Create inputreader directory

In order to start the work to split InputReader.cpp into multiple files,
we first create a reader directory to hold the source files for
libinputreader.

The affected files are also reformatted with clang-format.

Bug: 140139676
Test: libinputflinger and libinputflinger_tests builds successfully for
  crosshatch

Change-Id: I62b6b873e2a03e61655eb6214183c984306dcfdb
diff --git a/services/inputflinger/reader/include/InputReader.h b/services/inputflinger/reader/include/InputReader.h
new file mode 100644
index 0000000..1b8177c
--- /dev/null
+++ b/services/inputflinger/reader/include/InputReader.h
@@ -0,0 +1,1706 @@
+/*
+ * Copyright (C) 2010 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.
+ */
+
+#ifndef _UI_INPUT_READER_H
+#define _UI_INPUT_READER_H
+
+#include "EventHub.h"
+#include "InputListener.h"
+#include "InputReaderBase.h"
+#include "PointerControllerInterface.h"
+
+#include <input/DisplayViewport.h>
+#include <input/Input.h>
+#include <input/VelocityControl.h>
+#include <input/VelocityTracker.h>
+#include <ui/DisplayInfo.h>
+#include <utils/BitSet.h>
+#include <utils/Condition.h>
+#include <utils/KeyedVector.h>
+#include <utils/Mutex.h>
+#include <utils/Timers.h>
+
+#include <stddef.h>
+#include <unistd.h>
+#include <optional>
+#include <vector>
+
+namespace android {
+
+class InputDevice;
+class InputMapper;
+
+struct StylusState {
+    /* Time the stylus event was received. */
+    nsecs_t when;
+    /* Pressure as reported by the stylus, normalized to the range [0, 1.0]. */
+    float pressure;
+    /* The state of the stylus buttons as a bitfield (e.g. AMOTION_EVENT_BUTTON_SECONDARY). */
+    uint32_t buttons;
+    /* Which tool type the stylus is currently using (e.g. AMOTION_EVENT_TOOL_TYPE_ERASER). */
+    int32_t toolType;
+
+    void copyFrom(const StylusState& other) {
+        when = other.when;
+        pressure = other.pressure;
+        buttons = other.buttons;
+        toolType = other.toolType;
+    }
+
+    void clear() {
+        when = LLONG_MAX;
+        pressure = 0.f;
+        buttons = 0;
+        toolType = AMOTION_EVENT_TOOL_TYPE_UNKNOWN;
+    }
+};
+
+/* Internal interface used by individual input devices to access global input device state
+ * and parameters maintained by the input reader.
+ */
+class InputReaderContext {
+public:
+    InputReaderContext() {}
+    virtual ~InputReaderContext() {}
+
+    virtual void updateGlobalMetaState() = 0;
+    virtual int32_t getGlobalMetaState() = 0;
+
+    virtual void disableVirtualKeysUntil(nsecs_t time) = 0;
+    virtual bool shouldDropVirtualKey(nsecs_t now, InputDevice* device, int32_t keyCode,
+                                      int32_t scanCode) = 0;
+
+    virtual void fadePointer() = 0;
+
+    virtual void requestTimeoutAtTime(nsecs_t when) = 0;
+    virtual int32_t bumpGeneration() = 0;
+
+    virtual void getExternalStylusDevices(std::vector<InputDeviceInfo>& outDevices) = 0;
+    virtual void dispatchExternalStylusState(const StylusState& outState) = 0;
+
+    virtual InputReaderPolicyInterface* getPolicy() = 0;
+    virtual InputListenerInterface* getListener() = 0;
+    virtual EventHubInterface* getEventHub() = 0;
+
+    virtual uint32_t getNextSequenceNum() = 0;
+};
+
+/* The input reader reads raw event data from the event hub and processes it into input events
+ * that it sends to the input listener.  Some functions of the input reader, such as early
+ * event filtering in low power states, are controlled by a separate policy object.
+ *
+ * The InputReader owns a collection of InputMappers.  Most of the work it does happens
+ * on the input reader thread but the InputReader can receive queries from other system
+ * components running on arbitrary threads.  To keep things manageable, the InputReader
+ * uses a single Mutex to guard its state.  The Mutex may be held while calling into the
+ * EventHub or the InputReaderPolicy but it is never held while calling into the
+ * InputListener.
+ */
+class InputReader : public InputReaderInterface {
+public:
+    InputReader(std::shared_ptr<EventHubInterface> eventHub,
+                const sp<InputReaderPolicyInterface>& policy,
+                const sp<InputListenerInterface>& listener);
+    virtual ~InputReader();
+
+    virtual void dump(std::string& dump);
+    virtual void monitor();
+
+    virtual void loopOnce();
+
+    virtual void getInputDevices(std::vector<InputDeviceInfo>& outInputDevices);
+
+    virtual bool isInputDeviceEnabled(int32_t deviceId);
+
+    virtual int32_t getScanCodeState(int32_t deviceId, uint32_t sourceMask, int32_t scanCode);
+    virtual int32_t getKeyCodeState(int32_t deviceId, uint32_t sourceMask, int32_t keyCode);
+    virtual int32_t getSwitchState(int32_t deviceId, uint32_t sourceMask, int32_t sw);
+
+    virtual void toggleCapsLockState(int32_t deviceId);
+
+    virtual bool hasKeys(int32_t deviceId, uint32_t sourceMask, size_t numCodes,
+                         const int32_t* keyCodes, uint8_t* outFlags);
+
+    virtual void requestRefreshConfiguration(uint32_t changes);
+
+    virtual void vibrate(int32_t deviceId, const nsecs_t* pattern, size_t patternSize,
+                         ssize_t repeat, int32_t token);
+    virtual void cancelVibrate(int32_t deviceId, int32_t token);
+
+    virtual bool canDispatchToDisplay(int32_t deviceId, int32_t displayId);
+
+protected:
+    // These members are protected so they can be instrumented by test cases.
+    virtual InputDevice* createDeviceLocked(int32_t deviceId, int32_t controllerNumber,
+                                            const InputDeviceIdentifier& identifier,
+                                            uint32_t classes);
+
+    class ContextImpl : public InputReaderContext {
+        InputReader* mReader;
+
+    public:
+        explicit ContextImpl(InputReader* reader);
+
+        virtual void updateGlobalMetaState();
+        virtual int32_t getGlobalMetaState();
+        virtual void disableVirtualKeysUntil(nsecs_t time);
+        virtual bool shouldDropVirtualKey(nsecs_t now, InputDevice* device, int32_t keyCode,
+                                          int32_t scanCode);
+        virtual void fadePointer();
+        virtual void requestTimeoutAtTime(nsecs_t when);
+        virtual int32_t bumpGeneration();
+        virtual void getExternalStylusDevices(std::vector<InputDeviceInfo>& outDevices);
+        virtual void dispatchExternalStylusState(const StylusState& outState);
+        virtual InputReaderPolicyInterface* getPolicy();
+        virtual InputListenerInterface* getListener();
+        virtual EventHubInterface* getEventHub();
+        virtual uint32_t getNextSequenceNum();
+    } mContext;
+
+    friend class ContextImpl;
+
+private:
+    Mutex mLock;
+
+    Condition mReaderIsAliveCondition;
+
+    // This could be unique_ptr, but due to the way InputReader tests are written,
+    // it is made shared_ptr here. In the tests, an EventHub reference is retained by the test
+    // in parallel to passing it to the InputReader.
+    std::shared_ptr<EventHubInterface> mEventHub;
+    sp<InputReaderPolicyInterface> mPolicy;
+    sp<QueuedInputListener> mQueuedListener;
+
+    InputReaderConfiguration mConfig;
+
+    // used by InputReaderContext::getNextSequenceNum() as a counter for event sequence numbers
+    uint32_t mNextSequenceNum;
+
+    // The event queue.
