//
// Copyright 2010 The Android Open Source Project
//
// The input reader.
//
#define LOG_TAG "InputReader"

//#define LOG_NDEBUG 0

// Log debug messages for each raw event received from the EventHub.
#define DEBUG_RAW_EVENTS 0

// Log debug messages about touch screen filtering hacks.
#define DEBUG_HACKS 0

// Log debug messages about virtual key processing.
#define DEBUG_VIRTUAL_KEYS 0

// Log debug messages about pointers.
#define DEBUG_POINTERS 0

// Log debug messages about pointer assignment calculations.
#define DEBUG_POINTER_ASSIGNMENT 0

#include <cutils/log.h>
#include <ui/InputReader.h>

#include <stddef.h>
#include <unistd.h>
#include <errno.h>
#include <limits.h>
#include <math.h>

namespace android {

// --- Static Functions ---

template<typename T>
inline static T abs(const T& value) {
    return value < 0 ? - value : value;
}

template<typename T>
inline static T min(const T& a, const T& b) {
    return a < b ? a : b;
}

template<typename T>
inline static void swap(T& a, T& b) {
    T temp = a;
    a = b;
    b = temp;
}


int32_t updateMetaState(int32_t keyCode, bool down, int32_t oldMetaState) {
    int32_t mask;
    switch (keyCode) {
    case AKEYCODE_ALT_LEFT:
        mask = AMETA_ALT_LEFT_ON;
        break;
    case AKEYCODE_ALT_RIGHT:
        mask = AMETA_ALT_RIGHT_ON;
        break;
    case AKEYCODE_SHIFT_LEFT:
        mask = AMETA_SHIFT_LEFT_ON;
        break;
    case AKEYCODE_SHIFT_RIGHT:
        mask = AMETA_SHIFT_RIGHT_ON;
        break;
    case AKEYCODE_SYM:
        mask = AMETA_SYM_ON;
        break;
    default:
        return oldMetaState;
    }

    int32_t newMetaState = down ? oldMetaState | mask : oldMetaState & ~ mask
            & ~ (AMETA_ALT_ON | AMETA_SHIFT_ON);

    if (newMetaState & (AMETA_ALT_LEFT_ON | AMETA_ALT_RIGHT_ON)) {
        newMetaState |= AMETA_ALT_ON;
    }

    if (newMetaState & (AMETA_SHIFT_LEFT_ON | AMETA_SHIFT_RIGHT_ON)) {
        newMetaState |= AMETA_SHIFT_ON;
    }

    return newMetaState;
}

static const int32_t keyCodeRotationMap[][4] = {
        // key codes enumerated counter-clockwise with the original (unrotated) key first
        // no rotation,        90 degree rotation,  180 degree rotation, 270 degree rotation
        { AKEYCODE_DPAD_DOWN,   AKEYCODE_DPAD_RIGHT,  AKEYCODE_DPAD_UP,     AKEYCODE_DPAD_LEFT },
        { AKEYCODE_DPAD_RIGHT,  AKEYCODE_DPAD_UP,     AKEYCODE_DPAD_LEFT,   AKEYCODE_DPAD_DOWN },
        { AKEYCODE_DPAD_UP,     AKEYCODE_DPAD_LEFT,   AKEYCODE_DPAD_DOWN,   AKEYCODE_DPAD_RIGHT },
        { AKEYCODE_DPAD_LEFT,   AKEYCODE_DPAD_DOWN,   AKEYCODE_DPAD_RIGHT,  AKEYCODE_DPAD_UP },
};
static const int keyCodeRotationMapSize =
        sizeof(keyCodeRotationMap) / sizeof(keyCodeRotationMap[0]);

int32_t rotateKeyCode(int32_t keyCode, int32_t orientation) {
    if (orientation != InputReaderPolicyInterface::ROTATION_0) {
        for (int i = 0; i < keyCodeRotationMapSize; i++) {
            if (keyCode == keyCodeRotationMap[i][0]) {
                return keyCodeRotationMap[i][orientation];
            }
        }
    }
    return keyCode;
}

static inline bool sourcesMatchMask(uint32_t sources, uint32_t sourceMask) {
    return (sources & sourceMask & ~ AINPUT_SOURCE_CLASS_MASK) != 0;
}


// --- InputReader ---

InputReader::InputReader(const sp<EventHubInterface>& eventHub,
        const sp<InputReaderPolicyInterface>& policy,
        const sp<InputDispatcherInterface>& dispatcher) :
        mEventHub(eventHub), mPolicy(policy), mDispatcher(dispatcher),
        mGlobalMetaState(0) {
    configureExcludedDevices();
    updateGlobalMetaState();
    updateInputConfiguration();
}

InputReader::~InputReader() {
    for (size_t i = 0; i < mDevices.size(); i++) {
        delete mDevices.valueAt(i);
    }
}

void InputReader::loopOnce() {
    RawEvent rawEvent;
    mEventHub->getEvent(& rawEvent);

#if DEBUG_RAW_EVENTS
    LOGD("Input event: device=0x%x type=0x%x scancode=%d keycode=%d value=%d",
            rawEvent.deviceId, rawEvent.type, rawEvent.scanCode, rawEvent.keyCode,
            rawEvent.value);
#endif

    process(& rawEvent);
}

void InputReader::process(const RawEvent* rawEvent) {
    switch (rawEvent->type) {
    case EventHubInterface::DEVICE_ADDED:
        addDevice(rawEvent->when, rawEvent->deviceId);
        break;

    case EventHubInterface::DEVICE_REMOVED:
        removeDevice(rawEvent->when, rawEvent->deviceId);
        break;

    default:
        consumeEvent(rawEvent);
        break;
    }
}

void InputReader::addDevice(nsecs_t when, int32_t deviceId) {
    String8 name = mEventHub->getDeviceName(deviceId);
    uint32_t classes = mEventHub->getDeviceClasses(deviceId);

    InputDevice* device = createDevice(deviceId, name, classes);
    device->configure();

    bool added = false;
    { // acquire device registry writer lock
        RWLock::AutoWLock _wl(mDeviceRegistryLock);

        ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
        if (deviceIndex < 0) {
            mDevices.add(deviceId, device);
            added = true;
        }
    } // release device registry writer lock

    if (! added) {
        LOGW("Ignoring spurious device added event for deviceId %d.", deviceId);
        delete device;
        return;
    }

    if (device->isIgnored()) {
        LOGI("Device added: id=0x%x, name=%s (ignored non-input device)",
                deviceId, name.string());
    } else {
        LOGI("Device added: id=0x%x, name=%s, sources=%08x",
                deviceId, name.string(), device->getSources());
    }

    handleConfigurationChanged(when);
}

void InputReader::removeDevice(nsecs_t when, int32_t deviceId) {
    bool removed = false;
    InputDevice* device = NULL;
    { // acquire device registry writer lock
        RWLock::AutoWLock _wl(mDeviceRegistryLock);

        ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
        if (deviceIndex >= 0) {
            device = mDevices.valueAt(deviceIndex);
            mDevices.removeItemsAt(deviceIndex, 1);
            removed = true;
        }
    } // release device registry writer lock

    if (! removed) {
        LOGW("Ignoring spurious device removed event for deviceId %d.", deviceId);
        return;
    }

    device->reset();

    if (device->isIgnored()) {
        LOGI("Device removed: id=0x%x, name=%s (ignored non-input device)",
                device->getId(), device->getName().string());
    } else {
        LOGI("Device removed: id=0x%x, name=%s, sources=%08x",
                device->getId(), device->getName().string(), device->getSources());
    }

    delete device;

    handleConfigurationChanged(when);
}

InputDevice* InputReader::createDevice(int32_t deviceId, const String8& name, uint32_t classes) {
    InputDevice* device = new InputDevice(this, deviceId, name);

    const int32_t associatedDisplayId = 0; // FIXME: hardcoded for current single-display devices

    // Switch-like devices.
    if (classes & INPUT_DEVICE_CLASS_SWITCH) {
        device->addMapper(new SwitchInputMapper(device));
    }

    // Keyboard-like devices.
    uint32_t keyboardSources = 0;
    int32_t keyboardType = AINPUT_KEYBOARD_TYPE_NON_ALPHABETIC;
    if (classes & INPUT_DEVICE_CLASS_KEYBOARD) {
        keyboardSources |= AINPUT_SOURCE_KEYBOARD;
    }
    if (classes & INPUT_DEVICE_CLASS_ALPHAKEY) {
        keyboardType = AINPUT_KEYBOARD_TYPE_ALPHABETIC;
    }
    if (classes & INPUT_DEVICE_CLASS_DPAD) {
        keyboardSources |= AINPUT_SOURCE_DPAD;
    }
    if (classes & INPUT_DEVICE_CLASS_GAMEPAD) {
        keyboardSources |= AINPUT_SOURCE_GAMEPAD;
    }

    if (keyboardSources != 0) {
        device->addMapper(new KeyboardInputMapper(device,
                associatedDisplayId, keyboardSources, keyboardType));
    }

    // Trackball-like devices.
    if (classes & INPUT_DEVICE_CLASS_TRACKBALL) {
        device->addMapper(new TrackballInputMapper(device, associatedDisplayId));
    }

    // Touchscreen-like devices.
    if (classes & INPUT_DEVICE_CLASS_TOUCHSCREEN_MT) {
        device->addMapper(new MultiTouchInputMapper(device, associatedDisplayId));
    } else if (classes & INPUT_DEVICE_CLASS_TOUCHSCREEN) {
        device->addMapper(new SingleTouchInputMapper(device, associatedDisplayId));
    }

    return device;
}

void InputReader::consumeEvent(const RawEvent* rawEvent) {
    int32_t deviceId = rawEvent->deviceId;

    { // acquire device registry reader lock
        RWLock::AutoRLock _rl(mDeviceRegistryLock);

        ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
        if (deviceIndex < 0) {
            LOGW("Discarding event for unknown deviceId %d.", deviceId);
            return;
        }

        InputDevice* device = mDevices.valueAt(deviceIndex);
        if (device->isIgnored()) {
            //LOGD("Discarding event for ignored deviceId %d.", deviceId);
            return;
        }

        device->process(rawEvent);
    } // release device registry reader lock
}

void InputReader::handleConfigurationChanged(nsecs_t when) {
    // Reset global meta state because it depends on the list of all configured devices.
    updateGlobalMetaState();

    // Update input configuration.
    updateInputConfiguration();

    // Enqueue configuration changed.
    mDispatcher->notifyConfigurationChanged(when);
}

void InputReader::configureExcludedDevices() {
    Vector<String8> excludedDeviceNames;
    mPolicy->getExcludedDeviceNames(excludedDeviceNames);

    for (size_t i = 0; i < excludedDeviceNames.size(); i++) {
        mEventHub->addExcludedDevice(excludedDeviceNames[i]);
    }
}

void InputReader::updateGlobalMetaState() {
    { // acquire state lock
        AutoMutex _l(mStateLock);

        mGlobalMetaState = 0;

        { // acquire device registry reader lock
            RWLock::AutoRLock _rl(mDeviceRegistryLock);

            for (size_t i = 0; i < mDevices.size(); i++) {
                InputDevice* device = mDevices.valueAt(i);
                mGlobalMetaState |= device->getMetaState();
            }
        } // release device registry reader lock
    } // release state lock
}

int32_t InputReader::getGlobalMetaState() {
    { // acquire state lock
        AutoMutex _l(mStateLock);

        return mGlobalMetaState;
    } // release state lock
}

void InputReader::updateInputConfiguration() {
    { // acquire state lock
        AutoMutex _l(mStateLock);

        int32_t touchScreenConfig = InputConfiguration::TOUCHSCREEN_NOTOUCH;
        int32_t keyboardConfig = InputConfiguration::KEYBOARD_NOKEYS;
        int32_t navigationConfig = InputConfiguration::NAVIGATION_NONAV;
        { // acquire device registry reader lock
            RWLock::AutoRLock _rl(mDeviceRegistryLock);

