#+title: ef-themes: colorful and legible themes
#+author: Protesilaos Stavrou
#+email: info@protesilaos.com
#+language: en
#+options: ':t toc:nil author:t email:t num:t
#+startup: content
#+macro: stable-version 1.9.0
#+macro: release-date 2024-11-16
#+macro: development-version 1.10.0-dev
#+export_file_name: ef-themes.texi
#+texinfo_filename: ef-themes.info
#+texinfo_dir_category: Emacs misc features
#+texinfo_dir_title: Ef-Themes: (ef-themes)
#+texinfo_dir_desc: Colorful and legible themes
#+texinfo_header: @set MAINTAINERSITE @uref{https://protesilaos.com,maintainer webpage}
#+texinfo_header: @set MAINTAINER Protesilaos Stavrou
#+texinfo_header: @set MAINTAINEREMAIL @email{info@protesilaos.com}
#+texinfo_header: @set MAINTAINERCONTACT @uref{mailto:info@protesilaos.com,contact the maintainer}

#+texinfo: @insertcopying

This manual, written by Protesilaos Stavrou, describes the Emacs package
called ~ef-themes~, and provides every other piece of information
pertinent to it.

The documentation furnished herein corresponds to stable version
{{{stable-version}}}, released on {{{release-date}}}.  Any reference to
a newer feature which does not yet form part of the latest tagged
commit, is explicitly marked as such.

Current development target is {{{development-version}}}.

+ Package name (GNU ELPA): ~ef-themes~
+ Official manual: <https://protesilaos.com/emacs/ef-themes>
+ Change log: <https://protesilaos.com/emacs/ef-themes-changelog>
+ Sample pictures: <https://protesilaos.com/emacs/ef-themes-pictures>
+ Git repositories:
  + GitHub: <https://github.com/protesilaos/ef-themes>
  + GitLab: <https://gitlab.com/protesilaos/ef-themes>
+ Backronym: Eclectic Fashion in Themes Hides Exaggerated Markings,
  Embellishments, and Sparkles.

If you are viewing the README.org version of this file, please note that
the GNU ELPA machinery automatically generates an Info manual out of it.

#+toc: headlines 8 insert TOC here, with eight headline levels

* COPYING
:PROPERTIES:
:COPYING: t
:CUSTOM_ID: h:1d213fed-b9a9-401c-9b5d-c7df602c2f63
:END:

Copyright (C) 2022-2023  Free Software Foundation, Inc.

#+begin_quote
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.”
#+end_quote

* Installation
:PROPERTIES:
:CUSTOM_ID: h:dd9e06f2-eef0-4afe-8a12-b7af5d597108
:END:
#+cindex: Installation instructions

** GNU ELPA package
:PROPERTIES:
:CUSTOM_ID: h:400d57a6-3a66-4ebf-b2e1-58a42237e0c2
:END:

The package is available as ~ef-themes~.  Simply do:

: M-x package-refresh-contents
: M-x package-install

And search for it.

GNU ELPA provides the latest stable release.  Those who prefer to follow
the development process in order to report bugs or suggest changes, can
use the version of the package from the GNU-devel ELPA archive.  Read:
https://protesilaos.com/codelog/2022-05-13-emacs-elpa-devel/.

** Manual installation
:PROPERTIES:
:CUSTOM_ID: h:97fcd2cf-a80b-4a52-a8c7-40b65e563c70
:END:

Assuming your Emacs files are found in =~/.emacs.d/=, execute the
following commands in a shell prompt:

#+begin_src sh
cd ~/.emacs.d

# Create a directory for manually-installed packages
mkdir manual-packages

# Go to the new directory
cd manual-packages

# Clone this repo, naming it "ef-themes"
git clone https://github.com/protesilaos/ef-themes ef-themes
#+end_src

Finally, in your =init.el= (or equivalent) evaluate this:

#+begin_src emacs-lisp
;; Make Elisp files in that directory available to the user.
(add-to-list 'load-path "~/.emacs.d/manual-packages/ef-themes")
#+end_src

Everything is in place to set up the package.

* Sample configuration
:PROPERTIES:
:CUSTOM_ID: h:ac76ded0-af9b-4566-aff9-75142ef2d4ef
:END:

#+begin_src emacs-lisp
;; Make customisations that affect Emacs faces BEFORE loading a theme
;; (any change needs a theme re-load to take effect).
(require 'ef-themes)

;; If you like two specific themes and want to switch between them, you
;; can specify them in `ef-themes-to-toggle' and then invoke the command
;; `ef-themes-toggle'.  All the themes are included in the variable
;; `ef-themes-collection'.
(setq ef-themes-to-toggle '(ef-summer ef-winter))

(setq ef-themes-headings ; read the manual's entry or the doc string
      '((0 variable-pitch light 1.9)
        (1 variable-pitch light 1.8)
        (2 variable-pitch regular 1.7)
        (3 variable-pitch regular 1.6)
        (4 variable-pitch regular 1.5)
        (5 variable-pitch 1.4) ; absence of weight means `bold'
        (6 variable-pitch 1.3)
        (7 variable-pitch 1.2)
        (t variable-pitch 1.1)))

;; They are nil by default...
(setq ef-themes-mixed-fonts t
      ef-themes-variable-pitch-ui t)

;; Disable all other themes to avoid awkward blending:
(mapc #'disable-theme custom-enabled-themes)

;; Load the theme of choice:
(load-theme 'ef-summer :no-confirm)

;; OR use this to load the theme which also calls `ef-themes-post-load-hook':
(ef-themes-select 'ef-summer)

;; The themes we provide are recorded in the `ef-themes-dark-themes',
;; `ef-themes-light-themes'.

;; We also provide these commands, but do not assign them to any key:
;;
;; - `ef-themes-toggle'
;; - `ef-themes-select'
;; - `ef-themes-select-dark'
;; - `ef-themes-select-light'
;; - `ef-themes-load-random'
;; - `ef-themes-preview-colors'
;; - `ef-themes-preview-colors-current'
#+end_src

* Themes for red-green or blue-yellow color deficiency
:PROPERTIES:
:CUSTOM_ID: h:c8c3f312-692f-45d0-b490-78b501c99d41
:END:

Most items in the ~ef-themes~ collection are designed to use colors
from many parts of the spectrum.  Those items generally are
inappropriate for users with red-green or blue-yellow color deficiency
(deuteranopia and tritanopia, respectively).  We do, nonetheless,
provide light and dark themes that are optimized for such cases.  The
names of the themes are:

- ~ef-deuteranopia-dark~ and ~ef-deuteranopia-light~ for red-green
  color deficiency;
- ~ef-tritanopia-dark~ and ~ef-tritanopia-light~ for blue-yellow color
  deficiency;

[[#h:75d74aea-d17f-497f-a3b8-f0bf4c372de0][Loading a theme]].

* Customization options
:PROPERTIES:
:CUSTOM_ID: h:db8ba158-22f6-49f7-b2f2-1c8162e690dd
:END:

The ~ef-themes~ provide a limited set of user options which tweak
secondary aspects of the theme.  No option affects coloration or the
overall character of each theme ([[#h:a6dd030c-6b6c-4992-83e8-3438b4607b51][Principles]]).

All customizations need to be evaluated before loading a theme.  Any
change thus requires a theme re-load ([[#h:a6dd030c-6b6c-4992-83e8-3438b4607b51][Loading a theme]]).

** Disable other themes
:PROPERTIES:
:CUSTOM_ID: h:b22371a2-9428-4f83-a3ca-884be559cf1d
:END:

#+vindex: ef-themes-disable-other-themes
The user option ~ef-themes-disable-other-themes~ controls which themes
to disable when loading an Ef theme.

When the value is non-nil, the commands ~ef-themes-toggle~ and
~ef-themes-select~ will disable all other themes while loading the
specified Ef theme.  This is done to ensure that Emacs does not blend
two or more themes: such blends lead to awkward results that undermine
the work of the designer.

When the value is nil, the aforementioned commands will only disable
other themes within the Ef collection.

This option is provided because Emacs themes are not necessarily
limited to colors/faces: they can consist of an arbitrary set of
customizations.  Users who use such customization bundles must set
this variable to a nil value.

** Toggle between two Ef themes
:PROPERTIES:
:CUSTOM_ID: h:a58b8e21-0f8f-4763-9b47-185bf7e10043
:END:

#+vindex: ef-themes-to-toggle
#+findex: ef-themes-toggle
The user option ~ef-themes-to-toggle~ expects two symbols that name
items in the Ef themes collection.  The variable ~ef-themes-collection~
includes a list with all relevant symbols.  The user can then switch
between the two specified themes by invoking the ~ef-themes-toggle~
command.