+    static const int EVENT_BUFFER_SIZE = 256;
+    RawEvent mEventBuffer[EVENT_BUFFER_SIZE];
+
+    KeyedVector<int32_t, InputDevice*> mDevices;
+
+    // low-level input event decoding and device management
+    void processEventsLocked(const RawEvent* rawEvents, size_t count);
+
+    void addDeviceLocked(nsecs_t when, int32_t deviceId);
+    void removeDeviceLocked(nsecs_t when, int32_t deviceId);
+    void processEventsForDeviceLocked(int32_t deviceId, const RawEvent* rawEvents, size_t count);
+    void timeoutExpiredLocked(nsecs_t when);
+
+    void handleConfigurationChangedLocked(nsecs_t when);
+
+    int32_t mGlobalMetaState;
+    void updateGlobalMetaStateLocked();
+    int32_t getGlobalMetaStateLocked();
+
+    void notifyExternalStylusPresenceChanged();
+    void getExternalStylusDevicesLocked(std::vector<InputDeviceInfo>& outDevices);
+    void dispatchExternalStylusState(const StylusState& state);
+
+    void fadePointerLocked();
+
+    int32_t mGeneration;
+    int32_t bumpGenerationLocked();
+
+    void getInputDevicesLocked(std::vector<InputDeviceInfo>& outInputDevices);
+
+    nsecs_t mDisableVirtualKeysTimeout;
+    void disableVirtualKeysUntilLocked(nsecs_t time);
+    bool shouldDropVirtualKeyLocked(nsecs_t now, InputDevice* device, int32_t keyCode,
+                                    int32_t scanCode);
+
+    nsecs_t mNextTimeout;
+    void requestTimeoutAtTimeLocked(nsecs_t when);
+
+    uint32_t mConfigurationChangesToRefresh;
+    void refreshConfigurationLocked(uint32_t changes);
+
+    // state queries
+    typedef int32_t (InputDevice::*GetStateFunc)(uint32_t sourceMask, int32_t code);
+    int32_t getStateLocked(int32_t deviceId, uint32_t sourceMask, int32_t code,
+                           GetStateFunc getStateFunc);
+    bool markSupportedKeyCodesLocked(int32_t deviceId, uint32_t sourceMask, size_t numCodes,
+                                     const int32_t* keyCodes, uint8_t* outFlags);
+};
+
+/* Represents the state of a single input device. */
+class InputDevice {
+public:
+    InputDevice(InputReaderContext* context, int32_t id, int32_t generation,
+                int32_t controllerNumber, const InputDeviceIdentifier& identifier,
+                uint32_t classes);
+    ~InputDevice();
+
+    inline InputReaderContext* getContext() { return mContext; }
+    inline int32_t getId() const { return mId; }
+    inline int32_t getControllerNumber() const { return mControllerNumber; }
+    inline int32_t getGeneration() const { return mGeneration; }
+    inline const std::string getName() const { return mIdentifier.name; }
+    inline const std::string getDescriptor() { return mIdentifier.descriptor; }
+    inline uint32_t getClasses() const { return mClasses; }
+    inline uint32_t getSources() const { return mSources; }
+
+    inline bool isExternal() { return mIsExternal; }
+    inline void setExternal(bool external) { mIsExternal = external; }
+    inline std::optional<uint8_t> getAssociatedDisplayPort() const {
+        return mAssociatedDisplayPort;
+    }
+    inline std::optional<DisplayViewport> getAssociatedViewport() const {
+        return mAssociatedViewport;
+    }
+    inline void setMic(bool hasMic) { mHasMic = hasMic; }
+    inline bool hasMic() const { return mHasMic; }
+
+    inline bool isIgnored() { return mMappers.empty(); }
+
+    bool isEnabled();
+    void setEnabled(bool enabled, nsecs_t when);
+
+    void dump(std::string& dump);
+    void addMapper(InputMapper* mapper);
+    void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    void reset(nsecs_t when);
+    void process(const RawEvent* rawEvents, size_t count);
+    void timeoutExpired(nsecs_t when);
+    void updateExternalStylusState(const StylusState& state);
+
+    void getDeviceInfo(InputDeviceInfo* outDeviceInfo);
+    int32_t getKeyCodeState(uint32_t sourceMask, int32_t keyCode);
+    int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);
+    int32_t getSwitchState(uint32_t sourceMask, int32_t switchCode);
+    bool markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes, const int32_t* keyCodes,
+                               uint8_t* outFlags);
+    void vibrate(const nsecs_t* pattern, size_t patternSize, ssize_t repeat, int32_t token);
+    void cancelVibrate(int32_t token);
+    void cancelTouch(nsecs_t when);
+
+    int32_t getMetaState();
+    void updateMetaState(int32_t keyCode);
+
+    void fadePointer();
+
+    void bumpGeneration();
+
+    void notifyReset(nsecs_t when);
+
+    inline const PropertyMap& getConfiguration() { return mConfiguration; }
+    inline EventHubInterface* getEventHub() { return mContext->getEventHub(); }
+
+    bool hasKey(int32_t code) { return getEventHub()->hasScanCode(mId, code); }
+
+    bool hasAbsoluteAxis(int32_t code) {
+        RawAbsoluteAxisInfo info;
+        getEventHub()->getAbsoluteAxisInfo(mId, code, &info);
+        return info.valid;
+    }
+
+    bool isKeyPressed(int32_t code) {
+        return getEventHub()->getScanCodeState(mId, code) == AKEY_STATE_DOWN;
+    }
+
+    int32_t getAbsoluteAxisValue(int32_t code) {
+        int32_t value;
+        getEventHub()->getAbsoluteAxisValue(mId, code, &value);
+        return value;
+    }
+
+    std::optional<int32_t> getAssociatedDisplayId();
+
+private:
+    InputReaderContext* mContext;
+    int32_t mId;
+    int32_t mGeneration;
+    int32_t mControllerNumber;
+    InputDeviceIdentifier mIdentifier;
+    std::string mAlias;
+    uint32_t mClasses;
+
+    std::vector<InputMapper*> mMappers;
+
+    uint32_t mSources;
+    bool mIsExternal;
+    std::optional<uint8_t> mAssociatedDisplayPort;
+    std::optional<DisplayViewport> mAssociatedViewport;
+    bool mHasMic;
+    bool mDropUntilNextSync;
+
+    typedef int32_t (InputMapper::*GetStateFunc)(uint32_t sourceMask, int32_t code);
+    int32_t getState(uint32_t sourceMask, int32_t code, GetStateFunc getStateFunc);
+
+    PropertyMap mConfiguration;
+};
+
+/* Keeps track of the state of mouse or touch pad buttons. */
+class CursorButtonAccumulator {
+public:
+    CursorButtonAccumulator();
+    void reset(InputDevice* device);
+
+    void process(const RawEvent* rawEvent);
+
+    uint32_t getButtonState() const;
+
+private:
+    bool mBtnLeft;
+    bool mBtnRight;
+    bool mBtnMiddle;
+    bool mBtnBack;
+    bool mBtnSide;
+    bool mBtnForward;
+    bool mBtnExtra;
+    bool mBtnTask;
+
+    void clearButtons();
+};
+
+/* Keeps track of cursor movements. */
+
+class CursorMotionAccumulator {
+public:
+    CursorMotionAccumulator();
+    void reset(InputDevice* device);
+
+    void process(const RawEvent* rawEvent);
+    void finishSync();
+
+    inline int32_t getRelativeX() const { return mRelX; }
+    inline int32_t getRelativeY() const { return mRelY; }
