Tone down ediff faces

1 files changed, 43 insertions, 1 deletions

diff --git a/.emacs b/.emacs
index a6401a2..275518d 100644
--- a/.emacs
+++ b/.emacs
@@ -26,6 +26,46 @@
 ;; Examples: erc-modules, git-commit-setup-hook, package-archives.
 (add-to-list 'package-archives '("melpa" . "https://melpa.org/packages/") t)
 
+
+;; Theming
+
+;; AFAICT `modus-themes-deuteranopia' does not compose with
+;; `modus-themes-diffs'.  I like the red/blue palette, but I'd also
+;; like to get desaturated backgrounds… *and* I'd also like
+;; foregrounds to remain unset to keep syntax highlighting.  Tough
+;; customer, I know 😕
+
+(defun my/modus-ediff-bg (face)
+  (require 'color)
+  (let ((old-bg (face-background face nil t)))
+    (if (equal (modus-themes--current-theme) 'modus-vivendi)
+        (color-darken-name old-bg 25)
+      (color-lighten-name old-bg 12))))
+
+(defun my/modus-ediff-set-face (face)
+  (set-face-attribute
+   face nil
+   :inherit 'unspecified
+   :foreground 'unspecified
+   :background (my/modus-ediff-bg face)))
+
+(defun my/modus-ediff-face-list ()
+  (require 'ediff-init)
+  (let ((kinds '("current" "fine"))
+        (targets '("A" "B" "C" "Ancestor")))
+    (mapcan
+     (lambda (target)
+       (mapcar
+        (lambda (kind)
+          (let ((face-name (format "ediff-%s-diff-%s" kind target)))
+            (or (intern-soft face-name)
+                (error "Cannot find face named %s" face-name))))
+        kinds))
+     targets)))
+
+(defun my/modus-ediff ()
+  (mapc 'my/modus-ediff-set-face (my/modus-ediff-face-list)))
+
 (when (>= emacs-major-version 28)
   (setq modus-themes-bold-constructs t
         modus-themes-deuteranopia t
@@ -40,7 +80,9 @@
         modus-themes-prompts '(background)
         modus-themes-region '(bg-only)
         modus-themes-variable-pitch-ui t)
-  (load-theme 'modus-vivendi))
+  (load-theme 'modus-vivendi)
+  (my/modus-ediff)
+  (add-hook 'modus-themes-after-load-theme-hook 'my/modus-ediff))
 
 ;; Key bindings