If ~ef-themes-to-toggle~ does not specify two Ef themes, inform the user
about it while prompting with completion for a theme among our
collection (this is practically the same as the ~ef-themes-select~
command).

This command is in addition to the other ways of loading a theme, either
with minibuffer completion or at random ([[#h:58345e8c-2bec-459c-872c-a85a29e9fe97][Commands to load an Ef theme]]).

** Rotate among a list of Ef themes
:PROPERTIES:
:CUSTOM_ID: h:96bc23ed-40b2-43b4-ba47-b6a5c350563d
:END:

#+vindex: ef-themes-to-rotate
#+findex: ef-themes-rotate
The user option ~ef-themes-to-rotate~ defines a list of Ef themes that
can be used in rotation. The command ~ef-themes-rotate~ reads from
that list and switches to the next item. If the next item is the
current one, it moves to the one after.

Possible values for ~ef-themes-to-rotate~ are any of the themes
specified in value of the variable ~ef-themes-items~.

This command is in addition to the other ways of loading a theme, either
with minibuffer completion or at random ([[#h:58345e8c-2bec-459c-872c-a85a29e9fe97][Commands to load an Ef theme]]).

** Enable mixed fonts
:PROPERTIES:
:CUSTOM_ID: h:621d3bb9-5967-4f97-b253-7470bba9168c
:END:

#+vindex: ef-themes-mixed-fonts
The user option ~ef-themes-mixed-fonts~ controls whether strictly
spacing-sensitive constructs inherit from ~fixed-pitch~ (a monospaced
font family).

By default (a ~nil~ value for this user option) no face inherits from
~fixed-pitch~: they all use the default font family, regardless of
whether it is monospaced or not.

When ~ef-themes-mixed-fonts~ is set to a non-~nil~ value, faces such
as for Org tables, inline code, code blocks, and the like, are
rendered in a monospaced font at all times.  The user can thus set
their default font family to a proportionately spaced font without
worrying about breaking the alignment of relevant elements, or if they
simply prefer the aesthetics of mixed mono and proportionately spaced
font families.

A temporary switch to a proportionately spaced font (known in Emacs as
~variable-pitch~) can be enabled in the current buffer with the
activation of the built-in ~variable-pitch-mode~.

To get consistent typography, the user may need to edit the font
family of the ~fixed-pitch~ and ~variable-pitch~ faces.  The
=fontaine= package on GNU ELPA (by Protesilaos) can be helpful in this
regard.

** UI typeface
:PROPERTIES:
:CUSTOM_ID: h:7c3d1057-c4a7-43b3-b91b-9887264d4072
:END:

#+vindex: ef-themes-variable-pitch-ui
The user option ~ef-themes-variable-pitch-ui~ controls whether the
elements of the User Interface (UI) use a proportionately spaced font.
By default (a ~nil~ value), all UI elements use the default font
family.  When this user option is set to a non-~nil~ value, all UI
elements will inherit the face ~variable-pitch~, thus rendering them
in a proportionately spaced font.

In this context, the UI elements are:

- ~header-line~
- ~mode-line~ (active and inactive)
- ~tab-bar-mode~
- ~tab-line-mode~

To get consistent typography, the user may need to edit the font
family of the ~fixed-pitch~ and ~variable-pitch~ faces.  The
=fontaine= package on GNU ELPA (by Protesilaos) can be helpful in this
regard.

** Option for headings
:PROPERTIES:
:CUSTOM_ID: h:a7a02817-e324-43e9-a7d8-fde024530af6
:END:

#+vindex: ef-themes-headings
The user option ~ef-themes-headings~ provides support for individual
heading styles for regular heading levels 0 through 8, as well as the
Org agenda headings.

This is an alist that accepts a =(KEY . LIST-OF-VALUES)= combination.
The =KEY= is either a number, representing the heading's level (0
through 8) or ~t~, which pertains to the fallback style.  The named
keys =agenda-date= and =agenda-structure= apply to the Org agenda.

Level 0 is a special heading: it is used for what counts as a document
title or equivalent, such as the =#+title= construct we find in Org
files.  Levels 1-8 are regular headings.

The =LIST-OF-VALUES= covers symbols that refer to properties, as
described below.  Here is a complete sample with various stylistic
combinations, followed by a presentation of all available properties:

#+begin_src emacs-lisp
(setq ef-themes-headings
      '((1 light variable-pitch 1.5)
        (2 regular 1.3)
        (3 1.1)
        (agenda-date 1.3)
        (agenda-structure variable-pitch light 1.8)
        (t variable-pitch)))
#+end_src

By default (a ~nil~ value for this variable), all headings have a bold
typographic weight, a font family that is the same as the ~default~ face
(typically monospaced), and a height that is equal to the ~default~
face's height.

- A ~variable-pitch~ property changes the font family of the heading to
  that of the ~variable-pitch~ face (normally a proportionately spaced
  typeface).  Also check the =fontaine= package (by Protesilaos) for
  tweaking fonts via faces.

- The symbol of a weight attribute adjusts the font of the heading
  accordingly, such as ~light~, ~semibold~, etc.  Valid symbols are
  defined in the variable ~ef-themes-weights~.  The absence of a weight
  means that bold will be used by virtue of inheriting the ~bold~ face.

- A number, expressed as a floating point (e.g. 1.5), adjusts the height
  of the heading to that many times the base font size.  The default
  height is the same as 1.0, though it need not be explicitly stated.
  Instead of a floating point, an acceptable value can be in the form of
  a cons cell like =(height . FLOAT)= or =(height FLOAT)=, where =FLOAT=
  is the given number.

Combinations of any of those properties are expressed as a list, like in
these examples:

#+begin_src emacs-lisp
(semibold)
(variable-pitch semibold)
(variable-pitch semibold 1.3)
(variable-pitch semibold (height 1.3))   ; same as above
(variable-pitch semibold (height . 1.3)) ; same as above
#+end_src

The order in which the properties are set is not significant.

In user configuration files the form may look like this:

#+begin_src emacs-lisp
(setq ef-themes-headings
      '((1 light variable-pitch 1.5)
        (2 regular 1.3)
        (3 1.1)
        (t variable-pitch)))
#+end_src

When defining the styles per heading level, it is possible to pass a
non-~nil~ non-list value (e.g. ~t~) instead of a list of properties.
This will retain the original aesthetic for that level.  For example:

#+begin_src emacs-lisp
(setq ef-themes-headings
      '((1 . t)           ; keep the default style
        (2 variable-pitch 1.2)
        (t variable-pitch))) ; style for all unspecified headings

(setq ef-themes-headings
      '((1 variable-pitch 1.6)
        (2 1.3)
        (t . t))) ; default style for all unspecified levels
#+end_src

** Palette overrides
:PROPERTIES:
:CUSTOM_ID: h:4b923795-4b23-4345-81e5-d1c108a84b6a
:END:
#+cindex: Override color values and semantic color mappings

Each Ef theme specifies a color palette that declares named color
values and semantic color mappings:

+ Named colors consist of a symbol and a string that specifies a
  hexadecimal RGB value.  For example: =(blue-warmer "#5250ef")=.

+ The semantic color mappings associate an abstract construct with a
  given named color from the palette, like =(prose-done green-cooler)=.
  Both elements of the list are symbols, though the ~cadr~ (value) can
  be a string that specifies a color, such as =(prose-done "#5250ef")=.

