touchpad: always init the left/right palm edge to INT_MIN/MAX

[platform/upstream/libinput.git] / src / evdev-mt-touchpad.c

diff --git a/src/evdev-mt-touchpad.c b/src/evdev-mt-touchpad.c
index 1325355..5db204f 100644 (file)
--- a/src/evdev-mt-touchpad.c
+++ b/src/evdev-mt-touchpad.c
@@ -25,6 +25,7 @@
 #include <assert.h>
 #include <math.h>
 #include <stdbool.h>
+#include <limits.h>
 
 #include "evdev-mt-touchpad.h"
 
@@ -148,7 +149,7 @@ tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t)
 
        t->dirty = true;
        t->is_pointer = false;
-       t->is_palm = false;
+       t->palm.is_palm = false;
        t->state = TOUCH_END;
        t->pinned.is_pinned = false;
        assert(tp->nfingers_down >= 1);
@@ -340,7 +341,7 @@ static int
 tp_touch_active(struct tp_dispatch *tp, struct tp_touch *t)
 {
        return (t->state == TOUCH_BEGIN || t->state == TOUCH_UPDATE) &&
-               !t->is_palm &&
+               !t->palm.is_palm &&
                !t->pinned.is_pinned && tp_button_touch_active(tp, t);
 }
 
@@ -360,11 +361,26 @@ tp_set_pointer(struct tp_dispatch *tp, struct tp_touch *t)
 }
 
 static void
-tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t)
+tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
 {
-       /* once a palm, always a palm */
-       if (t->is_palm)
+       const int PALM_TIMEOUT = 200; /* ms */
+       const int DIRECTIONS = NE|E|SE|SW|W|NW;
+
+       /* If labelled a touch as palm, we unlabel as palm when
+          we move out of the palm edge zone within the timeout, provided
+          the direction is within 45 degrees of the horizontal.
+        */
+       if (t->palm.is_palm) {
+               if (time < t->palm.time + PALM_TIMEOUT &&
+                   (t->x > tp->palm.left_edge && t->x < tp->palm.right_edge)) {
+                       int dirs = vector_get_direction(t->x - t->palm.x, t->y - t->palm.y);
+                       if ((dirs & DIRECTIONS) && !(dirs & ~DIRECTIONS)) {
+                               t->palm.is_palm = false;
+                               tp_set_pointer(tp, t);
+                       }
+               }
                return;
+       }
 
        /* palm must start in exclusion zone, it's ok to move into
           the zone without being a palm */
@@ -379,7 +395,10 @@ tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t)
            tp_button_is_inside_softbutton_area(tp, t))
                return;
 
-       t->is_palm = true;
+       t->palm.is_palm = true;
+       t->palm.time = time;
+       t->palm.x = t->x;
+       t->palm.y = t->y;
 }
 
 static void
@@ -398,7 +417,7 @@ tp_process_state(struct tp_dispatch *tp, uint64_t time)
                        continue;
                }
 
-               tp_palm_detect(tp, t);
+               tp_palm_detect(tp, t, time);
 
                tp_motion_hysteresis(tp, t);
                tp_motion_history_push(t);
@@ -735,9 +754,21 @@ tp_init_palmdetect(struct tp_dispatch *tp,
 {
        int width;
 
+       tp->palm.right_edge = INT_MAX;
+       tp->palm.left_edge = INT_MIN;
+
+       /* We don't know how big the touchpad is */
+       if (device->abs.absinfo_x->resolution == 1)
+               return 0;
+
        width = abs(device->abs.absinfo_x->maximum -
                    device->abs.absinfo_x->minimum);
 
+       /* Enable palm detection on touchpads >= 80 mm. Anything smaller
+          probably won't need it, until we find out it does */
+       if (width/device->abs.absinfo_x->resolution < 80)
+               return 0;
+
        /* palm edges are 5% of the width on each side */
        tp->palm.right_edge = device->abs.absinfo_x->maximum - width * 0.05;
        tp->palm.left_edge = device->abs.absinfo_x->minimum + width * 0.05;