Add a new InputClassifier stage

The new InputClassifier stage could be used for additional processing
of input events prior to sending them to InputDispatcher. The new flow
of events will be InputReader -> InputClassifier -> InputDispatcher.

Here, we are calling the InputClassifier HAL and setting the MotionEvent
classification appropriately.

Bug: 62940136
Test: override notifyMotion to add extra flags to NotifyMotionArgs for
certain types of input events.
Test: atest inputflinger_tests

Change-Id: I2f390dc69f587ea25a3be8e4b8d5a207a5d529bf
diff --git a/services/inputflinger/InputClassifier.cpp b/services/inputflinger/InputClassifier.cpp
new file mode 100644
index 0000000..11427c3
--- /dev/null
+++ b/services/inputflinger/InputClassifier.cpp
@@ -0,0 +1,692 @@
+/*
+ * Copyright (C) 2019 The Android Open Source Project
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+#define LOG_TAG "InputClassifier"
+
+#include "InputClassifier.h"
+
+#include <algorithm>
+#include <cmath>
+#include <inttypes.h>
+#include <log/log.h>
+#if defined(__linux__)
+    #include <pthread.h>
+#endif
+#include <server_configurable_flags/get_flags.h>
+
+#include <android/hardware/input/classifier/1.0/IInputClassifier.h>
+
+using android::hardware::hidl_bitfield;
+using android::hardware::hidl_vec;
+using namespace android::hardware::input;
+
+namespace android {
+
+static constexpr bool DEBUG = false;
+
+// Category (=namespace) name for the input settings that are applied at boot time
+static const char* INPUT_NATIVE_BOOT = "input_native_boot";
+// Feature flag name for the deep press feature
+static const char* DEEP_PRESS_ENABLED = "deep_press_enabled";
+
+//Max number of elements to store in mEvents.
+static constexpr size_t MAX_EVENTS = 5;
+
+template<class K, class V>
+static V getValueForKey(const std::unordered_map<K, V>& map, K key, V defaultValue) {
+    auto it = map.find(key);
+    if (it == map.end()) {
+        return defaultValue;
+    }
+    return it->second;
+}
+
+static common::V1_0::Source getSource(uint32_t source) {
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_UNKNOWN) ==
+            common::V1_0::Source::UNKNOWN, "SOURCE_UNKNOWN mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_KEYBOARD) ==
+            common::V1_0::Source::KEYBOARD, "SOURCE_KEYBOARD mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_DPAD) ==
+            common::V1_0::Source::DPAD, "SOURCE_DPAD mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_GAMEPAD) ==
+            common::V1_0::Source::GAMEPAD, "SOURCE_GAMEPAD mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_TOUCHSCREEN) ==
+            common::V1_0::Source::TOUCHSCREEN, "SOURCE_TOUCHSCREEN mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_MOUSE) ==
+            common::V1_0::Source::MOUSE, "SOURCE_MOUSE mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_STYLUS) ==
+            common::V1_0::Source::STYLUS, "SOURCE_STYLUS mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_BLUETOOTH_STYLUS) ==
+            common::V1_0::Source::BLUETOOTH_STYLUS, "SOURCE_BLUETOOTH_STYLUS mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_TRACKBALL) ==
+            common::V1_0::Source::TRACKBALL, "SOURCE_TRACKBALL mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_MOUSE_RELATIVE) ==
+            common::V1_0::Source::MOUSE_RELATIVE, "SOURCE_MOUSE_RELATIVE mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_TOUCHPAD) ==
+            common::V1_0::Source::TOUCHPAD, "SOURCE_TOUCHPAD mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_TOUCH_NAVIGATION) ==
+            common::V1_0::Source::TOUCH_NAVIGATION, "SOURCE_TOUCH_NAVIGATION mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_JOYSTICK) ==
+            common::V1_0::Source::JOYSTICK, "SOURCE_JOYSTICK mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_ROTARY_ENCODER) ==
+            common::V1_0::Source::ROTARY_ENCODER, "SOURCE_ROTARY_ENCODER mismatch");
+    static_assert(static_cast<common::V1_0::Source>(AINPUT_SOURCE_ANY) ==
+            common::V1_0::Source::ANY, "SOURCE_ANY mismatch");
