services/input/InputReader.h

/*
 * 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 "InputDispatcher.h"
#include "PointerController.h"
#include "SpotController.h"

#include <ui/Input.h>
#include <ui/DisplayInfo.h>
#include <utils/KeyedVector.h>
#include <utils/threads.h>
#include <utils/Timers.h>
#include <utils/RefBase.h>
#include <utils/String8.h>
#include <utils/BitSet.h>

#include <stddef.h>
#include <unistd.h>

namespace android {

class InputDevice;
class InputMapper;


/*
 * Input reader policy interface.
 *
 * The input reader policy is used by the input reader to interact with the Window Manager
 * and other system components.
 *
 * The actual implementation is partially supported by callbacks into the DVM
 * via JNI.  This interface is also mocked in the unit tests.
 */
class InputReaderPolicyInterface : public virtual RefBase {
protected:
    InputReaderPolicyInterface() { }
    virtual ~InputReaderPolicyInterface() { }

public:
    /* Display orientations. */
    enum {
        ROTATION_0 = 0,
        ROTATION_90 = 1,
        ROTATION_180 = 2,
        ROTATION_270 = 3
    };

    /* Gets information about the display with the specified id.
     * Returns true if the display info is available, false otherwise.
     */
    virtual bool getDisplayInfo(int32_t displayId,
            int32_t* width, int32_t* height, int32_t* orientation) = 0;

    /* Determines whether to turn on some hacks we have to improve the touch interaction with a
     * certain device whose screen currently is not all that good.
     */
    virtual bool filterTouchEvents() = 0;

    /* Determines whether to turn on some hacks to improve touch interaction with another device
     * where touch coordinate data can get corrupted.
     */
    virtual bool filterJumpyTouchEvents() = 0;

    /* Gets the amount of time to disable virtual keys after the screen is touched
     * in order to filter out accidental virtual key presses due to swiping gestures
     * or taps near the edge of the display.  May be 0 to disable the feature.
     */
    virtual nsecs_t getVirtualKeyQuietTime() = 0;

    /* Gets the excluded device names for the platform. */
    virtual void getExcludedDeviceNames(Vector<String8>& outExcludedDeviceNames) = 0;

    /* Gets a pointer controller associated with the specified cursor device (ie. a mouse). */
    virtual sp<PointerControllerInterface> obtainPointerController(int32_t deviceId) = 0;

    /* Gets a spot controller associated with the specified touch pad device. */
    virtual sp<SpotControllerInterface> obtainSpotController(int32_t deviceId) = 0;
};


/* Processes raw input events and sends cooked event data to an input dispatcher. */
class InputReaderInterface : public virtual RefBase {
protected:
    InputReaderInterface() { }
    virtual ~InputReaderInterface() { }

public:
    /* Dumps the state of the input reader.
     *
     * This method may be called on any thread (usually by the input manager). */
    virtual void dump(String8& dump) = 0;

    /* Runs a single iteration of the processing loop.
     * Nominally reads and processes one incoming message from the EventHub.
     *
     * This method should be called on the input reader thread.
     */
    virtual void loopOnce() = 0;

    /* Gets the current input device configuration.
     *
     * This method may be called on any thread (usually by the input manager).
     */
    virtual void getInputConfiguration(InputConfiguration* outConfiguration) = 0;

    /* Gets information about the specified input device.
     * Returns OK if the device information was obtained or NAME_NOT_FOUND if there
     * was no such device.
     *
     * This method may be called on any thread (usually by the input manager).
     */
    virtual status_t getInputDeviceInfo(int32_t deviceId, InputDeviceInfo* outDeviceInfo) = 0;

    /* Gets the list of all registered device ids. */
    virtual void getInputDeviceIds(Vector<int32_t>& outDeviceIds) = 0;

    /* Query current input state. */
    virtual int32_t getScanCodeState(int32_t deviceId, uint32_t sourceMask,
            int32_t scanCode) = 0;
    virtual int32_t getKeyCodeState(int32_t deviceId, uint32_t sourceMask,
            int32_t keyCode) = 0;
    virtual int32_t getSwitchState(int32_t deviceId, uint32_t sourceMask,
            int32_t sw) = 0;