            InputDeviceInfo deviceInfo;
            for (size_t i = 0; i < mDevices.size(); i++) {
                InputDevice* device = mDevices.valueAt(i);
                device->getDeviceInfo(& deviceInfo);
                uint32_t sources = deviceInfo.getSources();

                if ((sources & AINPUT_SOURCE_TOUCHSCREEN) == AINPUT_SOURCE_TOUCHSCREEN) {
                    touchScreenConfig = InputConfiguration::TOUCHSCREEN_FINGER;
                }
                if ((sources & AINPUT_SOURCE_TRACKBALL) == AINPUT_SOURCE_TRACKBALL) {
                    navigationConfig = InputConfiguration::NAVIGATION_TRACKBALL;
                } else if ((sources & AINPUT_SOURCE_DPAD) == AINPUT_SOURCE_DPAD) {
                    navigationConfig = InputConfiguration::NAVIGATION_DPAD;
                }
                if (deviceInfo.getKeyboardType() == AINPUT_KEYBOARD_TYPE_ALPHABETIC) {
                    keyboardConfig = InputConfiguration::KEYBOARD_QWERTY;
                }
            }
        } // release device registry reader lock

        mInputConfiguration.touchScreen = touchScreenConfig;
        mInputConfiguration.keyboard = keyboardConfig;
        mInputConfiguration.navigation = navigationConfig;
    } // release state lock
}

void InputReader::getInputConfiguration(InputConfiguration* outConfiguration) {
    { // acquire state lock
        AutoMutex _l(mStateLock);

        *outConfiguration = mInputConfiguration;
    } // release state lock
}

status_t InputReader::getInputDeviceInfo(int32_t deviceId, InputDeviceInfo* outDeviceInfo) {
    { // acquire device registry reader lock
        RWLock::AutoRLock _rl(mDeviceRegistryLock);

        ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
        if (deviceIndex < 0) {
            return NAME_NOT_FOUND;
        }

        InputDevice* device = mDevices.valueAt(deviceIndex);
        if (device->isIgnored()) {
            return NAME_NOT_FOUND;
        }

        device->getDeviceInfo(outDeviceInfo);
        return OK;
    } // release device registy reader lock
}

void InputReader::getInputDeviceIds(Vector<int32_t>& outDeviceIds) {
    outDeviceIds.clear();

    { // acquire device registry reader lock
        RWLock::AutoRLock _rl(mDeviceRegistryLock);

        size_t numDevices = mDevices.size();
        for (size_t i = 0; i < numDevices; i++) {
            InputDevice* device = mDevices.valueAt(i);
            if (! device->isIgnored()) {
                outDeviceIds.add(device->getId());
            }
        }
    } // release device registy reader lock
}

int32_t InputReader::getKeyCodeState(int32_t deviceId, uint32_t sourceMask,
        int32_t keyCode) {
    return getState(deviceId, sourceMask, keyCode, & InputDevice::getKeyCodeState);
}

int32_t InputReader::getScanCodeState(int32_t deviceId, uint32_t sourceMask,
        int32_t scanCode) {
    return getState(deviceId, sourceMask, scanCode, & InputDevice::getScanCodeState);
}

int32_t InputReader::getSwitchState(int32_t deviceId, uint32_t sourceMask, int32_t switchCode) {
    return getState(deviceId, sourceMask, switchCode, & InputDevice::getSwitchState);
}

int32_t InputReader::getState(int32_t deviceId, uint32_t sourceMask, int32_t code,
        GetStateFunc getStateFunc) {
    { // acquire device registry reader lock
        RWLock::AutoRLock _rl(mDeviceRegistryLock);

        int32_t result = AKEY_STATE_UNKNOWN;
        if (deviceId >= 0) {
            ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
            if (deviceIndex >= 0) {
                InputDevice* device = mDevices.valueAt(deviceIndex);
                if (! device->isIgnored() && sourcesMatchMask(device->getSources(), sourceMask)) {
                    result = (device->*getStateFunc)(sourceMask, code);
                }
            }
        } else {
            size_t numDevices = mDevices.size();
            for (size_t i = 0; i < numDevices; i++) {
                InputDevice* device = mDevices.valueAt(i);
                if (! device->isIgnored() && sourcesMatchMask(device->getSources(), sourceMask)) {
                    result = (device->*getStateFunc)(sourceMask, code);
                    if (result >= AKEY_STATE_DOWN) {
                        return result;
                    }
                }
            }
        }
        return result;
    } // release device registy reader lock
}

bool InputReader::hasKeys(int32_t deviceId, uint32_t sourceMask,
        size_t numCodes, const int32_t* keyCodes, uint8_t* outFlags) {
    memset(outFlags, 0, numCodes);
    return markSupportedKeyCodes(deviceId, sourceMask, numCodes, keyCodes, outFlags);
}

bool InputReader::markSupportedKeyCodes(int32_t deviceId, uint32_t sourceMask, size_t numCodes,
        const int32_t* keyCodes, uint8_t* outFlags) {
    { // acquire device registry reader lock
        RWLock::AutoRLock _rl(mDeviceRegistryLock);
        bool result = false;
        if (deviceId >= 0) {
            ssize_t deviceIndex = mDevices.indexOfKey(deviceId);
            if (deviceIndex >= 0) {
                InputDevice* device = mDevices.valueAt(deviceIndex);
                if (! device->isIgnored() && sourcesMatchMask(device->getSources(), sourceMask)) {
                    result = device->markSupportedKeyCodes(sourceMask,
                            numCodes, keyCodes, outFlags);
                }
            }
        } else {
            size_t numDevices = mDevices.size();
            for (size_t i = 0; i < numDevices; i++) {
                InputDevice* device = mDevices.valueAt(i);
                if (! device->isIgnored() && sourcesMatchMask(device->getSources(), sourceMask)) {
                    result |= device->markSupportedKeyCodes(sourceMask,
                            numCodes, keyCodes, outFlags);
                }
            }
        }
        return result;
    } // release device registy reader lock
}


// --- InputReaderThread ---

InputReaderThread::InputReaderThread(const sp<InputReaderInterface>& reader) :
        Thread(/*canCallJava*/ true), mReader(reader) {
}

InputReaderThread::~InputReaderThread() {
}

bool InputReaderThread::threadLoop() {
    mReader->loopOnce();
    return true;
}


// --- InputDevice ---

InputDevice::InputDevice(InputReaderContext* context, int32_t id, const String8& name) :
        mContext(context), mId(id), mName(name), mSources(0) {
}

InputDevice::~InputDevice() {
    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        delete mMappers[i];
    }
    mMappers.clear();
}

void InputDevice::addMapper(InputMapper* mapper) {
    mMappers.add(mapper);
}

void InputDevice::configure() {
    mSources = 0;

    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        mapper->configure();
        mSources |= mapper->getSources();
    }
}

void InputDevice::reset() {
    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        mapper->reset();
    }
}

void InputDevice::process(const RawEvent* rawEvent) {
    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        mapper->process(rawEvent);
    }
}

void InputDevice::getDeviceInfo(InputDeviceInfo* outDeviceInfo) {
    outDeviceInfo->initialize(mId, mName);

