wheel: centralize wheel handling

Move the logic to handle wheels to its own file.
Refactor, no functional changes.

Signed-off-by: José Expósito <jose.exposito89@gmail.com>

4 files changed, 244 insertions, 160 deletions

diff --git a/meson.build b/meson.build
index 4269e39d..a423a962 100644
--- a/meson.build
+++ b/meson.build
@@ -368,6 +368,7 @@ src_libinput = src_libfilter + [
 	'src/evdev-tablet-pad.c',
 	'src/evdev-tablet-pad.h',
 	'src/evdev-tablet-pad-leds.c',
+	'src/evdev-wheel.c',
 	'src/path-seat.c',
 	'src/udev-seat.c',
 	'src/udev-seat.h',
diff --git a/src/evdev-fallback.c b/src/evdev-fallback.c
index 785ac6e2..19ae4a0a 100644
--- a/src/evdev-fallback.c
+++ b/src/evdev-fallback.c
@@ -68,18 +68,8 @@ fallback_notify_physical_button(struct fallback_dispatch *dispatch,
 				int button,
 				enum libinput_button_state state)
 {
-	if (button == BTN_MIDDLE)
-		dispatch->wheel.is_inhibited = (state == LIBINPUT_BUTTON_STATE_PRESSED);
-
-	/* Lenovo TrackPoint Keyboard II sends its own scroll events when its
-	 * trackpoint is moved while the middle button is pressed.
-	 * Do not inhibit the scroll events.
-	 * https://gitlab.freedesktop.org/libinput/libinput/-/issues/651
-	 */
-	if (evdev_device_has_model_quirk(device,
-					 QUIRK_MODEL_LENOVO_TRACKPOINT_KEYBOARD_2))
-		dispatch->wheel.is_inhibited = false;
-
+	fallback_wheel_notify_physical_button(dispatch, device, time,
+					      button, state);
 	evdev_pointer_notify_physical_button(device, time, button, state);
 }
 
@@ -102,10 +92,10 @@ fallback_interface_get_switch_state(struct evdev_dispatch *evdev_dispatch,
 			LIBINPUT_SWITCH_STATE_OFF;
 }
 
-static inline void
-normalize_delta(struct evdev_device *device,
-		const struct device_coords *delta,
-		struct normalized_coords *normalized)
+void
+fallback_normalize_delta(struct evdev_device *device,
+			 const struct device_coords *delta,
+			 struct normalized_coords *normalized)
 {
 	normalized->x = delta->x * DEFAULT_MOUSE_DPI / (double)device->dpi;
 	normalized->y = delta->y * DEFAULT_MOUSE_DPI / (double)device->dpi;
@@ -195,7 +185,7 @@ fallback_flush_relative_motion(struct fallback_dispatch *dispatch,
 
 	fallback_rotate_relative(dispatch, device);
 
-	normalize_delta(device, &dispatch->rel, &unaccel);
+	fallback_normalize_delta(device, &dispatch->rel, &unaccel);
 	raw.x = dispatch->rel.x;
 	raw.y = dispatch->rel.y;
 	dispatch->rel.x = 0;
@@ -224,110 +214,6 @@ fallback_flush_relative_motion(struct fallback_dispatch *dispatch,
 }
 
