nixos/surf-display: Add kiosk display manager session

nixos/modules/services/x11/desktop-managers/default.nix

@@ -20,7 +20,7 @@ in
   imports = [
     ./none.nix ./xterm.nix ./xfce.nix ./plasma5.nix ./lumina.nix
     ./lxqt.nix ./enlightenment.nix ./gnome3.nix ./kodi.nix ./maxx.nix
-    ./mate.nix ./pantheon.nix
+    ./mate.nix ./pantheon.nix ./surf-display.nix
   ];
 
   options = {

nixos/modules/services/x11/desktop-managers/surf-display.nix

@@ -0,0 +1,127 @@
+{ config, lib, pkgs, ... }:
+
+with lib;
+
+let
+  cfg = config.services.xserver.desktopManager.surf-display;
+
+  surfDisplayConf = ''
+    # Surf Kiosk Display: Wrap around surf browser and turn your
+    # system into a browser screen in KIOSK-mode.
+
+    # default download URI for all display screens if not configured individually
+    DEFAULT_WWW_URI="${cfg.defaultWwwUri}"
+
+    # Enforce fixed resolution for all displays (default: not set):
+    #DEFAULT_RESOLUTION="1920x1080"
+
+    # HTTP proxy URL, if needed (default: not set).
+    #HTTP_PROXY_URL="http://webcache:3128"
+
+    # Setting for internal inactivity timer to restart surf-display
+    # if the user goes inactive/idle.
+    INACTIVITY_INTERVAL="${builtins.toString cfg.inactivityInterval}"
+
+    # log to syslog instead of .xsession-errors
+    LOG_TO_SYSLOG="yes"
+
+    # Launch pulseaudio daemon if not already running.
+    WITH_PULSEAUDIO="yes"
+
+    # screensaver settings, see "man 1 xset" for possible options
+    SCREENSAVER_SETTINGS="${cfg.screensaverSettings}"
+
+    # disable right and middle pointer device click in browser sessions while keeping
+    # scrolling wheels' functionality intact... (consider "pointer" subcommand on
+    # xmodmap man page for details).
+    POINTER_BUTTON_MAP="${cfg.pointerButtonMap}"
+
+    # Hide idle mouse pointer.
+    HIDE_IDLE_POINTER="${cfg.hideIdlePointer}"
+
+    ${cfg.extraConfig}
+  '';
+
+in {
+  options = {
+    services.xserver.desktopManager.surf-display = {
+      enable = mkEnableOption "surf-display as a kiosk browser session";
+
+      defaultWwwUri = mkOption {
+        type = types.string;
+        default = "${pkgs.surf-display}/share/surf-display/empty-page.html";
+        example = "https://www.example.com/";
+        description = "Default URI to display.";
+      };
+
+      inactivityInterval = mkOption {
+        type = types.int;
+        default = 300;
+        example = "0";
+        description = ''
+          Setting for internal inactivity timer to restart surf-display if the
+          user goes inactive/idle to get a fresh session for the next user of
+          the kiosk.
+
+          If this value is set to zero, the whole feature of restarting due to
+          inactivity is disabled.
+        '';
+      };
+
+      screensaverSettings = mkOption {
+        type = types.string;
+        default = "";
+        description = ''
+          Screensaver settings, see <literal>man 1 xset</literal> for possible options.
+        '';
+      };
+
+      pointerButtonMap = mkOption {
+        type = types.string;
+        default = "1 0 0 4 5 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0";
+        description = ''
+          Disable right and middle pointer device click in browser sessions
+          while keeping scrolling wheels' functionality intact. See pointer
+          subcommand on <literal>man xmodmap</literal> for details.
+        '';
+      };
+
+      hideIdlePointer = mkOption {
+        type = types.string;
+        default = "yes";
+        example = "no";
+        description = "Hide idle mouse pointer.";
+      };
+
+      extraConfig = mkOption {
+        type = types.string;
+        default = "";
+        example = ''
+          # Enforce fixed resolution for all displays (default: not set):
+          DEFAULT_RESOLUTION="1920x1080"
+
+          # HTTP proxy URL, if needed (default: not set).
+          HTTP_PROXY_URL="http://webcache:3128"
+
+          # Configure individual display screens with host specific parameters:
+          DISPLAYS['display-host-0']="www_uri=https://www.displayserver.comany.net/display-1/index.html"
+          DISPLAYS['display-host-1']="www_uri=https://www.displayserver.comany.net/display-2/index.html"
+          DISPLAYS['display-host-2']="www_uri=https://www.displayserver.comany.net/display-3/index.html|res=1920x1280"
+          DISPLAYS['display-host-3']="www_uri=https://www.displayserver.comany.net/display-4/index.html"|res=1280x1024"
+          DISPLAYS['display-host-local-file']="www_uri=file:///usr/share/doc/surf-display/empty-page.html"
+        '';
+        description = ''
+          Extra configuration options to append to <literal>/etc/default/surf-display</literal>.
+        '';
+      };
+    };
+  };
+
+  config = mkIf cfg.enable {
+    services.xserver.displayManager.extraSessionFilePackages = [
+      pkgs.surf-display
+    ];
+
+    environment.etc."default/surf-display".text = surfDisplayConf;
+  };
+}