config: allow setting per-device scroll wheel speed

jay-config/src/_private/client.rs

@@ -532,6 +532,10 @@ impl Client {
         self.send(&ClientMessage::SetTransformMatrix { device, matrix })
     }
 
+    pub fn set_px_per_wheel_scroll(&self, device: InputDevice, px: f64) {
+        self.send(&ClientMessage::SetPxPerWheelScroll { device, px })
+    }
+
     pub fn device_name(&self, device: InputDevice) -> String {
         let res = self.send_with_response(&ClientMessage::GetDeviceName { device });
         get_response!(res, String::new(), GetDeviceName { name });

jay-config/src/_private/ipc.rs

@@ -270,6 +270,10 @@ pub enum ClientMessage<'a> {
     SetFont {
         font: &'a str,
     },
+    SetPxPerWheelScroll {
+        device: InputDevice,
+        px: f64,
+    },
 }
 
 #[derive(Encode, Decode, Debug)]