    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        mapper->populateDeviceInfo(outDeviceInfo);
    }
}

int32_t InputDevice::getKeyCodeState(uint32_t sourceMask, int32_t keyCode) {
    return getState(sourceMask, keyCode, & InputMapper::getKeyCodeState);
}

int32_t InputDevice::getScanCodeState(uint32_t sourceMask, int32_t scanCode) {
    return getState(sourceMask, scanCode, & InputMapper::getScanCodeState);
}

int32_t InputDevice::getSwitchState(uint32_t sourceMask, int32_t switchCode) {
    return getState(sourceMask, switchCode, & InputMapper::getSwitchState);
}

int32_t InputDevice::getState(uint32_t sourceMask, int32_t code, GetStateFunc getStateFunc) {
    int32_t result = AKEY_STATE_UNKNOWN;
    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        if (sourcesMatchMask(mapper->getSources(), sourceMask)) {
            result = (mapper->*getStateFunc)(sourceMask, code);
            if (result >= AKEY_STATE_DOWN) {
                return result;
            }
        }
    }
    return result;
}

bool InputDevice::markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
        const int32_t* keyCodes, uint8_t* outFlags) {
    bool result = false;
    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        if (sourcesMatchMask(mapper->getSources(), sourceMask)) {
            result |= mapper->markSupportedKeyCodes(sourceMask, numCodes, keyCodes, outFlags);
        }
    }
    return result;
}

int32_t InputDevice::getMetaState() {
    int32_t result = 0;
    size_t numMappers = mMappers.size();
    for (size_t i = 0; i < numMappers; i++) {
        InputMapper* mapper = mMappers[i];
        result |= mapper->getMetaState();
    }
    return result;
}


// --- InputMapper ---

InputMapper::InputMapper(InputDevice* device) :
        mDevice(device), mContext(device->getContext()) {
}

InputMapper::~InputMapper() {
}

void InputMapper::populateDeviceInfo(InputDeviceInfo* info) {
    info->addSource(getSources());
}

void InputMapper::configure() {
}

void InputMapper::reset() {
}

int32_t InputMapper::getKeyCodeState(uint32_t sourceMask, int32_t keyCode) {
    return AKEY_STATE_UNKNOWN;
}

int32_t InputMapper::getScanCodeState(uint32_t sourceMask, int32_t scanCode) {
    return AKEY_STATE_UNKNOWN;
}

int32_t InputMapper::getSwitchState(uint32_t sourceMask, int32_t switchCode) {
    return AKEY_STATE_UNKNOWN;
}

bool InputMapper::markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
        const int32_t* keyCodes, uint8_t* outFlags) {
    return false;
}

int32_t InputMapper::getMetaState() {
    return 0;
}

bool InputMapper::applyStandardPolicyActions(nsecs_t when, int32_t policyActions) {
    if (policyActions & InputReaderPolicyInterface::ACTION_APP_SWITCH_COMING) {
        getDispatcher()->notifyAppSwitchComing(when);
    }

    return policyActions & InputReaderPolicyInterface::ACTION_DISPATCH;
}


// --- SwitchInputMapper ---

SwitchInputMapper::SwitchInputMapper(InputDevice* device) :
        InputMapper(device) {
}

SwitchInputMapper::~SwitchInputMapper() {
}

uint32_t SwitchInputMapper::getSources() {
    return 0;
}

void SwitchInputMapper::process(const RawEvent* rawEvent) {
    switch (rawEvent->type) {
    case EV_SW:
        processSwitch(rawEvent->when, rawEvent->scanCode, rawEvent->value);
        break;
    }
}

void SwitchInputMapper::processSwitch(nsecs_t when, int32_t switchCode, int32_t switchValue) {
    uint32_t policyFlags = 0;
    int32_t policyActions = getPolicy()->interceptSwitch(
            when, switchCode, switchValue, policyFlags);

    applyStandardPolicyActions(when, policyActions);
}

int32_t SwitchInputMapper::getSwitchState(uint32_t sourceMask, int32_t switchCode) {
    return getEventHub()->getSwitchState(getDeviceId(), switchCode);
}


// --- KeyboardInputMapper ---

KeyboardInputMapper::KeyboardInputMapper(InputDevice* device, int32_t associatedDisplayId,
        uint32_t sources, int32_t keyboardType) :
        InputMapper(device), mAssociatedDisplayId(associatedDisplayId), mSources(sources),
        mKeyboardType(keyboardType) {
    initialize();
}

KeyboardInputMapper::~KeyboardInputMapper() {
}

void KeyboardInputMapper::initialize() {
    mMetaState = AMETA_NONE;
    mDownTime = 0;
}

uint32_t KeyboardInputMapper::getSources() {
    return mSources;
}

void KeyboardInputMapper::populateDeviceInfo(InputDeviceInfo* info) {
    InputMapper::populateDeviceInfo(info);

    info->setKeyboardType(mKeyboardType);
}

void KeyboardInputMapper::reset() {
    // Synthesize key up event on reset if keys are currently down.
    while (! mKeyDowns.isEmpty()) {
        const KeyDown& keyDown = mKeyDowns.top();
        nsecs_t when = systemTime(SYSTEM_TIME_MONOTONIC);
        processKey(when, false, keyDown.keyCode, keyDown.scanCode, 0);
    }

    InputMapper::reset();

    // Reinitialize.
    initialize();
    getContext()->updateGlobalMetaState();
}

void KeyboardInputMapper::process(const RawEvent* rawEvent) {
    switch (rawEvent->type) {
    case EV_KEY: {
        int32_t scanCode = rawEvent->scanCode;
        if (isKeyboardOrGamepadKey(scanCode)) {
            processKey(rawEvent->when, rawEvent->value != 0, rawEvent->keyCode, scanCode,
                    rawEvent->flags);
        }
        break;
    }
    }
}

bool KeyboardInputMapper::isKeyboardOrGamepadKey(int32_t scanCode) {
    return scanCode < BTN_MOUSE
        || scanCode >= KEY_OK
        || (scanCode >= BTN_GAMEPAD && scanCode < BTN_DIGI);
}