+    return static_cast<common::V1_0::Source>(source);
+}
+
+static common::V1_0::Action getAction(int32_t actionMasked) {
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_DOWN) ==
+            common::V1_0::Action::DOWN, "ACTION_DOWN mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_UP) ==
+            common::V1_0::Action::UP, "ACTION_UP mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_MOVE) ==
+            common::V1_0::Action::MOVE, "ACTION_MOVE mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_CANCEL) ==
+            common::V1_0::Action::CANCEL, "ACTION_CANCEL mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_OUTSIDE) ==
+            common::V1_0::Action::OUTSIDE, "ACTION_OUTSIDE mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_POINTER_DOWN) ==
+            common::V1_0::Action::POINTER_DOWN, "ACTION_POINTER_DOWN mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_POINTER_UP) ==
+            common::V1_0::Action::POINTER_UP, "ACTION_POINTER_UP mismatch");
+    static_assert(static_cast<common::V1_0::Action>( AMOTION_EVENT_ACTION_HOVER_MOVE) ==
+            common::V1_0::Action::HOVER_MOVE, "ACTION_HOVER_MOVE mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_SCROLL) ==
+            common::V1_0::Action::SCROLL, "ACTION_SCROLL mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_HOVER_ENTER) ==
+            common::V1_0::Action::HOVER_ENTER, "ACTION_HOVER_ENTER mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_HOVER_EXIT) ==
+            common::V1_0::Action::HOVER_EXIT, "ACTION_HOVER_EXIT mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_BUTTON_PRESS) ==
+            common::V1_0::Action::BUTTON_PRESS, "ACTION_BUTTON_PRESS mismatch");
+    static_assert(static_cast<common::V1_0::Action>(AMOTION_EVENT_ACTION_BUTTON_RELEASE) ==
+            common::V1_0::Action::BUTTON_RELEASE, "ACTION_BUTTON_RELEASE mismatch");
+    return static_cast<common::V1_0::Action>(actionMasked);
+}
+
+static common::V1_0::Button getActionButton(int32_t actionButton) {
+    static_assert(static_cast<common::V1_0::Button>(0) ==
+            common::V1_0::Button::NONE, "BUTTON_NONE mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_PRIMARY) ==
+            common::V1_0::Button::PRIMARY, "BUTTON_PRIMARY mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_SECONDARY) ==
+            common::V1_0::Button::SECONDARY, "BUTTON_SECONDARY mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_TERTIARY) ==
+            common::V1_0::Button::TERTIARY, "BUTTON_TERTIARY mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_BACK) ==
+            common::V1_0::Button::BACK, "BUTTON_BACK mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_FORWARD) ==
+            common::V1_0::Button::FORWARD, "BUTTON_FORWARD mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_STYLUS_PRIMARY) ==
+            common::V1_0::Button::STYLUS_PRIMARY, "BUTTON_STYLUS_PRIMARY mismatch");
+    static_assert(static_cast<common::V1_0::Button>(AMOTION_EVENT_BUTTON_STYLUS_SECONDARY) ==
+            common::V1_0::Button::STYLUS_SECONDARY, "BUTTON_STYLUS_SECONDARY mismatch");
+    return static_cast<common::V1_0::Button>(actionButton);
+}
+
+static hidl_bitfield<common::V1_0::Flag> getFlags(int32_t flags) {
+    static_assert(static_cast<common::V1_0::Flag>(AMOTION_EVENT_FLAG_WINDOW_IS_OBSCURED) ==
+            common::V1_0::Flag::WINDOW_IS_OBSCURED);
+    static_assert(static_cast<common::V1_0::Flag>(AMOTION_EVENT_FLAG_IS_GENERATED_GESTURE) ==
+            common::V1_0::Flag::IS_GENERATED_GESTURE);
+    static_assert(static_cast<common::V1_0::Flag>(AMOTION_EVENT_FLAG_TAINTED) ==
+            common::V1_0::Flag::TAINTED);
+    return static_cast<hidl_bitfield<common::V1_0::Flag>>(flags);
+}
+
+static hidl_bitfield<common::V1_0::PolicyFlag> getPolicyFlags(int32_t flags) {
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_WAKE) ==
+            common::V1_0::PolicyFlag::WAKE);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_VIRTUAL) ==
+            common::V1_0::PolicyFlag::VIRTUAL);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_FUNCTION) ==
