From d18b85c88ae1b4c89adca042a656d4be0342c436 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Exp=C3=B3sito?= <jose.exposito89@gmail.com>
Date: Mon, 20 Sep 2021 19:47:03 +0200
Subject: [PATCH] backend/libinput: handle high-res scroll events

Receive high-resolution scroll events from libinput and emit the
appropiate wlr_pointer signal.
---
 backend/libinput/events.c  | 14 ++++++++++++
 backend/libinput/pointer.c | 45 ++++++++++++++++++++++++++++++++++++++
 include/backend/libinput.h |  6 +++++
 3 files changed, 65 insertions(+)

diff --git a/backend/libinput/events.c b/backend/libinput/events.c
index 66773a814..ce208eca0 100644
--- a/backend/libinput/events.c
+++ b/backend/libinput/events.c
@@ -262,6 +262,20 @@ void handle_libinput_event(struct wlr_libinput_backend *backend,
 		handle_pointer_axis(event, libinput_dev);
 #endif
 		break;
+#if LIBINPUT_HAS_SCROLL_VALUE120
+	case LIBINPUT_EVENT_POINTER_SCROLL_WHEEL:
+		handle_pointer_axis_value120(event, libinput_dev,
+				WLR_AXIS_SOURCE_WHEEL);
+		break;
+	case LIBINPUT_EVENT_POINTER_SCROLL_FINGER:
+		handle_pointer_axis_value120(event, libinput_dev,
+				WLR_AXIS_SOURCE_FINGER);
+		break;
+	case LIBINPUT_EVENT_POINTER_SCROLL_CONTINUOUS:
+		handle_pointer_axis_value120(event, libinput_dev,
+				WLR_AXIS_SOURCE_CONTINUOUS);
+		break;
+#endif
 	case LIBINPUT_EVENT_TOUCH_DOWN:
 		handle_touch_down(event, libinput_dev);
 		break;
diff --git a/backend/libinput/pointer.c b/backend/libinput/pointer.c
index 2e799df63..a9a5df563 100644
--- a/backend/libinput/pointer.c
+++ b/backend/libinput/pointer.c
@@ -141,6 +141,51 @@ void handle_pointer_axis(struct libinput_event *event,
 	wlr_signal_emit_safe(&wlr_dev->pointer->events.frame, wlr_dev->pointer);
 }
 
+#if LIBINPUT_HAS_SCROLL_VALUE120
+void handle_pointer_axis_value120(struct libinput_event *event,
+		struct libinput_device *device,
+		enum wlr_axis_source source) {
+	struct wlr_input_device *wlr_dev =
+		get_appropriate_device(WLR_INPUT_DEVICE_POINTER, device);
+	if (!wlr_dev) {
+		wlr_log(WLR_DEBUG, "Got a pointer event for a device with no pointers?");
+		return;
+	}
+	struct libinput_event_pointer *pevent =
+		libinput_event_get_pointer_event(event);
+	struct wlr_event_pointer_axis_value120 wlr_event = { 0 };
+	wlr_event.device = wlr_dev;
+	wlr_event.time_msec =
+		usec_to_msec(libinput_event_pointer_get_time_usec(pevent));
+	wlr_event.source = source;
+
+	const enum libinput_pointer_axis axes[] = {
+		LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL,
+		LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL,
+	};
+	for (size_t i = 0; i < sizeof(axes) / sizeof(axes[0]); ++i) {
+		if (libinput_event_pointer_has_axis(pevent, axes[i])) {
+			switch (axes[i]) {
+			case LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL:
+				wlr_event.orientation = WLR_AXIS_ORIENTATION_VERTICAL;
+				break;
+			case LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL:
+				wlr_event.orientation = WLR_AXIS_ORIENTATION_HORIZONTAL;
+				break;
+			}
+			wlr_event.delta =
+				libinput_event_pointer_get_scroll_value(pevent, axes[i]);
+			if (source == WLR_AXIS_SOURCE_WHEEL) {
+				wlr_event.delta_value120 =
+					libinput_event_pointer_get_scroll_value_v120(pevent, axes[i]);
+			}
+			wlr_signal_emit_safe(&wlr_dev->pointer->events.axis_value120, &wlr_event);
+		}
+	}
+	wlr_signal_emit_safe(&wlr_dev->pointer->events.frame, wlr_dev->pointer);
+}
+#endif
+
 void handle_pointer_swipe_begin(struct libinput_event *event,
 		struct libinput_device *libinput_dev) {
 	struct wlr_input_device *wlr_dev =
diff --git a/include/backend/libinput.h b/include/backend/libinput.h
index 06e23a17a..142c0e3f4 100644
--- a/include/backend/libinput.h
+++ b/include/backend/libinput.h
@@ -7,6 +7,7 @@
 #include <wlr/backend/libinput.h>
 #include <wlr/interfaces/wlr_input_device.h>
 #include <wlr/types/wlr_input_device.h>
+#include <wlr/types/wlr_pointer.h>
 
 struct wlr_libinput_backend {
 	struct wlr_backend backend;
@@ -54,6 +55,11 @@ void handle_pointer_button(struct libinput_event *event,
 		struct libinput_device *device);
 void handle_pointer_axis(struct libinput_event *event,
 		struct libinput_device *device);
+#if LIBINPUT_HAS_SCROLL_VALUE120
+void handle_pointer_axis_value120(struct libinput_event *event,
+		struct libinput_device *device,
+		enum wlr_axis_source source);
+#endif
 void handle_pointer_swipe_begin(struct libinput_event *event,
 		struct libinput_device *device);
 void handle_pointer_swipe_update(struct libinput_event *event,