qtile-desktop: use i3lock instead of xscreensaver

nix/home-manager/profiles/qtile-desktop.nix

@@ -35,6 +35,23 @@ let
   terminalCommand = "${pkgs.alacritty}/bin/alacritty";
   # terminalCommand = "${pkgs.roxterm}/bin/roxterm";
 
+  screenLockCommand = pkgs.writeScript "screenLock" ''
+    #!${pkgs.bash}/bin/bash
+    export PATH=${with pkgs; lib.makeBinPath [
+      xlibs.xset i3lock
+    ]}:$PATH
+
+    revert() {
+      xset dpms 0 0 0
+    }
+
+    trap revert HUP INT TERM
+    xset +dpms dpms 5 5 5
+    i3lock -n -c 000000 -e -f
+
+    revert
+  '';
+
 
   qtileConfig = pkgs.writeScript "qtile_config.py" ''
 from libqtile.config import Key, Screen, Group, Drag, Click
@@ -264,9 +281,8 @@ in {
     screen-locker = {
       enable = true;
       inactiveInterval = 7;
-      lockCmd = "${pkgs.xscreensaver}/bin/xscreensaver-command -lock";
+      lockCmd = "${screenLockCommand}";
     };
-    xscreensaver.enable = true;
     network-manager-applet.enable = true;
     syncthing.enable = true;
     gpg-agent = {
@@ -299,7 +315,6 @@ in {
     # X Tools/Libraries
     lightdm
     qtile
-    xscreensaver
     gnome3.networkmanagerapplet
     autorandr
     arandr