+            common::V1_0::PolicyFlag::FUNCTION);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_GESTURE) ==
+            common::V1_0::PolicyFlag::GESTURE);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_INJECTED) ==
+            common::V1_0::PolicyFlag::INJECTED);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_TRUSTED) ==
+            common::V1_0::PolicyFlag::TRUSTED);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_FILTERED) ==
+            common::V1_0::PolicyFlag::FILTERED);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_DISABLE_KEY_REPEAT) ==
+            common::V1_0::PolicyFlag::DISABLE_KEY_REPEAT);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_INTERACTIVE) ==
+            common::V1_0::PolicyFlag::INTERACTIVE);
+    static_assert(static_cast<common::V1_0::PolicyFlag>(POLICY_FLAG_PASS_TO_USER) ==
+            common::V1_0::PolicyFlag::PASS_TO_USER);
+    return static_cast<hidl_bitfield<common::V1_0::PolicyFlag>>(flags);
+}
+
+static hidl_bitfield<common::V1_0::EdgeFlag> getEdgeFlags(int32_t flags) {
+    static_assert(static_cast<common::V1_0::EdgeFlag>(AMOTION_EVENT_EDGE_FLAG_NONE) ==
+            common::V1_0::EdgeFlag::NONE);
+    static_assert(static_cast<common::V1_0::EdgeFlag>(AMOTION_EVENT_EDGE_FLAG_TOP) ==
+            common::V1_0::EdgeFlag::TOP);
+    static_assert(static_cast<common::V1_0::EdgeFlag>(AMOTION_EVENT_EDGE_FLAG_BOTTOM) ==
+            common::V1_0::EdgeFlag::BOTTOM);
+    static_assert(static_cast<common::V1_0::EdgeFlag>(AMOTION_EVENT_EDGE_FLAG_LEFT) ==
+            common::V1_0::EdgeFlag::LEFT);
+    static_assert(static_cast<common::V1_0::EdgeFlag>(AMOTION_EVENT_EDGE_FLAG_RIGHT) ==
+            common::V1_0::EdgeFlag::RIGHT);
+    return static_cast<hidl_bitfield<common::V1_0::EdgeFlag>>(flags);
+}
+
+static hidl_bitfield<common::V1_0::Meta> getMetastate(int32_t state) {
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_NONE) ==
+            common::V1_0::Meta::NONE);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_ALT_ON) ==
+            common::V1_0::Meta::ALT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_ALT_LEFT_ON) ==
+            common::V1_0::Meta::ALT_LEFT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_ALT_RIGHT_ON) ==
+            common::V1_0::Meta::ALT_RIGHT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_SHIFT_ON) ==
+            common::V1_0::Meta::SHIFT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_SHIFT_LEFT_ON) ==
+            common::V1_0::Meta::SHIFT_LEFT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_SHIFT_RIGHT_ON) ==
+            common::V1_0::Meta::SHIFT_RIGHT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_SYM_ON) ==
+            common::V1_0::Meta::SYM_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_FUNCTION_ON) ==
+            common::V1_0::Meta::FUNCTION_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_CTRL_ON) ==
+            common::V1_0::Meta::CTRL_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_CTRL_LEFT_ON) ==
+            common::V1_0::Meta::CTRL_LEFT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_CTRL_RIGHT_ON) ==
+            common::V1_0::Meta::CTRL_RIGHT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_META_ON) ==
+            common::V1_0::Meta::META_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_META_LEFT_ON) ==
+            common::V1_0::Meta::META_LEFT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_META_RIGHT_ON) ==
+            common::V1_0::Meta::META_RIGHT_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_CAPS_LOCK_ON) ==
+            common::V1_0::Meta::CAPS_LOCK_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_NUM_LOCK_ON) ==
+            common::V1_0::Meta::NUM_LOCK_ON);
+    static_assert(static_cast<common::V1_0::Meta>(AMETA_SCROLL_LOCK_ON) ==
+            common::V1_0::Meta::SCROLL_LOCK_ON);
+    return static_cast<hidl_bitfield<common::V1_0::Meta>>(state);
+}
+
+static hidl_bitfield<common::V1_0::Button> getButtonState(int32_t buttonState) {
+    // No need for static_assert here.