void KeyboardInputMapper::processKey(nsecs_t when, bool down, int32_t keyCode, int32_t scanCode,
        uint32_t policyFlags) {
    if (down) {
        // Rotate key codes according to orientation.
        if (mAssociatedDisplayId >= 0) {
            int32_t orientation;
            if (! getPolicy()->getDisplayInfo(mAssociatedDisplayId, NULL, NULL, & orientation)) {
                return;
            }

            keyCode = rotateKeyCode(keyCode, orientation);
        }

        // Add key down.
        ssize_t keyDownIndex = findKeyDown(scanCode);
        if (keyDownIndex >= 0) {
            // key repeat, be sure to use same keycode as before in case of rotation
            keyCode = mKeyDowns.top().keyCode;
        } else {
            // key down
            mKeyDowns.push();
            KeyDown& keyDown = mKeyDowns.editTop();
            keyDown.keyCode = keyCode;
            keyDown.scanCode = scanCode;
        }
    } else {
        // Remove key down.
        ssize_t keyDownIndex = findKeyDown(scanCode);
        if (keyDownIndex >= 0) {
            // key up, be sure to use same keycode as before in case of rotation
            keyCode = mKeyDowns.top().keyCode;
            mKeyDowns.removeAt(size_t(keyDownIndex));
        } else {
            // key was not actually down
            LOGI("Dropping key up from device %s because the key was not down.  "
                    "keyCode=%d, scanCode=%d",
                    getDeviceName().string(), keyCode, scanCode);
            return;
        }
    }

    int32_t oldMetaState = mMetaState;
    int32_t newMetaState = updateMetaState(keyCode, down, oldMetaState);
    if (oldMetaState != newMetaState) {
        mMetaState = newMetaState;
        getContext()->updateGlobalMetaState();
    }

    /* Apply policy. */

    int32_t policyActions = getPolicy()->interceptKey(when,
            getDeviceId(), down, keyCode, scanCode, policyFlags);

    if (! applyStandardPolicyActions(when, policyActions)) {
        return; // event dropped
    }

    /* Enqueue key event for dispatch. */

    int32_t keyEventAction;
    if (down) {
        mDownTime = when;
        keyEventAction = AKEY_EVENT_ACTION_DOWN;
    } else {
        keyEventAction = AKEY_EVENT_ACTION_UP;
    }

    int32_t keyEventFlags = AKEY_EVENT_FLAG_FROM_SYSTEM;
    if (policyFlags & POLICY_FLAG_WOKE_HERE) {
        keyEventFlags = keyEventFlags | AKEY_EVENT_FLAG_WOKE_HERE;
    }

    getDispatcher()->notifyKey(when, getDeviceId(), AINPUT_SOURCE_KEYBOARD, policyFlags,
            keyEventAction, keyEventFlags, keyCode, scanCode,
            mMetaState, mDownTime);
}

ssize_t KeyboardInputMapper::findKeyDown(int32_t scanCode) {
    size_t n = mKeyDowns.size();
    for (size_t i = 0; i < n; i++) {
        if (mKeyDowns[i].scanCode == scanCode) {
            return i;
        }
    }
    return -1;
}

int32_t KeyboardInputMapper::getKeyCodeState(uint32_t sourceMask, int32_t keyCode) {
    return getEventHub()->getKeyCodeState(getDeviceId(), keyCode);
}

int32_t KeyboardInputMapper::getScanCodeState(uint32_t sourceMask, int32_t scanCode) {
    return getEventHub()->getScanCodeState(getDeviceId(), scanCode);
}

bool KeyboardInputMapper::markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
        const int32_t* keyCodes, uint8_t* outFlags) {
    return getEventHub()->markSupportedKeyCodes(getDeviceId(), numCodes, keyCodes, outFlags);
}

int32_t KeyboardInputMapper::getMetaState() {
    return mMetaState;
}


// --- TrackballInputMapper ---

TrackballInputMapper::TrackballInputMapper(InputDevice* device, int32_t associatedDisplayId) :
        InputMapper(device), mAssociatedDisplayId(associatedDisplayId) {
    mXPrecision = TRACKBALL_MOVEMENT_THRESHOLD;
    mYPrecision = TRACKBALL_MOVEMENT_THRESHOLD;
    mXScale = 1.0f / TRACKBALL_MOVEMENT_THRESHOLD;
    mYScale = 1.0f / TRACKBALL_MOVEMENT_THRESHOLD;

    initialize();
}

TrackballInputMapper::~TrackballInputMapper() {
}

uint32_t TrackballInputMapper::getSources() {
    return AINPUT_SOURCE_TRACKBALL;
}

void TrackballInputMapper::populateDeviceInfo(InputDeviceInfo* info) {
    InputMapper::populateDeviceInfo(info);

    info->addMotionRange(AINPUT_MOTION_RANGE_X, -1.0f, 1.0f, 0.0f, mXScale);
    info->addMotionRange(AINPUT_MOTION_RANGE_Y, -1.0f, 1.0f, 0.0f, mYScale);
}

void TrackballInputMapper::initialize() {
    mAccumulator.clear();

    mDown = false;
    mDownTime = 0;
}

void TrackballInputMapper::reset() {
    // Synthesize trackball button up event on reset if trackball button is currently down.
    if (mDown) {
        nsecs_t when = systemTime(SYSTEM_TIME_MONOTONIC);
        mAccumulator.fields |= Accumulator::FIELD_BTN_MOUSE;
        mAccumulator.btnMouse = false;
        sync(when);
    }

    InputMapper::reset();

    // Reinitialize.
    initialize();
}

void TrackballInputMapper::process(const RawEvent* rawEvent) {
    switch (rawEvent->type) {
    case EV_KEY:
        switch (rawEvent->scanCode) {
        case BTN_MOUSE:
            mAccumulator.fields |= Accumulator::FIELD_BTN_MOUSE;
            mAccumulator.btnMouse = rawEvent->value != 0;

            sync(rawEvent->when);
            mAccumulator.clear();
            break;
        }
        break;

    case EV_REL:
        switch (rawEvent->scanCode) {
        case REL_X:
            mAccumulator.fields |= Accumulator::FIELD_REL_X;
            mAccumulator.relX = rawEvent->value;
            break;
        case REL_Y:
            mAccumulator.fields |= Accumulator::FIELD_REL_Y;
            mAccumulator.relY = rawEvent->value;
            break;
        }
        break;

    case EV_SYN:
        switch (rawEvent->scanCode) {
        case SYN_REPORT:
            if (mAccumulator.isDirty()) {
                sync(rawEvent->when);
                mAccumulator.clear();
            }
            break;
        }
        break;
    }
}

void TrackballInputMapper::sync(nsecs_t when) {
    /* Get display properties so for rotation based on display orientation. */

    int32_t orientation;
    if (mAssociatedDisplayId >= 0) {
        if (! getPolicy()->getDisplayInfo(mAssociatedDisplayId, NULL, NULL, & orientation)) {
            return;
        }
    } else {
        orientation = InputReaderPolicyInterface::ROTATION_0;
    }