 static void
-fallback_flush_wheels(struct fallback_dispatch *dispatch,
-		      struct evdev_device *device,
-		      uint64_t time)
-{
-	struct normalized_coords wheel_degrees = { 0.0, 0.0 };
-	struct discrete_coords discrete = { 0.0, 0.0 };
-	struct wheel_v120 v120 = { 0.0, 0.0 };
-
-	if (!(device->seat_caps & EVDEV_DEVICE_POINTER))
-		return;
-
-	if (!dispatch->wheel.emulate_hi_res_wheel &&
-	    !dispatch->wheel.hi_res_event_received &&
-	    (dispatch->wheel.lo_res.x != 0 || dispatch->wheel.lo_res.y != 0)) {
-		evdev_log_bug_kernel(device,
-				     "device supports high-resolution scroll but only low-resolution events have been received.\n"
-				     "See %s/incorrectly-enabled-hires.html for details\n",
-				     HTTP_DOC_LINK);
-		dispatch->wheel.emulate_hi_res_wheel = true;
-		dispatch->wheel.hi_res.x = dispatch->wheel.lo_res.x * 120;
-		dispatch->wheel.hi_res.y = dispatch->wheel.lo_res.y * 120;
-	}
-
-	if (dispatch->wheel.is_inhibited) {
-		dispatch->wheel.hi_res.x = 0;
-		dispatch->wheel.hi_res.y = 0;
-		dispatch->wheel.lo_res.x = 0;
-		dispatch->wheel.lo_res.y = 0;
-		return;
-	}
-
-	if (device->model_flags & EVDEV_MODEL_LENOVO_SCROLLPOINT) {
-		struct normalized_coords unaccel = { 0.0, 0.0 };
-
-		dispatch->wheel.hi_res.y *= -1;
-		normalize_delta(device, &dispatch->wheel.hi_res, &unaccel);
-		evdev_post_scroll(device,
-				  time,
-				  LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS,
-				  &unaccel);
-		dispatch->wheel.hi_res.x = 0;
-		dispatch->wheel.hi_res.y = 0;
-
-		return;
-	}
-
-	if (dispatch->wheel.hi_res.y != 0) {
-		int value = dispatch->wheel.hi_res.y;
-
-		v120.y = -1 * value;
-		wheel_degrees.y = -1 * value/120.0 * device->scroll.wheel_click_angle.y;
-		evdev_notify_axis_wheel(
-			device,
-			time,
-			bit(LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL),
-			&wheel_degrees,
-			&v120);
-		dispatch->wheel.hi_res.y = 0;
-	}
-
-	if (dispatch->wheel.lo_res.y != 0) {
-		int value = dispatch->wheel.lo_res.y;
-
-		wheel_degrees.y = -1 * value * device->scroll.wheel_click_angle.y;
-		discrete.y = -1 * value;
-		evdev_notify_axis_legacy_wheel(
-			device,
-			time,
-			bit(LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL),
-			&wheel_degrees,
-			&discrete);
-		dispatch->wheel.lo_res.y = 0;
-	}
-
-	if (dispatch->wheel.hi_res.x != 0) {
-		int value = dispatch->wheel.hi_res.x;
-
-		v120.x = value;
-		wheel_degrees.x = value/120.0 * device->scroll.wheel_click_angle.x;
-		evdev_notify_axis_wheel(
-			device,
-			time,
-			bit(LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL),
-			&wheel_degrees,
-			&v120);
-		dispatch->wheel.hi_res.x = 0;
-	}
-
-	if (dispatch->wheel.lo_res.x != 0) {
-		int value = dispatch->wheel.lo_res.x;
-
-		wheel_degrees.x = value * device->scroll.wheel_click_angle.x;
-		discrete.x = value;
-		evdev_notify_axis_legacy_wheel(
-			device,
-			time,
-			bit(LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL),
-			&wheel_degrees,
-			&discrete);
-		dispatch->wheel.lo_res.x = 0;
-	}
-}
-
-static void
 fallback_flush_absolute_motion(struct fallback_dispatch *dispatch,
 			       struct evdev_device *device,
 			       uint64_t time)
@@ -895,29 +781,9 @@ fallback_process_relative(struct fallback_dispatch *dispatch,
 		dispatch->rel.y += e->value;
 		dispatch->pending_event |= EVDEV_RELATIVE_MOTION;
 		break;
-	case REL_WHEEL:
-		dispatch->wheel.lo_res.y += e->value;
-		if (dispatch->wheel.emulate_hi_res_wheel)
-			dispatch->wheel.hi_res.y += e->value * 120;
-		dispatch->pending_event |= EVDEV_WHEEL;
-		break;
-	case REL_HWHEEL:
-		dispatch->wheel.lo_res.x += e->value;
-		if (dispatch->wheel.emulate_hi_res_wheel)
-			dispatch->wheel.hi_res.x += e->value * 120;
-		dispatch->pending_event |= EVDEV_WHEEL;
-		break;
-	case REL_WHEEL_HI_RES:
-		dispatch->wheel.hi_res.y += e->value;
-		dispatch->wheel.hi_res_event_received = true;
-		dispatch->pending_event |= EVDEV_WHEEL;
-		break;
-	case REL_HWHEEL_HI_RES:
-		dispatch->wheel.hi_res.x += e->value;
-		dispatch->wheel.hi_res_event_received = true;
-		dispatch->pending_event |= EVDEV_WHEEL;
-		break;
 	}
+
+	fallback_wheel_process_relative(dispatch, device, e, time);
 }
 
 static inline void
@@ -1079,7 +945,7 @@ fallback_handle_state(struct fallback_dispatch *dispatch,
 	if (need_touch_frame)
 		touch_notify_frame(&device->base, time);
 
-	fallback_flush_wheels(dispatch, device, time);
+	fallback_wheel_handle_state(dispatch, device, time);
 
 	/* Buttons and keys */
 	if (dispatch->pending_event & EVDEV_KEY) {
@@ -1827,22 +1693,7 @@ fallback_dispatch_create(struct libinput_device *libinput_device)
 					want_config);
 	}
 
