tablet: Improve forced prox out behavior.

Some graphics tablets (most or all Wacom, for example) do not emit
proximity out events when the tablet pen goes out of range. To
compensate for this, libinput synthesizes proximity out events when no
events are received for a certain period of time. Unfortunately, on some
tablets, this is fairly failure prone when moving the pen slowly. As a
workaround, this patch causes libinput to avoid synthesizing proximity
out events when the pen is still in contact with the tablet pad, as
defined by the TABLET_TOOL_IN_CONTACT status.

(cherry picked from commit 8568cf1b3a002c9894ae0326170090637b466b55)

2 files changed, 42 insertions, 0 deletions

diff --git a/src/evdev-tablet.c b/src/evdev-tablet.c
index 943b5284..6358dc46 100644
--- a/src/evdev-tablet.c
+++ b/src/evdev-tablet.c
@@ -1944,6 +1944,11 @@ tablet_proximity_out_quirk_timer_func(uint64_t now, void *data)
 	};
 	struct input_event *e;
 
+	if (tablet_has_status(tablet, TABLET_TOOL_IN_CONTACT)) {
+		tablet_proximity_out_quirk_set_timer(tablet, now);
+		return;
+	}
+
 	if (tablet->quirks.last_event_time > now - FORCED_PROXOUT_TIMEOUT) {
 		tablet_proximity_out_quirk_set_timer(tablet,
 						     tablet->quirks.last_event_time);
diff --git a/test/test-tablet.c b/test/test-tablet.c
index 90b81a7f..f4915bc0 100644
--- a/test/test-tablet.c
+++ b/test/test-tablet.c
@@ -1534,6 +1534,42 @@ START_TEST(proximity_out_slow_event)
 }
 END_TEST
 
+START_TEST(proximity_out_not_during_contact)
+{
+	struct litest_device *dev = litest_current_device();
+	struct libinput *li = dev->libinput;
+	struct axis_replacement axes[] = {
+		{ ABS_DISTANCE, 0 },
+		{ ABS_PRESSURE, 10 },
+		{ -1, -1 }
+	};
+
+	litest_tablet_proximity_in(dev, 10, 10, axes);
+	litest_tablet_motion(dev, 12, 12, axes);
+	litest_drain_events(li);
+
+	litest_timeout_tablet_proxout();
+	libinput_dispatch(li);
+
+	/* No forced proxout yet */
+	litest_assert_empty_queue(li);
+
+	litest_axis_set_value(axes, ABS_PRESSURE, 0);
+	litest_tablet_motion(dev, 14, 14, axes);
+	litest_drain_events(li);
+
+	litest_timeout_tablet_proxout();
+	libinput_dispatch(li);
+
+	/* The forced prox out */
+	litest_assert_tablet_proximity_event(li,
+					     LIBINPUT_TABLET_TOOL_PROXIMITY_STATE_OUT);
+
+	litest_tablet_proximity_out(dev);
+	litest_assert_empty_queue(li);
+}
+END_TEST
+
 START_TEST(proximity_out_no_timeout)
 {
 	struct litest_device *dev = litest_current_device();
@@ -5756,6 +5792,7 @@ TEST_COLLECTION(tablet)
 	litest_add("tablet:proximity", proximity_range_button_press, LITEST_TABLET | LITEST_DISTANCE | LITEST_TOOL_MOUSE, LITEST_ANY);
 	litest_add("tablet:proximity", proximity_range_button_release, LITEST_TABLET | LITEST_DISTANCE | LITEST_TOOL_MOUSE, LITEST_ANY);
 	litest_add("tablet:proximity", proximity_out_slow_event, LITEST_TABLET | LITEST_DISTANCE, LITEST_ANY);
+	litest_add("tablet:proximity", proximity_out_not_during_contact, LITEST_TABLET | LITEST_DISTANCE, LITEST_ANY);
 	litest_add_for_device("tablet:proximity", proximity_out_no_timeout, LITEST_WACOM_ISDV4_4200_PEN);
 
 	litest_add_no_device("tablet:proximity", proximity_out_on_delete);