Custom themes are collections of settings that can be enabled or disabled as a unit. See Custom Themes in The GNU Emacs Manual. Each Custom theme is defined by an Emacs Lisp source file, which should follow the conventions described in this section. (Instead of writing a Custom theme by hand, you can also create one using a Customize-like interface; see Creating Custom Themes in The GNU Emacs Manual.)
A Custom theme file should be named foo-theme.el, where
foo is the theme name. The first Lisp form in the file should
be a call to deftheme
, and the last form should be a call to
provide-theme
.
This macro declares theme (a symbol) as the name of a Custom
theme. The optional argument doc should be a string describing
the theme; this is the description shown when the user invokes the
describe-theme
command or types ? in the ‘*Custom
Themes*’ buffer. The remaining arguments properties are used
pass a property list with theme attributes.
The following attributes are supported:
:family
A symbol designating what “family” a theme belongs to. A family of themes is a set of similar themes that differ by minor aspects, such as face colors that are meant for the light vs dark background of the frame.
:kind
A symbol. If a theme is enabled and this property has the value
color-scheme
, then the theme-choose-variant
command will
look for other available themes that belong to the same family in
order to switch the themes. Other values are currently unspecified
and should not be used.
:background-mode
A symbol, either light
or dark
. This attribute is
currently unused, but should still be specified.
Two special theme names are disallowed (using them causes an error):
user
is a dummy theme that stores the user’s direct
customization settings, and changed
is a dummy theme that
stores changes made outside of the Customize system.
This macro declares that the theme named theme has been fully specified.
In between deftheme
and provide-theme
are Lisp forms
specifying the theme settings: usually a call to
custom-theme-set-variables
and/or a call to
custom-theme-set-faces
.
This function specifies the Custom theme theme’s variable settings. theme should be a symbol. Each argument in args should be a list of the form
(var expression [now [request [comment]]])
where the list entries have the same meanings as in
custom-set-variables
. See Applying Customizations.
This function specifies the Custom theme theme’s face settings. theme should be a symbol. Each argument in args should be a list of the form
(face spec [now [comment]])
where the list entries have the same meanings as in
custom-set-faces
. See Applying Customizations.
In theory, a theme file can also contain other Lisp forms, which would be evaluated when loading the theme, but that is bad form. To protect against loading themes containing malicious code, Emacs displays the source file and asks for confirmation from the user before loading any non-built-in theme for the first time. As such, themes are not ordinarily byte-compiled, and source files usually take precedence when Emacs is looking for a theme to load.
The following functions are useful for programmatically enabling and disabling themes:
This function return a non-nil
value if theme (a symbol)
is the name of a Custom theme (i.e., a Custom theme which has been
loaded into Emacs, whether or not the theme is enabled). Otherwise,
it returns nil
.
The value of this variable is a list of themes loaded into Emacs.
Each theme is represented by a Lisp symbol (the theme name). The
default value of this variable is a list containing two dummy
themes: (user changed)
. The changed
theme stores
settings made before any Custom themes are applied (e.g., variables
set outside of Customize). The user
theme stores settings the
user has customized and saved. Any additional themes declared with
the deftheme
macro are added to the front of this list.
This function loads the Custom theme named theme from its source
file, looking for the source file in the directories specified by the
variable custom-theme-load-path
. See Custom Themes in The GNU Emacs Manual. It also enables the theme (unless the
optional argument no-enable is non-nil
), causing its
variable and face settings to take effect. It prompts the user for
confirmation before loading the theme, unless the optional argument
no-confirm is non-nil
.
This function searches custom-theme-load-path
for a file that
provides feature and then loads it. This is like the function
require
(see Features), except it searches
custom-theme-load-path
instead of load-path
(see Library Search). This can be useful in Custom themes that
need to load supporting Lisp files when require
is unsuitable
for that.
If feature, which should be a symbol, is not already present in
the current Emacs session according to featurep
, then
require-theme
searches for a file named feature with an
added ‘.elc’ or ‘.el’ suffix, in that order, in the
directories specified by custom-theme-load-path
.
If a file providing feature is successfully found and loaded,
then require-theme
returns feature. The optional
argument noerror determines what happens if the search or
loading fails. If it is nil
, the function signals an error;
otherwise, it returns nil
. If the file loads successfully but
does not provide feature, then require-theme
signals an
error; this cannot be suppressed.
This function enables the Custom theme named theme. It signals an error if no such theme has been loaded.
This function disables the Custom theme named theme. The theme
remains loaded, so that a subsequent call to enable-theme
will
re-enable it.