    /* Determine whether physical keys exist for the given framework-domain key codes. */
    virtual bool hasKeys(int32_t deviceId, uint32_t sourceMask,
            size_t numCodes, const int32_t* keyCodes, uint8_t* outFlags) = 0;
};


/* 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 InputReaderPolicyInterface* getPolicy() = 0;
    virtual InputDispatcherInterface* getDispatcher() = 0;
    virtual EventHubInterface* getEventHub() = 0;
};


/* The input reader reads raw event data from the event hub and processes it into input events
 * that it sends to the input dispatcher.  Some functions of the input reader, such as early
 * event filtering in low power states, are controlled by a separate policy object.
 *
 * IMPORTANT INVARIANT:
 *     Because the policy and dispatcher can potentially block or cause re-entrance into
 *     the input reader, the input reader never calls into other components while holding
 *     an exclusive internal lock whenever re-entrance can happen.
 */
class InputReader : public InputReaderInterface, protected InputReaderContext {
public:
    InputReader(const sp<EventHubInterface>& eventHub,
            const sp<InputReaderPolicyInterface>& policy,
            const sp<InputDispatcherInterface>& dispatcher);
    virtual ~InputReader();

    virtual void dump(String8& dump);

    virtual void loopOnce();

    virtual void getInputConfiguration(InputConfiguration* outConfiguration);

    virtual status_t getInputDeviceInfo(int32_t deviceId, InputDeviceInfo* outDeviceInfo);
    virtual void getInputDeviceIds(Vector<int32_t>& outDeviceIds);

    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 bool hasKeys(int32_t deviceId, uint32_t sourceMask,
            size_t numCodes, const int32_t* keyCodes, uint8_t* outFlags);

protected:
    // These methods are protected virtual so they can be overridden and instrumented
    // by test cases.
    virtual InputDevice* createDevice(int32_t deviceId, const String8& name, uint32_t classes);

private:
    sp<EventHubInterface> mEventHub;
    sp<InputReaderPolicyInterface> mPolicy;
    sp<InputDispatcherInterface> mDispatcher;

    virtual InputReaderPolicyInterface* getPolicy() { return mPolicy.get(); }
    virtual InputDispatcherInterface* getDispatcher() { return mDispatcher.get(); }
    virtual EventHubInterface* getEventHub() { return mEventHub.get(); }

    // The event queue.
    static const int EVENT_BUFFER_SIZE = 256;
    RawEvent mEventBuffer[EVENT_BUFFER_SIZE];

    // This reader/writer lock guards the list of input devices.
    // The writer lock must be held whenever the list of input devices is modified
    //   and then promptly released.
    // The reader lock must be held whenever the list of input devices is traversed or an
    //   input device in the list is accessed.
    // This lock only protects the registry and prevents inadvertent deletion of device objects
    // that are in use.  Individual devices are responsible for guarding their own internal state
    // as needed for concurrent operation.
    RWLock mDeviceRegistryLock;
    KeyedVector<int32_t, InputDevice*> mDevices;

    // low-level input event decoding and device management
    void processEvents(const RawEvent* rawEvents, size_t count);

    void addDevice(int32_t deviceId);
    void removeDevice(int32_t deviceId);
    void processEventsForDevice(int32_t deviceId, const RawEvent* rawEvents, size_t count);
    void timeoutExpired(nsecs_t when);

    void handleConfigurationChanged(nsecs_t when);
    void configureExcludedDevices();

    // state management for all devices
    Mutex mStateLock;

    int32_t mGlobalMetaState;
    virtual void updateGlobalMetaState();
    virtual int32_t getGlobalMetaState();

    virtual void fadePointer();

    InputConfiguration mInputConfiguration;
    void updateInputConfiguration();

    nsecs_t mDisableVirtualKeysTimeout; // only accessed by reader thread
    virtual void disableVirtualKeysUntil(nsecs_t time);
    virtual bool shouldDropVirtualKey(nsecs_t now,
            InputDevice* device, int32_t keyCode, int32_t scanCode);

    nsecs_t mNextTimeout; // only accessed by reader thread
    virtual void requestTimeoutAtTime(nsecs_t when);

