[PATCH libinput v3 09/17] touchpad: Rework is_pointer handling

[Hans de Goede]

We don't want touches in the button area to cause the pointer to move. So
instead of making a touch the pointer when it moves to TOUCH_BEGIN, wait
with making it the pointer until its buttons state moves to BUTTON_STATE_AREA.

Note that a touch in the main area of the touchpad will move to
BUTTON_STATE_AREA immediately.

While at it also refactor the is_pointer setting in general, removing
code duplicition wrt checking that another touch is not already
the pointer on unpinning a finger, and add safeguards that unpinning
does not make a finger which is not in button state BUTTON_STATE_AREA the
pointer, nor that the button code makes a pinned finger the pointer.

All these sanity checks are combined into a new tp_button_active function,
since they should be taken into account for 2 finger scrolling, etc. too.

Signed-off-by: Hans de Goede <hdegoede at redhat.com>
Signed-off-by: Peter Hutterer <peter.hutterer at who-t.net>
---
 src/evdev-mt-touchpad-buttons.c |  7 ++++++
 src/evdev-mt-touchpad.c         | 49 +++++++++++++++++++++--------------------
 src/evdev-mt-touchpad.h         |  6 +++++
 test/touchpad.c                 |  8 +++----
 4 files changed, 42 insertions(+), 28 deletions(-)

diff --git a/src/evdev-mt-touchpad-buttons.c b/src/evdev-mt-touchpad-buttons.c
index 61055ac..e47a55e 100644
--- a/src/evdev-mt-touchpad-buttons.c
+++ b/src/evdev-mt-touchpad-buttons.c
@@ -142,6 +142,7 @@ tp_button_set_state(struct tp_dispatch *tp, struct tp_touch *t,
 		break;
 	case BUTTON_STATE_AREA:
 		t->button.curr = BUTTON_EVENT_IN_AREA;
+		tp_set_pointer(tp, t);
 		break;
 	case BUTTON_STATE_BOTTOM:
 		break;
@@ -598,3 +599,9 @@ tp_post_button_events(struct tp_dispatch *tp, uint32_t time)
 
 	return rc;
 }
+
+int
+tp_button_touch_active(struct tp_dispatch *tp, struct tp_touch *t)
+{
+	return t->button.state == BUTTON_STATE_AREA;
+}
diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index 7f73f6e..924ba16 100644
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -152,8 +152,6 @@ tp_get_touch(struct tp_dispatch *tp, unsigned int slot)
 static inline void
 tp_begin_touch(struct tp_dispatch *tp, struct tp_touch *t)
 {
-	struct tp_touch *tmp = NULL;
-
 	if (t->state != TOUCH_UPDATE) {
 		tp_motion_history_reset(t);
 		t->dirty = true;
@@ -162,15 +160,6 @@ tp_begin_touch(struct tp_dispatch *tp, struct tp_touch *t)
 		tp->nfingers_down++;
 		assert(tp->nfingers_down >= 1);
 		tp->queued |= TOUCHPAD_EVENT_MOTION;
-
-		tp_for_each_touch(tp, tmp) {
-			if (tmp->is_pointer)
-				break;
-		}
-
-		if (!tmp->is_pointer) {
-			t->is_pointer = true;
-		}
 	}
 }
 
@@ -342,7 +331,6 @@ static void
 tp_unpin_finger(struct tp_dispatch *tp, struct tp_touch *t)
 {
 	unsigned int xdist, ydist;
-	struct tp_touch *tmp = NULL;
 
 	if (!t->pinned.is_pinned)
 		return;
@@ -350,19 +338,11 @@ tp_unpin_finger(struct tp_dispatch *tp, struct tp_touch *t)
 	xdist = abs(t->x - t->pinned.center_x);
 	ydist = abs(t->y - t->pinned.center_y);
 
-	if (xdist * xdist + ydist * ydist <
-			tp->buttons.motion_dist * tp->buttons.motion_dist)
-		return;
-
-	t->pinned.is_pinned = false;
-
-	tp_for_each_touch(tp, tmp) {
-		if (tmp->is_pointer)
-			break;
+	if (xdist * xdist + ydist * ydist >=
+			tp->buttons.motion_dist * tp->buttons.motion_dist) {
+		t->pinned.is_pinned = false;
+		tp_set_pointer(tp, t);
 	}
-
-	if (t->state != TOUCH_END && !tmp->is_pointer)
-		t->is_pointer = true;
 }
 
 static void
@@ -378,6 +358,27 @@ tp_pin_fingers(struct tp_dispatch *tp)
 	}
 }
 
+static int
+tp_touch_active(struct tp_dispatch *tp, struct tp_touch *t)
+{
+	return (t->state == TOUCH_BEGIN || t->state == TOUCH_UPDATE) &&
+		!t->pinned.is_pinned && tp_button_touch_active(tp, t);
+}
+
+void tp_set_pointer(struct tp_dispatch *tp, struct tp_touch *t)
+{
+	struct tp_touch *tmp = NULL;
+
+	/* Only set the touch as pointer if we don't have one yet */
+	tp_for_each_touch(tp, tmp) {
+		if (tmp->is_pointer)
+			return;
+	}
+
+	if (tp_touch_active(tp, t))
+		t->is_pointer = true;
+}
+
 static void
 tp_process_state(struct tp_dispatch *tp, uint32_t time)
 {
diff --git a/src/evdev-mt-touchpad.h b/src/evdev-mt-touchpad.h
index 8d8dd84..5509e93 100644
--- a/src/evdev-mt-touchpad.h
+++ b/src/evdev-mt-touchpad.h
@@ -200,6 +200,9 @@ struct tp_dispatch {
 void
 tp_get_delta(struct tp_touch *t, double *dx, double *dy);
 
+void
+tp_set_pointer(struct tp_dispatch *tp, struct tp_touch *t);
+
 int
 tp_tap_handle_state(struct tp_dispatch *tp, uint32_t time);
 
@@ -229,4 +232,7 @@ tp_post_button_events(struct tp_dispatch *tp, uint32_t time);
 int
 tp_button_handle_state(struct tp_dispatch *tp, uint32_t time);
 
+int
+tp_button_touch_active(struct tp_dispatch *tp, struct tp_touch *t);
+
 #endif
diff --git a/test/touchpad.c b/test/touchpad.c
index bbae6cd..959978e 100644
--- a/test/touchpad.c
+++ b/test/touchpad.c
@@ -70,10 +70,10 @@ START_TEST(touchpad_2fg_no_motion)
 
 	litest_drain_events(li);
 
-	litest_touch_down(dev, 0, 50, 50);
-	litest_touch_down(dev, 1, 70, 70);
-	litest_touch_move_to(dev, 0, 50, 50, 80, 50, 5);
-	litest_touch_move_to(dev, 1, 70, 70, 80, 50, 5);
+	litest_touch_down(dev, 0, 20, 20);
+	litest_touch_down(dev, 1, 70, 20);
+	litest_touch_move_to(dev, 0, 20, 20, 80, 80, 5);
+	litest_touch_move_to(dev, 1, 70, 20, 80, 50, 5);
 	litest_touch_up(dev, 0);
 	litest_touch_up(dev, 1);
 
-- 
1.9.0