+
+private:
+    int32_t mRelX;
+    int32_t mRelY;
+
+    void clearRelativeAxes();
+};
+
+/* Keeps track of cursor scrolling motions. */
+
+class CursorScrollAccumulator {
+public:
+    CursorScrollAccumulator();
+    void configure(InputDevice* device);
+    void reset(InputDevice* device);
+
+    void process(const RawEvent* rawEvent);
+    void finishSync();
+
+    inline bool haveRelativeVWheel() const { return mHaveRelWheel; }
+    inline bool haveRelativeHWheel() const { return mHaveRelHWheel; }
+
+    inline int32_t getRelativeX() const { return mRelX; }
+    inline int32_t getRelativeY() const { return mRelY; }
+    inline int32_t getRelativeVWheel() const { return mRelWheel; }
+    inline int32_t getRelativeHWheel() const { return mRelHWheel; }
+
+private:
+    bool mHaveRelWheel;
+    bool mHaveRelHWheel;
+
+    int32_t mRelX;
+    int32_t mRelY;
+    int32_t mRelWheel;
+    int32_t mRelHWheel;
+
+    void clearRelativeAxes();
+};
+
+/* Keeps track of the state of touch, stylus and tool buttons. */
+class TouchButtonAccumulator {
+public:
+    TouchButtonAccumulator();
+    void configure(InputDevice* device);
+    void reset(InputDevice* device);
+
+    void process(const RawEvent* rawEvent);
+
+    uint32_t getButtonState() const;
+    int32_t getToolType() const;
+    bool isToolActive() const;
+    bool isHovering() const;
+    bool hasStylus() const;
+
+private:
+    bool mHaveBtnTouch;
+    bool mHaveStylus;
+
+    bool mBtnTouch;
+    bool mBtnStylus;
+    bool mBtnStylus2;
+    bool mBtnToolFinger;
+    bool mBtnToolPen;
+    bool mBtnToolRubber;
+    bool mBtnToolBrush;
+    bool mBtnToolPencil;
+    bool mBtnToolAirbrush;
+    bool mBtnToolMouse;
+    bool mBtnToolLens;
+    bool mBtnToolDoubleTap;
+    bool mBtnToolTripleTap;
+    bool mBtnToolQuadTap;
+
+    void clearButtons();
+};
+
+/* Raw axis information from the driver. */
+struct RawPointerAxes {
+    RawAbsoluteAxisInfo x;
+    RawAbsoluteAxisInfo y;
+    RawAbsoluteAxisInfo pressure;
+    RawAbsoluteAxisInfo touchMajor;
+    RawAbsoluteAxisInfo touchMinor;
+    RawAbsoluteAxisInfo toolMajor;
+    RawAbsoluteAxisInfo toolMinor;
+    RawAbsoluteAxisInfo orientation;
+    RawAbsoluteAxisInfo distance;
+    RawAbsoluteAxisInfo tiltX;
+    RawAbsoluteAxisInfo tiltY;
+    RawAbsoluteAxisInfo trackingId;
+    RawAbsoluteAxisInfo slot;
+
+    RawPointerAxes();
+    inline int32_t getRawWidth() const { return x.maxValue - x.minValue + 1; }
+    inline int32_t getRawHeight() const { return y.maxValue - y.minValue + 1; }
+    void clear();
+};
+
+/* Raw data for a collection of pointers including a pointer id mapping table. */
+struct RawPointerData {
+    struct Pointer {
+        uint32_t id;
+        int32_t x;
+        int32_t y;
+        int32_t pressure;
+        int32_t touchMajor;
+        int32_t touchMinor;
+        int32_t toolMajor;
+        int32_t toolMinor;
+        int32_t orientation;
+        int32_t distance;
+        int32_t tiltX;
+        int32_t tiltY;
+        int32_t toolType; // a fully decoded AMOTION_EVENT_TOOL_TYPE constant
+        bool isHovering;
+    };
+
+    uint32_t pointerCount;
+    Pointer pointers[MAX_POINTERS];
+    BitSet32 hoveringIdBits, touchingIdBits;
+    uint32_t idToIndex[MAX_POINTER_ID + 1];
+
+    RawPointerData();
+    void clear();
+    void copyFrom(const RawPointerData& other);
+    void getCentroidOfTouchingPointers(float* outX, float* outY) const;
+
+    inline void markIdBit(uint32_t id, bool isHovering) {
+        if (isHovering) {
+            hoveringIdBits.markBit(id);
+        } else {
+            touchingIdBits.markBit(id);
+        }
+    }
+
+    inline void clearIdBits() {
+        hoveringIdBits.clear();
+        touchingIdBits.clear();
+    }
+
+    inline const Pointer& pointerForId(uint32_t id) const { return pointers[idToIndex[id]]; }
+
+    inline bool isHovering(uint32_t pointerIndex) { return pointers[pointerIndex].isHovering; }
+};
+
+/* Cooked data for a collection of pointers including a pointer id mapping table. */
+struct CookedPointerData {
+    uint32_t pointerCount;
+    PointerProperties pointerProperties[MAX_POINTERS];
+    PointerCoords pointerCoords[MAX_POINTERS];
+    BitSet32 hoveringIdBits, touchingIdBits;
+    uint32_t idToIndex[MAX_POINTER_ID + 1];
+
+    CookedPointerData();
+    void clear();
+    void copyFrom(const CookedPointerData& other);
+
+    inline const PointerCoords& pointerCoordsForId(uint32_t id) const {
+        return pointerCoords[idToIndex[id]];
+    }
+
+    inline PointerCoords& editPointerCoordsWithId(uint32_t id) {
+        return pointerCoords[idToIndex[id]];
+    }
+
+    inline PointerProperties& editPointerPropertiesWithId(uint32_t id) {
+        return pointerProperties[idToIndex[id]];
+    }
+
+    inline bool isHovering(uint32_t pointerIndex) const {
+        return hoveringIdBits.hasBit(pointerProperties[pointerIndex].id);
+    }
+
+    inline bool isTouching(uint32_t pointerIndex) const {
+        return touchingIdBits.hasBit(pointerProperties[pointerIndex].id);
+    }
+};
+
+/* Keeps track of the state of single-touch protocol. */
+class SingleTouchMotionAccumulator {
+public:
+    SingleTouchMotionAccumulator();
+
+    void process(const RawEvent* rawEvent);
+    void reset(InputDevice* device);
+
+    inline int32_t getAbsoluteX() const { return mAbsX; }
+    inline int32_t getAbsoluteY() const { return mAbsY; }
+    inline int32_t getAbsolutePressure() const { return mAbsPressure; }
+    inline int32_t getAbsoluteToolWidth() const { return mAbsToolWidth; }
+    inline int32_t getAbsoluteDistance() const { return mAbsDistance; }
+    inline int32_t getAbsoluteTiltX() const { return mAbsTiltX; }
+    inline int32_t getAbsoluteTiltY() const { return mAbsTiltY; }
+
+private:
+    int32_t mAbsX;
+    int32_t mAbsY;
+    int32_t mAbsPressure;
+    int32_t mAbsToolWidth;
+    int32_t mAbsDistance;
+    int32_t mAbsTiltX;
+    int32_t mAbsTiltY;
+
+    void clearAbsoluteAxes();
+};
+
+/* Keeps track of the state of multi-touch protocol. */
+class MultiTouchMotionAccumulator {
+public:
+    class Slot {
+    public:
+        inline bool isInUse() const { return mInUse; }
+        inline int32_t getX() const { return mAbsMTPositionX; }
+        inline int32_t getY() const { return mAbsMTPositionY; }
+        inline int32_t getTouchMajor() const { return mAbsMTTouchMajor; }
+        inline int32_t getTouchMinor() const {
+            return mHaveAbsMTTouchMinor ? mAbsMTTouchMinor : mAbsMTTouchMajor;
+        }
+        inline int32_t getToolMajor() const { return mAbsMTWidthMajor; }
+        inline int32_t getToolMinor() const {
+            return mHaveAbsMTWidthMinor ? mAbsMTWidthMinor : mAbsMTWidthMajor;
+        }
