[PATCH libinput 3/6] touchpad: make gestures optional

[Peter Hutterer]

Not all multi-finger touchpads are able to reliably produce gestures, so make
it optional. This patch just adds a boolean (currently always true) that gets
set on touchpad init time, i.e. it is not run-time configurable.

Three and four-finger gestures are filtered out in gesture_notify(), if the
cap isn't set the event is discarded.

For two-finger gestures we prevent a transition to PINCH, so we don't
inadvertently detect a pinch gesture and then not send events. This way, a 2fg
gesture is always scroll.

Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev-mt-touchpad-gestures.c | 5 ++++-
 src/evdev-mt-touchpad.c          | 3 ++-
 src/evdev-mt-touchpad.h          | 1 +
 3 files changed, 7 insertions(+), 2 deletions(-)

diff --git a/src/evdev-mt-touchpad-gestures.c b/src/evdev-mt-touchpad-gestures.c
index 3b1839e..da03c26 100644
--- a/src/evdev-mt-touchpad-gestures.c
+++ b/src/evdev-mt-touchpad-gestures.c
@@ -295,7 +295,7 @@ tp_gesture_twofinger_handle_state_unknown(struct tp_dispatch *tp, uint64_t time)
 	    ((dir2 & 0x80) && (dir1 & 0x01))) {
 		tp_gesture_set_scroll_buildup(tp);
 		return GESTURE_2FG_STATE_SCROLL;
-	} else {
+	} else if (tp->gesture.enabled) {
 		tp_gesture_get_pinch_info(tp,
 					  &tp->gesture.initial_distance,
 					  &tp->gesture.angle,
@@ -303,6 +303,8 @@ tp_gesture_twofinger_handle_state_unknown(struct tp_dispatch *tp, uint64_t time)
 		tp->gesture.prev_scale = 1.0;
 		return GESTURE_2FG_STATE_PINCH;
 	}
+
+	return GESTURE_2FG_STATE_UNKNOWN;
 }
 
 static enum tp_gesture_2fg_state
@@ -563,6 +565,7 @@ tp_gesture_handle_state(struct tp_dispatch *tp, uint64_t time)
 int
 tp_init_gesture(struct tp_dispatch *tp)
 {
+	tp->gesture.enabled = true;
 	tp->gesture.twofinger_state = GESTURE_2FG_STATE_NONE;
 
 	libinput_timer_init(&tp->gesture.finger_count_switch_timer,
diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index e110b9a..af1cd47 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -1918,7 +1918,8 @@ tp_init(struct tp_dispatch *tp,
 		return -1;
 
 	device->seat_caps |= EVDEV_DEVICE_POINTER;
-	device->seat_caps |= EVDEV_DEVICE_GESTURE;
+	if (tp->gesture.enabled)
+		device->seat_caps |= EVDEV_DEVICE_GESTURE;
 
 	return 0;
 }
diff --git a/src/evdev-mt-touchpad.h b/src/evdev-mt-touchpad.h
index a7961e7..3bd8425 100644
--- a/src/evdev-mt-touchpad.h
+++ b/src/evdev-mt-touchpad.h
@@ -246,6 +246,7 @@ struct tp_dispatch {
 	} accel;
 
 	struct {
+		bool enabled;
 		bool started;
 		unsigned int finger_count;
 		unsigned int finger_count_pending;
-- 
2.4.3