    // state queries
    typedef int32_t (InputDevice::*GetStateFunc)(uint32_t sourceMask, int32_t code);
    int32_t getState(int32_t deviceId, uint32_t sourceMask, int32_t code,
            GetStateFunc getStateFunc);
    bool markSupportedKeyCodes(int32_t deviceId, uint32_t sourceMask, size_t numCodes,
            const int32_t* keyCodes, uint8_t* outFlags);
};


/* Reads raw events from the event hub and processes them, endlessly. */
class InputReaderThread : public Thread {
public:
    InputReaderThread(const sp<InputReaderInterface>& reader);
    virtual ~InputReaderThread();

private:
    sp<InputReaderInterface> mReader;

    virtual bool threadLoop();
};


/* Represents the state of a single input device. */
class InputDevice {
public:
    InputDevice(InputReaderContext* context, int32_t id, const String8& name);
    ~InputDevice();

    inline InputReaderContext* getContext() { return mContext; }
    inline int32_t getId() { return mId; }
    inline const String8& getName() { return mName; }
    inline uint32_t getSources() { return mSources; }

    inline bool isExternal() { return mIsExternal; }
    inline void setExternal(bool external) { mIsExternal = external; }

    inline bool isIgnored() { return mMappers.isEmpty(); }

    void dump(String8& dump);
    void addMapper(InputMapper* mapper);
    void configure();
    void reset();
    void process(const RawEvent* rawEvents, size_t count);
    void timeoutExpired(nsecs_t when);

    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);

    int32_t getMetaState();

    void fadePointer();

    inline const PropertyMap& getConfiguration() {
        return mConfiguration;
    }

private:
    InputReaderContext* mContext;
    int32_t mId;

    Vector<InputMapper*> mMappers;

    String8 mName;
    uint32_t mSources;
    bool mIsExternal;

    typedef int32_t (InputMapper::*GetStateFunc)(uint32_t sourceMask, int32_t code);
    int32_t getState(uint32_t sourceMask, int32_t code, GetStateFunc getStateFunc);

    PropertyMap mConfiguration;
};


/* 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.
 */
class InputMapper {
public:
    InputMapper(InputDevice* device);
    virtual ~InputMapper();

    inline InputDevice* getDevice() { return mDevice; }
    inline int32_t getDeviceId() { return mDevice->getId(); }
    inline const String8 getDeviceName() { return mDevice->getName(); }
    inline InputReaderContext* getContext() { return mContext; }
    inline InputReaderPolicyInterface* getPolicy() { return mContext->getPolicy(); }
    inline InputDispatcherInterface* getDispatcher() { return mContext->getDispatcher(); }
    inline EventHubInterface* getEventHub() { return mContext->getEventHub(); }

    virtual uint32_t getSources() = 0;
    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
    virtual void dump(String8& dump);
    virtual void configure();
    virtual void reset();
    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 int32_t getMetaState();

    virtual void fadePointer();

protected:
    InputDevice* mDevice;
    InputReaderContext* mContext;

    static void dumpRawAbsoluteAxisInfo(String8& dump,
            const RawAbsoluteAxisInfo& axis, const char* name);
};


class SwitchInputMapper : public InputMapper {
public:
    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);

private:
    void processSwitch(nsecs_t when, int32_t switchCode, int32_t switchValue);
};


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(String8& dump);
    virtual void configure();
    virtual void reset();
    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();

private:
    Mutex mLock;

    struct KeyDown {
        int32_t keyCode;
        int32_t scanCode;
    };

    uint32_t mSource;
    int32_t mKeyboardType;