+        inline int32_t getOrientation() const { return mAbsMTOrientation; }
+        inline int32_t getTrackingId() const { return mAbsMTTrackingId; }
+        inline int32_t getPressure() const { return mAbsMTPressure; }
+        inline int32_t getDistance() const { return mAbsMTDistance; }
+        inline int32_t getToolType() const;
+
+    private:
+        friend class MultiTouchMotionAccumulator;
+
+        bool mInUse;
+        bool mHaveAbsMTTouchMinor;
+        bool mHaveAbsMTWidthMinor;
+        bool mHaveAbsMTToolType;
+
+        int32_t mAbsMTPositionX;
+        int32_t mAbsMTPositionY;
+        int32_t mAbsMTTouchMajor;
+        int32_t mAbsMTTouchMinor;
+        int32_t mAbsMTWidthMajor;
+        int32_t mAbsMTWidthMinor;
+        int32_t mAbsMTOrientation;
+        int32_t mAbsMTTrackingId;
+        int32_t mAbsMTPressure;
+        int32_t mAbsMTDistance;
+        int32_t mAbsMTToolType;
+
+        Slot();
+        void clear();
+    };
+
+    MultiTouchMotionAccumulator();
+    ~MultiTouchMotionAccumulator();
+
+    void configure(InputDevice* device, size_t slotCount, bool usingSlotsProtocol);
+    void reset(InputDevice* device);
+    void process(const RawEvent* rawEvent);
+    void finishSync();
+    bool hasStylus() const;
+
+    inline size_t getSlotCount() const { return mSlotCount; }
+    inline const Slot* getSlot(size_t index) const { return &mSlots[index]; }
+
+private:
+    int32_t mCurrentSlot;
+    Slot* mSlots;
+    size_t mSlotCount;
+    bool mUsingSlotsProtocol;
+    bool mHaveStylus;
+
+    void clearSlots(int32_t initialSlot);
+};
+
+/* An input mapper transforms raw input events into cooked event data.
+ * A single input device can have multiple associated input mappers in order to interpret
+ * different classes of events.
+ *
+ * InputMapper lifecycle:
+ * - create
+ * - configure with 0 changes
+ * - reset
+ * - process, process, process (may occasionally reconfigure with non-zero changes or reset)
+ * - reset
+ * - destroy
+ */
+class InputMapper {
+public:
+    explicit InputMapper(InputDevice* device);
+    virtual ~InputMapper();
+
+    inline InputDevice* getDevice() { return mDevice; }
+    inline int32_t getDeviceId() { return mDevice->getId(); }
+    inline const std::string getDeviceName() { return mDevice->getName(); }
+    inline InputReaderContext* getContext() { return mContext; }
+    inline InputReaderPolicyInterface* getPolicy() { return mContext->getPolicy(); }
+    inline InputListenerInterface* getListener() { return mContext->getListener(); }
+    inline EventHubInterface* getEventHub() { return mContext->getEventHub(); }
+
+    virtual uint32_t getSources() = 0;
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent) = 0;
+    virtual void timeoutExpired(nsecs_t when);
+
+    virtual int32_t getKeyCodeState(uint32_t sourceMask, int32_t keyCode);
+    virtual int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);
+    virtual int32_t getSwitchState(uint32_t sourceMask, int32_t switchCode);
+    virtual bool markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
+                                       const int32_t* keyCodes, uint8_t* outFlags);
+    virtual void vibrate(const nsecs_t* pattern, size_t patternSize, ssize_t repeat, int32_t token);
+    virtual void cancelVibrate(int32_t token);
+    virtual void cancelTouch(nsecs_t when);
+
+    virtual int32_t getMetaState();
+    virtual void updateMetaState(int32_t keyCode);
+
+    virtual void updateExternalStylusState(const StylusState& state);
+
+    virtual void fadePointer();
+    virtual std::optional<int32_t> getAssociatedDisplayId() { return std::nullopt; }
+
+protected:
+    InputDevice* mDevice;
+    InputReaderContext* mContext;
+
+    status_t getAbsoluteAxisInfo(int32_t axis, RawAbsoluteAxisInfo* axisInfo);
+    void bumpGeneration();
+
+    static void dumpRawAbsoluteAxisInfo(std::string& dump, const RawAbsoluteAxisInfo& axis,
+                                        const char* name);
+    static void dumpStylusState(std::string& dump, const StylusState& state);
+};
+
+class SwitchInputMapper : public InputMapper {
+public:
+    explicit SwitchInputMapper(InputDevice* device);
+    virtual ~SwitchInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void process(const RawEvent* rawEvent);
+
+    virtual int32_t getSwitchState(uint32_t sourceMask, int32_t switchCode);
+    virtual void dump(std::string& dump);
+
+private:
+    uint32_t mSwitchValues;
+    uint32_t mUpdatedSwitchMask;
+
+    void processSwitch(int32_t switchCode, int32_t switchValue);
+    void sync(nsecs_t when);
+};
+
+class VibratorInputMapper : public InputMapper {
+public:
+    explicit VibratorInputMapper(InputDevice* device);
+    virtual ~VibratorInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void process(const RawEvent* rawEvent);
+
+    virtual void vibrate(const nsecs_t* pattern, size_t patternSize, ssize_t repeat, int32_t token);
+    virtual void cancelVibrate(int32_t token);
+    virtual void timeoutExpired(nsecs_t when);
+    virtual void dump(std::string& dump);
+
+private:
+    bool mVibrating;
+    nsecs_t mPattern[MAX_VIBRATE_PATTERN_SIZE];
+    size_t mPatternSize;
+    ssize_t mRepeat;
+    int32_t mToken;
+    ssize_t mIndex;
+    nsecs_t mNextStepTime;
+
+    void nextStep();
+    void stopVibrating();
+};
+
+class KeyboardInputMapper : public InputMapper {
+public:
+    KeyboardInputMapper(InputDevice* device, uint32_t source, int32_t keyboardType);
+    virtual ~KeyboardInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+    virtual int32_t getKeyCodeState(uint32_t sourceMask, int32_t keyCode);
+    virtual int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);
+    virtual bool markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
+                                       const int32_t* keyCodes, uint8_t* outFlags);
+
+    virtual int32_t getMetaState();
+    virtual void updateMetaState(int32_t keyCode);
+    virtual std::optional<int32_t> getAssociatedDisplayId();
+
+private:
+    // The current viewport.
+    std::optional<DisplayViewport> mViewport;
+
+    struct KeyDown {
+        int32_t keyCode;
+        int32_t scanCode;
+    };
+
+    uint32_t mSource;
+    int32_t mKeyboardType;
+
+    std::vector<KeyDown> mKeyDowns; // keys that are down
+    int32_t mMetaState;
+    nsecs_t mDownTime; // time of most recent key down
+
+    int32_t mCurrentHidUsage; // most recent HID usage seen this packet, or 0 if none
+
+    struct LedState {
+        bool avail; // led is available
+        bool on;    // we think the led is currently on
+    };
+    LedState mCapsLockLedState;
+    LedState mNumLockLedState;
+    LedState mScrollLockLedState;
+
+    // Immutable configuration parameters.
