waybar: use config.wayland.systemd.target

Also add `ConditionEnvironment`.

modules/programs/waybar.nix

@@ -2,7 +2,8 @@
 
 let
   inherit (lib)
-    all filterAttrs hasAttr isStorePath literalExpression optionalAttrs types;
+    all filterAttrs hasAttr isStorePath literalExpression optionalAttrs optional
+    types;
   inherit (lib.options) mkEnableOption mkOption;
   inherit (lib.modules) mkIf mkMerge;
 
@@ -198,7 +199,8 @@ in {
 
     systemd.target = mkOption {
       type = str;
-      default = "graphical-session.target";
+      default = config.wayland.systemd.target;
+      defaultText = literalExpression "config.wayland.systemd.target";
       example = "sway-session.target";
       description = ''
         The systemd target that will automatically start the Waybar service.
@@ -308,8 +310,13 @@ in {
           Description =
             "Highly customizable Wayland bar for Sway and Wlroots based compositors.";
           Documentation = "https://github.com/Alexays/Waybar/wiki";
-          PartOf = [ "graphical-session.target" ];
-          After = [ "graphical-session-pre.target" ];
+          PartOf = [ cfg.systemd.target ];
+          After = [ cfg.systemd.target ];
+          ConditionEnvironment = "WAYLAND_DISPLAY";
+          X-Restart-Triggers = optional (settings != [ ])
+            "${config.xdg.configFile."waybar/config".source}"
+            ++ optional (cfg.style != null)
+            "${config.xdg.configFile."waybar/style.css".source}";
         };
 
         Service = {

tests/modules/programs/waybar/deprecated-modules-option.nix

@@ -1,6 +1,4 @@
-{ config, lib, pkgs, ... }:
-
-with lib;
+{ config, ... }:
 
 {
   config = {

tests/modules/programs/waybar/settings-complex.nix

@@ -1,6 +1,4 @@
-{ config, lib, pkgs, ... }:
-
-with lib;
+{ config, ... }:
 
 {
   config = {

tests/modules/programs/waybar/settings-with-attrs.nix

@@ -1,7 +1,5 @@
 { config, lib, pkgs, ... }:
 
-with lib;
-
 {
   config = {
     home.stateVersion = "21.11";

tests/modules/programs/waybar/styling.nix

@@ -1,6 +1,4 @@
-{ config, lib, pkgs, ... }:
-
-with lib;
+{ config, ... }:
 
 {
   config = {

tests/modules/programs/waybar/systemd-with-graphical-session-target.nix

@@ -1,6 +1,4 @@
-{ config, lib, pkgs, ... }:
-
-with lib;
+{ config, ... }:
 
 {
   config = {

tests/modules/programs/waybar/systemd-with-graphical-session-target.service

@@ -8,7 +8,8 @@ KillMode=mixed
 Restart=on-failure
 
 [Unit]
-After=graphical-session-pre.target
+After=sway-session.target
+ConditionEnvironment=WAYLAND_DISPLAY
 Description=Highly customizable Wayland bar for Sway and Wlroots based compositors.
 Documentation=https://github.com/Alexays/Waybar/wiki
-PartOf=graphical-session.target
+PartOf=sway-session.target