Adds option to force nixvim background transparency

Author: willemml

modules/nixvim/nixvim.nix

@@ -4,32 +4,61 @@
   options,
   ...
 }: {
-  options.stylix.targets.nixvim.enable =
-    config.lib.stylix.mkEnableTarget "nixvim" (config.programs ? nixvim);
+  options.stylix.targets.nixvim = {
+    enable =
+      config.lib.stylix.mkEnableTarget "nixvim" (config.programs ? nixvim);
+    transparent_bg = {
+      main = lib.mkEnableOption "background transparency for the main NeoVim window";
+      sign_column = lib.mkEnableOption "background transparency for the NeoVim sign column";
+    };
+  };
 
   config = lib.mkIf ((config.programs ? nixvim) && config.stylix.targets.nixvim.enable) (
     lib.optionalAttrs (builtins.hasAttr "nixvim" options.programs) {
-      programs.nixvim.colorschemes.base16.customColorScheme = let
-        colors = config.lib.stylix.colors.withHashtag;
-      in {
-        base00 = colors.base00;
-        base01 = colors.base01;
-        base02 = colors.base02;
-        base03 = colors.base03;
-        base04 = colors.base04;
-        base05 = colors.base05;
-        base06 = colors.base06;
-        base07 = colors.base07;
-        base08 = colors.base08;
-        base09 = colors.base09;
-        base0A = colors.base0A;
-        base0B = colors.base0B;
-        base0C = colors.base0C;
-        base0D = colors.base0D;
-        base0E = colors.base0E;
-        base0F = colors.base0F;
+      programs.nixvim = {
+        colorschemes.base16 = {
+          customColorScheme = let
+            colors = config.lib.stylix.colors.withHashtag;
+          in {
+            base00 = colors.base00;
+            base01 = colors.base01;
+            base02 = colors.base02;
+            base03 = colors.base03;
+            base04 = colors.base04;
+            base05 = colors.base05;
+            base06 = colors.base06;
+            base07 = colors.base07;
+            base08 = colors.base08;
+            base09 = colors.base09;
+            base0A = colors.base0A;
+            base0B = colors.base0B;
+            base0C = colors.base0C;
+            base0D = colors.base0D;
+            base0E = colors.base0E;
+            base0F = colors.base0F;
+          };
+
+          enable = true;
+        };
+
+        extraConfigLuaPost = let
+          transparency_cfg = config.stylix.targets.nixvim.transparent_bg;
+          vim_cmds = lib.strings.concatLines ((lib.optionals transparency_cfg.main [
+              "highlight Normal guibg=none"
+              "highlight NonText guibg=none"
+              "highlight Normal ctermbg=none"
+              "highlight NonText ctermbg=none"
+            ])
+            ++ (lib.optionals transparency_cfg.sign_column [
+              "highlight SignColumn guibg=none"
+              "highlight SignColumn ctermbg=none"
+            ]));
+        in ''
+          vim.cmd([[
+          ${vim_cmds}
+          ]])
+        '';
       };
-      programs.nixvim.colorschemes.base16.enable = true;
     }
   );
 }