+    struct Parameters {
+        bool orientationAware;
+        bool handlesKeyRepeat;
+    } mParameters;
+
+    void configureParameters();
+    void dumpParameters(std::string& dump);
+
+    int32_t getOrientation();
+    int32_t getDisplayId();
+
+    bool isKeyboardOrGamepadKey(int32_t scanCode);
+    bool isMediaKey(int32_t keyCode);
+
+    void processKey(nsecs_t when, bool down, int32_t scanCode, int32_t usageCode);
+
+    bool updateMetaStateIfNeeded(int32_t keyCode, bool down);
+
+    ssize_t findKeyDown(int32_t scanCode);
+
+    void resetLedState();
+    void initializeLedState(LedState& ledState, int32_t led);
+    void updateLedState(bool reset);
+    void updateLedStateForModifier(LedState& ledState, int32_t led, int32_t modifier, bool reset);
+    std::optional<DisplayViewport> findViewport(nsecs_t when,
+                                                const InputReaderConfiguration* config);
+};
+
+class CursorInputMapper : public InputMapper {
+public:
+    explicit CursorInputMapper(InputDevice* device);
+    virtual ~CursorInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+    virtual int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);
+
+    virtual void fadePointer();
+
+    virtual std::optional<int32_t> getAssociatedDisplayId();
+
+private:
+    // Amount that trackball needs to move in order to generate a key event.
+    static const int32_t TRACKBALL_MOVEMENT_THRESHOLD = 6;
+
+    // Immutable configuration parameters.
+    struct Parameters {
+        enum Mode {
+            MODE_POINTER,
+            MODE_POINTER_RELATIVE,
+            MODE_NAVIGATION,
+        };
+
+        Mode mode;
+        bool hasAssociatedDisplay;
+        bool orientationAware;
+    } mParameters;
+
+    CursorButtonAccumulator mCursorButtonAccumulator;
+    CursorMotionAccumulator mCursorMotionAccumulator;
+    CursorScrollAccumulator mCursorScrollAccumulator;
+
+    int32_t mSource;
+    float mXScale;
+    float mYScale;
+    float mXPrecision;
+    float mYPrecision;
+
+    float mVWheelScale;
+    float mHWheelScale;
+
+    // Velocity controls for mouse pointer and wheel movements.
+    // The controls for X and Y wheel movements are separate to keep them decoupled.
+    VelocityControl mPointerVelocityControl;
+    VelocityControl mWheelXVelocityControl;
+    VelocityControl mWheelYVelocityControl;
+
+    int32_t mOrientation;
+
+    sp<PointerControllerInterface> mPointerController;
+
+    int32_t mButtonState;
+    nsecs_t mDownTime;
+
+    void configureParameters();
+    void dumpParameters(std::string& dump);
+
+    void sync(nsecs_t when);
+};
+
+class RotaryEncoderInputMapper : public InputMapper {
+public:
+    explicit RotaryEncoderInputMapper(InputDevice* device);
+    virtual ~RotaryEncoderInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+private:
+    CursorScrollAccumulator mRotaryEncoderScrollAccumulator;
+
+    int32_t mSource;
+    float mScalingFactor;
+    int32_t mOrientation;
+
+    void sync(nsecs_t when);
+};
+
+class TouchInputMapper : public InputMapper {
+public:
+    explicit TouchInputMapper(InputDevice* device);
+    virtual ~TouchInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+    virtual int32_t getKeyCodeState(uint32_t sourceMask, int32_t keyCode);
+    virtual int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);
+    virtual bool markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
+                                       const int32_t* keyCodes, uint8_t* outFlags);
+
+    virtual void fadePointer();
+    virtual void cancelTouch(nsecs_t when);
+    virtual void timeoutExpired(nsecs_t when);
+    virtual void updateExternalStylusState(const StylusState& state);
+    virtual std::optional<int32_t> getAssociatedDisplayId();
+
+protected:
+    CursorButtonAccumulator mCursorButtonAccumulator;
+    CursorScrollAccumulator mCursorScrollAccumulator;
+    TouchButtonAccumulator mTouchButtonAccumulator;
+
+    struct VirtualKey {
+        int32_t keyCode;
+        int32_t scanCode;
+        uint32_t flags;
+
+        // computed hit box, specified in touch screen coords based on known display size
+        int32_t hitLeft;
+        int32_t hitTop;
+        int32_t hitRight;
+        int32_t hitBottom;
+
+        inline bool isHit(int32_t x, int32_t y) const {
+            return x >= hitLeft && x <= hitRight && y >= hitTop && y <= hitBottom;
+        }
+    };
+
+    // Input sources and device mode.
+    uint32_t mSource;
+
+    enum DeviceMode {
+        DEVICE_MODE_DISABLED,   // input is disabled
+        DEVICE_MODE_DIRECT,     // direct mapping (touchscreen)
+        DEVICE_MODE_UNSCALED,   // unscaled mapping (touchpad)
+        DEVICE_MODE_NAVIGATION, // unscaled mapping with assist gesture (touch navigation)
+        DEVICE_MODE_POINTER,    // pointer mapping (pointer)
+    };
+    DeviceMode mDeviceMode;
+
+    // The reader's configuration.
+    InputReaderConfiguration mConfig;
+
+    // Immutable configuration parameters.
+    struct Parameters {
+        enum DeviceType {
+            DEVICE_TYPE_TOUCH_SCREEN,
+            DEVICE_TYPE_TOUCH_PAD,
+            DEVICE_TYPE_TOUCH_NAVIGATION,
+            DEVICE_TYPE_POINTER,
+        };
+
+        DeviceType deviceType;
+        bool hasAssociatedDisplay;
+        bool associatedDisplayIsExternal;
+        bool orientationAware;
+        bool hasButtonUnderPad;
+        std::string uniqueDisplayId;
+
+        enum GestureMode {
+            GESTURE_MODE_SINGLE_TOUCH,
+            GESTURE_MODE_MULTI_TOUCH,
+        };
+        GestureMode gestureMode;
+
+        bool wake;
+    } mParameters;
+
+    // Immutable calibration parameters in parsed form.
+    struct Calibration {
+        // Size
+        enum SizeCalibration {
+            SIZE_CALIBRATION_DEFAULT,
+            SIZE_CALIBRATION_NONE,
+            SIZE_CALIBRATION_GEOMETRIC,
+            SIZE_CALIBRATION_DIAMETER,
+            SIZE_CALIBRATION_BOX,
+            SIZE_CALIBRATION_AREA,
+        };
+
+        SizeCalibration sizeCalibration;
+
+        bool haveSizeScale;
+        float sizeScale;
+        bool haveSizeBias;
+        float sizeBias;
+        bool haveSizeIsSummed;
+        bool sizeIsSummed;
+
+        // Pressure
+        enum PressureCalibration {
+            PRESSURE_CALIBRATION_DEFAULT,
+            PRESSURE_CALIBRATION_NONE,
+            PRESSURE_CALIBRATION_PHYSICAL,
+            PRESSURE_CALIBRATION_AMPLITUDE,
+        };
+
+        PressureCalibration pressureCalibration;
+        bool havePressureScale;
+        float pressureScale;
+
+        // Orientation
+        enum OrientationCalibration {
+            ORIENTATION_CALIBRATION_DEFAULT,
+            ORIENTATION_CALIBRATION_NONE,
+            ORIENTATION_CALIBRATION_INTERPOLATED,
+            ORIENTATION_CALIBRATION_VECTOR,
+        };
+
+        OrientationCalibration orientationCalibration;
+
+        // Distance
+        enum DistanceCalibration {
+            DISTANCE_CALIBRATION_DEFAULT,
+            DISTANCE_CALIBRATION_NONE,
+            DISTANCE_CALIBRATION_SCALED,
+        };
+
+        DistanceCalibration distanceCalibration;
+        bool haveDistanceScale;
+        float distanceScale;
+
+        enum CoverageCalibration {
+            COVERAGE_CALIBRATION_DEFAULT,
+            COVERAGE_CALIBRATION_NONE,
+            COVERAGE_CALIBRATION_BOX,
+        };
+
+        CoverageCalibration coverageCalibration;
+
+        inline void applySizeScaleAndBias(float* outSize) const {
+            if (haveSizeScale) {
+                *outSize *= sizeScale;
+            }
+            if (haveSizeBias) {
+                *outSize += sizeBias;
+            }
+            if (*outSize < 0) {
+                *outSize = 0;
+            }
+        }
+    } mCalibration;
+
+    // Affine location transformation/calibration
+    struct TouchAffineTransformation mAffineTransform;
+
+    RawPointerAxes mRawPointerAxes;
+
+    struct RawState {
+        nsecs_t when;
+
+        // Raw pointer sample data.
