refactor: move subtle color hack to +color-subtle and fix an edge case

Author: abougouffa

core/me-builtin.el

@@ -139,19 +139,15 @@
   ;; Show trailing whitespace in `prog-mode' and `conf-mode'
   (+setq-hook! (prog-mode conf-mode) show-trailing-whitespace t)
 
-  ;; Lighter color for trailing whitespaces
-  (defun +face--lighter-trailing-whitespace-h (&rest _args)
+  ;; Subtle color for trailing whitespaces
+  (defun +face--subtle-trailing-whitespace-h (&rest _args)
     (with-eval-after-load 'faces
       (when (display-graphic-p)
-        (require 'color)
-        (set-face-background
-         'trailing-whitespace
-         (funcall (if (eq 'light (frame-parameter nil 'background-mode)) #'color-lighten-name #'color-darken-name)
-                  (face-attribute 'error :foreground nil t)
-                  50)))))
+        (when-let* ((new-color (+color-subtle 'error 50)))
+          (set-face-background 'trailing-whitespace new-color)))))
 
   (dolist (hook '(enable-theme-functions disable-theme-functions server-after-make-frame-hook))
-    (add-hook hook #'+face--lighter-trailing-whitespace-h))
+    (add-hook hook #'+face--subtle-trailing-whitespace-h))
 
   ;; By default, Emacs asks before quitting with "C-x C-c", but when running an
   ;; Emacs Client session, it won't ask unless a file is not saved. I hit "C-x

core/me-lib.el

@@ -1027,6 +1027,25 @@ scaling factor for the font in Emacs' `face-font-rescale-alist'. See the
    :overline (face-attribute 'default :foreground nil t)
    :background (face-attribute 'default :background nil t)))
 
+(autoload 'color-darken-name "color")
+(autoload 'color-lighten-name "color")
+
+(defun +color-subtle (base-color percentage &optional face-attr)
+  "Make a more subtle color based on BASE-COLOR and PERCENTAGE.
+
+We mean by subtle here, a darker color in dark themes and a lighter
+color in light themes.
+
+BASE-COLOR can be a color (string) or a face.
+When it is a face, the FACE-ATTR needs to be provided, otherwise, the
+:background attribute will be used."
+  (let ((base-color (if (facep base-color)
+                        (face-attribute base-color (or face-attr :background) nil t)
+                      base-color)))
+    (when (color-defined-p base-color)
+      (funcall (if (eq 'light (frame-parameter nil 'background-mode)) #'color-lighten-name #'color-darken-name)
+               base-color percentage))))
+
 
 
 ;;; Lazy on-demand modules

modules/me-editor.el

@@ -126,13 +126,7 @@ In some files, there is a mix of spaces and tabs. This uses
      (with-eval-after-load 'selection-highlight-mode
        (with-eval-after-load 'isearch
          (when (display-graphic-p)
-           (require 'color)
-           (let ((new-color (funcall
-                             (if (eq 'light (frame-parameter nil 'background-mode))
-                                 #'color-lighten-name
-                               #'color-darken-name)
-                             (face-attribute 'isearch :background nil t)
-                             5)))
+           (when-let* ((new-color (+color-subtle 'isearch 5)))
              (set-face-background 'selection-highlight-mode-match-face new-color)
              (set-face-background 'selection-highlight-mode-alternate-match-face new-color))))))))