From 0d320c87c99e93b2feb1703f5bfd5d4fcc0a2857 Mon Sep 17 00:00:00 2001
From: Peter Hutterer <peter.hutterer@who-t.net>
Date: Mon, 13 Jul 2015 14:14:42 +1000
Subject: [PATCH libinput] touchpad: only edge-scroll while the finger is in
 the edge area

When the touch leaves the area for edge scrolling after starting to scroll,
discard any movement. This signals to the user that they've left the area and
forces them to lift the finger to switch back to motion. If the finger moves
back into the area, scrolling continues.

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>
---
 src/evdev-mt-touchpad-edge-scroll.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/evdev-mt-touchpad-edge-scroll.c b/src/evdev-mt-touchpad-edge-scroll.c
index ca9ef4a..4f8362c 100644
--- a/src/evdev-mt-touchpad-edge-scroll.c
+++ b/src/evdev-mt-touchpad-edge-scroll.c
@@ -384,6 +384,11 @@ tp_edge_scroll_post_events(struct tp_dispatch *tp, uint64_t time)
 		if (t->palm.state != PALM_NONE)
 			continue;
 
+		/* only scroll with the finger in the previous edge */
+		if (t->scroll.edge &&
+		    (tp_touch_get_edge(tp, t) & t->scroll.edge) == 0)
+			continue;
+
 		switch (t->scroll.edge) {
 			case EDGE_NONE:
 				if (t->scroll.direction != -1) {
-- 
2.4.3