+    // The button values have already been asserted in getActionButton(..) above
+    return static_cast<hidl_bitfield<common::V1_0::Button>>(buttonState);
+}
+
+static common::V1_0::ToolType getToolType(int32_t toolType) {
+    static_assert(static_cast<common::V1_0::ToolType>(AMOTION_EVENT_TOOL_TYPE_UNKNOWN) ==
+            common::V1_0::ToolType::UNKNOWN);
+    static_assert(static_cast<common::V1_0::ToolType>(AMOTION_EVENT_TOOL_TYPE_FINGER) ==
+            common::V1_0::ToolType::FINGER);
+    static_assert(static_cast<common::V1_0::ToolType>(AMOTION_EVENT_TOOL_TYPE_STYLUS) ==
+            common::V1_0::ToolType::STYLUS);
+    static_assert(static_cast<common::V1_0::ToolType>(AMOTION_EVENT_TOOL_TYPE_MOUSE) ==
+            common::V1_0::ToolType::MOUSE);
+    static_assert(static_cast<common::V1_0::ToolType>(AMOTION_EVENT_TOOL_TYPE_ERASER) ==
+            common::V1_0::ToolType::ERASER);
+    return static_cast<common::V1_0::ToolType>(toolType);
+}
+
+static common::V1_0::Axis getAxis(uint64_t axis) {
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_X) ==
+            common::V1_0::Axis::X);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_Y) ==
+            common::V1_0::Axis::Y);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_PRESSURE) ==
+            common::V1_0::Axis::PRESSURE);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_SIZE) ==
+            common::V1_0::Axis::SIZE);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_TOUCH_MAJOR) ==
+            common::V1_0::Axis::TOUCH_MAJOR);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_TOUCH_MINOR) ==
+            common::V1_0::Axis::TOUCH_MINOR);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_TOOL_MAJOR) ==
+            common::V1_0::Axis::TOOL_MAJOR);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_TOOL_MINOR) ==
+            common::V1_0::Axis::TOOL_MINOR);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_ORIENTATION) ==
+            common::V1_0::Axis::ORIENTATION);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_VSCROLL) ==
+            common::V1_0::Axis::VSCROLL);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_HSCROLL) ==
+            common::V1_0::Axis::HSCROLL);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_Z) ==
+            common::V1_0::Axis::Z);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RX) ==
+            common::V1_0::Axis::RX);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RY) ==
+            common::V1_0::Axis::RY);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RZ) ==
+            common::V1_0::Axis::RZ);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_HAT_X) ==
+            common::V1_0::Axis::HAT_X);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_HAT_Y) ==
+            common::V1_0::Axis::HAT_Y);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_LTRIGGER) ==
+            common::V1_0::Axis::LTRIGGER);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RTRIGGER) ==
+            common::V1_0::Axis::RTRIGGER);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_THROTTLE) ==
+            common::V1_0::Axis::THROTTLE);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RUDDER) ==
+            common::V1_0::Axis::RUDDER);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_WHEEL) ==
+            common::V1_0::Axis::WHEEL);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GAS) ==
+            common::V1_0::Axis::GAS);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_BRAKE) ==
+            common::V1_0::Axis::BRAKE);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_DISTANCE) ==
+            common::V1_0::Axis::DISTANCE);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_TILT) ==
+            common::V1_0::Axis::TILT);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_SCROLL) ==
