[PATCH libinput] Make touch event slots seat wide

[Jonas Ådahl]

Since a Wayland compositor have to represent all touch devices of a seat
as one virtual device, lets make that easier by making the slots of
touch events seat wide unique.

Signed-off-by: Jonas Ådahl <jadahl at gmail.com>
---
 src/evdev.c            | 24 +++++++++++++++++++++---
 src/evdev.h            |  3 +++
 src/libinput-private.h |  1 +
 src/libinput.h         |  4 ++--
 4 files changed, 27 insertions(+), 5 deletions(-)

diff --git a/src/evdev.c b/src/evdev.c
index 2bc301b..80210fb 100644
--- a/src/evdev.c
+++ b/src/evdev.c
@@ -109,7 +109,9 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 {
 	int32_t cx, cy;
 	int slot;
+	uint32_t seat_slot;
 	struct libinput_device *base = &device->base;
+	struct libinput_seat *seat = base->seat;
 
 	slot = device->mt.slot;
 
@@ -128,9 +130,13 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 		if (!(device->seat_caps & EVDEV_DEVICE_TOUCH))
 			break;
 
+		seat_slot = ffs(~seat->slot_map) - 1;
+		device->mt.slots[slot].seat_slot = seat_slot;
+		seat->slot_map |= 1 << seat_slot;
+
 		touch_notify_touch(base,
 				   time,
-				   slot,
+				   seat_slot,
 				   li_fixed_from_int(device->mt.slots[slot].x),
 				   li_fixed_from_int(device->mt.slots[slot].y),
 				   LIBINPUT_TOUCH_TYPE_DOWN);
@@ -139,6 +145,8 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 		if (!(device->seat_caps & EVDEV_DEVICE_TOUCH))
 			break;
 
+		seat_slot = device->mt.slots[slot].seat_slot;
+
 		touch_notify_touch(base,
 				   time,
 				   slot,
@@ -150,9 +158,12 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 		if (!(device->seat_caps & EVDEV_DEVICE_TOUCH))
 			break;
 
+		seat_slot = device->mt.slots[slot].seat_slot;
+		seat->slot_map &= ~(1 << seat_slot);
+
 		touch_notify_touch(base,
 				   time,
-				   slot,
+				   seat_slot,
 				   0, 0,
 				   LIBINPUT_TOUCH_TYPE_UP);
 		break;
@@ -160,6 +171,10 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 		if (!(device->seat_caps & EVDEV_DEVICE_TOUCH))
 			break;
 
+		seat_slot = ffs(~seat->slot_map) - 1;
+		device->abs.seat_slot = seat_slot;
+		seat->slot_map |= 1 << seat_slot;
+
 		transform_absolute(device, &cx, &cy);
 		touch_notify_touch(base,
 				   time,
@@ -173,7 +188,7 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 		if (device->seat_caps & EVDEV_DEVICE_TOUCH) {
 			touch_notify_touch(base,
 					   time,
-					   slot,
+					   device->abs.seat_slot,
 					   li_fixed_from_int(cx),
 					   li_fixed_from_int(cy),
 					   LIBINPUT_TOUCH_TYPE_DOWN);
@@ -188,6 +203,9 @@ evdev_flush_pending_event(struct evdev_device *device, uint32_t time)
 		if (!(device->seat_caps & EVDEV_DEVICE_TOUCH))
 			break;
 
+		seat_slot = device->abs.seat_slot;
+		seat->slot_map &= ~(1 << seat_slot);
+
 		touch_notify_touch(base,
 				   time,
 				   0, 0, 0, LIBINPUT_TOUCH_TYPE_UP);
diff --git a/src/evdev.h b/src/evdev.h
index 37c32e5..b0feb28 100644
--- a/src/evdev.h
+++ b/src/evdev.h
@@ -64,6 +64,8 @@ struct evdev_device {
 		int min_x, max_x, min_y, max_y;
 		int32_t x, y;
 
+		uint32_t seat_slot;
+
 		int apply_calibration;
 		float calibration[6];
 	} abs;
@@ -71,6 +73,7 @@ struct evdev_device {
 	struct {
 		int slot;
 		struct {
+			uint32_t seat_slot;
 			int32_t x, y;
 		} slots[MAX_SLOTS];
 	} mt;
diff --git a/src/libinput-private.h b/src/libinput-private.h
index 0d7de90..2eea012 100644
--- a/src/libinput-private.h
+++ b/src/libinput-private.h
@@ -57,6 +57,7 @@ struct libinput_seat {
 	struct list devices_list;
 	void *user_data;
 	int refcount;
+	uint32_t slot_map;
 	char *physical_name;
 	char *logical_name;
 	libinput_seat_destroy_func destroy;
diff --git a/src/libinput.h b/src/libinput.h
index e2d83bf..9cd9d5b 100644
--- a/src/libinput.h
+++ b/src/libinput.h
@@ -568,8 +568,8 @@ libinput_event_touch_get_time(
 /**
  * @ingroup event_touch
  *
- * Get the currently active slot on this device. See the kernel's multitouch
- * protocol B documentation for more information.
+ * Get the slot of the touch event. A slot is a seat wide unique identifyer
+ * of a touch point.
  *
  * @note this function should not be called for LIBINPUT_EVENT_TOUCH_FRAME.
  *
-- 
1.8.3.2