-	/* On kernel < 5.0 we need to emulate high-resolution
-	   wheel scroll events */
-	if ((libevdev_has_event_code(device->evdev,
-				     EV_REL,
-				     REL_WHEEL) &&
-	     !libevdev_has_event_code(device->evdev,
-				      EV_REL,
-				      REL_WHEEL_HI_RES)) ||
-	    (libevdev_has_event_code(device->evdev,
-				     EV_REL,
-				     REL_HWHEEL) &&
-	     !libevdev_has_event_code(device->evdev,
-				      EV_REL,
-				     REL_HWHEEL_HI_RES)))
-	    dispatch->wheel.emulate_hi_res_wheel = true;
-
+	fallback_init_wheel(dispatch, device);
 	fallback_init_debounce(dispatch);
 	fallback_init_arbitration(dispatch, device);
 
diff --git a/src/evdev-fallback.h b/src/evdev-fallback.h
index e8c20631..3b3e3188 100644
--- a/src/evdev-fallback.h
+++ b/src/evdev-fallback.h
@@ -254,5 +254,30 @@ fallback_notify_physical_button(struct fallback_dispatch *dispatch,
 				uint64_t time,
 				int button,
 				enum libinput_button_state state);
+void
+fallback_normalize_delta(struct evdev_device *device,
+			 const struct device_coords *delta,
+			 struct normalized_coords *normalized);
+
+void
+fallback_init_wheel(struct fallback_dispatch *dispatch,
+		    struct evdev_device *device);
+
+void
+fallback_wheel_notify_physical_button(struct fallback_dispatch *dispatch,
+				      struct evdev_device *device,
+				      uint64_t time,
+				      int button,
+				      enum libinput_button_state state);
+
+void
+fallback_wheel_process_relative(struct fallback_dispatch *dispatch,
+				struct evdev_device *device,
+				struct input_event *e, uint64_t time);
+
+void
+fallback_wheel_handle_state(struct fallback_dispatch *dispatch,
+			    struct evdev_device *device,
+			    uint64_t time);
 
