custom-push-theme

code: custom.el

(defun custom-push-theme (prop symbol theme mode &optional value)

"Record VALUE for face or variable SYMBOL in custom theme THEME.

symbol `set', then VALUE is the value to use. If it is the symbol

`reset', then SYMBOL will be removed from THEME (VALUE is ignored).

See `custom-known-themes' for a list of known themes."

(unless (memq prop '(theme-value theme-face))

(error "Unknown theme property"))

(let* ((old (get symbol prop))

(setting (assq theme old)) ; '(theme value)

(theme-settings ; '(prop symbol theme value)

(get theme 'theme-settings)))

(cond

;; Remove a setting:

((eq mode 'reset)

(when setting

(let (res)

(dolist (theme-setting theme-settings)

(if (and (eq (car theme-setting) prop)

(eq (cadr theme-setting) symbol))

(setq res theme-setting)))

(put theme 'theme-settings (delq res theme-settings)))

(put symbol prop (delq setting old))))

;; Alter an existing setting:

(setting

(let (res)

(dolist (theme-setting theme-settings)

(if (and (eq (car theme-setting) prop)

(eq (cadr theme-setting) symbol))

(setq res theme-setting)))

(put theme 'theme-settings

(cons (list prop symbol theme value)

(delq res theme-settings)))

;; It's tempting to use setcar here, but that could

;; inadvertently modify other properties in SYMBOL's proplist,

;; if those just happen to share elements with the value of PROP.

(put symbol prop (cons (list theme value) (delq setting old)))))

;; Add a new setting:

(t

(when (custom--should-apply-setting theme)

(unless old

;; If the user changed a variable outside of Customize, save

;; the value to a fake theme, `changed'. If the theme is

;; later disabled, we use this to bring back the old value.

;;

;; For faces, we just use `face--new-frame-defaults' to

;; recompute when the theme is disabled.

(when (and (eq prop 'theme-value)

(boundp symbol))

(let ((sv (get symbol 'standard-value))

(val (symbol-value symbol)))

(unless (or

;; We only do this trick if the current value

;; is different from the standard value.

(and sv (equal (eval (car sv)) val))

;; And we don't do it if we would end up recording

;; the same value for the user theme. This way we avoid

;; having ((user VALUE) (changed VALUE)). That would be

;; useless, because we don't disable the user theme.

(and (eq theme 'user) (equal (custom-quote val) value)))

(setq old `((changed ,(custom-quote val))))))))

(put symbol prop (cons (list theme value) old)))

(put theme 'theme-settings

(cons (list prop symbol theme value) theme-settings))))))