37.12.6 Functions for Working with Faces

Here are additional functions for creating and working with faces.

Function: face-list

This function returns a list of all defined face names.

Function: face-id face

This function returns the face number of face face. This is a number that uniquely identifies a face at low levels within Emacs. It is seldom necessary to refer to a face by its face number.

Function: face-documentation face

This function returns the documentation string of face face, or nil if none was specified for it.

Function: face-equal face1 face2 &optional frame

This returns t if the faces face1 and face2 have the same attributes for display.

Function: face-differs-from-default-p face &optional frame

This returns non-nil if the face face displays differently from the default face.

A face alias provides an equivalent name for a face. You can define a face alias by giving the alias symbol the face-alias property, with a value of the target face name. The following example makes modeline an alias for the mode-line face.

(put 'modeline 'face-alias 'mode-line)

Macro: define-obsolete-face-alias obsolete-face current-face when

This macro defines obsolete-face as an alias for current-face, and also marks it as obsolete, indicating that it may be removed in future. when should be a string indicating when obsolete-face was made obsolete (usually a version number string).