#+vindex: ef-themes-common-palette-overrides
Both of those subsets can be overridden, thus refashioning the theme.
Overrides are either shared, by being stored in the user option
~ef-themes-common-palette-overrides~, or they are specific to the
theme they name.  In the latter case, the naming scheme of each
palette variable is =THEME-NAME-palette-overrides=, thus yielding:

#+vindex: ef-arbutus-palette-overrides
- ~ef-arbutus-palette-overrides~

#+vindex: ef-autumn-palette-overrides
- ~ef-autumn-palette-overrides~

#+vindex: ef-bio-palette-overrides
- ~ef-bio-palette-overrides~

#+vindex: ef-cherie-palette-overrides
- ~ef-cherie-palette-overrides~

#+vindex: ef-cyprus-palette-overrides
- ~ef-cyprus-palette-overrides~

#+vindex: ef-dark-palette-overrides
- ~ef-dark-palette-overrides~

#+vindex: ef-day-palette-overrides
- ~ef-day-palette-overrides~

#+vindex: ef-deuteranopia-dark-palette-overrides
- ~ef-deuteranopia-dark-palette-overrides~

#+vindex: ef-deuteranopia-light-palette-overrides
- ~ef-deuteranopia-light-palette-overrides~

#+vindex: ef-dream-palette-overrides
- ~ef-dream-palette-overrides~

#+vindex: ef-duo-dark-palette-overrides
- ~ef-duo-dark-palette-overrides~

#+vindex: ef-duo-light-palette-overrides
- ~ef-duo-light-palette-overrides~

#+vindex: ef-eagle-palette-overrides
- ~ef-eagle-palette-overrides~

#+vindex: ef-elea-dark-palette-overrides
- ~ef-elea-dark-palette-overrides~

#+vindex: ef-elea-light-palette-overrides
- ~ef-elea-light-palette-overrides~

#+vindex: ef-frost-palette-overrides
- ~ef-frost-palette-overrides~

#+vindex: ef-kassio-palette-overrides
- ~ef-kassio-palette-overrides~

#+vindex: ef-light-palette-overrides
- ~ef-light-palette-overrides~

#+vindex: ef-maris-dark-palette-overrides
- ~ef-maris-dark-palette-overrides~

#+vindex: ef-maris-light-palette-overrides
- ~ef-maris-light-palette-overrides~

#+vindex: ef-melissa-dark-palette-overrides
- ~ef-melissa-dark-palette-overrides~

#+vindex: ef-melissa-light-palette-overrides
- ~ef-melissa-light-palette-overrides~

#+vindex: ef-night-palette-overrides
- ~ef-night-palette-overrides~

#+vindex: ef-owl-palette-overrides
- ~ef-owl-palette-overrides~

#+vindex: ef-reverie-palette-overrides
- ~ef-reverie-palette-overrides~

#+vindex: ef-rosa-palette-overrides
- ~ef-rosa-palette-overrides~

#+vindex: ef-spring-palette-overrides
- ~ef-spring-palette-overrides~

#+vindex: ef-summer-palette-overrides
- ~ef-summer-palette-overrides~

#+vindex: ef-symbiosis-palette-overrides
- ~ef-symbiosis-palette-overrides~

#+vindex: ef-trio-dark-palette-overrides
- ~ef-trio-dark-palette-overrides~

#+vindex: ef-trio-light-palette-overrides
- ~ef-trio-light-palette-overrides~

#+vindex: ef-tritanopia-dark-palette-overrides
- ~ef-tritanopia-dark-palette-overrides~

#+vindex: ef-tritanopia-light-palette-overrides
- ~ef-tritanopia-light-palette-overrides~

#+vindex: ef-winter-palette-overrides
- ~ef-winter-palette-overrides~

Theme-specific overrides take precedence over the shared ones.  It is
strongly advised that shared overrides do NOT alter color values, as
those will not be appropriate for both dark and light themes.  Common
overrides are best limited to the semantic color mappings as those use
the color value that corresponds to the active theme (e.g. make the
cursor =blue-warmer= in all themes, whatever the value of
=blue-warmer= is in each theme).

The value of any overrides' variable must mirror a theme's palette.
Palette variables are named after their theme as =THEME-NAME-palette=.
For example, the ~ef-summer-palette~ is like this:

#+begin_src emacs-lisp
(defconst ef-summer-palette
  '(
;;; Basic values

    (bg-main     "#fff2f3")
    (fg-main     "#4f4073")
    (bg-dim      "#f2e4ea")
    (fg-dim      "#786e74")
    (bg-alt      "#efd3e4")
    (fg-alt      "#af4988")

    (bg-active   "#cfb3c4")
    (bg-inactive "#f7ebee")

;;; Basic hues for foreground values

    (red             "#d3303a")
    (red-warmer      "#e00033")
    (red-cooler      "#d50f7f")
    (red-faint       "#c24552")

    ;; ...

    (blue            "#375ce6")
    (blue-warmer     "#5250ef")
    (blue-cooler     "#065fff")
    (blue-faint      "#6060d0")

    ;; ...

;;; Mappings

    ;; ...

;;;; Code mappings

    (builtin magenta)
    (comment yellow-faint)
    (constant red-cooler)
    (fnname magenta-warmer)
    (keyword magenta-cooler)
    (preprocessor green-warmer)
    (docstring cyan-faint)
    (string yellow-warmer)
    (type cyan-warmer)
    (variable blue-warmer)

    ;; ...
    ))
#+end_src

The ~ef-summer-palette-overrides~ targets the entries that need to be
changed.  For example, to make the cursor orange, use a shade of red
for comments, and apply a cyan hue to keywords:

#+begin_src emacs-lisp
(setq ef-summer-palette-overrides
      '((cursor "#ef9050")
        (comment red-faint)
        (keyword cyan-cooler)))
#+end_src

Changes take effect upon theme reload.  Overrides are removed by
setting their variable to a ~nil~ value.

The common accented foregrounds in each palette follow a predictable
naming scheme: =HUE{,-warmer,-cooler,-faint,-intense}=.  =HUE= is one
of the six basic colors: red, green, blue, yellow, magenta, cyan.

Named colors that are meant to be used as backgrounds contain =bg= in
their name, such as =bg-red-intense=.  While special purpose
foregrounds that are meant to be combined with such backgrounds,
contain =fg= in their name, such as =fg-removed= which complements
=bg-removed=.

Named colors can be previewed with the ~ef-themes-preview-colors~
command.  Changes to color values are reflected in the preview of the
theme's palette ([[#h:8dd67bf5-879e-46e5-b277-5bac141f53d1][Preview theme colors]]).  They are shown at the top of
the buffer.  In the above example, the first instance of =blue-warmer=
is the override and the second is the original one.

** Stylistic variants using palette overrides
:PROPERTIES:
:CUSTOM_ID: h:df1199d8-eaba-47db-805d-6b568a577bf3
:END:

This section contains practical examples of overriding the palette of
the themes ([[#h:4b923795-4b23-4345-81e5-d1c108a84b6a][Palette overrides]]). Users can copy the code to their init
file, evaluate it, and then re-load the theme for changes to take
effect. To apply overrides at startup simply define them before the
call that loads the theme.

*** Make the region more intense
:PROPERTIES:
:CUSTOM_ID: h:c8605d37-66e1-42aa-986e-d7514c3af6fe
:END:

This is one of our practical examples to override the semantic colors
of the Ef themes ([[#h:df1199d8-eaba-47db-805d-6b568a577bf3][Stylistic variants using palette overrides]]). Here we
show how to make the region override the underlying text colors(i.e.
to be more legible) and how to make the background more intense.

[[#h:a5140c9c-18b2-45db-8021-38d0b5074116][Do not extend the region background]].

#+begin_src emacs-lisp
;; These overrides are common to all Ef themes.  We also provide
;; theme-specific options, such as `ef-summer-palette-overrides'.
;;
;; In general, the theme-specific overrides are better for overriding
;; color values, such as redefining what `blue-faint' looks like.  The
;; common overrides are best used for changes to semantic color
;; mappings, as we show below.
;;
;; Use the command `ef-themes-preview-colors' or its variant
;; `ef-themes-preview-colors-current' to review the available palette
;; entries.


;; Use an intense background combined with the theme's intense
;; foreground.
(setq ef-themes-common-palette-overrides
      '((bg-region bg-magenta-intense)
        (fg-region fg-intense)))

;; Same idea as above, but less pronounced.
(setq ef-themes-common-palette-overrides
      '((bg-region bg-magenta-subtle)
        (fg-region fg-main)))
#+end_src


* Loading a theme
:PROPERTIES:
:CUSTOM_ID: h:75d74aea-d17f-497f-a3b8-f0bf4c372de0
:END:

Emacs can load and maintain enabled multiple themes at once.  This
typically leads to awkward styling and weird combinations.  The theme
looks broken and the designer's intent is misunderstood.  Before
loading one of the ~ef-themes~, the user is encouraged to disable all
others ([[#h:b22371a2-9428-4f83-a3ca-884be559cf1d][Disable other themes]]):

#+begin_src emacs-lisp
(mapc #'disable-theme custom-enabled-themes)
#+end_src

Then load the theme of choice.  For example:

#+begin_src emacs-lisp
(load-theme 'ef-summer :no-confirm)
#+end_src

The =:no-confirm= is optional.  It simply skips the step where Emacs
asks the user whether they are sure about loading the theme.

Consider adding code like the above to the user configuration file, such
as =init.el=.

