touch: Ignore tool events if another is active

On the Drallion stylus when the errse button is pressed the digitizer
will send an BTN_TOOL_RUBBER event before a BTN_TOUCH event and then a
BTN_TOOL_PEN. This sequence should be considered an POINTER_TYPE_ERASER
and not a POINTER_TYPE_PEN.

Bug: b:139781900
Change-Id: I268ef0d72e25fa374832ed529a4b54559bc0f805
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2076530Reviewed-by: Sean O'Brien <seobrien@chromium.org>
Commit-Queue: Mathew King <mathewk@chromium.org>
Cr-Commit-Position: refs/heads/master@{#746660}

ui/events/ozone/evdev/event_device_test_util.cc

@@ -995,6 +995,39 @@ const DeviceCapabilities kXboxElite = {
     base::size(kXboxEliteAxes),
 };
 
+const DeviceAbsoluteAxis kDrallionStylusAxes[] = {
+    {ABS_X, {0, 0, 30931, 0, 0, 100}},
+    {ABS_Y, {0, 0, 17399, 0, 0, 100}},
+    {ABS_PRESSURE, {0, 0, 4095, 0, 0, 0}},
+    {ABS_TILT_X, {0, -90, 90, 0, 0, 57}},
+    {ABS_TILT_Y, {0, -90, 90, 0, 0, 57}},
+    {ABS_MISC, {0, 0, 65535, 0, 0, 0}},
+};
+
+const DeviceCapabilities kDrallionStylus = {
+    /* path */
+    "/sys/devices/pci0000:00/0000:00:15.0/i2c_designware.0/i2c-7/"
+    "i2c-WCOM48E2:00/0018:2D1F:4971.0001/input/input6/event5",
+    /* name */ "WCOM48E2:00 2D1F:4971 Pen",
+    /* phys */ "i2c-WCOM48E2:00",
+    /* uniq */ "",
+    /* bustype */ "0018",
+    /* vendor */ "2d1f",
+    /* product */ "4971",
+    /* version */ "0100",
+    /* prop */ "0",
+    /* ev */ "1b",
+    /* key */ "1c03 0 0 0 0 0",
+    /* rel */ "0",
+    /* abs */ "1000d000003",
+    /* msc */ "11",
+    /* sw */ "0",
+    /* led */ "0",
+    /* ff */ "0",
+    kDrallionStylusAxes,
+    base::size(kDrallionStylusAxes),
+};
+
 // NB: Please use the capture_device_capabilities.py script to add more
 // test data here. This will help ensure the data matches what the kernel
 // reports for a real device and is entered correctly.

ui/events/ozone/evdev/event_device_test_util.h

@@ -88,6 +88,7 @@ extern const DeviceCapabilities kNocturneStylus;
 extern const DeviceCapabilities kKohakuTouchscreen;
 extern const DeviceCapabilities kKohakuStylus;
 extern const DeviceCapabilities kXboxElite;
+extern const DeviceCapabilities kDrallionStylus;
 }  // namspace ui
 
 #endif  // UI_EVENTS_OZONE_EVDEV_EVENT_DEVICE_TEST_UTIL_H_

ui/events/ozone/evdev/touch_event_converter_evdev.cc

@@ -364,8 +364,12 @@ void TouchEventConverterEvdev::ProcessKey(const input_event& input) {
     case BTN_TOOL_PEN:
     case BTN_TOOL_RUBBER:
       if (input.value > 0) {
+        if (events_[current_slot_].tool_code != 0)
+          break;
         events_[current_slot_].tool_code = input.code;
       } else {
+        if (events_[current_slot_].tool_code != input.code)
+          break;
         events_[current_slot_].tool_code = 0;
       }
       events_[current_slot_].altered = true;

ui/events/ozone/evdev/touch_event_converter_evdev_unittest.cc

@@ -1624,6 +1624,55 @@ TEST_F(TouchEventConverterEvdevTest, ActiveStylusMotion) {
   EXPECT_EQ(0.f / 1024, event.pointer_details.force);
 }
 
+TEST_F(TouchEventConverterEvdevTest, ActiveStylusDrallionRubberSequence) {
+  ui::MockTouchEventConverterEvdev* dev = device();
+  EventDeviceInfo devinfo;
+  EXPECT_TRUE(CapabilitiesToDeviceInfo(kDrallionStylus, &devinfo));
+  dev->Initialize(devinfo);
+
+
+  struct input_event mock_kernel_queue[] = {
+    {{0, 0}, EV_KEY, BTN_TOOL_RUBBER, 1},
+    {{0, 0}, EV_KEY, BTN_TOUCH, 1},
+    {{0, 0}, EV_KEY, BTN_TOOL_PEN, 1},
+    {{0, 0}, EV_SYN, SYN_REPORT, 0},
+    {{0, 0}, EV_ABS, ABS_X, 4008},
+    {{0, 0}, EV_ABS, ABS_Y, 11247},
+    {{0, 0}, EV_SYN, SYN_REPORT, 0},
+    {{0, 0}, EV_ABS, ABS_X, 4004},
+    {{0, 0}, EV_ABS, ABS_Y, 11248},
+    {{0, 0}, EV_SYN, SYN_REPORT, 0},
+    {{0, 0}, EV_KEY, BTN_TOUCH, 0},
+    {{0, 0}, EV_KEY, BTN_TOOL_PEN, 0},
+    {{0, 0}, EV_KEY, BTN_TOOL_RUBBER, 0},
+    {{0, 0}, EV_SYN, SYN_REPORT, 0},
+  };
+
+  dev->ConfigureReadMock(mock_kernel_queue, base::size(mock_kernel_queue), 0);
+  dev->ReadNow();
+  EXPECT_EQ(4u, size());
+
+  ui::TouchEventParams event = dispatched_touch_event(0);
+  EXPECT_EQ(ET_TOUCH_PRESSED, event.type);
+  EXPECT_EQ(EventPointerType::POINTER_TYPE_ERASER,
+            event.pointer_details.pointer_type);
+
+  event = dispatched_touch_event(1);
+  EXPECT_EQ(ET_TOUCH_MOVED, event.type);
+  EXPECT_EQ(EventPointerType::POINTER_TYPE_ERASER,
+            event.pointer_details.pointer_type);
+
+  event = dispatched_touch_event(2);
+  EXPECT_EQ(ET_TOUCH_MOVED, event.type);
+  EXPECT_EQ(EventPointerType::POINTER_TYPE_ERASER,
+            event.pointer_details.pointer_type);
+
+  event = dispatched_touch_event(3);
+  EXPECT_EQ(ET_TOUCH_RELEASED, event.type);
+  EXPECT_EQ(EventPointerType::POINTER_TYPE_ERASER,
+            event.pointer_details.pointer_type);
+}
+
 TEST_F(TouchEventConverterEvdevTest, ActiveStylusBarrelButtonWhileHovering) {
   ui::MockTouchEventConverterEvdev* dev = device();
   EventDeviceInfo devinfo;