    /* Update saved trackball state */

    uint32_t fields = mAccumulator.fields;
    bool downChanged = fields & Accumulator::FIELD_BTN_MOUSE;

    if (downChanged) {
        if (mAccumulator.btnMouse) {
            mDown = true;
            mDownTime = when;
        } else {
            mDown = false;
        }
    }

    /* Apply policy */

    uint32_t policyFlags = 0;
    int32_t policyActions = getPolicy()->interceptGeneric(when, policyFlags);

    if (! applyStandardPolicyActions(when, policyActions)) {
        return; // event dropped
    }

    /* Enqueue motion event for dispatch. */

    int32_t motionEventAction;
    if (downChanged) {
        motionEventAction = mDown ? AMOTION_EVENT_ACTION_DOWN : AMOTION_EVENT_ACTION_UP;
    } else {
        motionEventAction = AMOTION_EVENT_ACTION_MOVE;
    }

    int32_t pointerId = 0;
    PointerCoords pointerCoords;
    pointerCoords.x = fields & Accumulator::FIELD_REL_X
            ? mAccumulator.relX * mXScale : 0;
    pointerCoords.y = fields & Accumulator::FIELD_REL_Y
            ? mAccumulator.relY * mYScale : 0;
    pointerCoords.pressure = 1.0f; // XXX Consider making this 1.0f if down, 0 otherwise.
    pointerCoords.size = 0;
    pointerCoords.touchMajor = 0;
    pointerCoords.touchMinor = 0;
    pointerCoords.toolMajor = 0;
    pointerCoords.toolMinor = 0;
    pointerCoords.orientation = 0;

    float temp;
    switch (orientation) {
    case InputReaderPolicyInterface::ROTATION_90:
        temp = pointerCoords.x;
        pointerCoords.x = pointerCoords.y;
        pointerCoords.y = - temp;
        break;

    case InputReaderPolicyInterface::ROTATION_180:
        pointerCoords.x = - pointerCoords.x;
        pointerCoords.y = - pointerCoords.y;
        break;

    case InputReaderPolicyInterface::ROTATION_270:
        temp = pointerCoords.x;
        pointerCoords.x = - pointerCoords.y;
        pointerCoords.y = temp;
        break;
    }

    int32_t metaState = mContext->getGlobalMetaState();
    getDispatcher()->notifyMotion(when, getDeviceId(), AINPUT_SOURCE_TRACKBALL, policyFlags,
            motionEventAction, metaState, AMOTION_EVENT_EDGE_FLAG_NONE,
            1, & pointerId, & pointerCoords, mXPrecision, mYPrecision, mDownTime);
}


// --- TouchInputMapper ---

TouchInputMapper::TouchInputMapper(InputDevice* device, int32_t associatedDisplayId) :
        InputMapper(device), mAssociatedDisplayId(associatedDisplayId),
        mSurfaceOrientation(-1), mSurfaceWidth(-1), mSurfaceHeight(-1) {
    initialize();
}

TouchInputMapper::~TouchInputMapper() {
}

uint32_t TouchInputMapper::getSources() {
    return mAssociatedDisplayId >= 0 ? AINPUT_SOURCE_TOUCHSCREEN : AINPUT_SOURCE_TOUCHPAD;
}

void TouchInputMapper::populateDeviceInfo(InputDeviceInfo* info) {
    InputMapper::populateDeviceInfo(info);

    // FIXME: Should ensure the surface information is up to date so that orientation changes
    // are noticed immediately.  Unfortunately we will need to add some extra locks here
    // to prevent race conditions.
    // configureSurface();

    info->addMotionRange(AINPUT_MOTION_RANGE_X, mOrientedRanges.x);
    info->addMotionRange(AINPUT_MOTION_RANGE_Y, mOrientedRanges.y);
    info->addMotionRange(AINPUT_MOTION_RANGE_PRESSURE, mOrientedRanges.pressure);
    info->addMotionRange(AINPUT_MOTION_RANGE_SIZE, mOrientedRanges.size);
    info->addMotionRange(AINPUT_MOTION_RANGE_TOUCH_MAJOR, mOrientedRanges.touchMajor);
    info->addMotionRange(AINPUT_MOTION_RANGE_TOUCH_MINOR, mOrientedRanges.touchMinor);
    info->addMotionRange(AINPUT_MOTION_RANGE_TOOL_MAJOR, mOrientedRanges.toolMajor);
    info->addMotionRange(AINPUT_MOTION_RANGE_TOOL_MINOR, mOrientedRanges.toolMinor);
    info->addMotionRange(AINPUT_MOTION_RANGE_ORIENTATION, mOrientedRanges.orientation);
}

void TouchInputMapper::initialize() {
    mLastTouch.clear();
    mDownTime = 0;
    mCurrentVirtualKey.down = false;

    for (uint32_t i = 0; i < MAX_POINTERS; i++) {
        mAveragingTouchFilter.historyStart[i] = 0;
        mAveragingTouchFilter.historyEnd[i] = 0;
    }

    mJumpyTouchFilter.jumpyPointsDropped = 0;
}

void TouchInputMapper::configure() {
    InputMapper::configure();

    // Configure basic parameters.
    mParameters.useBadTouchFilter = getPolicy()->filterTouchEvents();
    mParameters.useAveragingTouchFilter = getPolicy()->filterTouchEvents();
    mParameters.useJumpyTouchFilter = getPolicy()->filterJumpyTouchEvents();

    // Configure absolute axis information.
    configureAxes();

    // Configure pressure factors.
    if (mAxes.pressure.valid) {
        mPressureOrigin = mAxes.pressure.minValue;
        mPressureScale = 1.0f / mAxes.pressure.getRange();
    } else {
        mPressureOrigin = 0;
        mPressureScale = 1.0f;
    }

    mOrientedRanges.pressure.min = 0.0f;
    mOrientedRanges.pressure.max = 1.0f;
    mOrientedRanges.pressure.flat = 0.0f;
    mOrientedRanges.pressure.fuzz = mPressureScale;

