[PATCH libinput 5/7] evdev: sync the initial x/y position for touchscreens

[Peter Hutterer]

Unlikely, but there's the odd chance of the first touch coming in with the
same X or Y coordinate the kernel already has internally. This would generate
a x/0 or 0/y event in libinput.

Sync the slot state on init, at least for Protocol B devices. For Protocol A
devices and mtdev, don't bother.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev.c  | 12 ++++++++--
 test/touch.c | 72 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 82 insertions(+), 2 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index d45264b..48c969d 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -1781,8 +1781,16 @@ evdev_configure_mt_device(struct evdev_device *device)
 
 	for (slot = 0; slot < num_slots; ++slot) {
 		slots[slot].seat_slot = -1;
-		slots[slot].point.x = 0;
-		slots[slot].point.y = 0;
+
+		if (evdev_need_mtdev(device))
+			continue;
+
+		slots[slot].point.x = libevdev_get_slot_value(evdev,
+							      slot,
+							      ABS_MT_POSITION_X);
+		slots[slot].point.y = libevdev_get_slot_value(evdev,
+							      slot,
+							      ABS_MT_POSITION_Y);
 	}
 	device->mt.slots = slots;
 	device->mt.slots_len = num_slots;
diff --git a/test/touch.c b/test/touch.c
index d78deed..828c6ed 100644
--- a/test/touch.c
+++ b/test/touch.c
@@ -582,9 +582,79 @@ START_TEST(touch_protocol_a_2fg_touch)
 }
 END_TEST
 
+START_TEST(touch_initial_state)
+{
+	struct litest_device *dev;
+	struct libinput *libinput1, *libinput2;
+	struct libinput_event *ev1, *ev2;
+	struct libinput_event_touch *t1, *t2;
+	struct libinput_device *device1, *device2;
+	int axis = _i; /* looped test */
+
+	dev = litest_current_device();
+	device1 = dev->libinput_device;
+	libinput_device_config_tap_set_enabled(device1,
+					       LIBINPUT_CONFIG_TAP_DISABLED);
+
+	libinput1 = dev->libinput;
+	litest_touch_down(dev, 0, 40, 60);
+	litest_touch_up(dev, 0);
+
+	/* device is now on some x/y value */
+	litest_drain_events(libinput1);
+
+	libinput2 = litest_create_context();
+	device2 = libinput_path_add_device(libinput2,
+					   libevdev_uinput_get_devnode(
+							       dev->uinput));
+	libinput_device_config_tap_set_enabled(device2,
+					       LIBINPUT_CONFIG_TAP_DISABLED);
+	litest_drain_events(libinput2);
+
+	if (axis == ABS_X)
+		litest_touch_down(dev, 0, 40, 70);
+	else
+		litest_touch_down(dev, 0, 70, 60);
+	litest_touch_up(dev, 0);
+
+	litest_wait_for_event(libinput1);
+	litest_wait_for_event(libinput2);
+
+	while (libinput_next_event_type(libinput1)) {
+		ev1 = libinput_get_event(libinput1);
+		ev2 = libinput_get_event(libinput2);
+
+		t1 = litest_is_touch_event(ev1, 0);
+		t2 = litest_is_touch_event(ev2, 0);
+
+		ck_assert_int_eq(libinput_event_get_type(ev1),
+				 libinput_event_get_type(ev2));
+
+		if (libinput_event_get_type(ev1) == LIBINPUT_EVENT_TOUCH_UP ||
+		    libinput_event_get_type(ev1) == LIBINPUT_EVENT_TOUCH_FRAME)
+			break;
+
+		ck_assert_int_eq(libinput_event_touch_get_x(t1),
+				 libinput_event_touch_get_x(t2));
+		ck_assert_int_eq(libinput_event_touch_get_y(t1),
+				 libinput_event_touch_get_y(t2));
+
+		libinput_event_destroy(ev1);
+		libinput_event_destroy(ev2);
+	}
+
+	libinput_event_destroy(ev1);
+	libinput_event_destroy(ev2);
+
+	libinput_unref(libinput2);
+}
+END_TEST
+
 int
 main(int argc, char **argv)
 {
+	struct range axes = { ABS_X, ABS_Y + 1};
+
 	litest_add("touch:frame", touch_frame_events, LITEST_TOUCH, LITEST_ANY);
 	litest_add_no_device("touch:abs-transform", touch_abs_transform);
 	litest_add_no_device("touch:many-slots", touch_many_slots);
@@ -605,5 +675,7 @@ main(int argc, char **argv)
 	litest_add("touch:protocol a", touch_protocol_a_touch, LITEST_PROTOCOL_A, LITEST_ANY);
 	litest_add("touch:protocol a", touch_protocol_a_2fg_touch, LITEST_PROTOCOL_A, LITEST_ANY);
 
+	litest_add_ranged("touch:state", touch_initial_state, LITEST_TOUCH, LITEST_PROTOCOL_A, &axes);
+
 	return litest_run(argc, argv);
 }
-- 
2.3.5