40.
If a function ask you to choose from a menu that is larger than this
value, it will use the minibuffer.
Largest number of items for which it works to choose one with a
character.
For a larger number, use the minibuffer.
Whether to use the minibuffer to ask for a choice.
If nil, the default, read a single character.
Appendix A GNU Free Documentation License
Version 1.3, 3 November 2008
Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
https://fsf.org/
Everyone is permitted to copy and distribute verbatim copies
of this license document, but changing it is not allowed.
- PREAMBLE
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This License is a kind of “copyleft”, which means that derivative
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We have designed this License in order to use it for manuals for free
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giving the public permission to use the Modified Version under the
terms of this License, in the form shown in the Addendum below.
- Preserve in that license notice the full lists of Invariant Sections
and required Cover Texts given in the Document’s license notice.
- Include an unaltered copy of this License.
- Preserve the section Entitled “History”, Preserve its Title, and add
to it an item stating at least the title, year, new authors, and
publisher of the Modified Version as given on the Title Page. If
there is no section Entitled “History” in the Document, create one
stating the title, year, authors, and publisher of the Document as
given on its Title Page, then add an item describing the Modified
Version as stated in the previous sentence.
- Preserve the network location, if any, given in the Document for
public access to a Transparent copy of the Document, and likewise
the network locations given in the Document for previous versions
it was based on. These may be placed in the “History” section.
You may omit a network location for a work that was published at
least four years before the Document itself, or if the original
publisher of the version it refers to gives permission.
- For any section Entitled “Acknowledgements” or “Dedications”, Preserve
the Title of the section, and preserve in the section all the
substance and tone of each of the contributor acknowledgements and/or
dedications given therein.
- Preserve all the Invariant Sections of the Document,
unaltered in their text and in their titles. Section numbers
or the equivalent are not considered part of the section titles.
- Delete any section Entitled “Endorsements”. Such a section
may not be included in the Modified Version.
- Do not retitle any existing section to be Entitled “Endorsements” or
to conflict in title with any Invariant Section.
- Preserve any Warranty Disclaimers.
If the Modified Version includes new front-matter sections or
appendices that qualify as Secondary Sections and contain no material
copied from the Document, you may at your option designate some or all
of these sections as invariant. To do this, add their titles to the
list of Invariant Sections in the Modified Version’s license notice.
These titles must be distinct from any other section titles.
You may add a section Entitled “Endorsements”, provided it contains
nothing but endorsements of your Modified Version by various
parties—for example, statements of peer review or that the text has
been approved by an organization as the authoritative definition of a
standard.
You may add a passage of up to five words as a Front-Cover Text, and a
passage of up to 25 words as a Back-Cover Text, to the end of the list
of Cover Texts in the Modified Version. Only one passage of
Front-Cover Text and one of Back-Cover Text may be added by (or
through arrangements made by) any one entity. If the Document already
includes a cover text for the same cover, previously added by you or
by arrangement made by the same entity you are acting on behalf of,
you may not add another; but you may replace the old one, on explicit
permission from the previous publisher that added the old one.
The author(s) and publisher(s) of the Document do not by this License
give permission to use their names for publicity for or to assert or
imply endorsement of any Modified Version.
- COMBINING DOCUMENTS
You may combine the Document with other documents released under this
License, under the terms defined in section 4 above for modified
versions, provided that you include in the combination all of the
Invariant Sections of all of the original documents, unmodified, and
list them all as Invariant Sections of your combined work in its
license notice, and that you preserve all their Warranty Disclaimers.
The combined work need only contain one copy of this License, and
multiple identical Invariant Sections may be replaced with a single
copy. If there are multiple Invariant Sections with the same name but
different contents, make the title of each such section unique by
adding at the end of it, in parentheses, the name of the original
author or publisher of that section if known, or else a unique number.
Make the same adjustment to the section titles in the list of
Invariant Sections in the license notice of the combined work.
In the combination, you must combine any sections Entitled “History”
in the various original documents, forming one section Entitled
“History”; likewise combine any sections Entitled “Acknowledgements”,
and any sections Entitled “Dedications”. You must delete all
sections Entitled “Endorsements.”
- COLLECTIONS OF DOCUMENTS
You may make a collection consisting of the Document and other documents
released under this License, and replace the individual copies of this
License in the various documents with a single copy that is included in
the collection, provided that you follow the rules of this License for
verbatim copying of each of the documents in all other respects.
You may extract a single document from such a collection, and distribute
it individually under this License, provided you insert a copy of this
License into the extracted document, and follow this License in all
other respects regarding verbatim copying of that document.
- AGGREGATION WITH INDEPENDENT WORKS
A compilation of the Document or its derivatives with other separate
and independent documents or works, in or on a volume of a storage or
distribution medium, is called an “aggregate” if the copyright
resulting from the compilation is not used to limit the legal rights
of the compilation’s users beyond what the individual works permit.
