home: wm: screen-lock: add 'notify.delay' setting

home/wm/default.nix

@@ -61,7 +61,26 @@ in
         };
       };
 
-      notify = my.mkDisableOption "Notify when about to lock the screen";
+      notify = {
+        enable = my.mkDisableOption "Notify when about to lock the screen";
+
+        delay = mkOption {
+          type = with types;
+            addCheck int (x:
+              let
+                cfg = config.my.home.wm.screen-lock.notify;
+                cornerCfg = config.my.home.wm.screen-lock.cornerLock;
+              in
+              (cfg.enable && cornerCfg.enable) -> cornerCfg.delay >= x);
+          default = 5;
+          example = 15;
+          description = ''
+            How many seconds in advance should there be a notification.
+            This value must be at lesser than or equal to `cornerLock.delay`
+            when both options are enabled.
+          '';
+        };
+      };
 
       timeout = mkOption {
         type = types.ints.between 1 60;

home/wm/screen-lock.nix

@@ -1,6 +1,14 @@
 { config, lib, pkgs, ... }:
 let
   cfg = config.my.home.wm.screen-lock;
+
+  notficationCmd =
+    let
+      duration = toString (cfg.notify.delay * 1000);
+      notifyCmd = "${pkgs.libnotify}/bin/notify-send -u critical -t ${duration}";
+    in
+    # Needs to be surrounded by quotes for systemd to launch it correctly
+    ''"${notifyCmd} -- 'Locking in ${toString cfg.notify.delay} seconds'"'';
 in
 {
   config = lib.mkIf cfg.enable {
@@ -19,11 +27,11 @@ in
         "${toString cfg.cornerLock.delay}"
         "-corners"
         "+00-"
-      ] ++ lib.optionals cfg.notify [
+      ] ++ lib.optionals cfg.notify.enable [
         "-notify"
-        "5"
+        "${toString cfg.notify.delay}"
         "-notifier"
-        ''"${pkgs.libnotify}/bin/notify-send -u critical -t 5000 -- 'Locking in 5 seconds'"''
+        notficationCmd
       ];
     };
   };