commit a01862db90c24a8e7d8b7ca8bc4d60baec2af335
Author: Tom Hughes <tom@compton.nu>
Date:   Sat Dec 13 10:37:31 2014 +0000

    Add support for a "middle" area in the bottom clickpad

diff --git a/src/evdev-mt-touchpad-buttons.c b/src/evdev-mt-touchpad-buttons.c
index 6af3fcf..f48d2ed 100644
--- a/src/evdev-mt-touchpad-buttons.c
+++ b/src/evdev-mt-touchpad-buttons.c
@@ -64,6 +64,7 @@ static inline const char*
 button_event_to_str(enum button_event event) {
 	switch(event) {
 	CASE_RETURN_STRING(BUTTON_EVENT_IN_BOTTOM_R);
+	CASE_RETURN_STRING(BUTTON_EVENT_IN_BOTTOM_M);
 	CASE_RETURN_STRING(BUTTON_EVENT_IN_BOTTOM_L);
 	CASE_RETURN_STRING(BUTTON_EVENT_IN_TOP_R);
 	CASE_RETURN_STRING(BUTTON_EVENT_IN_TOP_M);
@@ -94,7 +95,15 @@ static inline bool
 is_inside_bottom_left_area(struct tp_dispatch *tp, struct tp_touch *t)
 {
 	return is_inside_bottom_button_area(tp, t) &&
-	       !is_inside_bottom_right_area(tp, t);
+	       t->x < tp->buttons.bottom_area.leftbutton_right_edge;
+}
+
+static inline bool
+is_inside_bottom_middle_area(struct tp_dispatch *tp, struct tp_touch *t)
+{
+	return is_inside_bottom_button_area(tp, t) &&
+	       t->x >= tp->buttons.bottom_area.leftbutton_right_edge &&
+	       t->x <= tp->buttons.bottom_area.rightbutton_left_edge;
 }
 
 static inline bool
@@ -183,6 +192,7 @@ tp_button_none_handle_event(struct tp_dispatch *tp,
 {
 	switch (event) {
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 		tp_button_set_state(tp, t, BUTTON_STATE_BOTTOM, event);
 		break;
@@ -211,6 +221,7 @@ tp_button_area_handle_event(struct tp_dispatch *tp,
 {
 	switch (event) {
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 	case BUTTON_EVENT_IN_TOP_R:
 	case BUTTON_EVENT_IN_TOP_M:
@@ -234,6 +245,7 @@ tp_button_bottom_handle_event(struct tp_dispatch *tp,
 {
 	switch (event) {
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 		if (event != t->button.curr)
 			tp_button_set_state(tp, t, BUTTON_STATE_BOTTOM,
@@ -262,6 +274,7 @@ tp_button_top_handle_event(struct tp_dispatch *tp,
 {
 	switch (event) {
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 		tp_button_set_state(tp, t, BUTTON_STATE_TOP_TO_IGNORE, event);
 		break;
@@ -292,6 +305,7 @@ tp_button_top_new_handle_event(struct tp_dispatch *tp,
 {
 	switch(event) {
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 		tp_button_set_state(tp, t, BUTTON_STATE_AREA, event);
 		break;
@@ -336,6 +350,7 @@ tp_button_top_to_ignore_handle_event(struct tp_dispatch *tp,
 					    event);
 		break;
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 	case BUTTON_EVENT_IN_AREA:
 		break;
@@ -358,6 +373,7 @@ tp_button_ignore_handle_event(struct tp_dispatch *tp,
 {
 	switch (event) {
 	case BUTTON_EVENT_IN_BOTTOM_R:
+	case BUTTON_EVENT_IN_BOTTOM_M:
 	case BUTTON_EVENT_IN_BOTTOM_L:
 	case BUTTON_EVENT_IN_TOP_R:
 	case BUTTON_EVENT_IN_TOP_M:
@@ -429,6 +445,8 @@ tp_button_handle_state(struct tp_dispatch *tp, uint64_t time)
 		} else if (t->dirty) {
 			if (is_inside_bottom_right_area(tp, t))
 				tp_button_handle_event(tp, t, BUTTON_EVENT_IN_BOTTOM_R, time);
+			else if (is_inside_bottom_middle_area(tp, t))
+				tp_button_handle_event(tp, t, BUTTON_EVENT_IN_BOTTOM_M, time);
 			else if (is_inside_bottom_left_area(tp, t))
 				tp_button_handle_event(tp, t, BUTTON_EVENT_IN_BOTTOM_L, time);
 			else if (is_inside_top_right_area(tp, t))
@@ -523,6 +541,7 @@ tp_init_softbuttons(struct tp_dispatch *tp,
 	}
 
 	tp->buttons.bottom_area.rightbutton_left_edge = width/2 + xoffset;
+	tp->buttons.bottom_area.leftbutton_right_edge = width/2 + xoffset;
 
 	if (tp->buttons.has_topbuttons) {
 		/* T440s has the top button line 5mm from the top, event
@@ -742,6 +761,7 @@ tp_post_softbutton_buttons(struct tp_dispatch *tp, uint64_t time)
 				break;
 			case BUTTON_EVENT_IN_TOP_M:
 				is_top = 1;
+			case BUTTON_EVENT_IN_BOTTOM_M:
 				button |= MIDDLE;
 				break;
 			case BUTTON_EVENT_IN_TOP_R:
diff --git a/src/evdev-mt-touchpad.h b/src/evdev-mt-touchpad.h
index 1450288..3c49c3d 100644
--- a/src/evdev-mt-touchpad.h
+++ b/src/evdev-mt-touchpad.h
@@ -60,6 +60,7 @@ enum touch_state {
 
 enum button_event {
 	BUTTON_EVENT_IN_BOTTOM_R = 30,
+	BUTTON_EVENT_IN_BOTTOM_M,
 	BUTTON_EVENT_IN_BOTTOM_L,
 	BUTTON_EVENT_IN_TOP_R,
 	BUTTON_EVENT_IN_TOP_M,
@@ -222,6 +223,7 @@ struct tp_dispatch {
 		struct {
 			int32_t top_edge;
 			int32_t rightbutton_left_edge;
+			int32_t leftbutton_right_edge;
 		} bottom_area;
 
 		struct {