When the Document is included in an aggregate, this License does not
apply to the other works in the aggregate which are not themselves
derivative works of the Document.
If the Cover Text requirement of section 3 is applicable to these
copies of the Document, then if the Document is less than one half of
the entire aggregate, the Document’s Cover Texts may be placed on
covers that bracket the Document within the aggregate, or the
electronic equivalent of covers if the Document is in electronic form.
Otherwise they must appear on printed covers that bracket the whole
aggregate.
- TRANSLATION
Translation is considered a kind of modification, so you may
distribute translations of the Document under the terms of section 4.
Replacing Invariant Sections with translations requires special
permission from their copyright holders, but you may include
translations of some or all Invariant Sections in addition to the
original versions of these Invariant Sections. You may include a
translation of this License, and all the license notices in the
Document, and any Warranty Disclaimers, provided that you also include
the original English version of this License and the original versions
of those notices and disclaimers. In case of a disagreement between
the translation and the original version of this License or a notice
or disclaimer, the original version will prevail.
If a section in the Document is Entitled “Acknowledgements”,
“Dedications”, or “History”, the requirement (section 4) to Preserve
its Title (section 1) will typically require changing the actual
title.
- TERMINATION
You may not copy, modify, sublicense, or distribute the Document
except as expressly provided under this License. Any attempt
otherwise to copy, modify, sublicense, or distribute it is void, and
will automatically terminate your rights under this License.
However, if you cease all violation of this License, then your license
from a particular copyright holder is reinstated (a) provisionally,
unless and until the copyright holder explicitly and finally
terminates your license, and (b) permanently, if the copyright holder
fails to notify you of the violation by some reasonable means prior to
60 days after the cessation.
Moreover, your license from a particular copyright holder is
reinstated permanently if the copyright holder notifies you of the
violation by some reasonable means, this is the first time you have
received notice of violation of this License (for any work) from that
copyright holder, and you cure the violation prior to 30 days after
your receipt of the notice.
Termination of your rights under this section does not terminate the
licenses of parties who have received copies or rights from you under
this License. If your rights have been terminated and not permanently
reinstated, receipt of a copy of some or all of the same material does
not give you any rights to use it.
- FUTURE REVISIONS OF THIS LICENSE
The Free Software Foundation may publish new, revised versions
of the GNU Free Documentation License from time to time. Such new
versions will be similar in spirit to the present version, but may
differ in detail to address new problems or concerns. See
https://www.gnu.org/licenses/.
Each version of the License is given a distinguishing version number.
If the Document specifies that a particular numbered version of this
License “or any later version” applies to it, you have the option of
following the terms and conditions either of that specified version or
of any later version that has been published (not as a draft) by the
Free Software Foundation. If the Document does not specify a version
number of this License, you may choose any version ever published (not
as a draft) by the Free Software Foundation. If the Document
specifies that a proxy can decide which future versions of this
License can be used, that proxy’s public statement of acceptance of a
version permanently authorizes you to choose that version for the
Document.
- RELICENSING
“Massive Multiauthor Collaboration Site” (or “MMC Site”) means any
World Wide Web server that publishes copyrightable works and also
provides prominent facilities for anybody to edit those works. A
public wiki that anybody can edit is an example of such a server. A
“Massive Multiauthor Collaboration” (or “MMC”) contained in the
site means any set of copyrightable works thus published on the MMC
site.
“CC-BY-SA” means the Creative Commons Attribution-Share Alike 3.0
license published by Creative Commons Corporation, a not-for-profit
corporation with a principal place of business in San Francisco,
California, as well as future copyleft versions of that license
published by that same organization.
“Incorporate” means to publish or republish a Document, in whole or
in part, as part of another Document.
An MMC is “eligible for relicensing” if it is licensed under this
License, and if all works that were first published under this License
somewhere other than this MMC, and subsequently incorporated in whole
or in part into the MMC, (1) had no cover texts or invariant sections,
and (2) were thus incorporated prior to November 1, 2008.
The operator of an MMC Site may republish an MMC contained in the site
under CC-BY-SA on the same site at any time before August 1, 2009,
provided the MMC is eligible for relicensing.
ADDENDUM: How to use this License for your documents
To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and
license notices just after the title page:
Copyright (C) year your name.
Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3
or any later version published by the Free Software Foundation;
with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
Texts. A copy of the license is included in the section entitled ``GNU
Free Documentation License''.
If you have Invariant Sections, Front-Cover Texts and Back-Cover Texts,
replace the “with…Texts.” line with this:
with the Invariant Sections being list their titles, with
the Front-Cover Texts being list, and with the Back-Cover Texts
being list.
If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.
If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of
free software license, such as the GNU General Public License,
to permit their use in free software.
Index
This is an alphabetical listing of all concepts, functions, commands,
variables, and widgets described in this manual.
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