NOTE: If you plan on using the ~ef-themes-post-load-hook~, the above
method will not work.  Instead, you need to load the theme from your
init file with ~ef-themes-select~ ([[#h:58345e8c-2bec-459c-872c-a85a29e9fe97][Commands to load an Ef theme]]).  For
example:

#+begin_src emacs-lisp
;; like `load-theme' but also call `ef-themes-post-load-hook'
(ef-themes-select 'ef-summer)
#+end_src

* Commands to load an Ef theme
:PROPERTIES:
:CUSTOM_ID: h:58345e8c-2bec-459c-872c-a85a29e9fe97
:END:

#+vindex: ef-themes-post-load-hook
The commands mentioned herein call ~ef-themes-post-load-hook~ at the
end.  This is for advanced users who want to trigger some code after an
Ef theme is loaded ([[#h:5b74bd9e-e7f2-46b3-af2e-7c45b2e69245][Use colors from the active Ef theme]]).  The same goes
for ~ef-themes-toggle~ and ~ef-themes-rotate~.

- [[#h:a58b8e21-0f8f-4763-9b47-185bf7e10043][Toggle between two Ef themes]]
- [[#h:96bc23ed-40b2-43b4-ba47-b6a5c350563d][Rotate among a list of Ef themes]]
- [[#h:1dbea3c9-de9a-4bb4-b540-654bea70ba4d][A theme-agnostic hook for theme loading]].

#+findex: ef-themes-select
The themes can also be loaded interactively.  The command
~ef-themes-select~ (call it with =M-x=) prompts with minibuffer
completion for a theme among the collection of items we provide.  It
then loads the selected theme.  Internally, ~ef-themes-select~ takes
care to disable any other Ef theme, though it does not disable other
themes.  This is by design to let users maintain theme blending when
they want it.  Otherwise, the user is encouraged to disable all other
themes and stick with the Ef themes:

#+begin_src emacs-lisp
(mapc #'disable-theme custom-enabled-themes)
#+end_src

The ~ef-themes-select~ command can also be called from the user's init
file to load the theme of their choice ([[#h:75d74aea-d17f-497f-a3b8-f0bf4c372de0][Loading a theme]]).  For example:

#+begin_src emacs-lisp
;; like `load-theme' but also call `ef-themes-post-load-hook'
(ef-themes-select 'ef-summer)
#+end_src

When ~ef-themes-select~ is called with a prefix argument (=C-u= by
default), it first produces a minibuffer prompt to limit the choice to
dark or light themes, and then shows only the relevant subset.

#+findex: ef-themes-select-dark
#+findex: ef-themes-select-light
Instead of calling ~ef-themese-select~ with a prefix argument, users
can invoke either of ~ef-themes-select-dark~, ~ef-themes-select-light~
commands.  Those behave the same as ~ef-themes-select~ except they
limit the interaction to dark or light Ef themes, respectively.

#+findex: ef-themes-load-random
The command ~ef-themes-load-random~ is for those who appreciate a bit of
serendipity in their life.  When call interactively with =M-x= it loads
a random theme from the Ef themes collection.  The selection excludes
the current Ef theme.  Calling ~ef-themes-load-random~ with a prefix
argument (=C-u= by default) makes the command limit the random selection
to either light or dark themes.  The user is prompted at the minibuffer
to pick among the two sets.

The ~ef-themes-load-random~ can also be called from Lisp (e.g. from the
=init.el= file):

#+begin_src emacs-lisp
(ef-themes-load-random)
#+end_src

This has the effect of loading an Ef theme at random, as described
above.  It is also possible to limit the set with either of those:

#+begin_src emacs-lisp
;; Load a light Ef theme at random
(ef-themes-load-random 'light)

;; Load a dark Ef theme at random
(ef-themes-load-random 'dark)
#+end_src

The author of the Ef themes likes to check with their operating system
to determine if the desktop environment outside of Emacs is using a
light/dark theme and then loads an appropriate Ef theme at random:

#+begin_src emacs-lisp
;; Check GNOME's gsettings database for the dark theme preference.  If
;; it is enabled, we want to load a dark Ef theme at random.  Otherwise
;; we load a random light theme.
(if (string-match-p
     "dark"
     (shell-command-to-string "gsettings get org.gnome.desktop.interface color-scheme"))
    (ef-themes-load-random 'dark)
  (ef-themes-load-random 'light))
#+end_src

* Preview theme colors
:PROPERTIES:
:CUSTOM_ID: h:8dd67bf5-879e-46e5-b277-5bac141f53d1
:END:

#+findex: ef-themes-preview-colors
The command ~ef-themes-preview-colors~ uses minibuffer completion to
select an item from the Ef themes and then produces a buffer with
previews of its color palette entries.  The buffer has a naming scheme
which reflects the given choice, like =ef-summer-preview-colors= for the
~ef-summer~ theme.

#+findex: ef-themes-preview-colors-current
The command ~ef-themes-preview-colors-current~ skips the minibuffer
selection process and just produces a preview for the current Ef theme.

When called with a prefix argument (=C-u= with the default key
bindings), these commands will show a preview of the palette's
semantic color mappings instead of the named colors.

#+findex: ef-themes-list-colors
#+findex: ef-themes-list-colors-current
Aliases for those commands are ~ef-themes-list-colors~ and
~ef-themes-list-colors-current~.

Overrides to color values are reflected in the buffers produced by the
aforementioned commands ([[#h:4b923795-4b23-4345-81e5-d1c108a84b6a][Palette overrides]]).

Each row shows a foreground and background coloration using the
underlying value it references.  For example a line with =#d3303a= (a
shade of red) will show red text followed by a stripe with that same
color as a backdrop.

The name of the buffer describes the given Ef theme and what the
contents are, such as =*ef-summer-list-colors*= for named colors and
=*ef-summer-list-mappings*= for the semantic color mappings.

* Use colors from the active Ef theme
:PROPERTIES:
:CUSTOM_ID: h:5b74bd9e-e7f2-46b3-af2e-7c45b2e69245
:END:

#+findex: ef-themes-with-colors
Advanced users may want to call color variables from the palette of the
active Ef theme.  The macro ~ef-themes-with-colors~ supplies those to
any form called inside of it.  For example:

#+begin_src emacs-lisp
(ef-themes-with-colors
  (list bg-main fg-main bg-mode-line cursor))
;; => ("#fff2f3" "#5f456f" "#ffa4dc" "#cf0090")
#+end_src

The above return value is for =ef-summer= when that is the active Ef
theme.  Switching to another theme and evaluating this code anew will
give us the relevant results for that theme.  The same with =ef-winter=:

#+begin_src emacs-lisp
(ef-themes-with-colors
  (list bg-main fg-main bg-mode-line cursor))
;; => ("#0f0b15" "#b8c6d5" "#5f1f5f" "#ff6ff0")
#+end_src

[[#h:152326a3-9356-4158-8adb-83c42c2ef117][Do-It-Yourself customizations]].

The palette of each Ef theme is considered stable.  No removals shall be
made.  Though please note that some tweaks to individual hues or color
mapping are still possible.  At any rate, we will not outright break any
code that uses ~ef-themes-with-colors~.

* Do-It-Yourself customizations
:PROPERTIES:
:CUSTOM_ID: h:152326a3-9356-4158-8adb-83c42c2ef117
:END:

This section documents how the user can further tweak the Ef themes to
their liking.

** Get a single color from the palette
:PROPERTIES:
:CUSTOM_ID: h:cc1633d3-8e83-45b5-b258-804935f9ee0d
:END:

[[#h:ec0adf54-c037-4c53-81b8-7eab2303794d][The general approach to advanced DIY changes]].

#+findex: ef-themes-get-color-value
The fuction ~ef-themes-get-color-value~ can be called from Lisp to
return the value of a color from the active Ef theme palette.  It
takea a =COLOR= argument and an optional =OVERRIDES=.

=COLOR= is a symbol that represents a named color entry in the
palette.

[[#h:8dd67bf5-879e-46e5-b277-5bac141f53d1][Preview theme colors]].

If the value is the name of another color entry in the palette (so a
mapping), this function recurs until it finds the underlying color
value.

With an optional =OVERRIDES= argument as a non-nil value, it accounts
for palette overrides.  Else it reads only the default palette.

[[#h:4b923795-4b23-4345-81e5-d1c108a84b6a][Palette overrides]].

With optional =THEME= as a symbol among ~ef-themes-collection~, use
the palette of that item.  Else use the current Ef theme.

If =COLOR= is not present in the palette, this function returns the
=unspecified= symbol, which is safe when used as a face attribute's
value.

An example with ~ef-summer~ to show how this function behaves
with/without overrides and when recursive mappings are introduced.

