ozone: evdev: Fix ghost touches aligned with first touch

The ABS_X and ABS_Y axes are not part of the MT protocol and should therefore not be used to update MT slot positions. The symptom of this was secondary touches warping to the position of the first touch in the X and/or Y axis, since ABS_X/Y always corresponds to the first touch. BUG=407386 TEST=chrome on pixel with --ash-touch-hud NOTRY=true Review URL: https://codereview.chromium.org/506303002 Cr-Commit-Position: refs/heads/master@{#292263}
SaschaDeWaal · Aug 27, 2014 · 86c315c · 86c315c
1 parent 8e8153d
commit 86c315c
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Showing 2 changed files with 46 additions and 4 deletions.
diff --git a/ui/events/ozone/evdev/touch_event_converter_evdev.cc b/ui/events/ozone/evdev/touch_event_converter_evdev.cc
@@ -203,7 +203,6 @@ void TouchEventConverterEvdev::ProcessAbs(const input_event& input) {
       altered_slots_.set(current_slot_);
       events_[current_slot_].major_ = input.value;
       break;
-    case ABS_X:
     case ABS_MT_POSITION_X:
       altered_slots_.set(current_slot_);
       events_[current_slot_].x_ = TuxelsToPixels(input.value,
@@ -212,7 +211,6 @@ void TouchEventConverterEvdev::ProcessAbs(const input_event& input) {
                                                  x_min_pixels_,
                                                  x_num_pixels_);
       break;
-    case ABS_Y:
     case ABS_MT_POSITION_Y:
       altered_slots_.set(current_slot_);
       events_[current_slot_].y_ = TuxelsToPixels(input.value,
@@ -231,7 +229,6 @@ void TouchEventConverterEvdev::ProcessAbs(const input_event& input) {
       }
       break;
     case ABS_MT_PRESSURE:
-    case ABS_PRESSURE:
       altered_slots_.set(current_slot_);
       events_[current_slot_].pressure_ = input.value - pressure_min_;
       events_[current_slot_].pressure_ /= pressure_max_ - pressure_min_;
@@ -241,7 +238,7 @@ void TouchEventConverterEvdev::ProcessAbs(const input_event& input) {
       altered_slots_.set(current_slot_);
       break;
     default:
-      NOTIMPLEMENTED() << "invalid code for EV_ABS: " << input.code;
+      DVLOG(5) << "unhandled code for EV_ABS: " << input.code;
   }
 }
 

diff --git a/ui/events/ozone/evdev/touch_event_converter_evdev_unittest.cc b/ui/events/ozone/evdev/touch_event_converter_evdev_unittest.cc
@@ -479,3 +479,48 @@ TEST_F(TouchEventConverterEvdevTest, Unsync) {
   dev->ReadNow();
   EXPECT_EQ(2u, dev->size());
 }
+
+// crbug.com/407386
+TEST_F(TouchEventConverterEvdevTest,
+       DontChangeMultitouchPositionFromLegacyAxes) {
+  ui::MockTouchEventConverterEvdev* dev = device();
+
+  struct input_event mock_kernel_queue[] = {
+      {{0, 0}, EV_ABS, ABS_MT_SLOT, 0},
+      {{0, 0}, EV_ABS, ABS_MT_TRACKING_ID, 100},
+      {{0, 0}, EV_ABS, ABS_MT_POSITION_X, 999},
+      {{0, 0}, EV_ABS, ABS_MT_POSITION_Y, 888},
+      {{0, 0}, EV_ABS, ABS_MT_PRESSURE, 55},
+      {{0, 0}, EV_ABS, ABS_MT_SLOT, 1},
+      {{0, 0}, EV_ABS, ABS_MT_TRACKING_ID, 200},
+      {{0, 0}, EV_ABS, ABS_MT_PRESSURE, 44},
+      {{0, 0}, EV_ABS, ABS_MT_POSITION_X, 777},
+      {{0, 0}, EV_ABS, ABS_MT_POSITION_Y, 666},
+      {{0, 0}, EV_ABS, ABS_X, 999},
+      {{0, 0}, EV_ABS, ABS_Y, 888},
+      {{0, 0}, EV_ABS, ABS_PRESSURE, 55},
+      {{0, 0}, EV_SYN, SYN_REPORT, 0},
+  };
+
+  // Check that two events are generated.
+  dev->ConfigureReadMock(mock_kernel_queue, arraysize(mock_kernel_queue), 0);
+  dev->ReadNow();
+
+  const unsigned int kExpectedEventCount = 2;
+  EXPECT_EQ(kExpectedEventCount, dev->size());
+  if (kExpectedEventCount != dev->size())
+    return;
+
+  ui::TouchEvent* ev0 = dev->event(0);
+  ui::TouchEvent* ev1 = dev->event(1);
+
+  EXPECT_EQ(0, ev0->touch_id());
+  EXPECT_EQ(999, ev0->x());
+  EXPECT_EQ(888, ev0->y());
+  EXPECT_FLOAT_EQ(0.8333333f, ev0->force());
+
+  EXPECT_EQ(1, ev1->touch_id());
+  EXPECT_EQ(777, ev1->x());
+  EXPECT_EQ(666, ev1->y());
+  EXPECT_FLOAT_EQ(0.4666666f, ev1->force());
+}