Inhibit taps immediately after a finger is lifted

The intentional tap starts with a finger in the air. This patch
treats the sequence up-down-up as unintentional, unless performed
with a single finger. Fixes the problem with accidental taps during
multi-finger gestures.

Signed-off-by: Henrik Rydberg <rydberg@euromail.se>

1 files changed, 6 insertions, 1 deletions

diff --git a/src/gestures-tapping.c b/src/gestures-tapping.c
index 8727639..5474731 100644
--- a/src/gestures-tapping.c
+++ b/src/gestures-tapping.c
@@ -24,6 +24,7 @@
 #include <math.h>
 
 static const int TAP_MIN_GAP_MS = 25;
+static const int TAP_MIN_UP_MS = 200;
 
 static const int fm_mask = 0x07;
 
@@ -44,6 +45,9 @@ int gru_tapping(struct grail *ge,
         struct gesture_recognizer *gru = ge->gru;
         struct tapping_model *state = &gru->tapping;
         struct move_model *move = &gru->move;
+        grail_time_t up = move->time - state->end;
+        if (move->ntouch && move->ntouch < state->ntouch)
+                state->end = move->time;
         if (move->ntouch > state->ntouch) {
                 if (state->active) {
                         gin_gid_discard(ge, state->gid);
@@ -67,7 +71,8 @@ int gru_tapping(struct grail *ge,
                 int x = state->prop[GRAIL_PROP_TAP_X];
                 int y = state->prop[GRAIL_PROP_TAP_Y];
                 int t = move->time - state->start;
-                if (t < TAP_MIN_GAP_MS || t > move->fm[FM_X].bar_ms) {
+                if (t < TAP_MIN_GAP_MS || t > move->fm[FM_X].bar_ms ||
+                    up < TAP_MIN_UP_MS) {
                         gin_gid_discard(ge, state->gid);
                         state->ntouch = move->ntouch;
                         state->active = 0;