Variable: custom-known-themes
custom-known-themes is a variable defined in custom.el.gz.
Value
(user changed)
Documentation
Themes that have been defined with deftheme.
The default value is the list (user changed). The theme changed
contains the settings before custom themes are applied. The theme
user contains all the settings the user customized and saved.
Additional themes declared with the deftheme macro will be added
to the front of this list.
Source Code
;; Defined in /usr/src/emacs/lisp/custom.el.gz
;;; Custom Themes
;; Custom themes are collections of settings that can be enabled or
;; disabled as a unit.
;; Each Custom theme is defined by a symbol, called the theme name.
;; The `theme-settings' property of the theme name records the
;; variable and face settings of the theme. This property is a list
;; of elements, each of the form
;;
;; (PROP SYMBOL THEME VALUE)
;;
;; - PROP is either `theme-value' or `theme-face'
;; - SYMBOL is the face or variable name
;; - THEME is the theme name (redundant, but simplifies the code)
;; - VALUE is an expression that gives the theme's setting for SYMBOL.
;;
;; The theme name also has a `theme-feature' property, whose value is
;; specified when the theme is defined (see `custom-declare-theme').
;; Usually, this is just a symbol named THEME-theme. This lets
;; external libraries call (require 'foo-theme).
;; In addition, each symbol (either a variable or a face) affected by
;; an *enabled* theme has a `theme-value' or `theme-face' property,
;; which is a list of elements each of the form
;;
;; (THEME VALUE)
;;
;; which have the same meanings as in `theme-settings'.
;;
;; The `theme-value' and `theme-face' lists are ordered by decreasing
;; theme precedence. Thus, the first element is always the one that
;; is in effect.
;; Each theme is stored in a theme file, with filename THEME-theme.el.
;; Loading a theme basically involves calling (load "THEME-theme")
;; This is done by the function `load-theme'. Loading a theme
;; automatically enables it.
;;
;; When a theme is enabled, the `theme-value' and `theme-face'
;; properties for the affected symbols are set. When a theme is
;; disabled, its settings are removed from the `theme-value' and
;; `theme-face' properties, but the theme's own `theme-settings'
;; property remains unchanged.
(defvar custom-known-themes '(user changed)
"Themes that have been defined with `deftheme'.
The default value is the list (user changed). The theme `changed'
contains the settings before custom themes are applied. The theme
`user' contains all the settings the user customized and saved.
Additional themes declared with the `deftheme' macro will be added
to the front of this list.")