#+begin_src emacs-lisp
;; Here we show the recursion of palette mappings.  In general, it is
;; better for the user to specify named colors to avoid possible
;; confusion with their configuration, though those still work as
;; expected.
(setq ef-themes-common-palette-overrides
      '((cursor red)
        (prompt cursor)
        (variable prompt)))

;; Ignore the overrides and get the original value.
(ef-themes-get-color-value 'variable)
;; => "#5250ef"

;; Read from the overrides and deal with any recursion to find the
;; underlying value.
(ef-themes-get-color-value 'variable :overrides)
;; => "#d3303a"
#+end_src

** The general approach to advanced DIY changes
:PROPERTIES:
:CUSTOM_ID: h:ec0adf54-c037-4c53-81b8-7eab2303794d
:END:

When the user wants to customize Emacs faces there are two
considerations they need to make if they care about robustness:

1. Do not hardcode color values, but instead use the relevant variables
   from the Ef themes.
2. Make the changes persist through theme changes between the Ef themes
   collection.

For point 1 we provide the ~ef-themes-with-colors~ macro, while for
point 2 we have the ~ef-themes-post-load-hook~.

[[#h:5b74bd9e-e7f2-46b3-af2e-7c45b2e69245][Use colors from the active Ef theme]].

[[#h:58345e8c-2bec-459c-872c-a85a29e9fe97][Commands to load an Ef theme]].

[[#h:1dbea3c9-de9a-4bb4-b540-654bea70ba4d][A theme-agnostic hook for theme loading]].

We need to wrap our code in the ~ef-themes-with-colors~ and declare it
as a function which we then add to the hook.  Here we show the general
approach of putting those pieces together.

To customize faces in a way that mirrors the Ef themes' source code,
we use the built-in ~custom-set-faces~.  The value it accepts has the
same syntax as that found in =ef-themes.el=, specifically the
~ef-themes-faces~ constant.  It thus is easy to copy lines from there
and tweak them.  Let's pick a couple of font-lock faces (used in all
programming modes, among others):

#+begin_src emacs-lisp
(defun my-ef-themes-custom-faces ()
  "My customizations on top of the Ef themes.
This function is added to the `ef-themes-post-load-hook'."
  (ef-themes-with-colors
    (custom-set-faces
     ;; These are the default specifications
     `(font-lock-comment-face ((,c :inherit italic :foreground ,comment)))
     `(font-lock-variable-name-face ((,c :foreground ,variable))))))

;; Using the hook lets our changes persist when we use the commands
;; `ef-themes-toggle', `ef-themes-select', and `ef-themes-load-random'.
(add-hook 'ef-themes-post-load-hook #'my-ef-themes-custom-faces)
#+end_src

Each item in the Ef themes collection has its own color mapping.  So
the color value of the =comment= variable will differ from theme to
theme.  For the purpose of our demonstration, we make variables look
like comments and comments like variables:

#+begin_src emacs-lisp
(defun my-ef-themes-custom-faces ()
  "My customizations on top of the Ef themes.
This function is added to the `ef-themes-post-load-hook'."
  (ef-themes-with-colors
    (custom-set-faces
     `(font-lock-comment-face ((,c :foreground ,variable)))
     `(font-lock-variable-name-face ((,c :inherit italic :foreground ,comment))))))

;; Using the hook lets our changes persist when we use the commands
;; `ef-themes-toggle', `ef-themes-select', and `ef-themes-load-random'.
(add-hook 'ef-themes-post-load-hook #'my-ef-themes-custom-faces)
#+end_src

All changes take effect when a theme is loaded again.  As such, it is
better to use ~ef-themes-select~ at startup so that the function added
to the hook gets applied properly upon first load.  Like this:

#+begin_src emacs-lisp
(defun my-ef-themes-custom-faces ()
  "My customizations on top of the Ef themes.
This function is added to the `ef-themes-post-load-hook'."
  (ef-themes-with-colors
    (custom-set-faces
     `(font-lock-comment-face ((,c :foreground ,variable)))
     `(font-lock-variable-name-face ((,c :inherit italic :foreground ,comment))))))

;; Using the hook lets our changes persist when we use the commands
;; `ef-themes-toggle', `ef-themes-select', and `ef-themes-load-random'.
(add-hook 'ef-themes-post-load-hook #'my-ef-themes-custom-faces)

;; Load the theme and run `ef-themes-post-load-hook'
(ef-themes-select 'ef-summer) ; Instead of (load-theme 'ef-summer :no-confirm)
#+end_src

Please contact us if you have specific questions about this mechanism.
We are willing to help and shall provide comprehensive documentation
where necessary.

** A theme-agnostic hook for theme loading
:PROPERTIES:
:CUSTOM_ID: h:1dbea3c9-de9a-4bb4-b540-654bea70ba4d
:END:

The themes are designed with the intent to be useful to Emacs users of
varying skill levels, from beginners to experts.  This means that we try
to make things easier by not expecting anyone reading this document to
be proficient in Emacs Lisp or programming in general.

Such a case is with the use of the ~ef-themes-post-load-hook~, which is
called after the evaluation of any of the commands we provide for
loading a theme ([[#h:58345e8c-2bec-459c-872c-a85a29e9fe97][Commands to load an Ef theme]]).  We recommend using that
hook for advanced customizations, because (1) we know for sure that it
is available once the themes are loaded, and (2) anyone consulting this
manual, especially the sections on enabling and loading the themes, will
be in a good position to benefit from that hook.

Advanced users who have a need to switch between the Ef themes and other
items (e.g. my ~modus-themes~) will find that such a hook does not meet
their requirements: it only works with the Ef themes and only with the
aforementioned functions.

A theme-agnostic setup can be configured thus:

#+begin_src emacs-lisp
(defvar after-enable-theme-hook nil
   "Normal hook run after enabling a theme.")

(defun run-after-enable-theme-hook (&rest _args)
   "Run `after-enable-theme-hook'."
   (run-hooks 'after-enable-theme-hook))

(advice-add 'enable-theme :after #'run-after-enable-theme-hook)
#+end_src

This creates the ~after-enable-theme-hook~ and makes it run after each
call to ~enable-theme~, which means that it will work for all themes and
also has the benefit that it does not depend on functions such as
~ef-themes-select~ and the others mentioned in this manual.  The
function ~enable-theme~ is called internally by ~load-theme~, so the
hook works everywhere.

The downside of the theme-agnostic hook is that any functions added to
it will likely not be able to benefit from macro calls that read the
active theme, such as ~ef-themes-with-colors~ (the Modus themes have
an equivalent macro).  Not all Emacs themes have the same
capabilities.

In this document, we always mention ~ef-themes-post-load-hook~ though
the user can replace it with ~after-enable-theme-hook~ should they need
to (provided they understand the implications).

** Do not extend the region background
:PROPERTIES:
:CUSTOM_ID: h:a5140c9c-18b2-45db-8021-38d0b5074116
:END:

By the default, the background of the ~region~ face extends from the
end of the line to the edge of the window.  To limit it to the end of
the line, we need to override the face's =:extend= attribute.  Adding
this to the Emacs configuration file will suffice:

#+begin_src emacs-lisp
;; Do not extend `region' background past the end of the line.
(custom-set-faces
 '(region ((t :extend nil))))
#+end_src

[[#h:c8605d37-66e1-42aa-986e-d7514c3af6fe][Make the region more intense]].

** Add support for hl-todo
:PROPERTIES:
:CUSTOM_ID: h:19c549dc-d13f-45c4-a727-3618591d5c4f
:END:

The =hl-todo= package provides the user option ~hl-todo-keyword-faces~:
it specifies an association list of =(KEYWORD . COLOR-VALUE)= pairs.
There are no faces, which the theme could style seamlessly.  As such, it
rests on the user to specify appropriate color values.  This can be done
either by hardcoding colors, which is inefficient, or by using the macro
~ef-themes-with-colors~ ([[#h:ec0adf54-c037-4c53-81b8-7eab2303794d][The general approach to DIY changes]]).  Here we
show the latter method.

#+begin_src emacs-lisp
(defun my-ef-themes-hl-todo-faces ()
  "Configure `hl-todo-keyword-faces' with Ef themes colors.
The exact color values are taken from the active Ef theme."
  (ef-themes-with-colors
    (setq hl-todo-keyword-faces
          `(("HOLD" . ,yellow)
            ("TODO" . ,red)
            ("NEXT" . ,blue)
            ("THEM" . ,magenta)
            ("PROG" . ,cyan-warmer)
            ("OKAY" . ,green-warmer)
            ("DONT" . ,yellow-warmer)
            ("FAIL" . ,red-warmer)
            ("BUG" . ,red-warmer)
            ("DONE" . ,green)
            ("NOTE" . ,blue-warmer)
            ("KLUDGE" . ,cyan)
            ("HACK" . ,cyan)
            ("TEMP" . ,red)
            ("FIXME" . ,red-warmer)
            ("XXX+" . ,red-warmer)
            ("REVIEW" . ,red)
            ("DEPRECATED" . ,yellow)))))

(add-hook 'ef-themes-post-load-hook #'my-ef-themes-hl-todo-faces)
#+end_src

To find the names of the color variables, the user can rely on the
commands for previewing the palette ([[#h:8dd67bf5-879e-46e5-b277-5bac141f53d1][Preview theme colors]]).

