From f8581a5a955cc279e6c951f1b001df49adfaaf73 Mon Sep 17 00:00:00 2001
From: Chris Martin <ch.martin@gmail.com>
Date: Fri, 18 Sep 2015 02:42:09 -0700
Subject: [PATCH] synaptics: add scrollDelta option

---
 nixos/modules/services/x11/hardware/synaptics.nix | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/nixos/modules/services/x11/hardware/synaptics.nix b/nixos/modules/services/x11/hardware/synaptics.nix
index 29cc31d70a0..2981e7545e8 100644
--- a/nixos/modules/services/x11/hardware/synaptics.nix
+++ b/nixos/modules/services/x11/hardware/synaptics.nix
@@ -62,6 +62,13 @@ in {
         description = "Cursor speed factor for highest-speed finger motion.";
       };
 
+      scrollDelta = mkOption {
+        type = types.nullOr types.int;
+        default = null;
+        example = 75;
+        description = "Move distance of the finger for a scroll event.";
+      };
+
       twoFingerScroll = mkOption {
         type = types.bool;
         default = false;
@@ -191,7 +198,9 @@ in {
           ${optionalString cfg.palmDetect ''Option "PalmDetect" "1"''}
           ${optionalString (cfg.palmMinWidth != null) ''Option "PalmMinWidth" "${toString cfg.palmMinWidth}"''}
           ${optionalString (cfg.palmMinZ != null) ''Option "PalmMinZ" "${toString cfg.palmMinZ}"''}
-          ${if cfg.horizontalScroll then "" else ''Option "HorizScrollDelta" "0"''}
+          ${optionalString (cfg.scrollDelta != null) ''Option "VertScrollDelta" "${toString cfg.scrollDelta}"''}
+          ${if !cfg.horizontalScroll then ''Option "HorizScrollDelta" "0"''
+            else (optionalString (cfg.scrollDelta != null) ''Option "HorizScrollDelta" "${toString cfg.scrollDelta}"'')}
           ${cfg.additionalOptions}
         EndSection
       '';