    // Immutable configuration parameters.
    struct Parameters {
        int32_t associatedDisplayId;
        bool orientationAware;
    } mParameters;

    struct LockedState {
        Vector<KeyDown> keyDowns; // keys that are down
        int32_t metaState;
        nsecs_t downTime; // time of most recent key down

        struct LedState {
            bool avail; // led is available
            bool on;    // we think the led is currently on
        };
        LedState capsLockLedState;
        LedState numLockLedState;
        LedState scrollLockLedState;
    } mLocked;

    void initializeLocked();

    void configureParameters();
    void dumpParameters(String8& dump);

    bool isKeyboardOrGamepadKey(int32_t scanCode);

    void processKey(nsecs_t when, bool down, int32_t keyCode, int32_t scanCode,
            uint32_t policyFlags);

    ssize_t findKeyDownLocked(int32_t scanCode);

    void resetLedStateLocked();
    void initializeLedStateLocked(LockedState::LedState& ledState, int32_t led);
    void updateLedStateLocked(bool reset);
    void updateLedStateForModifierLocked(LockedState::LedState& ledState, int32_t led,
            int32_t modifier, bool reset);
};


class CursorInputMapper : public InputMapper {
public:
    CursorInputMapper(InputDevice* device);
    virtual ~CursorInputMapper();

    virtual uint32_t getSources();
    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
    virtual void dump(String8& dump);
    virtual void configure();
    virtual void reset();
    virtual void process(const RawEvent* rawEvent);

    virtual int32_t getScanCodeState(uint32_t sourceMask, int32_t scanCode);

    virtual void fadePointer();

private:
    // Amount that trackball needs to move in order to generate a key event.
    static const int32_t TRACKBALL_MOVEMENT_THRESHOLD = 6;

    Mutex mLock;

    // Immutable configuration parameters.
    struct Parameters {
        enum Mode {
            MODE_POINTER,
            MODE_NAVIGATION,
        };

        Mode mode;
        int32_t associatedDisplayId;
        bool orientationAware;
    } mParameters;

    struct Accumulator {
        enum {
            FIELD_BUTTONS = 1,
            FIELD_REL_X = 2,
            FIELD_REL_Y = 4,
            FIELD_REL_WHEEL = 8,
            FIELD_REL_HWHEEL = 16,
        };

        uint32_t fields;

        uint32_t buttonDown;
        uint32_t buttonUp;

        int32_t relX;
        int32_t relY;
        int32_t relWheel;
        int32_t relHWheel;

        inline void clear() {
            fields = 0;
        }
    } mAccumulator;

    int32_t mSource;
    float mXScale;
    float mYScale;
    float mXPrecision;
    float mYPrecision;

    bool mHaveVWheel;
    bool mHaveHWheel;
    float mVWheelScale;
    float mHWheelScale;

    sp<PointerControllerInterface> mPointerController;

    struct LockedState {
        uint32_t buttonState;
        nsecs_t downTime;
    } mLocked;

    void initializeLocked();

    void configureParameters();
    void dumpParameters(String8& dump);

    void sync(nsecs_t when);
};


class TouchInputMapper : public InputMapper {
public:
    TouchInputMapper(InputDevice* device);
    virtual ~TouchInputMapper();

    virtual uint32_t getSources();
    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
    virtual void dump(String8& dump);
    virtual void configure();
    virtual void reset();

    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();

protected:
    Mutex mLock;

    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;
        }
    };

    // Raw data for a single pointer.
    struct PointerData {
        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;

        inline bool operator== (const PointerData& other) const {
            return id == other.id
                    && x == other.x
                    && y == other.y
                    && pressure == other.pressure
                    && touchMajor == other.touchMajor
                    && touchMinor == other.touchMinor
                    && toolMajor == other.toolMajor
                    && toolMinor == other.toolMinor
                    && orientation == other.orientation;
        }
        inline bool operator!= (const PointerData& other) const {
            return !(*this == other);
        }
    };

    // Raw data for a collection of pointers including a pointer id mapping table.
    struct TouchData {
        uint32_t pointerCount;
        PointerData pointers[MAX_POINTERS];
        BitSet32 idBits;
        uint32_t idToIndex[MAX_POINTER_ID + 1];
        uint32_t buttonState;

        void copyFrom(const TouchData& other) {
            pointerCount = other.pointerCount;
            idBits = other.idBits;
            buttonState = other.buttonState;

            for (uint32_t i = 0; i < pointerCount; i++) {
                pointers[i] = other.pointers[i];

                int id = pointers[i].id;
                idToIndex[id] = other.idToIndex[id];
            }
        }

        inline void clear() {
            pointerCount = 0;
            idBits.clear();
            buttonState = 0;
        }
    };