+            common::V1_0::Axis::SCROLL);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RELATIVE_X) ==
+            common::V1_0::Axis::RELATIVE_X);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_RELATIVE_Y) ==
+            common::V1_0::Axis::RELATIVE_Y);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_1) ==
+            common::V1_0::Axis::GENERIC_1);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_2) ==
+            common::V1_0::Axis::GENERIC_2);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_3) ==
+            common::V1_0::Axis::GENERIC_3);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_4) ==
+            common::V1_0::Axis::GENERIC_4);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_5) ==
+            common::V1_0::Axis::GENERIC_5);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_6) ==
+            common::V1_0::Axis::GENERIC_6);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_7) ==
+            common::V1_0::Axis::GENERIC_7);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_8) ==
+            common::V1_0::Axis::GENERIC_8);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_9) ==
+            common::V1_0::Axis::GENERIC_9);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_10) ==
+            common::V1_0::Axis::GENERIC_10);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_11) ==
+            common::V1_0::Axis::GENERIC_11);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_12) ==
+            common::V1_0::Axis::GENERIC_12);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_13) ==
+            common::V1_0::Axis::GENERIC_13);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_14) ==
+            common::V1_0::Axis::GENERIC_14);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_15) ==
+            common::V1_0::Axis::GENERIC_15);
+    static_assert(static_cast<common::V1_0::Axis>(AMOTION_EVENT_AXIS_GENERIC_16) ==
+            common::V1_0::Axis::GENERIC_16);
+    return static_cast<common::V1_0::Axis>(axis);
+}
+
+static common::V1_0::VideoFrame getHalVideoFrame(const TouchVideoFrame& frame) {
+    common::V1_0::VideoFrame out;
+    out.width = frame.getWidth();
+    out.height = frame.getHeight();
+    out.data = frame.getData();
+    struct timeval timestamp = frame.getTimestamp();
+    out.timestamp = seconds_to_nanoseconds(timestamp.tv_sec) +
+             microseconds_to_nanoseconds(timestamp.tv_usec);
+    return out;
+}
+
+static std::vector<common::V1_0::VideoFrame> convertVideoFrames(
+        const std::vector<TouchVideoFrame>& frames) {
+    std::vector<common::V1_0::VideoFrame> out;
+    for (const TouchVideoFrame& frame : frames) {
+        out.push_back(getHalVideoFrame(frame));
+    }
+    return out;
+}
+
+static uint8_t getActionIndex(int32_t action) {
+    return (action & AMOTION_EVENT_ACTION_POINTER_INDEX_MASK) >>
+            AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
+}
+
+static void getHidlPropertiesAndCoords(const NotifyMotionArgs& args,
+        std::vector<common::V1_0::PointerProperties>* outPointerProperties,
+        std::vector<common::V1_0::PointerCoords>* outPointerCoords) {
+    outPointerProperties->reserve(args.pointerCount);
+    outPointerCoords->reserve(args.pointerCount);
+    for (size_t i = 0; i < args.pointerCount; i++) {
+        common::V1_0::PointerProperties properties;
+        properties.id = args.pointerProperties[i].id;
+        properties.toolType = getToolType(args.pointerProperties[i].toolType);
+        outPointerProperties->push_back(properties);
+
+        common::V1_0::PointerCoords coords;
+        BitSet64 bits (args.pointerCoords[i].bits);
+        std::vector<float> values;
+        size_t index = 0;
+        while (!bits.isEmpty()) {
+            uint32_t axis = bits.clearFirstMarkedBit();
+            coords.bits |= 1 << static_cast<uint64_t>(getAxis(axis));