+        RawPointerData rawPointerData;
+
+        int32_t buttonState;
+
+        // Scroll state.
+        int32_t rawVScroll;
+        int32_t rawHScroll;
+
+        void copyFrom(const RawState& other) {
+            when = other.when;
+            rawPointerData.copyFrom(other.rawPointerData);
+            buttonState = other.buttonState;
+            rawVScroll = other.rawVScroll;
+            rawHScroll = other.rawHScroll;
+        }
+
+        void clear() {
+            when = 0;
+            rawPointerData.clear();
+            buttonState = 0;
+            rawVScroll = 0;
+            rawHScroll = 0;
+        }
+    };
+
+    struct CookedState {
+        // Cooked pointer sample data.
+        CookedPointerData cookedPointerData;
+
+        // Id bits used to differentiate fingers, stylus and mouse tools.
+        BitSet32 fingerIdBits;
+        BitSet32 stylusIdBits;
+        BitSet32 mouseIdBits;
+
+        int32_t buttonState;
+
+        void copyFrom(const CookedState& other) {
+            cookedPointerData.copyFrom(other.cookedPointerData);
+            fingerIdBits = other.fingerIdBits;
+            stylusIdBits = other.stylusIdBits;
+            mouseIdBits = other.mouseIdBits;
+            buttonState = other.buttonState;
+        }
+
+        void clear() {
+            cookedPointerData.clear();
+            fingerIdBits.clear();
+            stylusIdBits.clear();
+            mouseIdBits.clear();
+            buttonState = 0;
+        }
+    };
+
+    std::vector<RawState> mRawStatesPending;
+    RawState mCurrentRawState;
+    CookedState mCurrentCookedState;
+    RawState mLastRawState;
+    CookedState mLastCookedState;
+
+    // State provided by an external stylus
+    StylusState mExternalStylusState;
+    int64_t mExternalStylusId;
+    nsecs_t mExternalStylusFusionTimeout;
+    bool mExternalStylusDataPending;
+
+    // True if we sent a HOVER_ENTER event.
+    bool mSentHoverEnter;
+
+    // Have we assigned pointer IDs for this stream
+    bool mHavePointerIds;
+
+    // Is the current stream of direct touch events aborted
+    bool mCurrentMotionAborted;
+
+    // The time the primary pointer last went down.
+    nsecs_t mDownTime;
+
+    // The pointer controller, or null if the device is not a pointer.
+    sp<PointerControllerInterface> mPointerController;
+
+    std::vector<VirtualKey> mVirtualKeys;
+
+    virtual void configureParameters();
+    virtual void dumpParameters(std::string& dump);
+    virtual void configureRawPointerAxes();
+    virtual void dumpRawPointerAxes(std::string& dump);
+    virtual void configureSurface(nsecs_t when, bool* outResetNeeded);
+    virtual void dumpSurface(std::string& dump);
+    virtual void configureVirtualKeys();
+    virtual void dumpVirtualKeys(std::string& dump);
+    virtual void parseCalibration();
+    virtual void resolveCalibration();
+    virtual void dumpCalibration(std::string& dump);
+    virtual void updateAffineTransformation();
+    virtual void dumpAffineTransformation(std::string& dump);
+    virtual void resolveExternalStylusPresence();
+    virtual bool hasStylus() const = 0;
+    virtual bool hasExternalStylus() const;
+
+    virtual void syncTouch(nsecs_t when, RawState* outState) = 0;
+
+private:
+    // The current viewport.
+    // The components of the viewport are specified in the display's rotated orientation.
+    DisplayViewport mViewport;
+
+    // The surface orientation, width and height set by configureSurface().
+    // The width and height are derived from the viewport but are specified
+    // in the natural orientation.
+    // The surface origin specifies how the surface coordinates should be translated
+    // to align with the logical display coordinate space.
+    int32_t mSurfaceWidth;
+    int32_t mSurfaceHeight;
+    int32_t mSurfaceLeft;
+    int32_t mSurfaceTop;
+
+    // Similar to the surface coordinates, but in the raw display coordinate space rather than in
+    // the logical coordinate space.
+    int32_t mPhysicalWidth;
+    int32_t mPhysicalHeight;
+    int32_t mPhysicalLeft;
+    int32_t mPhysicalTop;
+
+    // The orientation may be different from the viewport orientation as it specifies
+    // the rotation of the surface coordinates required to produce the viewport's
+    // requested orientation, so it will depend on whether the device is orientation aware.
+    int32_t mSurfaceOrientation;
+
+    // Translation and scaling factors, orientation-independent.
+    float mXTranslate;
+    float mXScale;
+    float mXPrecision;
+
+    float mYTranslate;
+    float mYScale;
+    float mYPrecision;
+
+    float mGeometricScale;
+
+    float mPressureScale;
+
+    float mSizeScale;
+
+    float mOrientationScale;
+
+    float mDistanceScale;
+
+    bool mHaveTilt;
+    float mTiltXCenter;
+    float mTiltXScale;
+    float mTiltYCenter;
+    float mTiltYScale;
+
+    bool mExternalStylusConnected;
+
+    // Oriented motion ranges for input device info.
+    struct OrientedRanges {
+        InputDeviceInfo::MotionRange x;
+        InputDeviceInfo::MotionRange y;
+        InputDeviceInfo::MotionRange pressure;
+
+        bool haveSize;
+        InputDeviceInfo::MotionRange size;
+
+        bool haveTouchSize;
+        InputDeviceInfo::MotionRange touchMajor;
+        InputDeviceInfo::MotionRange touchMinor;
+
+        bool haveToolSize;
+        InputDeviceInfo::MotionRange toolMajor;
+        InputDeviceInfo::MotionRange toolMinor;
+
+        bool haveOrientation;
+        InputDeviceInfo::MotionRange orientation;
+
+        bool haveDistance;
+        InputDeviceInfo::MotionRange distance;
+
+        bool haveTilt;
+        InputDeviceInfo::MotionRange tilt;
+
+        OrientedRanges() { clear(); }
+
+        void clear() {
+            haveSize = false;
+            haveTouchSize = false;
+            haveToolSize = false;
+            haveOrientation = false;
+            haveDistance = false;
+            haveTilt = false;
+        }
+    } mOrientedRanges;
+
+    // Oriented dimensions and precision.
+    float mOrientedXPrecision;
+    float mOrientedYPrecision;
+
+    struct CurrentVirtualKeyState {
+        bool down;
+        bool ignored;
+        nsecs_t downTime;
+        int32_t keyCode;
+        int32_t scanCode;
+    } mCurrentVirtualKey;
+
+    // Scale factor for gesture or mouse based pointer movements.