    // Input sources supported by the device.
    uint32_t mTouchSource; // sources when reporting touch data
    uint32_t mPointerSource; // sources when reporting pointer gestures

    // Immutable configuration parameters.
    struct Parameters {
        enum DeviceType {
            DEVICE_TYPE_TOUCH_SCREEN,
            DEVICE_TYPE_TOUCH_PAD,
            DEVICE_TYPE_POINTER,
        };

        DeviceType deviceType;
        int32_t associatedDisplayId;
        bool orientationAware;

        bool useBadTouchFilter;
        bool useJumpyTouchFilter;
        bool useAveragingTouchFilter;
        nsecs_t virtualKeyQuietTime;
    } mParameters;

    // Immutable calibration parameters in parsed form.
    struct Calibration {
        // Touch Size
        enum TouchSizeCalibration {
            TOUCH_SIZE_CALIBRATION_DEFAULT,
            TOUCH_SIZE_CALIBRATION_NONE,
            TOUCH_SIZE_CALIBRATION_GEOMETRIC,
            TOUCH_SIZE_CALIBRATION_PRESSURE,
        };

        TouchSizeCalibration touchSizeCalibration;

        // Tool Size
        enum ToolSizeCalibration {
            TOOL_SIZE_CALIBRATION_DEFAULT,
            TOOL_SIZE_CALIBRATION_NONE,
            TOOL_SIZE_CALIBRATION_GEOMETRIC,
            TOOL_SIZE_CALIBRATION_LINEAR,
            TOOL_SIZE_CALIBRATION_AREA,
        };

        ToolSizeCalibration toolSizeCalibration;
        bool haveToolSizeLinearScale;
        float toolSizeLinearScale;
        bool haveToolSizeLinearBias;
        float toolSizeLinearBias;
        bool haveToolSizeAreaScale;
        float toolSizeAreaScale;
        bool haveToolSizeAreaBias;
        float toolSizeAreaBias;
        bool haveToolSizeIsSummed;
        bool toolSizeIsSummed;

        // Pressure
        enum PressureCalibration {
            PRESSURE_CALIBRATION_DEFAULT,
            PRESSURE_CALIBRATION_NONE,
            PRESSURE_CALIBRATION_PHYSICAL,
            PRESSURE_CALIBRATION_AMPLITUDE,
        };
        enum PressureSource {
            PRESSURE_SOURCE_DEFAULT,
            PRESSURE_SOURCE_PRESSURE,
            PRESSURE_SOURCE_TOUCH,
        };

        PressureCalibration pressureCalibration;
        PressureSource pressureSource;
        bool havePressureScale;
        float pressureScale;

        // Size
        enum SizeCalibration {
            SIZE_CALIBRATION_DEFAULT,
            SIZE_CALIBRATION_NONE,
            SIZE_CALIBRATION_NORMALIZED,
        };

        SizeCalibration sizeCalibration;

        // Orientation
        enum OrientationCalibration {
            ORIENTATION_CALIBRATION_DEFAULT,
            ORIENTATION_CALIBRATION_NONE,
            ORIENTATION_CALIBRATION_INTERPOLATED,
            ORIENTATION_CALIBRATION_VECTOR,
        };

        OrientationCalibration orientationCalibration;
    } mCalibration;

    // Raw axis information from the driver.
    struct RawAxes {
        RawAbsoluteAxisInfo x;
        RawAbsoluteAxisInfo y;
        RawAbsoluteAxisInfo pressure;
        RawAbsoluteAxisInfo touchMajor;
        RawAbsoluteAxisInfo touchMinor;
        RawAbsoluteAxisInfo toolMajor;
        RawAbsoluteAxisInfo toolMinor;
        RawAbsoluteAxisInfo orientation;
    } mRawAxes;

