add touchpad config

modules/default.nix

@@ -14,6 +14,7 @@
     system/gaming.nix
 
     desktop/plasma.nix
+    desktop/touchpad.nix
     desktop/pulseaudio.nix
   ];
 }

modules/desktop/touchpad.nix

@@ -0,0 +1,177 @@
+{ config, lib, pkgs, modulesPath, ... }:
+
+# Touch pad configuration interface
+
+let
+  scrollMethods = {
+    twoFingers = 1;
+    touchPadEdges = 2;
+  };
+  rightClickMethods = {
+    bottomRight = 1;
+    twoFingers = 2;
+  };
+  accelerationProfiles = {
+    none = 1;
+    default = 2;
+  };
+in
+{
+  # Copy of https://github.com/nix-community/plasma-manager/blob/trunk/modules/input.nix#L69
+  options.lumpiasty.touchPad = {
+    enable = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = true;
+      description = ''
+        Whether to enable the touchpad.
+      '';
+    };
+    name = lib.mkOption {
+      type = with lib.types; nullOr str;
+      default = null;
+      example = "PNP0C50:00 0911:5288 Touchpad";
+      description = ''
+        The name of the touchpad.
+
+        This can be found by looking at the `Name` attribute in the section in
+        the `/proc/bus/input/devices` path belonging to the touchpad.
+      '';
+    };
+    vendorId = lib.mkOption {
+      type = with lib.types; nullOr str;
+      default = null;
+      example = "0911";
+      description = ''
+        The vendor ID of the touchpad.
+
+        This can be found by looking at the `Vendor` attribute in the section in
+        the `/proc/bus/input/devices` path belonging to the touchpad.
+      '';
+    };
+    productId = lib.mkOption {
+      type = with lib.types; nullOr str;
+      default = null;
+      example = "5288";
+      description = ''
+        The product ID of the touchpad.
+
+        This can be found by looking at the `Product` attribute in the section in
+        the `/proc/bus/input/devices` path belonging to the touchpad.
+      '';
+    };
+    disableWhileTyping = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = true;
+      description = ''
+        Whether to disable the touchpad while typing.
+      '';
+    };
+    leftHanded = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = false;
+      description = ''
+        Whether to swap the left and right buttons.
+      '';
+    };
+    middleButtonEmulation = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = false;
+      description = ''
+        Whether to enable middle mouse click emulation by pressing the left and right buttons at the same time.
+        Activating this increases the click latency by 50ms.
+      '';
+    };
+    pointerSpeed = lib.mkOption {
+      type = with lib.types; nullOr (numbers.between (-1) 1);
+      default = null;
+      example = "0";
+      description = ''
+        How fast the pointer moves.
+      '';
+    };
+    accelerationProfile = lib.mkOption {
+      type = with lib.types; nullOr (enum (builtins.attrNames accelerationProfiles));
+      default = null;
+      example = "none";
+      description = "Set the touchpad acceleration profile.";
+      apply = profile: if (profile == null) then null else accelerationProfiles."${profile}";
+    };
+    naturalScroll = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = true;
+      description = ''
+        Whether to enable natural scrolling for the touchpad.
+      '';
+    };
+    tapToClick = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = true;
+      description = ''
+        Whether to enable tap-to-click for the touchpad.
+      '';
+    };
+    tapAndDrag = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = true;
+      description = ''
+        Whether to enable tap-and-drag for the touchpad.
+      '';
+    };
+    tapDragLock = lib.mkOption {
+      type = with lib.types; nullOr bool;
+      default = null;
+      example = true;
+      description = ''
+        Whether to enable the tap-and-drag lock for the touchpad.
+      '';
+    };
+    scrollMethod = lib.mkOption {
+      type = with lib.types; nullOr (enum (builtins.attrNames scrollMethods));
+      default = null;
+      example = "touchPadEdges";
+      description = ''
+        Configure how scrolling is performed on the touchpad.
+      '';
+      apply = method: if (method == null) then null else scrollMethods."${method}";
+    };
+    scrollSpeed = lib.mkOption {
+      type = with lib.types; nullOr (numbers.between 0.1 20);
+      default = null;
+      example = 0.1;
+      description = ''
+        Configure the scrolling speed of the touchpad. Lower is slower.
+        If unset, KDE Plasma will default to 0.3.
+      '';
+    };
+    rightClickMethod = lib.mkOption {
+      type = with lib.types; nullOr (enum (builtins.attrNames rightClickMethods));
+      default = null;
+      example = "twoFingers";
+      description = ''
+        Configure how right-clicking is performed on the touchpad.
+      '';
+      apply = method: if (method == null) then null else rightClickMethods."${method}";
+    };
+    twoFingerTap = lib.mkOption {
+      type =
+        with lib.types;
+        nullOr (enum [
+          "rightClick"
+          "middleClick"
+        ]);
+      default = null;
+      example = "twoFingers";
+      description = ''
+        Configure what a two-finger tap maps to on the touchpad.
+      '';
+      apply = v: if (v == null) then null else (v == "middleClick");
+    };
+  };
+}