[PATCH libinput 11/19] touchpad: Filter motion in a certain number of tap states

[Peter Hutterer]

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev-mt-touchpad-tap.c | 23 ++++++++++++++++++++++-
 src/evdev-mt-touchpad.c     | 22 +++++++++++-----------
 src/evdev-mt-touchpad.h     |  1 +
 3 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/src/evdev-mt-touchpad-tap.c b/src/evdev-mt-touchpad-tap.c
index 7ac592b..bc7acbd 100644
--- a/src/evdev-mt-touchpad-tap.c
+++ b/src/evdev-mt-touchpad-tap.c
@@ -504,6 +504,7 @@ int
 tp_tap_handle_state(struct tp_dispatch *tp, uint32_t time)
 {
 	struct tp_touch *t;
+	int filter_motion = 0;
 
 	if (tp->queued & TOUCHPAD_EVENT_BUTTON_PRESS)
 		tp_tap_handle_event(tp, TAP_EVENT_BUTTON, time);
@@ -521,7 +522,27 @@ tp_tap_handle_state(struct tp_dispatch *tp, uint32_t time)
 			tp_tap_handle_event(tp, TAP_EVENT_MOTION, time);
 	}
 
-	return 0;
+	/**
+	 * In any state where motion exceeding the move threshold would
+	 * move to the next state, filter that motion until we actually
+	 * exceed it. This prevents small motion events while we're waiting
+	 * on a decision if a tap is a tap.
+	 */
+	switch (tp->tap.state) {
+	case TAP_STATE_TOUCH:
+	case TAP_STATE_TAPPED:
+	case TAP_STATE_DRAGGING_OR_DOUBLETAP:
+	case TAP_STATE_TOUCH_2:
+	case TAP_STATE_TOUCH_3:
+		filter_motion = 1;
+		break;
+
+	default:
+		break;
+
+	}
+
+	return filter_motion;
 }
 
 static void
diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index d1268f6..873ddf0 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -369,20 +369,20 @@ tp_post_events(struct tp_dispatch *tp, uint32_t time)
 		return;
 	}
 
-	tp_tap_handle_state(tp, time);
-
-	if (t->history.count < 4)
+	if (tp_tap_handle_state(tp, time) != 0)
 		return;
 
-	tp_get_delta(t, &dx, &dy);
-	tp_filter_motion(tp, &dx, &dy, time);
+	if (t->history.count >= TOUCHPAD_MIN_SAMPLES) {
+		tp_get_delta(t, &dx, &dy);
+		tp_filter_motion(tp, &dx, &dy, time);
 
-	if (dx != 0 || dy != 0)
-		pointer_notify_motion(
-			&tp->device->base,
-			time,
-			li_fixed_from_double(dx),
-			li_fixed_from_double(dy));
+		if (dx != 0 || dy != 0)
+			pointer_notify_motion(
+				&tp->device->base,
+				time,
+				li_fixed_from_double(dx),
+				li_fixed_from_double(dy));
+	}
 
 	tp_post_button_events(tp, time);
 }
diff --git a/src/evdev-mt-touchpad.h b/src/evdev-mt-touchpad.h
index 973b478..a5cfaa6 100644
--- a/src/evdev-mt-touchpad.h
+++ b/src/evdev-mt-touchpad.h
@@ -30,6 +30,7 @@
 #include "filter.h"
 
 #define TOUCHPAD_HISTORY_LENGTH 4
+#define TOUCHPAD_MIN_SAMPLES 4
 
 enum touchpad_event {
 	TOUCHPAD_EVENT_NONE		= 0,
-- 
1.8.4.2