    // Current and previous touch sample data.
    TouchData mCurrentTouch;
    PointerCoords mCurrentTouchCoords[MAX_POINTERS];

    TouchData mLastTouch;
    PointerCoords mLastTouchCoords[MAX_POINTERS];

    // 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;

    struct LockedState {
        Vector<VirtualKey> virtualKeys;

        // The surface orientation and width and height set by configureSurfaceLocked().
        int32_t surfaceOrientation;
        int32_t surfaceWidth, surfaceHeight;

        // The associated display orientation and width and height set by configureSurfaceLocked().
        int32_t associatedDisplayOrientation;
        int32_t associatedDisplayWidth, associatedDisplayHeight;

        // Translation and scaling factors, orientation-independent.
        float xScale;
        float xPrecision;

        float yScale;
        float yPrecision;

        float geometricScale;

        float toolSizeLinearScale;
        float toolSizeLinearBias;
        float toolSizeAreaScale;
        float toolSizeAreaBias;

        float pressureScale;

        float sizeScale;

        float orientationScale;

        // Oriented motion ranges for input device info.
        struct OrientedRanges {
            InputDeviceInfo::MotionRange x;
            InputDeviceInfo::MotionRange y;

            bool havePressure;
            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;
        } orientedRanges;

        // Oriented dimensions and precision.
        float orientedSurfaceWidth, orientedSurfaceHeight;
        float orientedXPrecision, orientedYPrecision;

        struct CurrentVirtualKeyState {
            bool down;
            nsecs_t downTime;
            int32_t keyCode;
            int32_t scanCode;
        } currentVirtualKey;

        // Scale factor for gesture based pointer movements.
        float pointerGestureXMovementScale;
        float pointerGestureYMovementScale;

        // Scale factor for gesture based zooming and other freeform motions.
        float pointerGestureXZoomScale;
        float pointerGestureYZoomScale;

        // The maximum swipe width squared.
        int32_t pointerGestureMaxSwipeWidthSquared;
    } mLocked;

    virtual void configureParameters();
    virtual void dumpParameters(String8& dump);
    virtual void configureRawAxes();
    virtual void dumpRawAxes(String8& dump);
    virtual bool configureSurfaceLocked();
    virtual void dumpSurfaceLocked(String8& dump);
    virtual void configureVirtualKeysLocked();
    virtual void dumpVirtualKeysLocked(String8& dump);
    virtual void parseCalibration();
    virtual void resolveCalibration();
    virtual void dumpCalibration(String8& dump);

    enum TouchResult {
        // Dispatch the touch normally.
        DISPATCH_TOUCH,
        // Do not dispatch the touch, but keep tracking the current stroke.
        SKIP_TOUCH,
        // Do not dispatch the touch, and drop all information associated with the current stoke
        // so the next movement will appear as a new down.
        DROP_STROKE
    };

    void syncTouch(nsecs_t when, bool havePointerIds);

private:
    /* Maximum number of historical samples to average. */
    static const uint32_t AVERAGING_HISTORY_SIZE = 5;

    /* Slop distance for jumpy pointer detection.
     * The vertical range of the screen divided by this is our epsilon value. */
    static const uint32_t JUMPY_EPSILON_DIVISOR = 212;

    /* Number of jumpy points to drop for touchscreens that need it. */
    static const uint32_t JUMPY_TRANSITION_DROPS = 3;
    static const uint32_t JUMPY_DROP_LIMIT = 3;

    /* Maximum squared distance for averaging.
     * If moving farther than this, turn of averaging to avoid lag in response. */
    static const uint64_t AVERAGING_DISTANCE_LIMIT = 75 * 75;

    struct AveragingTouchFilterState {
        // Individual history tracks are stored by pointer id
        uint32_t historyStart[MAX_POINTERS];
        uint32_t historyEnd[MAX_POINTERS];
        struct {
            struct {
                int32_t x;
                int32_t y;
                int32_t pressure;
            } pointers[MAX_POINTERS];
        } historyData[AVERAGING_HISTORY_SIZE];
    } mAveragingTouchFilter;

    struct JumpyTouchFilterState {
        uint32_t jumpyPointsDropped;
    } mJumpyTouchFilter;

    struct PointerDistanceHeapElement {
        uint32_t currentPointerIndex : 8;
        uint32_t lastPointerIndex : 8;
        uint64_t distance : 48; // squared distance
    };

