taffybar: tighten session and host handling

dotfiles/config/taffybar/strixi-minaj.css

@@ -0,0 +1,6 @@
+@import url("taffybar.css");
+
+/* Host-specific density tweaks for strixi-minaj. */
+.taffy-box {
+	font-size: 10pt;
+}

dotfiles/config/taffybar/taffybar.hs

@@ -265,7 +265,15 @@ defaultCssFiles = ["taffybar.css"]
 
 cssFilesByHostname :: [(String, [FilePath])]
 cssFilesByHostname =
-  [("ryzen-shine", ["ryzen-shine.css"])]
+  [ ("ryzen-shine", ["ryzen-shine.css"]),
+    ("strixi-minaj", ["strixi-minaj.css"])
+  ]
+
+compactBarHosts :: [String]
+compactBarHosts =
+  [ "ryzen-shine",
+    "strixi-minaj"
+  ]
 
 laptopHosts :: [String]
 laptopHosts =
@@ -695,9 +703,9 @@ mkSimpleTaffyConfig hostName backend cssFiles =
       barLevels = Nothing,
       barPosition = Top,
       widgetSpacing = 0,
-      barPadding = if hostName == "ryzen-shine" then 2 else 4,
+      barPadding = if hostName `elem` compactBarHosts then 2 else 4,
       barHeight =
-        if hostName == "ryzen-shine"
+        if hostName `elem` compactBarHosts
           then ScreenRatio $ 1 / 40
           else ScreenRatio $ 1 / 33,
       cssPaths = cssFiles

nixos/taffybar.nix

@@ -69,6 +69,21 @@ let
   taffybarExecCondition = pkgs.writeShellScript "taffybar-exec-condition" ''
     ${skipTaffybarInOtherShells} || exit 1
 
+    runtime_dir="''${XDG_RUNTIME_DIR:-/run/user/$(${pkgs.coreutils}/bin/id -u)}"
+    if [ "''${XDG_SESSION_TYPE:-}" = "wayland" ] || [ -n "''${WAYLAND_DISPLAY:-}" ]; then
+      if [ -z "''${WAYLAND_DISPLAY:-}" ] || [ ! -S "$runtime_dir/$WAYLAND_DISPLAY" ]; then
+        exit 1
+      fi
+    elif [ -n "''${DISPLAY:-}" ]; then
+      display_number="''${DISPLAY#:}"
+      display_number="''${display_number%%.*}"
+      if [ -z "$display_number" ] || [ ! -S "/tmp/.X11-unix/X$display_number" ]; then
+        exit 1
+      fi
+    else
+      exit 1
+    fi
+
     if [ -x /run/current-system/sw/bin/desktop_shell_ui ]; then
       exec /run/current-system/sw/bin/desktop_shell_ui exec-condition taffybar
     fi
@@ -91,6 +106,11 @@ makeEnable config "myModules.taffybar" false {
       services."status-notifier-watcher".package = pkgs.lib.mkForce
         inputs.imalison-taffybar.packages.${system}.status-notifier-item;
 
+      systemd.user.targets.tray.Unit = {
+        PartOf = [ "graphical-session.target" ];
+        StopWhenUnneeded = true;
+      };
+
       # Disable kded6's statusnotifierwatcher module so it doesn't race with
       # the Haskell status-notifier-watcher for the org.kde.StatusNotifierWatcher bus name.
       xdg.configFile."kded6rc".text = ''