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 c7fd3a1..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"
 
@@ -148,6 +149,7 @@ tp_end_touch(struct tp_dispatch *tp, struct tp_touch *t)
 
        t->dirty = true;
        t->is_pointer = false;
+       t->palm.is_palm = false;
        t->state = TOUCH_END;
        t->pinned.is_pinned = false;
        assert(tp->nfingers_down >= 1);
@@ -339,6 +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->palm.is_palm &&
                !t->pinned.is_pinned && tp_button_touch_active(tp, t);
 }
 
@@ -358,6 +361,47 @@ tp_set_pointer(struct tp_dispatch *tp, struct tp_touch *t)
 }
 
 static void
+tp_palm_detect(struct tp_dispatch *tp, struct tp_touch *t, uint64_t time)
+{
+       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 */
+       if (t->state != TOUCH_BEGIN ||
+           (t->x > tp->palm.left_edge && t->x < tp->palm.right_edge))
+               return;
+
+       /* don't detect palm in software button areas, it's
+          likely that legitimate touches start in the area
+          covered by the exclusion zone */
+       if (tp->buttons.is_clickpad &&
+           tp_button_is_inside_softbutton_area(tp, t))
+               return;
+
+       t->palm.is_palm = true;
+       t->palm.time = time;
+       t->palm.x = t->x;
+       t->palm.y = t->y;
+}
+
+static void
 tp_process_state(struct tp_dispatch *tp, uint64_t time)
 {
        struct tp_touch *t;
@@ -373,6 +417,8 @@ tp_process_state(struct tp_dispatch *tp, uint64_t time)
                        continue;
                }
 
+               tp_palm_detect(tp, t, time);
+
                tp_motion_hysteresis(tp, t);
                tp_motion_history_push(t);
 
@@ -703,6 +749,35 @@ tp_init_scroll(struct tp_dispatch *tp)
 }
 
 static int
+tp_init_palmdetect(struct tp_dispatch *tp,
+                  struct evdev_device *device)
+{
+       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;
+
+       return 0;
+}
+
+
+static int
 tp_init(struct tp_dispatch *tp,
        struct evdev_device *device)
 {
@@ -738,6 +813,9 @@ tp_init(struct tp_dispatch *tp,
        if (tp_init_buttons(tp, device) != 0)
                return -1;
 
+       if (tp_init_palmdetect(tp, device) != 0)
+               return -1;
+
        return 0;
 }