+            float value = args.pointerCoords[i].values[index++];
+            values.push_back(value);
+        }
+        coords.values = values;
+        outPointerCoords->push_back(coords);
+    }
+}
+
+static common::V1_0::MotionEvent getMotionEvent(const NotifyMotionArgs& args) {
+    common::V1_0::MotionEvent event;
+    event.deviceId = args.deviceId;
+    event.source = getSource(args.source);
+    event.displayId = args.displayId;
+    event.downTime = args.downTime;
+    event.eventTime = args.eventTime;
+    event.action = getAction(args.action & AMOTION_EVENT_ACTION_MASK);
+    event.actionIndex = getActionIndex(args.action);
+    event.actionButton = getActionButton(args.actionButton);
+    event.flags = getFlags(args.flags);
+    event.policyFlags = getPolicyFlags(args.policyFlags);
+    event.edgeFlags = getEdgeFlags(args.edgeFlags);
+    event.metaState = getMetastate(args.metaState);
+    event.buttonState = getButtonState(args.buttonState);
+    event.xPrecision = args.xPrecision;
+    event.yPrecision = args.yPrecision;
+
+    std::vector<common::V1_0::PointerProperties> pointerProperties;
+    std::vector<common::V1_0::PointerCoords> pointerCoords;
+    getHidlPropertiesAndCoords(args, /*out*/&pointerProperties, /*out*/&pointerCoords);
+    event.pointerProperties = pointerProperties;
+    event.pointerCoords = pointerCoords;
+
+    event.deviceTimestamp = args.deviceTimestamp;
+    event.frames = convertVideoFrames(args.videoFrames);
+
+    return event;
+}
+
+static MotionClassification getMotionClassification(common::V1_0::Classification classification) {
+    static_assert(MotionClassification::NONE ==
+            static_cast<MotionClassification>(common::V1_0::Classification::NONE));
+    static_assert(MotionClassification::AMBIGUOUS_GESTURE ==
+            static_cast<MotionClassification>(common::V1_0::Classification::AMBIGUOUS_GESTURE));
+    static_assert(MotionClassification::DEEP_PRESS ==
+            static_cast<MotionClassification>(common::V1_0::Classification::DEEP_PRESS));
+    return static_cast<MotionClassification>(classification);
+}
+
+static bool isTouchEvent(const NotifyMotionArgs& args) {
+    return args.source == AINPUT_SOURCE_TOUCHPAD || args.source == AINPUT_SOURCE_TOUCHSCREEN;
+}
+
+// Check if the "deep touch" feature is on.
+static bool deepPressEnabled() {
+    std::string flag_value = server_configurable_flags::GetServerConfigurableFlag(
+            INPUT_NATIVE_BOOT, DEEP_PRESS_ENABLED, "true");
+    std::transform(flag_value.begin(), flag_value.end(), flag_value.begin(), ::tolower);
+    if (flag_value == "1" || flag_value == "true") {
+        ALOGI("Deep press feature enabled.");
+        return true;
+    }
+    ALOGI("Deep press feature is not enabled.");
+    return false;
+}
+
+
+// --- ClassifierEvent ---
+
+ClassifierEvent::ClassifierEvent(std::unique_ptr<NotifyMotionArgs> args) :
+        type(ClassifierEventType::MOTION), args(std::move(args)) { };
+ClassifierEvent::ClassifierEvent(std::unique_ptr<NotifyDeviceResetArgs> args) :
+        type(ClassifierEventType::DEVICE_RESET), args(std::move(args)) { };
+ClassifierEvent::ClassifierEvent(ClassifierEventType type, std::unique_ptr<NotifyArgs> args) :
+        type(type), args(std::move(args)) { };
+
+ClassifierEvent::ClassifierEvent(ClassifierEvent&& other) :
+        type(other.type), args(std::move(other.args)) { };
+
+ClassifierEvent& ClassifierEvent::operator=(ClassifierEvent&& other) {
+    type = other.type;
+    args = std::move(other.args);
+    return *this;
+}
+
+ClassifierEvent ClassifierEvent::createHalResetEvent() {
+    return ClassifierEvent(ClassifierEventType::HAL_RESET, nullptr);
+}
+
+ClassifierEvent ClassifierEvent::createExitEvent() {
+    return ClassifierEvent(ClassifierEventType::EXIT, nullptr);
+}
+
+std::optional<int32_t> ClassifierEvent::getDeviceId() const {
