[PATCH xf86-input-synaptics 1/2] Count number of multitouch touches for multitouch finger count

[Chase Douglas]

The evdev protocol only goes up to three touches for non-multitouch
devices. If you perform a four touch tap, the finger count will only go
up to three touches if you roll your fingers, or will always be 0 if all
four touches land at the same time.

This change ensures the correct finger count is reported.

Signed-off-by: Chase Douglas <chase.douglas at canonical.com>
---
I test build with HAVE_MULTITOUCH undefined to be sure it didn't break
anything.

 src/eventcomm.c |   16 ++++++++++++++--
 1 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/src/eventcomm.c b/src/eventcomm.c
index 3721c91..b485377 100644
--- a/src/eventcomm.c
+++ b/src/eventcomm.c
@@ -72,6 +72,7 @@ struct eventcomm_proto_data
     int axis_map[MT_ABS_SIZE];
     int cur_slot;
     ValuatorMask **last_mt_vals;
+    int num_touches;
 #endif
 };
 
@@ -565,6 +566,7 @@ EventProcessTouchEvent(InputInfoPtr pInfo, struct SynapticsHwState *hw,
             if (ev->value >= 0)
             {
                 hw->slot_state[slot_index] = SLOTSTATE_OPEN;
+                proto_data->num_touches++;
 
                 if (slot_index >= 0)
                     valuator_mask_copy(hw->mt_mask[slot_index],
@@ -574,7 +576,10 @@ EventProcessTouchEvent(InputInfoPtr pInfo, struct SynapticsHwState *hw,
                                 "Attempted to copy values from out-of-range "
                                 "slot, touch events may be incorrect.\n");
             } else
+            {
                 hw->slot_state[slot_index] = SLOTSTATE_CLOSE;
+                proto_data->num_touches--;
+            }
         } else
         {
             int map = proto_data->axis_map[ev->code - ABS_MT_TOUCH_MAJOR];
@@ -607,10 +612,17 @@ EventProcessTouchEvent(InputInfoPtr pInfo, struct SynapticsHwState *hw,
  * @param comm Assembled information from previous events.
  * @return The number of fingers currently set.
  */
-static int count_fingers(const struct CommData *comm)
+static int count_fingers(InputInfoPtr pInfo, const struct CommData *comm)
 {
+    SynapticsPrivate *priv = (SynapticsPrivate *)pInfo->private;
+    struct eventcomm_proto_data *proto_data = priv->proto_data;
     int fingers = 0;
 
+#ifdef HAVE_MULTITOUCH
+    if (priv->has_touch)
+        return proto_data->num_touches;
+#endif
+
     if (comm->oneFinger)
 	fingers = 1;
     else if (comm->twoFingers)
@@ -653,7 +665,7 @@ EventReadHwState(InputInfoPtr pInfo,
 	case EV_SYN:
 	    switch (ev.code) {
 	    case SYN_REPORT:
-		hw->numFingers = count_fingers(comm);
+		hw->numFingers = count_fingers(pInfo, comm);
 		hw->millis = 1000 * ev.time.tv_sec + ev.time.tv_usec / 1000;
 		SynapticsCopyHwState(hwRet, hw);
 		return TRUE;
-- 
1.7.9.1