** Make the mode line like the ~modus-themes~ default
:PROPERTIES:
:CUSTOM_ID: h:69ea8788-33b9-42f9-a4f1-92ee22074d2b
:END:

The Ef themes do not use a =:box= attribute for their mode lines, while
the active one has an accented background.  Users may prefer the
approach that my ~modus-themes~ follow by default, where both active and
inactive mode lines use shades of gray and have a border around them.

Try something like this, using the approach we have already explained
about ~ef-themes-with-colors~ ([[#h:ec0adf54-c037-4c53-81b8-7eab2303794d][The general approach to DIY changes]]):

#+begin_src emacs-lisp
(defun my-ef-themes-mode-line ()
  "Tweak the style of the mode lines."
  (ef-themes-with-colors
    (custom-set-faces
     `(mode-line ((,c :background ,bg-active :foreground ,fg-main :box (:line-width 1 :color ,fg-dim))))
     `(mode-line-inactive ((,c :box (:line-width 1 :color ,bg-active)))))))

(add-hook 'ef-themes-post-load-hook #'my-ef-themes-mode-line)
#+end_src

If you want the active mode line to retain its accented background but
also have a border around it, change this line from the above snippet:

#+begin_src emacs-lisp
(mode-line ((,c :background ,bg-active :foreground ,fg-main :box (:line-width 1 :color ,fg-dim))))
#+end_src

To this:

#+begin_src emacs-lisp
`(mode-line ((,c :background ,bg-mode-line :foreground ,fg-mode-line :box (:line-width 1 :color ,fg-dim))))
#+end_src

** Configure bold and italic faces
:PROPERTIES:
:CUSTOM_ID: h:8c0b05b7-5624-4051-844c-3c4882658782
:END:
#+cindex: Bold and italic fonts

The Ef themes do not hardcode a ~:weight~ or ~:slant~ attribute in the
faces they cover.  Instead, they configure the generic faces called
~bold~ and ~italic~ to use the appropriate styles and then instruct all
relevant faces that require emphasis to inherit from them.

This practically means that users can change the particularities of what
it means for a construct to be bold/italic, by tweaking the ~bold~ and
~italic~ faces.  Cases where that can be useful include:

+ The default typeface does not have a variant with slanted glyphs
  (e.g. Fira Mono/Code as of this writing on 2022-08-23), so the user
  wants to add another family for the italics, such as Hack.

+ The typeface of choice provides a multitude of weights and the user
  prefers the light one by default.  To prevent the bold weight from
  being too heavy compared to the light one, they opt to make ~bold~ use a
  semibold weight.

+ The typeface distinguishes between oblique and italic forms by
  providing different font variants (the former are just slanted
  versions of the upright forms, while the latter have distinguishing
  features as well).  In this case, the user wants to specify the font
  that applies to the ~italic~ face.

To achieve those effects, one must first be sure that the fonts they use
have support for those features.

In this example, we set the default font family to Fira Code, while we
choose to render italics in the Hack typeface (obviously one needs to
pick fonts that work in tandem):

#+begin_src emacs-lisp
(set-face-attribute 'default nil :family "Fira Code" :height 110)
(set-face-attribute 'italic nil :family "Hack")
#+end_src

And here we play with different weights, using Source Code Pro:

#+begin_src emacs-lisp
(set-face-attribute 'default nil :family "Source Code Pro" :height 110 :weight 'light)
(set-face-attribute 'bold nil :weight 'semibold)
#+end_src

To reset the font family, one can use this:

#+begin_src emacs-lisp
(set-face-attribute 'italic nil :family 'unspecified)
#+end_src

Consider the =fontaine= package on GNU ELPA (by Protesilaos) which
provides the means to configure font families via faces.

** Tweak =org-modern= timestamps
:PROPERTIES:
:CUSTOM_ID: h:32e3b7b2-3b53-4ec2-bd4e-fa24235e447d
:END:

The =org-modern= package uses faces and text properties to make Org
buffers more aesthetically pleasing.  It affects tables, timestamps,
lists, headings, and more.

In previous versions of the Ef themes, we mistakenly affected one of its
faces: the ~org-modern-label~.  It changed the intended looks and
prevented the user option ~org-modern-label-border~ from having its
desired effect.  As such, we no longer override that face.

Users who were used to the previous design and who generally do not
configure the user options of =org-modern= may thus notice a change in
how clocktables (or generally tables with timestamps) are aligned.  The
simplest solution is to instruct the mode to not prettify timestamps, by
setting the user option ~org-modern-timestamp~ to ~nil~.  For example, by
adding this to the init file:

#+begin_src emacs-lisp
(setq org-modern-timestamp nil)
#+end_src

Alignment in tables will also depend on the use of proportionately
spaced fonts.  Enable the relevant option to work with those without any
further trouble ([[#h:621d3bb9-5967-4f97-b253-7470bba9168c][Enable mixed fonts]]).

For any further issues, you are welcome to ask for help.

** Tweak goto-address-mode faces
:PROPERTIES:
:CUSTOM_ID: h:d42f726c-44e5-4dd6-b77e-e6ca0bab3189
:END:

The built-in ~goto-address-mode~ uses heuristics to identify URLs and
email addresses in the current buffer.  It then applies a face to them
to change their style.  Some packages, such as =notmuch=, use this
minor-mode automatically.

The faces are not declared with ~defface~, meaning that it is better
that the theme does not modify them.  The user is thus encouraged to
consider including this in their setup:

#+begin_src emacs-lisp
(setq goto-address-url-face 'link
      goto-address-url-mouse-face 'highlight
      goto-address-mail-face 'link
      goto-address-mail-mouse-face 'highlight)
#+end_src

My personal preference is to set ~goto-address-mail-face~ to ~nil~,
because it otherwise adds too much visual noise to the buffer (email
addresses stand out more, due to the use of the uncommon =@= caharacter
but also because they are often enclosed in angled brackets).

* Faces defined by the Ef themes
:PROPERTIES:
:CUSTOM_ID: h:34afcc9a-a5f1-4023-b01a-abf5b8a6199d
:END:

The themes define some faces to make it possible to achieve
consistency between various groups of faces.  For example, all "marks
for selection" use the ~ef-themes-mark-select~ face.  If, say, the
user wants to edit this face to include an underline, the change will
apply to lots of packages, like Dired, Trashed, Ibuffer.

[[#h:152326a3-9356-4158-8adb-83c42c2ef117][Do-It-Yourself customizations]].

All the faces defined by the themes:

+ ~ef-themes-fixed-pitch~
+ ~ef-themes-heading-0~
+ ~ef-themes-heading-1~
+ ~ef-themes-heading-2~
+ ~ef-themes-heading-3~
+ ~ef-themes-heading-4~
+ ~ef-themes-heading-5~
+ ~ef-themes-heading-6~
+ ~ef-themes-heading-7~
+ ~ef-themes-heading-8~
+ ~ef-themes-key-binding~
+ ~ef-themes-mark-delete~
+ ~ef-themes-mark-other~
+ ~ef-themes-mark-select~
+ ~ef-themes-ui-variable-pitch~
+ ~ef-themes-underline-error~
+ ~ef-themes-underline-info~
+ ~ef-themes-underline-warning~

* Supported packages or face groups
:PROPERTIES:
:CUSTOM_ID: h:c8d80daf-d039-40c4-bb74-e7814a9b4c79
:END:

The ~ef-themes~ will only ever support a curated list of packages based
on my judgement ([[#h:ea2eedd7-a473-4826-9b83-31bf3ac2c5f7][Packages that are hard to support]]).  Nevertheless, the
list of explicitly or implicitly supported packages already covers
everything most users need.