+    switch (type) {
+        case ClassifierEventType::MOTION: {
+            NotifyMotionArgs* motionArgs = static_cast<NotifyMotionArgs*>(args.get());
+            return motionArgs->deviceId;
+        }
+        case ClassifierEventType::DEVICE_RESET: {
+            NotifyDeviceResetArgs* deviceResetArgs =
+                    static_cast<NotifyDeviceResetArgs*>(args.get());
+            return deviceResetArgs->deviceId;
+        }
+        case ClassifierEventType::HAL_RESET: {
+            return std::nullopt;
+        }
+        case ClassifierEventType::EXIT: {
+            return std::nullopt;
+        }
+    }
+}
+
+// --- MotionClassifier ---
+
+MotionClassifier::MotionClassifier(
+        sp<android::hardware::input::classifier::V1_0::IInputClassifier> service) :
+        mEvents(MAX_EVENTS), mService(service) {
+    mHalThread = std::thread(&MotionClassifier::callInputClassifierHal, this);
+#if defined(__linux__)
+    // Set the thread name for debugging
+    pthread_setname_np(mHalThread.native_handle(), "InputClassifier");
+#endif
+}
+
+MotionClassifier::~MotionClassifier() {
+    requestExit();
+    mHalThread.join();
+}
+
+void MotionClassifier::ensureHalThread(const char* function) {
+    if (DEBUG) {
+        if (std::this_thread::get_id() != mHalThread.get_id()) {
+            ALOGE("Function %s should only be called from InputClassifier thread", function);
+        }
+    }
+}
+
+/**
+ * Obtain the classification from the HAL for a given MotionEvent.
+ * Should only be called from the InputClassifier thread (mHalThread).
+ * Should not be called from the thread that notifyMotion runs on.
+ *
+ * There is no way to provide a timeout for a HAL call. So if the HAL takes too long
+ * to return a classification, this would directly impact the touch latency.
+ * To remove any possibility of negatively affecting the touch latency, the HAL
+ * is called from a dedicated thread.
+ */
+void MotionClassifier::callInputClassifierHal() {
+    ensureHalThread(__func__);
+    while (true) {
+        ClassifierEvent event = mEvents.pop();
+        switch (event.type) {
+            case ClassifierEventType::MOTION: {
+                NotifyMotionArgs* motionArgs = static_cast<NotifyMotionArgs*>(event.args.get());
+                common::V1_0::MotionEvent motionEvent = getMotionEvent(*motionArgs);
+                common::V1_0::Classification halClassification = mService->classify(motionEvent);
+                updateClassification(motionArgs->deviceId, motionArgs->eventTime,
+                        getMotionClassification(halClassification));
+                break;
+            }
+            case ClassifierEventType::DEVICE_RESET: {
+                const int32_t deviceId = *(event.getDeviceId());
+                mService->resetDevice(deviceId);
+                setClassification(deviceId, MotionClassification::NONE);
+                break;
+            }
+            case ClassifierEventType::HAL_RESET: {
+                mService->reset();
+                clearClassifications();
+                break;
+            }
+            case ClassifierEventType::EXIT: {
+                clearClassifications();
+                return;
+            }
+        }
+    }
+}
+
+void MotionClassifier::requestExit() {
+    reset();
+    mEvents.push(ClassifierEvent::createExitEvent());
+}
+
+void MotionClassifier::updateClassification(int32_t deviceId, nsecs_t eventTime,
+        MotionClassification classification) {
+    std::scoped_lock lock(mLock);
+    const nsecs_t lastDownTime = getValueForKey(mLastDownTimes, deviceId, static_cast<nsecs_t>(0));
+    if (eventTime < lastDownTime) {
+        // HAL just finished processing an event that belonged to an earlier gesture,
+        // but new gesture is already in progress. Drop this classification.