 #endif
diff --git a/src/evdev-wheel.c b/src/evdev-wheel.c
new file mode 100644
index 00000000..5cbaf3b9
--- /dev/null
+++ b/src/evdev-wheel.c
@@ -0,0 +1,207 @@
+/*
+ * Copyright © 2010 Intel Corporation
+ * Copyright © 2013 Jonas Ådahl
+ * Copyright © 2013-2017 Red Hat, Inc.
+ * Copyright © 2017 James Ye <jye836@gmail.com>
+ * Copyright © 2021 José Expósito
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#include "config.h"
+
+#include "evdev-fallback.h"
+#include "util-input-event.h"
+
+void
+fallback_wheel_process_relative(struct fallback_dispatch *dispatch,
+				struct evdev_device *device,
+				struct input_event *e, uint64_t time)
+{
+	switch (e->code) {
+	case REL_WHEEL:
+		dispatch->wheel.lo_res.y += e->value;
+		if (dispatch->wheel.emulate_hi_res_wheel)
+			dispatch->wheel.hi_res.y += e->value * 120;
+		dispatch->pending_event |= EVDEV_WHEEL;
+		break;
+	case REL_HWHEEL:
+		dispatch->wheel.lo_res.x += e->value;
+		if (dispatch->wheel.emulate_hi_res_wheel)
+			dispatch->wheel.hi_res.x += e->value * 120;
+		dispatch->pending_event |= EVDEV_WHEEL;
+		break;
+	case REL_WHEEL_HI_RES:
+		dispatch->wheel.hi_res.y += e->value;
+		dispatch->wheel.hi_res_event_received = true;
+		dispatch->pending_event |= EVDEV_WHEEL;
+		break;
+	case REL_HWHEEL_HI_RES:
+		dispatch->wheel.hi_res.x += e->value;
+		dispatch->wheel.hi_res_event_received = true;
+		dispatch->pending_event |= EVDEV_WHEEL;
+		break;
+	}
+}
+
+void
+fallback_wheel_notify_physical_button(struct fallback_dispatch *dispatch,
+				      struct evdev_device *device,
+				      uint64_t time,
+				      int button,
+				      enum libinput_button_state state)
+{
+	if (button == BTN_MIDDLE)
+		dispatch->wheel.is_inhibited = (state == LIBINPUT_BUTTON_STATE_PRESSED);
+
+	/* Lenovo TrackPoint Keyboard II sends its own scroll events when its
+	 * trackpoint is moved while the middle button is pressed.
+	 * Do not inhibit the scroll events.
+	 * https://gitlab.freedesktop.org/libinput/libinput/-/issues/651
+	 */
+	if (evdev_device_has_model_quirk(device,
+					 QUIRK_MODEL_LENOVO_TRACKPOINT_KEYBOARD_2))
+		dispatch->wheel.is_inhibited = false;
+}
+
+void
+fallback_wheel_handle_state(struct fallback_dispatch *dispatch,
+			    struct evdev_device *device,
+			    uint64_t time)
+{
+	struct normalized_coords wheel_degrees = { 0.0, 0.0 };
+	struct discrete_coords discrete = { 0.0, 0.0 };
+	struct wheel_v120 v120 = { 0.0, 0.0 };
+
+	if (!(device->seat_caps & EVDEV_DEVICE_POINTER))
+		return;
+
+	if (!dispatch->wheel.emulate_hi_res_wheel &&
+	    !dispatch->wheel.hi_res_event_received &&
+	    (dispatch->wheel.lo_res.x != 0 || dispatch->wheel.lo_res.y != 0)) {
+		evdev_log_bug_kernel(device,
+				     "device supports high-resolution scroll but only low-resolution events have been received.\n"
+				     "See %s/incorrectly-enabled-hires.html for details\n",
+				     HTTP_DOC_LINK);
+		dispatch->wheel.emulate_hi_res_wheel = true;
+		dispatch->wheel.hi_res.x = dispatch->wheel.lo_res.x * 120;
+		dispatch->wheel.hi_res.y = dispatch->wheel.lo_res.y * 120;
+	}
+
+	if (dispatch->wheel.is_inhibited) {
+		dispatch->wheel.hi_res.x = 0;
+		dispatch->wheel.hi_res.y = 0;
+		dispatch->wheel.lo_res.x = 0;
+		dispatch->wheel.lo_res.y = 0;
+		return;
+	}
+
+	if (device->model_flags & EVDEV_MODEL_LENOVO_SCROLLPOINT) {
+		struct normalized_coords unaccel = { 0.0, 0.0 };
+
+		dispatch->wheel.hi_res.y *= -1;
+		fallback_normalize_delta(device, &dispatch->wheel.hi_res, &unaccel);
+		evdev_post_scroll(device,
+				  time,
+				  LIBINPUT_POINTER_AXIS_SOURCE_CONTINUOUS,
+				  &unaccel);
+		dispatch->wheel.hi_res.x = 0;
+		dispatch->wheel.hi_res.y = 0;
+
+		return;
+	}
+
+	if (dispatch->wheel.hi_res.y != 0) {
+		int value = dispatch->wheel.hi_res.y;
+
+		v120.y = -1 * value;
+		wheel_degrees.y = -1 * value/120.0 * device->scroll.wheel_click_angle.y;
+		evdev_notify_axis_wheel(
+			device,
+			time,
+			bit(LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL),
+			&wheel_degrees,
+			&v120);
+		dispatch->wheel.hi_res.y = 0;
+	}
+
+	if (dispatch->wheel.lo_res.y != 0) {
+		int value = dispatch->wheel.lo_res.y;
+
+		wheel_degrees.y = -1 * value * device->scroll.wheel_click_angle.y;
+		discrete.y = -1 * value;
+		evdev_notify_axis_legacy_wheel(
+			device,
+			time,
+			bit(LIBINPUT_POINTER_AXIS_SCROLL_VERTICAL),
+			&wheel_degrees,
+			&discrete);
+		dispatch->wheel.lo_res.y = 0;
+	}
+
+	if (dispatch->wheel.hi_res.x != 0) {
+		int value = dispatch->wheel.hi_res.x;
+
+		v120.x = value;
+		wheel_degrees.x = value/120.0 * device->scroll.wheel_click_angle.x;
+		evdev_notify_axis_wheel(
+			device,
+			time,
+			bit(LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL),
+			&wheel_degrees,
+			&v120);
+		dispatch->wheel.hi_res.x = 0;
+	}
+
+	if (dispatch->wheel.lo_res.x != 0) {
+		int value = dispatch->wheel.lo_res.x;
+
+		wheel_degrees.x = value * device->scroll.wheel_click_angle.x;
+		discrete.x = value;
+		evdev_notify_axis_legacy_wheel(
+			device,
+			time,
+			bit(LIBINPUT_POINTER_AXIS_SCROLL_HORIZONTAL),
+			&wheel_degrees,
+			&discrete);
+		dispatch->wheel.lo_res.x = 0;
+	}
+}
+
+void
+fallback_init_wheel(struct fallback_dispatch *dispatch,
+		    struct evdev_device *device)
+{
+	/* On kernel < 5.0 we need to emulate high-resolution
+	   wheel scroll events */
+	if ((libevdev_has_event_code(device->evdev,
+				     EV_REL,
+				     REL_WHEEL) &&
+	     !libevdev_has_event_code(device->evdev,
+				      EV_REL,
+				      REL_WHEEL_HI_RES)) ||
+	    (libevdev_has_event_code(device->evdev,
+				     EV_REL,
+				     REL_HWHEEL) &&
+	     !libevdev_has_event_code(device->evdev,
+				      EV_REL,
+				      REL_HWHEEL_HI_RES)))
+		dispatch->wheel.emulate_hi_res_wheel = true;
+}