** Explicitly supported packages or face groups
:PROPERTIES:
:CUSTOM_ID: h:8e87733c-9fc9-45cd-9b9e-97b11f4f6c05
:END:

- ace-window
- all basic faces
- all-the-icons
- all-the-icons-dired
- all-the-icons-ibuffer
- ansi-color
- auctex
- auto-dim-other-buffers
- avy
- breadcrumb
- bongo
- bookmark
- calendar and diary
- cider
- centaur-tabs
- change-log and log-view (part of VC)
- chart
- clojure-mode
- company
- compilation
- completions
- consult
- corfu
- corfu-candidate-overlay
- csv-mode
- custom (=M-x customize=)
- dashboard
- denote
- dictionary
- diff-hl
- diff-mode
- dired
- dired-subtree
- diredfl
- dirvish
- display-fill-column-indicator-mode
- doom-modeline
- ediff
- eglot
- eldoc
- elfeed
- embark
- epa
- erc
- ert
- eshell
- evil
- eww
- flycheck
- flymake
- flyspell
- font-lock
- forge
- git-commit
- git-gutter
- git-gutter-fr
- git-rebase
- gnus
- hexl-mode
- hi-lock (=M-x highlight-regexp=)
- highlight-indentation
- ibuffer
- image-dired
- imenu-list
- info
- isearch, occur, query-replace
- jit-spell
- jinx
- keycast
- lin
- line numbers (~display-line-numbers-mode~ and global variant)
- magit
- man
- marginalia
- markdown-mode
- mct
- messages
- mode-line
- mood-line
- mu4e
- nerd-icons
- nerd-icons-completion
- nerd-icons-dired
- nerd-icons-ibuffer
- neotree
- notmuch
- olivetti
- orderless
- org
- org-habit
- org-modern
- outline-mode
- outline-minor-faces
- package (=M-x list-packages=)
- pdf-tools
- perspective
- proced
- powerline
- pulsar
- pulse
- rainbow-delimiters
- rcirc
- recursion-indicator
- regexp-builder (re-builder)
- rst-mode
- ruler-mode
- shell-script-mode (sh-mode)
- shortdoc
- show-paren-mode
- shr
- smerge
- tab-bar-mode
- tab-line-mode
- tempel
- term
- textsec
- tldr
- transient
- trashed
- tree-sitter
- tty-menu
- vc (=vc-dir.el=, =vc-hooks.el=)
- vertico
- vterm
- vundo
- wgrep
- which-function-mode
- which-key
- whitespace-mode
- widget
- window-divider-mode
- window-tool-bar-mode
- writegood-mode
- woman
- ztree

** Implicitly supported packages or face groups
:PROPERTIES:
:CUSTOM_ID: h:7d1acc40-a2ce-4e6d-a230-35ddffc00690
:END:

Those are known to work with the Ef themes either because their colors
are appropriate or because they inherit from basic faces which the
themes already cover:

- apropos
- dim-autoload
- hl-todo
- icomplete
- ido
- mct
- multiple-cursors
- paren-face
- sxhkdrc-mode
- xref

Note that "implicitly supported" does not mean that they always fit in
perfectly.  If there are refinements we need to made, then we need to
intervene ([[#h:8e87733c-9fc9-45cd-9b9e-97b11f4f6c05][Explicitly supported packages or face groups]]).

** Packages that are hard to support
:PROPERTIES:
:CUSTOM_ID: h:ea2eedd7-a473-4826-9b83-31bf3ac2c5f7
:END:

These are difficult to support due to their (i) incompatibility with the
design of the ~ef-themes~, (ii) complexity or multiple points of entry,
(iii) external dependencies, (iv) existence of better alternatives in my
opinion, or (v) inconsiderate use of color out-of-the-box and implicit
unwillingness to be good Emacs citizens:

- avy :: its UI is prone to visual breakage and is hard to style
  correctly.

- calibredb :: has an external dependency that I don't use.

- ctrlf :: use the built-in isearch or the ~consult-line~ command of
  =consult=.

- dired+ :: it is complex and makes inconsiderate use of color.

- ein (Emacs IPython Notebook) :: external dependency that I don't use.

- ement.el :: has an external dependency that I don't use.

- helm :: it is complex and makes inconsiderate use of color.  Prefer
  the =vertico=, =consult=, and =embark= packages.

- info+ :: it is complex and makes inconsiderate use of color.

- ivy/counsel/swiper :: use the =vertico=, =consult=, and =embark=
  packages which are designed to be compatible with standard Emacs
  mechanisms and are modular.

- lsp-mode :: has external dependencies that I don't use.

- solaire :: in principle, it is incompatible with practically every
  theme that is not designed around it.  Emacs does not distinguish
  between "UI" and "syntax" buffers.

- sx :: has an external dependency that I don't use.

- telega :: has an external dependency that I don't use (I don't even
  have a smartphone).

- treemacs :: it has too many dependencies and does too many things.

- web-mode :: I don't use all those Web technologies and cannot test
  this properly without support from an expert.  It also defines lots of
  faces that hardcode color values for no good reason.

The above list is non-exhaustive though you get the idea.

* Principles
:PROPERTIES:
:CUSTOM_ID: h:a6dd030c-6b6c-4992-83e8-3438b4607b51
:END:

+ No customization options that affect the coloration of individual
  components like a heading or a construct in the code!  Either you
  like them or you don't.  To change the attributes of individual
  faces, it is better to do it in user-level configurations
  ([[#h:152326a3-9356-4158-8adb-83c42c2ef117][Do-It-Yourself customizations]]).  Report the issue and I can help
  with the relevant code.  Providing customizations that refashion a
  wide set of themes is not maintainable due to the sheer magnitude of
  all the possible combinations.

+ Curated list of supported faces ([[#h:c8d80daf-d039-40c4-bb74-e7814a9b4c79][Supported packages or face groups]]).
  I will only cover what I use and/or know is in a well-maintained
  state.  Styling a package requires a lot of work as one must (i) know
  how the package works, (ii) see all its interfaces in action, (iii)
  make sure that the color combinations look consistent with the rest of
  the theme.

+ Minimum contrast ratio of 4.5:1 against the main background (WCAG AA
  standard).  Emphasis on "minimum" as themes can always have more
  contrast.  Use my ~modus-themes~ package (also built into Emacs 28
  or higher) if you need top-class accessibility in this regard.

+ If two elements are functionally distinct, the theme must render
  this fact conspicuous ([[#h:b59f315c-6d25-4225-b99b-c06594fa3bf0][Let Org tags inherit the heading color?]]).

+ Respect the decisions of the upstream package provider or, else, do
  not make weird things with faces.  I only override the design choice
  of a package if it is absolutely necessary and then still try to
  conform with the principle of least surprise.

+ When there is an inescapable trade-off between usability and
  aesthetics, I will always opt for the former, without prejudice to
  the aforementioned principles.

** Minimal VS maximal scope
:PROPERTIES:
:CUSTOM_ID: h:fb219b87-ab95-401a-a742-a2fc451bf9f7
:END:

The ~ef-themes~ are meant to be minimal in scope, as opposed to my
~modus-themes~ whose accessibility requirements make them maximalist by
necessity.  The ~modus-themes~ are such because:

1. Accessibility is not a one-size-fits-all.  Customisation options are
   necessary to empower users.
2. Accessibility is as good as its weakest link.  If the user spends all
   day using FOO package, it needs to be perfectly legible, otherwise
   the whole theme fails to deliver on its promise.

The ~ef-themes~ can afford to be more minimal because they do not have
such a lofty accessibility target.

* FAQ
:PROPERTIES:
:CUSTOM_ID: h:a6d5c6f1-84c5-4d74-ba39-b5ccda05497a
:END:

** What does Ef mean?
:PROPERTIES:
:CUSTOM_ID: h:22a92ee8-eda6-4c29-b850-b2709a7239c0
:END:

"Ef" is a Greek word (ευ), commonly used as a prefix to denote
something good, nice, and/or easy.  For example, eftopia (ευτοπία) is
the opposite of dystopia (δυστοπία): a good place as opposed to a bad
place.

** Will you stop using the modus-themes?
:PROPERTIES:
:CUSTOM_ID: h:33c9b520-0af2-441c-a2e8-2945522feb3e
:END:

No.  For my workflow, accessibility is the most important quality.  The
~modus-themes~ will remain my default choice.

** Then why develop the ef-themes?
:PROPERTIES:
:CUSTOM_ID: h:ca441ae7-2e18-4dd2-9f5d-e3b806456251
:END:

Because I think that users deserve "pretty" themes that (i) do make some
considerations for legibility, and (ii) are not designed on a whimsy.

The ~ef-themes~ are my answer to those who (i) like my ~modus-themes~,
(ii) want something with a bit more flair, and (iii) are fine with a
bit more relaxed accessibility target.

