From ab7790b983d85a3de9d9dffeb02a919aded6eba6 Mon Sep 17 00:00:00 2001
From: Evie Litherland-Smith <evie.litherland-smith@ukaea.uk>
Date: Thu, 20 Jun 2024 16:25:50 +0100
Subject: [PATCH] Move Emacs font settings to theme, which is then loaded in
 extraConfig

---
 programs/emacs/default.nix | 33 ++++++++++++++++++++++-----------
 1 file changed, 22 insertions(+), 11 deletions(-)

diff --git a/programs/emacs/default.nix b/programs/emacs/default.nix
index 5123599..5d700d7 100644
--- a/programs/emacs/default.nix
+++ b/programs/emacs/default.nix
@@ -23,20 +23,31 @@
     enable = true;
     package = pkgs.emacs29-pgtk;
     extraConfig = let
-      shell = "${pkgs.zsh}/bin/zsh";
-      font = "${fonts.monospace.name}-${toString fonts.sizes.applications}";
       fixed-font-family = "${fonts.monospace.name}";
       variable-font-family = "${fonts.sansSerif.name}";
-      alpha = "100"; # "90";
+      custom-theme-name = "nix";
+      custom-theme = pkgs.writeTextFile {
+        name = "custom-emacs-theme";
+        destination = "/${custom-theme-name}-theme.el";
+        text = ''
+          (deftheme ${custom-theme-name}
+            "Use Nix customised fonts for main faces")
+
+          (custom-theme-set-faces
+           '${custom-theme-name}
+           '(default ((t (:family "${fixed-font-family}" :height 120))))
+           '(fixed-pitch ((t (:family "${fixed-font-family}"))))
+           '(fixed-pitch-serif ((t (:family "${fixed-font-family}"))))
+           '(variable-pitch ((t (:family "${variable-font-family}")))))
+
+          (provide-theme '${custom-theme-name})
+        '';
+      };
+      custom-theme-hash = builtins.hashFile "sha256" "${custom-theme}/${custom-theme-name}-theme.el";
     in ''
-      (customize-set-variable 'shell-file-name "${shell}")
-      (add-to-list 'initial-frame-alist '(font . "${font}"))
-      (add-to-list 'default-frame-alist '(font . "${font}"))
-      (set-face-attribute 'fixed-pitch nil :family "${fixed-font-family}")
-      (set-face-attribute 'fixed-pitch-serif nil :family "${fixed-font-family}")
-      (set-face-attribute 'variable-pitch nil :family "${variable-font-family}")
-      (add-to-list 'initial-frame-alist '(alpha-background . ${alpha}))
-      (add-to-list 'default-frame-alist '(alpha-background . ${alpha}))
+      (add-to-list 'custom-theme-load-path "${custom-theme}")
+      (add-to-list 'custom-safe-themes "${custom-theme-hash}")
+      (load-theme '${custom-theme-name})
     '';
     extraPackages = epkgs:
       with epkgs; [