    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,

            // 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.
            CLICK_OR_DRAG,

            // Exactly one finger, button is not pressed.
            // Pointer follows the active finger.
            // Emits HOVER_MOVE events at the pointer location.
            HOVER,

            // More than two fingers involved but they haven't moved enough for us
            // to figure out what is intended.
            INDETERMINATE_MULTITOUCH,

            // 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.
            // The centroid is fixed when entering this state.
            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.
            // The centroid is fixed when entering this state.
            FREEFORM,

            // Waiting for quiet time to end before starting the next gesture.
            QUIET,
        };

        // 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;
        uint32_t currentGesturePointerCount;
        BitSet32 currentGestureIdBits;
        uint32_t currentGestureIdToIndex[MAX_POINTER_ID + 1];
        PointerCoords currentGestureCoords[MAX_POINTERS];

        Mode lastGestureMode;
        uint32_t lastGesturePointerCount;
        BitSet32 lastGestureIdBits;
        uint32_t lastGestureIdToIndex[MAX_POINTER_ID + 1];
        PointerCoords lastGestureCoords[MAX_POINTERS];

        // Tracks for all pointers originally went down.
        TouchData touchOrigin;

        // Describes how touch ids are mapped to gesture ids for freeform gestures.
        uint32_t freeformTouchToGestureIdMap[MAX_POINTER_ID + 1];

        // Initial centroid of the movement.
        // Used to calculate how far the touch pointers have moved since the gesture started.
        int32_t initialCentroidX;
        int32_t initialCentroidY;

        // Initial pointer location.
        // Used to track where the pointer was when the gesture started.
        float initialPointerX;
        float initialPointerY;

        // Time the pointer gesture last went down.
        nsecs_t downTime;

        // Time we started waiting for a tap gesture.
        nsecs_t tapTime;

        // Time we started waiting for quiescence.
        nsecs_t quietTime;

        // A velocity tracker for determining whether to switch active pointers during drags.
        VelocityTracker velocityTracker;

        void reset() {
            activeTouchId = -1;
            activeGestureId = -1;
            currentGestureMode = NEUTRAL;
            currentGesturePointerCount = 0;
            currentGestureIdBits.clear();
            lastGestureMode = NEUTRAL;
            lastGesturePointerCount = 0;
            lastGestureIdBits.clear();
            touchOrigin.clear();
            initialCentroidX = 0;
            initialCentroidY = 0;
            initialPointerX = 0;
            initialPointerY = 0;
            downTime = 0;
            velocityTracker.clear();
            resetTapTime();
            resetQuietTime();
        }

        void resetTapTime() {
            tapTime = LLONG_MIN;
        }

        void resetQuietTime() {
            quietTime = LLONG_MIN;
        }
    } mPointerGesture;

    void initializeLocked();

    TouchResult consumeOffScreenTouches(nsecs_t when, uint32_t policyFlags);
    void dispatchTouches(nsecs_t when, uint32_t policyFlags);
    void prepareTouches(int32_t* outEdgeFlags, float* outXPrecision, float* outYPrecision);
    void dispatchPointerGestures(nsecs_t when, uint32_t policyFlags);
    void preparePointerGestures(nsecs_t when,
            bool* outCancelPreviousGesture, bool* outFinishPreviousGesture);

    // 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 flags, uint32_t metaState, int32_t edgeFlags,
            const PointerCoords* coords, const uint32_t* idToIndex, BitSet32 idBits,
            int32_t changedId, float xPrecision, float yPrecision, nsecs_t downTime);

