DefineFaceConstant

Arguments to macro ‘define-face-const’:

• FOREGROUND is either nil or a string naming the new face’s foreground color.
• BACKGROUND is either nil or a string naming the new face’s background color.

FOREGROUND (or BACKGROUND) nil means do not set the foreground (or the BACKGROUND). If both are nil, the new variable’s value is nil. The value of the new variable (new face or nil) is returned.

Only colors (strings) satisfying ‘x-color-defined-p’ are accepted. Black is used in place of any unacceptable foreground color name. White is used in place of any unacceptable background color name.

The name of the new constant variable is as follows:

• If both FOREGROUND and BACKGROUND are strings: FOREGROUND-on-BACKGROUND-face
• If only FOREGROUND is a string: FOREGROUND-foreground-face
• If only BACKGROUND is a string: BACKGROUND-background-face

Examples of use:

 (define-face-const \"Blue\" \"Thistle\") => (defconst 'blue-on-thistle-face)
       where (face-foreground 'blue-on-thistle-face) = \"Blue\"
             (face-background 'blue-on-thistle-face) = \"Thistle\"

 (define-face-const \"Blue\" nil) => (defconst 'blue-foreground-face)
       where (face-foreground 'blue-foreground-face) = \"Blue\"

 (define-face-const nil \"Thistle\") => (defconst 'thistle-background-face)
       where (face-background 'thistle-background-face) = \"Thistle\"

If color ZZZZZZ is undefined:

 (define-face-const \"Blue\" \"ZZZZZZ\") => (defconst 'blue-on-white-face)
       where (face-foreground 'blue-on-white-face) = \"Blue\"
             (face-background 'blue-on-white-face) = \"White\"

 (define-face-const \"ZZZZZZ\" \"Pink\") => (defconst 'black-on-pink-face)
       where (face-foreground 'black-on-pink-face) = \"Black\"
             (face-background 'black-on-pink-face) = \"Pink\"