+        ALOGW("Received late classification. Late by at least %" PRId64 " ms.",
+                nanoseconds_to_milliseconds(lastDownTime - eventTime));
+        return;
+    }
+    mClassifications[deviceId] = classification;
+}
+
+void MotionClassifier::setClassification(int32_t deviceId, MotionClassification classification) {
+    std::scoped_lock lock(mLock);
+    mClassifications[deviceId] = classification;
+}
+
+void MotionClassifier::clearClassifications() {
+    std::scoped_lock lock(mLock);
+    mClassifications.clear();
+}
+
+MotionClassification MotionClassifier::getClassification(int32_t deviceId) {
+    std::scoped_lock lock(mLock);
+    return getValueForKey(mClassifications, deviceId, MotionClassification::NONE);
+}
+
+void MotionClassifier::updateLastDownTime(int32_t deviceId, nsecs_t downTime) {
+    std::scoped_lock lock(mLock);
+    mLastDownTimes[deviceId] = downTime;
+    mClassifications[deviceId] = MotionClassification::NONE;
+}
+
+MotionClassification MotionClassifier::classify(const NotifyMotionArgs& args) {
+    if (!mService) {
+        // If HAL is not present, do nothing
+        return MotionClassification::NONE;
+    }
+    if ((args.action & AMOTION_EVENT_ACTION_MASK) == AMOTION_EVENT_ACTION_DOWN) {
+        updateLastDownTime(args.deviceId, args.downTime);
+    }
+
+    ClassifierEvent event(std::make_unique<NotifyMotionArgs>(args));
+    bool elementAdded = mEvents.push(std::move(event));
+    if (!elementAdded) {
+        // Queue should not ever overfill. Suspect HAL is slow.
+        ALOGE("Dropped element with eventTime %" PRIu64, args.eventTime);
+        reset();
+        return MotionClassification::NONE;
+    }
+    return getClassification(args.deviceId);
+}
+
+void MotionClassifier::reset() {
+    mEvents.clear();
+    mEvents.push(ClassifierEvent::createHalResetEvent());
+}
+
+/**
+ * Per-device reset. Clear the outstanding events that are going to be sent to HAL.
+ * Request InputClassifier thread to call resetDevice for this particular device.
+ */
+void MotionClassifier::reset(const NotifyDeviceResetArgs& args) {
+    int32_t deviceId = args.deviceId;
+    // Clear the pending events right away, to avoid unnecessary work done by the HAL.
+    mEvents.erase([deviceId](const ClassifierEvent& event) {
+            std::optional<int32_t> eventDeviceId = event.getDeviceId();
+            return eventDeviceId && (*eventDeviceId == deviceId);
+    });
+    mEvents.push(std::make_unique<NotifyDeviceResetArgs>(args));
+}
+
+// --- InputClassifier ---
+
+InputClassifier::InputClassifier(const sp<InputListenerInterface>& listener) :
+        mListener(listener) {
+    if (deepPressEnabled()) {
+        sp<android::hardware::input::classifier::V1_0::IInputClassifier> service =
+                classifier::V1_0::IInputClassifier::getService();
+        if (service) {
+            mMotionClassifier = std::make_unique<MotionClassifier>(service);
+        } else {
+            ALOGI("Could not obtain InputClassifier HAL");
+        }
+    }
+};
+
+void InputClassifier::notifyConfigurationChanged(const NotifyConfigurationChangedArgs* args) {
+    // pass through
+    mListener->notifyConfigurationChanged(args);
+}
+
+void InputClassifier::notifyKey(const NotifyKeyArgs* args) {
+    // pass through
+    mListener->notifyKey(args);
+}
+
+void InputClassifier::notifyMotion(const NotifyMotionArgs* args) {
+    if (mMotionClassifier && isTouchEvent(*args)) {
+        // We only cover touch events, for now.
+        NotifyMotionArgs newArgs = NotifyMotionArgs(*args);
+        newArgs.classification = mMotionClassifier->classify(newArgs);
+        args = &newArgs;
+    }
+    mListener->notifyMotion(args);
+}
+
+void InputClassifier::notifySwitch(const NotifySwitchArgs* args) {
+    // pass through
+    mListener->notifySwitch(args);
+}
+
+void InputClassifier::notifyDeviceReset(const NotifyDeviceResetArgs* args) {
+    if (mMotionClassifier) {
+        mMotionClassifier->reset(*args);
+    }
+    // continue to next stage
+    mListener->notifyDeviceReset(args);
+}
+
+} // namespace android
\ No newline at end of file