    // Configure size factors.
    if (mAxes.size.valid) {
        mSizeOrigin = mAxes.size.minValue;
        mSizeScale = 1.0f / mAxes.size.getRange();
    } else {
        mSizeOrigin = 0;
        mSizeScale = 1.0f;
    }

    mOrientedRanges.size.min = 0.0f;
    mOrientedRanges.size.max = 1.0f;
    mOrientedRanges.size.flat = 0.0f;
    mOrientedRanges.size.fuzz = mSizeScale;

    // Configure orientation factors.
    if (mAxes.orientation.valid && mAxes.orientation.maxValue > 0) {
        mOrientationScale = float(M_PI_2) / mAxes.orientation.maxValue;
    } else {
        mOrientationScale = 0.0f;
    }

    mOrientedRanges.orientation.min = - M_PI_2;
    mOrientedRanges.orientation.max = M_PI_2;
    mOrientedRanges.orientation.flat = 0;
    mOrientedRanges.orientation.fuzz = mOrientationScale;

    // Configure surface dimensions and orientation.
    configureSurface();
}

void TouchInputMapper::configureAxes() {
    mAxes.x.valid = false;
    mAxes.y.valid = false;
    mAxes.pressure.valid = false;
    mAxes.size.valid = false;
    mAxes.touchMajor.valid = false;
    mAxes.touchMinor.valid = false;
    mAxes.toolMajor.valid = false;
    mAxes.toolMinor.valid = false;
    mAxes.orientation.valid = false;
}

bool TouchInputMapper::configureSurface() {
    // Update orientation and dimensions if needed.
    int32_t orientation;
    int32_t width, height;
    if (mAssociatedDisplayId >= 0) {
        if (! getPolicy()->getDisplayInfo(mAssociatedDisplayId, & width, & height, & orientation)) {
            return false;
        }
    } else {
        orientation = InputReaderPolicyInterface::ROTATION_0;
        width = mAxes.x.getRange();
        height = mAxes.y.getRange();
    }

    bool orientationChanged = mSurfaceOrientation != orientation;
    if (orientationChanged) {
        mSurfaceOrientation = orientation;
    }

    bool sizeChanged = mSurfaceWidth != width || mSurfaceHeight != height;
    if (sizeChanged) {
        mSurfaceWidth = width;
        mSurfaceHeight = height;

        // Compute size-dependent translation and scaling factors and place virtual keys.
        if (mAxes.x.valid && mAxes.y.valid) {
            mXOrigin = mAxes.x.minValue;
            mYOrigin = mAxes.y.minValue;

            LOGI("Device configured: id=0x%x, name=%s (display size was changed)",
                    getDeviceId(), getDeviceName().string());

            mXScale = float(width) / mAxes.x.getRange();
            mYScale = float(height) / mAxes.y.getRange();
            mXPrecision = 1.0f / mXScale;
            mYPrecision = 1.0f / mYScale;

            configureVirtualKeys();
        } else {
            mXOrigin = 0;
            mYOrigin = 0;
            mXScale = 1.0f;
            mYScale = 1.0f;
            mXPrecision = 1.0f;
            mYPrecision = 1.0f;
        }

        // Configure touch and tool area ranges.
        float diagonal = sqrt(float(width * width + height * height));
        float diagonalFuzz = sqrt(mXScale * mXScale + mYScale * mYScale);

        mOrientedRanges.touchMajor.min = 0.0f;
        mOrientedRanges.touchMajor.max = diagonal;
        mOrientedRanges.touchMajor.flat = 0.0f;
        mOrientedRanges.touchMajor.fuzz = diagonalFuzz;
        mOrientedRanges.touchMinor = mOrientedRanges.touchMajor;

        mOrientedRanges.toolMinor = mOrientedRanges.toolMajor = mOrientedRanges.touchMajor;
    }

    if (orientationChanged || sizeChanged) {
        // Compute oriented surface dimensions, precision, and scales.
        float orientedXScale, orientedYScale;
        switch (mSurfaceOrientation) {
        case InputReaderPolicyInterface::ROTATION_90:
        case InputReaderPolicyInterface::ROTATION_270:
            mOrientedSurfaceWidth = mSurfaceHeight;
            mOrientedSurfaceHeight = mSurfaceWidth;
            mOrientedXPrecision = mYPrecision;
            mOrientedYPrecision = mXPrecision;
            orientedXScale = mYScale;
            orientedYScale = mXScale;
            break;
        default:
            mOrientedSurfaceWidth = mSurfaceWidth;
            mOrientedSurfaceHeight = mSurfaceHeight;
            mOrientedXPrecision = mXPrecision;
            mOrientedYPrecision = mYPrecision;
            orientedXScale = mXScale;
            orientedYScale = mYScale;
            break;
        }

        // Configure position ranges.
        mOrientedRanges.x.min = 0;
        mOrientedRanges.x.max = mOrientedSurfaceWidth;
        mOrientedRanges.x.flat = 0;
        mOrientedRanges.x.fuzz = orientedXScale;

        mOrientedRanges.y.min = 0;
        mOrientedRanges.y.max = mOrientedSurfaceHeight;
        mOrientedRanges.y.flat = 0;
        mOrientedRanges.y.fuzz = orientedYScale;
    }

    return true;
}

void TouchInputMapper::configureVirtualKeys() {
    assert(mAxes.x.valid && mAxes.y.valid);

    Vector<InputReaderPolicyInterface::VirtualKeyDefinition> virtualKeyDefinitions;
    getPolicy()->getVirtualKeyDefinitions(getDeviceName(), virtualKeyDefinitions);

    { // acquire virtual key lock
        AutoMutex _l(mVirtualKeyLock);

        mVirtualKeys.clear();

        if (virtualKeyDefinitions.size() == 0) {
            return;
        }

        mVirtualKeys.setCapacity(virtualKeyDefinitions.size());

        int32_t touchScreenLeft = mAxes.x.minValue;
        int32_t touchScreenTop = mAxes.y.minValue;
        int32_t touchScreenWidth = mAxes.x.getRange();
        int32_t touchScreenHeight = mAxes.y.getRange();

        for (size_t i = 0; i < virtualKeyDefinitions.size(); i++) {
            const InputReaderPolicyInterface::VirtualKeyDefinition& virtualKeyDefinition =
                    virtualKeyDefinitions[i];

            mVirtualKeys.add();
            VirtualKey& virtualKey = mVirtualKeys.editTop();

            virtualKey.scanCode = virtualKeyDefinition.scanCode;
            int32_t keyCode;
            uint32_t flags;
            if (getEventHub()->scancodeToKeycode(getDeviceId(), virtualKey.scanCode,
                    & keyCode, & flags)) {
                LOGW("  VirtualKey %d: could not obtain key code, ignoring", virtualKey.scanCode);
                mVirtualKeys.pop(); // drop the key
                continue;
            }

            virtualKey.keyCode = keyCode;
            virtualKey.flags = flags;

