Introduce tapping from any finger configuration

The current code only emits taps from zero fingers to N fingers.
This patch introduces tapping from any prior finger configuration.
A tap is defined as an increased number of fingers followed by a
decrease within the tap timeout. A tap is reported as the maximum
number of fingers present during the tap sequence.

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

2 files changed, 34 insertions, 50 deletions

diff --git a/src/gestures-tapping.c b/src/gestures-tapping.c
index 371dbde..fe7b7fe 100644
--- a/src/gestures-tapping.c
+++ b/src/gestures-tapping.c
@@ -23,10 +23,6 @@
 #include "grail-recognizer.h"
 #include <math.h>
 
-static const int TAP_BEGIN = 0;
-static const int TAP_END = 1;
-static const int TAP_CANCEL = 2;
-
 static const int TAP_MIN_GAP_MS = 25;
 
 static const int fm_mask = 0x03;
@@ -48,61 +44,49 @@ int gru_tapping(struct grail *ge,
         struct gesture_recognizer *gru = ge->gru;
         struct tapping_model *state = &gru->tapping;
         struct move_model *move = &gru->move;
-        if (move->ntouch) {
-                if (state->status == TAP_CANCEL)
-                        return 0;
-                state->status = TAP_BEGIN;
-                if (!state->ntouch)
-                        state->start = move->time;
-                if (move->ntouch >= state->ntouch) {
-                        set_props(ge->gin, state, move, frame);
-                }
-                if (move->ntouch > state->ntouch) {
-                        state->ntouch = move->ntouch;
-                        if (state->active) {
-                                gin_gid_discard(ge, state->gid);
-                                state->active = 0;
-                        }
+        if (move->ntouch > state->ntouch) {
+                if (state->active) {
+                        gin_gid_discard(ge, state->gid);
+                        state->active = 0;
                 }
-                if (!state->active) {
+                state->start = move->time;
+                state->ntouch = move->ntouch;
+                set_props(ge->gin, state, move, frame);
+                if (state->ntouch <= 5) {
                         int type = GRAIL_TYPE_TAP1 + state->ntouch - 1;
                         state->gid = gin_gid_begin(ge, type, PRIO_TAP, frame);
                         state->active = 1;
                 }
-        } else if (state->status == TAP_BEGIN && state->ntouch) {
-                state->status = TAP_END;
-        } else {
-                state->status = TAP_BEGIN;
-                state->ntouch = 0;
                 return 0;
         }
-        if (state->ntouch < 1 || state->ntouch > 5)
-                state->status = TAP_CANCEL;
-        if (move->time - state->start > move->fm[FM_X].bar_ms)
-                state->status = TAP_CANCEL;
-        if (state->status == TAP_END &&
-            move->time - state->start < TAP_MIN_GAP_MS)
-                state->status = TAP_CANCEL;
-        if (move->active & fm_mask)
-                state->status = TAP_CANCEL;
-        if (state->status == TAP_CANCEL) {
-                if (state->active) {
+        if (!state->active) {
+                state->ntouch = move->ntouch;
+                return 0;
+        }
+        if (move->ntouch < state->ntouch) {
+                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) {
                         gin_gid_discard(ge, state->gid);
+                        state->ntouch = move->ntouch;
                         state->active = 0;
+                        return 0;
                 }
-                state->ntouch = 0;
-                return 0;
+                state->prop[GRAIL_PROP_TAP_DT] = t;
+                gin_gid_event(ge, state->gid, x, y, state->ntouch,
+                              state->prop, state->nprop, 1);
+                state->ntouch = move->ntouch;
+                state->active = 0;
+                return 1;
         }
-        if (state->status != TAP_END ||
-            move->time - state->start < TAP_MIN_GAP_MS)
+        if (!move->ntouch)
                 return 0;
-        state->prop[GRAIL_PROP_TAP_DT] = move->time - state->start;
-        gin_gid_event(ge, state->gid,
-                      state->prop[GRAIL_PROP_TAP_X],
-                      state->prop[GRAIL_PROP_TAP_Y], state->ntouch,
-                      state->prop, state->nprop, 1);
-        state->status = TAP_BEGIN;
-        state->ntouch = 0;
-        state->active = 0;
-        return 1;
+        set_props(ge->gin, state, move, frame);
+        if ((move->active & fm_mask) ||
+            move->time - state->start > move->fm[FM_X].bar_ms) {
+                gin_gid_discard(ge, state->gid);
+                state->active = 0;
+        }
+        return 0;
 }
diff --git a/src/grail-gestures.h b/src/grail-gestures.h
index e716757..5a242d9 100644
--- a/src/grail-gestures.h
+++ b/src/grail-gestures.h
@@ -98,7 +98,7 @@ int gru_winrotate(struct grail *ge,
 
 struct tapping_model {
         grail_time_t start;
-        int status, ntouch;
+        int ntouch;
         int active, gid;
         int nprop;
         grail_prop_t prop[DIM_GRAIL_PROP];