+    float mPointerXMovementScale;
+    float mPointerYMovementScale;
+
+    // Scale factor for gesture based zooming and other freeform motions.
+    float mPointerXZoomScale;
+    float mPointerYZoomScale;
+
+    // The maximum swipe width.
+    float mPointerGestureMaxSwipeWidth;
+
+    struct PointerDistanceHeapElement {
+        uint32_t currentPointerIndex : 8;
+        uint32_t lastPointerIndex : 8;
+        uint64_t distance : 48; // squared distance
+    };
+
+    enum PointerUsage {
+        POINTER_USAGE_NONE,
+        POINTER_USAGE_GESTURES,
+        POINTER_USAGE_STYLUS,
+        POINTER_USAGE_MOUSE,
+    };
+    PointerUsage mPointerUsage;
+
+    struct PointerGesture {
+        enum Mode {
+            // No fingers, button is not pressed.
+            // Nothing happening.
+            NEUTRAL,
+
+            // No fingers, button is not pressed.
+            // Tap detected.
+            // Emits DOWN and UP events at the pointer location.
+            TAP,
+
+            // Exactly one finger dragging following a tap.
+            // Pointer follows the active finger.
+            // Emits DOWN, MOVE and UP events at the pointer location.
+            //
+            // Detect double-taps when the finger goes up while in TAP_DRAG mode.
+            TAP_DRAG,
+
+            // Button is pressed.
+            // Pointer follows the active finger if there is one.  Other fingers are ignored.
+            // Emits DOWN, MOVE and UP events at the pointer location.
+            BUTTON_CLICK_OR_DRAG,
+
+            // Exactly one finger, button is not pressed.
+            // Pointer follows the active finger.
+            // Emits HOVER_MOVE events at the pointer location.
+            //
+            // Detect taps when the finger goes up while in HOVER mode.
+            HOVER,
+
+            // Exactly two fingers but neither have moved enough to clearly indicate
+            // whether a swipe or freeform gesture was intended.  We consider the
+            // pointer to be pressed so this enables clicking or long-pressing on buttons.
+            // Pointer does not move.
+            // Emits DOWN, MOVE and UP events with a single stationary pointer coordinate.
+            PRESS,
+
+            // Exactly two fingers moving in the same direction, button is not pressed.
+            // Pointer does not move.
+            // Emits DOWN, MOVE and UP events with a single pointer coordinate that
+            // follows the midpoint between both fingers.
+            SWIPE,
+
+            // Two or more fingers moving in arbitrary directions, button is not pressed.
+            // Pointer does not move.
+            // Emits DOWN, POINTER_DOWN, MOVE, POINTER_UP and UP events that follow
+            // each finger individually relative to the initial centroid of the finger.
+            FREEFORM,
+
+            // Waiting for quiet time to end before starting the next gesture.
+            QUIET,
+        };
+
+        // Time the first finger went down.
+        nsecs_t firstTouchTime;
+
+        // The active pointer id from the raw touch data.
+        int32_t activeTouchId; // -1 if none
+
+        // The active pointer id from the gesture last delivered to the application.
+        int32_t activeGestureId; // -1 if none
+
+        // Pointer coords and ids for the current and previous pointer gesture.
+        Mode currentGestureMode;
+        BitSet32 currentGestureIdBits;
+        uint32_t currentGestureIdToIndex[MAX_POINTER_ID + 1];
+        PointerProperties currentGestureProperties[MAX_POINTERS];
+        PointerCoords currentGestureCoords[MAX_POINTERS];
+
+        Mode lastGestureMode;
+        BitSet32 lastGestureIdBits;
+        uint32_t lastGestureIdToIndex[MAX_POINTER_ID + 1];
+        PointerProperties lastGestureProperties[MAX_POINTERS];
+        PointerCoords lastGestureCoords[MAX_POINTERS];
+
+        // Time the pointer gesture last went down.
+        nsecs_t downTime;
+
+        // Time when the pointer went down for a TAP.
+        nsecs_t tapDownTime;
+
+        // Time when the pointer went up for a TAP.
+        nsecs_t tapUpTime;
+
+        // Location of initial tap.
+        float tapX, tapY;
+
+        // Time we started waiting for quiescence.
+        nsecs_t quietTime;
+
+        // Reference points for multitouch gestures.
+        float referenceTouchX; // reference touch X/Y coordinates in surface units
+        float referenceTouchY;
+        float referenceGestureX; // reference gesture X/Y coordinates in pixels
+        float referenceGestureY;
+
+        // Distance that each pointer has traveled which has not yet been
+        // subsumed into the reference gesture position.
+        BitSet32 referenceIdBits;
+        struct Delta {
+            float dx, dy;
+        };
+        Delta referenceDeltas[MAX_POINTER_ID + 1];
+
+        // Describes how touch ids are mapped to gesture ids for freeform gestures.
+        uint32_t freeformTouchToGestureIdMap[MAX_POINTER_ID + 1];
+
+        // A velocity tracker for determining whether to switch active pointers during drags.
+        VelocityTracker velocityTracker;
+
+        void reset() {
+            firstTouchTime = LLONG_MIN;
+            activeTouchId = -1;
+            activeGestureId = -1;
+            currentGestureMode = NEUTRAL;
+            currentGestureIdBits.clear();
+            lastGestureMode = NEUTRAL;
+            lastGestureIdBits.clear();
+            downTime = 0;
+            velocityTracker.clear();
+            resetTap();
+            resetQuietTime();
+        }
+
+        void resetTap() {
+            tapDownTime = LLONG_MIN;
+            tapUpTime = LLONG_MIN;
+        }
+
+        void resetQuietTime() { quietTime = LLONG_MIN; }
+    } mPointerGesture;
+
+    struct PointerSimple {
+        PointerCoords currentCoords;
+        PointerProperties currentProperties;
+        PointerCoords lastCoords;
+        PointerProperties lastProperties;
+
+        // True if the pointer is down.
+        bool down;
+
+        // True if the pointer is hovering.
+        bool hovering;
+
+        // Time the pointer last went down.
+        nsecs_t downTime;
+
+        void reset() {
+            currentCoords.clear();
+            currentProperties.clear();
+            lastCoords.clear();
+            lastProperties.clear();
+            down = false;
+            hovering = false;
+            downTime = 0;
+        }
+    } mPointerSimple;
+
+    // The pointer and scroll velocity controls.