** Difference between ef-themes and modus-themes?
:PROPERTIES:
:CUSTOM_ID: h:9efafe65-1a2c-4f50-88bf-885f60afe27e
:END:

The main difference between the two projects is that the
~modus-themes~ are much more strict with maintaining the highest
standard for contrast (I won't delve into the technicalities, though
the manual of the ~modus-themes~ does elaborate on the minutiae).
Whereas the ~ef-themes~ do not have such a commitment: they are
legible, but might go a bit below the desired target in certain cases.

For the user who has already narrowed their search to the Modus and Ef
themes, the criterion should be the eye test.  If any of those items
looks good/usable, then that is what matters.  A bit of
experimentation provides greater insight than tomes on theoretical
nuances---no value in overthinking it.

Between the ~ef-themes~ and the ~modus-themes~, I provide a broad
range of options for users who need varying degrees of legibility.
The ~modus-themes~ are the ones with the highest contrast.

I have always maintained the view that (i) there is no such thing as a
one-size-fits-all for accessibility due to innate differences in color
perception between individuals as well as hardware capabilities, and
(ii) no theme can handle accessibility on its own, as one needs to
consider typography as well as environmental factors.

[ For my preferred typography, check Iosevka Comfy:
  <https://protesilaos.com/emacs/iosevka-comfy-pictures>. ]

Technically, the very high contrast of the ~modus-themes~ demands that
they are not---and can never be---as colorful as the ~ef-themes~.
Their colors are less saturated.  In terms of presentation, this means
that the ~modus-themes~ may appear more minimalist (or "clean") once
one gets used to their level of contrast.  In general: do not trust
initial impressions and give the themes a fair chance (if one is used
to low contrast settings, the ~modus-themes~ feel hard to get used to,
though this is natural as the eye adapts accordingly).

The ~ef-themes~ are more colorful, which can make them more/less
pleasant to work with, depending on one's subjectivity.  Within the
~ef-themes~, there is considerable diversity, as each of the 20 items
has its own character, expressed as a unique color palette and color
mapping.  No two themes are alike.  For example, for light themes
~ef-summer~ gives the user a completely different vibe than
~ef-frost~, while for dark themes ~ef-bio~ and ~ef-cherie~ each have
their unique charm.

I cannot possibly say which the "best" is.  This is a subjective
evaluation.  For me personally, both projects are technically
excellent in terms of conforming with their stated ends.
Aesthetically, I like them all, which is why I develop/maintain them.
I am not prioritising one over the others.

Note that I am emphasising legibility, though this should not discount
the meticulous work that goes into thematic consistency.  I do not
write about this topic because it does not really matter to the
average user.  Consistency is not something that should actively be
calling for one's attention, though it is "there" for those who wish
to pay attention.  In short: I am not picking random colors and
implementing them on a whimsy.  Theme development is not easy.

** Too many options, what should I do?
:PROPERTIES:
:CUSTOM_ID: h:3c0201ed-2c06-4981-a3a3-3d15bc4eec00
:END:

Take a deep breath, drink some water, get some fresh air, and take it
one step at a time.  You don't have to try all the themes outright.
For a light theme, go with =ef-light=; for a dark one use =ef-dark=.
They have generic names exactly for this reason.  Then make the
necessary tweaks to toggle between those two and don't worry anymore
about the abundance of choice ([[#h:a58b8e21-0f8f-4763-9b47-185bf7e10043][Toggle between two Ef themes]]).  Good
luck!

** Let Org tags inherit the heading color?
:PROPERTIES:
:CUSTOM_ID: h:b59f315c-6d25-4225-b99b-c06594fa3bf0
:END:

Upstream Org defines tags in headings to have the same color as the rest
of the heading's text.  However, tags are a distinct component of the
heading as noted in the doc string of the ~org-get-heading~ function.
Tags also are functionally different than the ordinary text of the
heading: they are a clickable link/button.  It thus is a matter of
usability to render this distinction clear at the visual level: I do not
agree with upstream Org's design decision.

Normally, we would style a link to have an underline.  However, this
design does not look right in headings (as it doesn't look right in,
e.g., the headings in a listing of emails or the unread items in the
Elfeed list of entries).  We thus have to go with the next option, which
is to use a distinct foreground color that differentiates the tag from
its context, while accounting for theme-wide usability and consistency.

The overarching principle is that when two things function differently,
they have to look apart even if the difference is small.

The assumption that tags are right-aligned (per Org's default behaviour)
does not hold, as there exists a user option to disable this effect:
~org-auto-align-tags~.  The author of the ~ef-themes~ uses this option
because the way Org performs this alignment using literal spaces does
not work properly with (i) proportionately spaced fonts, (ii) varying
heading heights, (iii) different levels of indentation.  Realigning tags
by inserting spaces also creates noise in version-controlled files,
which is undesirable.

** Add something like Nord or Zenburn?
:PROPERTIES:
:CUSTOM_ID: h:103def23-def7-48f9-b14b-4089e4e13242
:END:

In general, I am not against the idea of drawing inspiration from other
themes.  Note though that every item in the ~ef-themes~ collection is
designed from scratch to work in accordance with the principles of this
project ([[#h:a6dd030c-6b6c-4992-83e8-3438b4607b51][Principles]]).

Each palette is an original implementation.  The six basic hues of red,
green, blue, yellow, magenta, cyan are implemented as quartets of a
base, warmer, cooler, and faint variants.

All themes have their own color mapping, which is conducted in
accordance with the exact values of the aforementioned hues and their
innate relations.

Copying another project's palette is generally not possible or not
desirable, not even if that is my ~modus-themes~ (they, too, have a
different set of requirements).

Furthermore, trying to mimic another theme generally is an exercise with
prior constraints, as we are always labouring under the expectation of
remaining faithful to the original.  This can lead to awkward
compromises and sub-optimal choices, which make no sense for a project
with opinionanted design principles.

* Acknowledgements
:PROPERTIES:
:CUSTOM_ID: h:5d8753d2-cc10-44a7-9467-dcd62157718b
:END:
#+cindex: Contributors

This project is meant to be a collective effort.  Every bit of help
matters.

+ Author/maintainer :: Protesilaos Stavrou.

+ Contributions to code or the manual :: Alex Lu, Christopher League,
  Eshel Yaron, Gautier Ponsinet, Oleksii (Alex) Koval, Pedro Cunha,
  Philip Kaludercic, Ryan Kaskel, Walheimat.

+ Ideas and/or user feedback :: Adam Porter (alphapapa), Alan Schmitt,
  Amo DelBello, Anthony Chavez, Benjamin (zealotrush), Bruno Boal,
  Daniel Mendler, Federico Stilman, Filippo Argiolas, Iris Garcia,
  Jean-Philippe Gagné Guay, Len Trigg, Jonas Collberg, Saša Janiška,
  Spike-Leung, Steve Molitor, Summer Emacs, Sven Seebeck, Thanos
  Apollo, Zoltán Király, goldfita, marasenna, newhallroad.

* GNU Free Documentation License
:PROPERTIES:
:CUSTOM_ID: h:a349a898-0068-4529-ab3b-167c1b7b8534
:END:

#+texinfo: @include doclicense.texi

#+begin_export html
<pre>

                GNU Free Documentation License
                 Version 1.3, 3 November 2008


 Copyright (C) 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.

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and modification of the Modified Version to whoever possesses a copy
of it.  In addition, you must do these things in the Modified Version:

A. Use in the Title Page (and on the covers, if any) a title distinct
   from that of the Document, and from those of previous versions
   (which should, if there were any, be listed in the History section
   of the Document).  You may use the same title as a previous version
   if the original publisher of that version gives permission.
B. List on the Title Page, as authors, one or more persons or entities
   responsible for authorship of the modifications in the Modified
   Version, together with at least five of the principal authors of the
   Document (all of its principal authors, if it has fewer than five),
   unless they release you from this requirement.
C. State on the Title page the name of the publisher of the
   Modified Version, as the publisher.
D. Preserve all the copyright notices of the Document.
E. Add an appropriate copyright notice for your modifications
   adjacent to the other copyright notices.
F. Include, immediately after the copyright notices, a license notice
   giving the public permission to use the Modified Version under the
   terms of this License, in the form shown in the Addendum below.
G. Preserve in that license notice the full lists of Invariant Sections
   and required Cover Texts given in the Document's license notice.
H. Include an unaltered copy of this License.
I. 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.
J. 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.
K. 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.
L. 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.
M. Delete any section Entitled "Endorsements".  Such a section
   may not be included in the Modified Version.
N. Do not retitle any existing section to be Entitled "Endorsements"
   or to conflict in title with any Invariant Section.
O. 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.


5. 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".


6. 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.


7. 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.


8. 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.


9. 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.


10. 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.

11. 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.
</pre>
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