    // Updates pointer coords for pointers with specified ids that have moved.
    // Returns true if any of them changed.
    bool updateMovedPointerCoords(const PointerCoords* inCoords, const uint32_t* inIdToIndex,
            PointerCoords* outCoords, const uint32_t* outIdToIndex, BitSet32 idBits) const;

    void suppressSwipeOntoVirtualKeys(nsecs_t when);

    bool isPointInsideSurfaceLocked(int32_t x, int32_t y);
    const VirtualKey* findVirtualKeyHitLocked(int32_t x, int32_t y);

    bool applyBadTouchFilter();
    bool applyJumpyTouchFilter();
    void applyAveragingTouchFilter();
    void calculatePointerIds();
};


class SingleTouchInputMapper : public TouchInputMapper {
public:
    SingleTouchInputMapper(InputDevice* device);
    virtual ~SingleTouchInputMapper();

    virtual void reset();
    virtual void process(const RawEvent* rawEvent);

protected:
    virtual void configureRawAxes();

private:
    struct Accumulator {
        enum {
            FIELD_BTN_TOUCH = 1,
            FIELD_ABS_X = 2,
            FIELD_ABS_Y = 4,
            FIELD_ABS_PRESSURE = 8,
            FIELD_ABS_TOOL_WIDTH = 16,
            FIELD_BUTTONS = 32,
        };

        uint32_t fields;

        bool btnTouch;
        int32_t absX;
        int32_t absY;
        int32_t absPressure;
        int32_t absToolWidth;

        uint32_t buttonDown;
        uint32_t buttonUp;

        inline void clear() {
            fields = 0;
            buttonDown = 0;
            buttonUp = 0;
        }
    } mAccumulator;

    bool mDown;
    int32_t mX;
    int32_t mY;
    int32_t mPressure;
    int32_t mToolWidth;
    uint32_t mButtonState;

    void initialize();

    void sync(nsecs_t when);
};


class MultiTouchInputMapper : public TouchInputMapper {
public:
    MultiTouchInputMapper(InputDevice* device);
    virtual ~MultiTouchInputMapper();

    virtual void reset();
    virtual void process(const RawEvent* rawEvent);

protected:
    virtual void configureRawAxes();

private:
    struct Accumulator {
        enum {
            FIELD_ABS_MT_POSITION_X = 1,
            FIELD_ABS_MT_POSITION_Y = 2,
            FIELD_ABS_MT_TOUCH_MAJOR = 4,
            FIELD_ABS_MT_TOUCH_MINOR = 8,
            FIELD_ABS_MT_WIDTH_MAJOR = 16,
            FIELD_ABS_MT_WIDTH_MINOR = 32,
            FIELD_ABS_MT_ORIENTATION = 64,
            FIELD_ABS_MT_TRACKING_ID = 128,
            FIELD_ABS_MT_PRESSURE = 256,
        };

        uint32_t pointerCount;
        struct Pointer {
            uint32_t fields;

            int32_t absMTPositionX;
            int32_t absMTPositionY;
            int32_t absMTTouchMajor;
            int32_t absMTTouchMinor;
            int32_t absMTWidthMajor;
            int32_t absMTWidthMinor;
            int32_t absMTOrientation;
            int32_t absMTTrackingId;
            int32_t absMTPressure;

            inline void clear() {
                fields = 0;
            }
        } pointers[MAX_POINTERS + 1]; // + 1 to remove the need for extra range checks

        // Bitfield of buttons that went down or up.
        uint32_t buttonDown;
        uint32_t buttonUp;

        inline void clear() {
            pointerCount = 0;
            pointers[0].clear();
            buttonDown = 0;
            buttonUp = 0;
        }
    } mAccumulator;

    uint32_t mButtonState;

    void initialize();

    void sync(nsecs_t when);
};


class JoystickInputMapper : public InputMapper {
public:
    JoystickInputMapper(InputDevice* device);
    virtual ~JoystickInputMapper();

    virtual uint32_t getSources();
    virtual void populateDeviceInfo(InputDeviceInfo* deviceInfo);
    virtual void dump(String8& dump);
    virtual void configure();
    virtual void reset();
    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 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) {
            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->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);
};

} // namespace android

#endif // _UI_INPUT_READER_H