+    VelocityControl mPointerVelocityControl;
+    VelocityControl mWheelXVelocityControl;
+    VelocityControl mWheelYVelocityControl;
+
+    std::optional<DisplayViewport> findViewport();
+
+    void resetExternalStylus();
+    void clearStylusDataPendingFlags();
+
+    void sync(nsecs_t when);
+
+    bool consumeRawTouches(nsecs_t when, uint32_t policyFlags);
+    void processRawTouches(bool timeout);
+    void cookAndDispatch(nsecs_t when);
+    void dispatchVirtualKey(nsecs_t when, uint32_t policyFlags, int32_t keyEventAction,
+                            int32_t keyEventFlags);
+
+    void dispatchTouches(nsecs_t when, uint32_t policyFlags);
+    void dispatchHoverExit(nsecs_t when, uint32_t policyFlags);
+    void dispatchHoverEnterAndMove(nsecs_t when, uint32_t policyFlags);
+    void dispatchButtonRelease(nsecs_t when, uint32_t policyFlags);
+    void dispatchButtonPress(nsecs_t when, uint32_t policyFlags);
+    const BitSet32& findActiveIdBits(const CookedPointerData& cookedPointerData);
+    void cookPointerData();
+    void abortTouches(nsecs_t when, uint32_t policyFlags);
+
+    void dispatchPointerUsage(nsecs_t when, uint32_t policyFlags, PointerUsage pointerUsage);
+    void abortPointerUsage(nsecs_t when, uint32_t policyFlags);
+
+    void dispatchPointerGestures(nsecs_t when, uint32_t policyFlags, bool isTimeout);
+    void abortPointerGestures(nsecs_t when, uint32_t policyFlags);
+    bool preparePointerGestures(nsecs_t when, bool* outCancelPreviousGesture,
+                                bool* outFinishPreviousGesture, bool isTimeout);
+
+    void dispatchPointerStylus(nsecs_t when, uint32_t policyFlags);
+    void abortPointerStylus(nsecs_t when, uint32_t policyFlags);
+
+    void dispatchPointerMouse(nsecs_t when, uint32_t policyFlags);
+    void abortPointerMouse(nsecs_t when, uint32_t policyFlags);
+
+    void dispatchPointerSimple(nsecs_t when, uint32_t policyFlags, bool down, bool hovering);
+    void abortPointerSimple(nsecs_t when, uint32_t policyFlags);
+
+    bool assignExternalStylusId(const RawState& state, bool timeout);
+    void applyExternalStylusButtonState(nsecs_t when);
+    void applyExternalStylusTouchState(nsecs_t when);
+
+    // Dispatches a motion event.
+    // If the changedId is >= 0 and the action is POINTER_DOWN or POINTER_UP, the
+    // method will take care of setting the index and transmuting the action to DOWN or UP
+    // it is the first / last pointer to go down / up.
+    void dispatchMotion(nsecs_t when, uint32_t policyFlags, uint32_t source, int32_t action,
+                        int32_t actionButton, int32_t flags, int32_t metaState, int32_t buttonState,
+                        int32_t edgeFlags, const PointerProperties* properties,
+                        const PointerCoords* coords, const uint32_t* idToIndex, BitSet32 idBits,
+                        int32_t changedId, float xPrecision, float yPrecision, nsecs_t downTime);
+
+    // Updates pointer coords and properties for pointers with specified ids that have moved.
+    // Returns true if any of them changed.
+    bool updateMovedPointers(const PointerProperties* inProperties, const PointerCoords* inCoords,
+                             const uint32_t* inIdToIndex, PointerProperties* outProperties,
+                             PointerCoords* outCoords, const uint32_t* outIdToIndex,
+                             BitSet32 idBits) const;
+
+    bool isPointInsideSurface(int32_t x, int32_t y);
+    const VirtualKey* findVirtualKeyHit(int32_t x, int32_t y);
+
+    static void assignPointerIds(const RawState* last, RawState* current);
+
+    const char* modeToString(DeviceMode deviceMode);
+};
+
+class SingleTouchInputMapper : public TouchInputMapper {
+public:
+    explicit SingleTouchInputMapper(InputDevice* device);
+    virtual ~SingleTouchInputMapper();
+
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+protected:
+    virtual void syncTouch(nsecs_t when, RawState* outState);
+    virtual void configureRawPointerAxes();
+    virtual bool hasStylus() const;
+
+private:
+    SingleTouchMotionAccumulator mSingleTouchMotionAccumulator;
+};
+
+class MultiTouchInputMapper : public TouchInputMapper {
+public:
+    explicit MultiTouchInputMapper(InputDevice* device);
+    virtual ~MultiTouchInputMapper();
+
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+protected:
+    virtual void syncTouch(nsecs_t when, RawState* outState);
+    virtual void configureRawPointerAxes();
+    virtual bool hasStylus() const;
+
+private:
+    MultiTouchMotionAccumulator mMultiTouchMotionAccumulator;
+
+    // Specifies the pointer id bits that are in use, and their associated tracking id.
+    BitSet32 mPointerIdBits;
+    int32_t mPointerTrackingIdMap[MAX_POINTER_ID + 1];
+};
+
+class ExternalStylusInputMapper : public InputMapper {
+public:
+    explicit ExternalStylusInputMapper(InputDevice* device);
+    virtual ~ExternalStylusInputMapper() = default;
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+    virtual void sync(nsecs_t when);
+
+private:
+    SingleTouchMotionAccumulator mSingleTouchMotionAccumulator;
+    RawAbsoluteAxisInfo mRawPressureAxis;
+    TouchButtonAccumulator mTouchButtonAccumulator;
+
+    StylusState mStylusState;
+};
+
+class JoystickInputMapper : public InputMapper {
+public:
+    explicit JoystickInputMapper(InputDevice* device);
+    virtual ~JoystickInputMapper();
+
+    virtual uint32_t getSources();
+    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
+    virtual void dump(std::string& dump);
+    virtual void configure(nsecs_t when, const InputReaderConfiguration* config, uint32_t changes);
+    virtual void reset(nsecs_t when);
+    virtual void process(const RawEvent* rawEvent);
+
+private:
+    struct Axis {
+        RawAbsoluteAxisInfo rawAxisInfo;
+        AxisInfo axisInfo;
+
+        bool explicitlyMapped; // true if the axis was explicitly assigned an axis id
+
+        float scale;      // scale factor from raw to normalized values
+        float offset;     // offset to add after scaling for normalization
+        float highScale;  // scale factor from raw to normalized values of high split
+        float highOffset; // offset to add after scaling for normalization of high split
+
+        float min;        // normalized inclusive minimum
+        float max;        // normalized inclusive maximum
+        float flat;       // normalized flat region size
+        float fuzz;       // normalized error tolerance
+        float resolution; // normalized resolution in units/mm
+
+        float filter;           // filter out small variations of this size
+        float currentValue;     // current value
+        float newValue;         // most recent value
+        float highCurrentValue; // current value of high split
+        float highNewValue;     // most recent value of high split
+
+        void initialize(const RawAbsoluteAxisInfo& rawAxisInfo, const AxisInfo& axisInfo,
+                        bool explicitlyMapped, float scale, float offset, float highScale,
+                        float highOffset, float min, float max, float flat, float fuzz,
+                        float resolution) {
+            this->rawAxisInfo = rawAxisInfo;
+            this->axisInfo = axisInfo;
+            this->explicitlyMapped = explicitlyMapped;
+            this->scale = scale;
+            this->offset = offset;
+            this->highScale = highScale;
+            this->highOffset = highOffset;
+            this->min = min;
+            this->max = max;
+            this->flat = flat;
+            this->fuzz = fuzz;
+            this->resolution = resolution;
+            this->filter = 0;
+            resetValue();
+        }
+
+        void resetValue() {
+            this->currentValue = 0;
+            this->newValue = 0;
+            this->highCurrentValue = 0;
+            this->highNewValue = 0;
+        }
+    };
+
+    // Axes indexed by raw ABS_* axis index.
+    KeyedVector<int32_t, Axis> mAxes;
+
+    void sync(nsecs_t when, bool force);
+
+    bool haveAxis(int32_t axisId);
+    void pruneAxes(bool ignoreExplicitlyMappedAxes);
+    bool filterAxes(bool force);
+
+    static bool hasValueChangedSignificantly(float filter, float newValue, float currentValue,
+                                             float min, float max);
+    static bool hasMovedNearerToValueWithinFilteredRange(float filter, float newValue,
+                                                         float currentValue, float thresholdValue);
+
+    static bool isCenteredAxis(int32_t axis);
+    static int32_t getCompatAxis(int32_t axis);
+
+    static void addMotionRange(int32_t axisId, const Axis& axis, InputDeviceInfo* info);
+    static void setPointerCoordsAxisValue(PointerCoords* pointerCoords, int32_t axis, float value);
+};
+
+} // namespace android
+
+#endif // _UI_INPUT_READER_H