Added scroll_factor input variable to ipc output

sway/ipc-json.c

@@ -1,3 +1,4 @@
+#include <float.h>
 #include <json.h>
 #include <libevdev/libevdev.h>
 #include <stdio.h>
@@ -1002,6 +1003,17 @@ json_object *ipc_json_describe_input(struct sway_input_device *device) {
 		}
 	}
 
+	if (device->wlr_device->type == WLR_INPUT_DEVICE_POINTER) {
+		struct input_config *ic = input_device_get_config(device);
+		float scroll_factor = 1.0f;
+		if (ic != NULL && !isnan(ic->scroll_factor) && 
+				ic->scroll_factor != FLT_MIN) {
+			scroll_factor = ic->scroll_factor;
+		}
+		json_object_object_add(object, "scroll_factor", 
+				json_object_new_double(scroll_factor));
+	}
+
 	if (wlr_input_device_is_libinput(device->wlr_device)) {
 		struct libinput_device *libinput_dev;
 		libinput_dev = wlr_libinput_get_device_handle(device->wlr_device);

sway/sway-ipc.7.scd

@@ -1131,6 +1131,9 @@ following properties:
 |- xkb_active_layout_index
 :  integer
 :  (Only keyboards) The index of the active keyboard layout in use
+|- scroll_factor
+:  floating
+:  (Only pointers) Multiplier applied on scroll event values.
 |- libinput
 :  object
 :  (Only libinput devices) An object describing the current device settings.