feat(niri,xbacklight): Brightness control

modules/home/users/crumb/niri.nix

@@ -73,7 +73,7 @@ in {
 
         spawn-at-startup =
           [{ command = [ "${pkgs.swaynotificationcenter}/bin/swaync" ]; }
-           { command = [ "${pkgs.gammastep}/bin/gammastep" "-o" "-O" "4000k"
+           { command = [ (lib.getExe pkgs.gammastep) "-o" "-O" "4000k"
                          "-b" "0.9:0.9" "-l" "0:0"]; }]
           ++ lib.optional
             (! builtins.isNull cfg.wallpaper)
@@ -175,7 +175,7 @@ in {
               { title = "Discord.*@"; }
             ];
             excludes = [
-              # ... except when explicitly targeting the window.
+              # ...except when explicitly targeting the window.
               { is-window-cast-target = true; }
             ];
             block-out-from = "screen-capture";
@@ -226,8 +226,9 @@ in {
         binds = {
           "Mod+Q".action.close-window = [];
           "Mod+Shift+Q".action.quit = [];
-          "Mod+Ctrl+L".action.spawn = ["${pkgs.swaylock}/bin/swaylock"];
-          "Mod+D".action.spawn = ["${pkgs.fuzzel}/bin/fuzzel"];
+          "Mod+Ctrl+L".action.spawn = [ (lib.getExe pkgs.swaylock) ];
+          "Mod+D".action.spawn = [ (lib.getExe pkgs.fuzzel) ];
+          "XF86LaunchB".action.spawn = [ (lib.getExe pkgs.fuzzel) ];
           "Mod+Shift+Slash".action.show-hotkey-overlay = [];
 
           # Powers off the monitors.  They will be powered back on upon any
@@ -279,7 +280,12 @@ in {
           "Mod+Shift+J".action.move-window-down = []; 
           "Mod+Shift+K".action.move-window-up = []; 
           "Mod+Shift+L".action.move-column-right = []; 
-            
+
+          "XF86MonBrightnessDown".action.spawn =
+            ["${lib.getExe pkgs.acpilight}" "-dec" "10"];
+          "XF86MonBrightnessUp".action.spawn =
+            ["${lib.getExe pkgs.acpilight}" "-inc" "10"];
+
           "Mod+1".action.focus-workspace = [1];
           "Mod+2".action.focus-workspace = [2];
           "Mod+3".action.focus-workspace = [3];

modules/nixos/xbacklight-permissions.nix

@@ -0,0 +1,35 @@
+{ config, lib, pkgs, ... }:
+
+let cfg = config.sydnix.xbacklight-permissions;
+in {
+  options.sydnix.xbacklight-permissions = {
+    enable =
+      lib.mkEnableOption "the user group that is allowed to use xbacklight";
+    group = lib.mkOption {
+      type = lib.types.str;
+      default = "xbacklight";
+    };
+    paths = lib.mkOption {
+      type = with lib.types; listOf str;
+      default = [
+        "/sys/class/backlight/intel_backlight/brightness"
+      ];
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    users.groups.${cfg.group} = {};
+
+    systemd.tmpfiles.settings."50-xbacklight" =
+      lib.mergeAttrsList
+        (builtins.map
+          (path: {
+            ${path}.z = {
+              inherit (cfg) group;
+              mode = "0664";
+              user = "root";
+            };
+          })
+          cfg.paths);
+  };
+}