            // convert the key definition's display coordinates into touch coordinates for a hit box
            int32_t halfWidth = virtualKeyDefinition.width / 2;
            int32_t halfHeight = virtualKeyDefinition.height / 2;

            virtualKey.hitLeft = (virtualKeyDefinition.centerX - halfWidth)
                    * touchScreenWidth / mSurfaceWidth + touchScreenLeft;
            virtualKey.hitRight= (virtualKeyDefinition.centerX + halfWidth)
                    * touchScreenWidth / mSurfaceWidth + touchScreenLeft;
            virtualKey.hitTop = (virtualKeyDefinition.centerY - halfHeight)
                    * touchScreenHeight / mSurfaceHeight + touchScreenTop;
            virtualKey.hitBottom = (virtualKeyDefinition.centerY + halfHeight)
                    * touchScreenHeight / mSurfaceHeight + touchScreenTop;

            LOGI("  VirtualKey %d: keyCode=%d hitLeft=%d hitRight=%d hitTop=%d hitBottom=%d",
                    virtualKey.scanCode, virtualKey.keyCode,
                    virtualKey.hitLeft, virtualKey.hitRight, virtualKey.hitTop, virtualKey.hitBottom);
        }
    } // release virtual key lock
}

void TouchInputMapper::reset() {
    // Synthesize touch up event if touch is currently down.
    // This will also take care of finishing virtual key processing if needed.
    if (mLastTouch.pointerCount != 0) {
        nsecs_t when = systemTime(SYSTEM_TIME_MONOTONIC);
        mCurrentTouch.clear();
        syncTouch(when, true);
    }

    InputMapper::reset();

    // Reinitialize.
    initialize();
}

void TouchInputMapper::syncTouch(nsecs_t when, bool havePointerIds) {
    /* Refresh associated display information and update our size configuration if needed. */

    if (! configureSurface()) {
        return;
    }

    /* Apply policy */

    uint32_t policyFlags = 0;
    int32_t policyActions = getPolicy()->interceptGeneric(when, policyFlags);

    if (! applyStandardPolicyActions(when, policyActions)) {
        mLastTouch.clear();
        return; // event dropped
    }

    /* Preprocess pointer data */

    if (mParameters.useBadTouchFilter) {
        if (applyBadTouchFilter()) {
            havePointerIds = false;
        }
    }

    if (mParameters.useJumpyTouchFilter) {
        if (applyJumpyTouchFilter()) {
            havePointerIds = false;
        }
    }

    if (! havePointerIds) {
        calculatePointerIds();
    }

    TouchData temp;
    TouchData* savedTouch;
    if (mParameters.useAveragingTouchFilter) {
        temp.copyFrom(mCurrentTouch);
        savedTouch = & temp;

        applyAveragingTouchFilter();
    } else {
        savedTouch = & mCurrentTouch;
    }

    /* Process touches and virtual keys */

    TouchResult touchResult = consumeOffScreenTouches(when, policyFlags);
    if (touchResult == DISPATCH_TOUCH) {
        dispatchTouches(when, policyFlags);
    }

    /* Copy current touch to last touch in preparation for the next cycle. */

    if (touchResult == DROP_STROKE) {
        mLastTouch.clear();
    } else {
        mLastTouch.copyFrom(*savedTouch);
    }
}

TouchInputMapper::TouchResult TouchInputMapper::consumeOffScreenTouches(
        nsecs_t when, uint32_t policyFlags) {
    int32_t keyEventAction, keyEventFlags;
    int32_t keyCode, scanCode, downTime;
    TouchResult touchResult;

    { // acquire virtual key lock
        AutoMutex _l(mVirtualKeyLock);

        if (mCurrentVirtualKey.down) {
            if (mCurrentTouch.pointerCount == 0) {
                // Pointer went up while virtual key was down.
                mCurrentVirtualKey.down = false;
#if DEBUG_VIRTUAL_KEYS
                LOGD("VirtualKeys: Generating key up: keyCode=%d, scanCode=%d",
                        mCurrentVirtualKey.keyCode, mCurrentVirtualKey.scanCode);
#endif
                keyEventAction = AKEY_EVENT_ACTION_UP;
                keyEventFlags = AKEY_EVENT_FLAG_FROM_SYSTEM | AKEY_EVENT_FLAG_VIRTUAL_HARD_KEY;
                touchResult = SKIP_TOUCH;
                goto DispatchVirtualKey;
            }

            if (mCurrentTouch.pointerCount == 1) {
                int32_t x = mCurrentTouch.pointers[0].x;
                int32_t y = mCurrentTouch.pointers[0].y;
                const VirtualKey* virtualKey = findVirtualKeyHitLvk(x, y);
                if (virtualKey && virtualKey->keyCode == mCurrentVirtualKey.keyCode) {
                    // Pointer is still within the space of the virtual key.
                    return SKIP_TOUCH;
                }
            }

            // Pointer left virtual key area or another pointer also went down.
            // Send key cancellation and drop the stroke so subsequent motions will be
            // considered fresh downs.  This is useful when the user swipes away from the
            // virtual key area into the main display surface.
            mCurrentVirtualKey.down = false;
#if DEBUG_VIRTUAL_KEYS
            LOGD("VirtualKeys: Canceling key: keyCode=%d, scanCode=%d",
                    mCurrentVirtualKey.keyCode, mCurrentVirtualKey.scanCode);
#endif
            keyEventAction = AKEY_EVENT_ACTION_UP;
            keyEventFlags = AKEY_EVENT_FLAG_FROM_SYSTEM | AKEY_EVENT_FLAG_VIRTUAL_HARD_KEY
                    | AKEY_EVENT_FLAG_CANCELED;
            touchResult = DROP_STROKE;
            goto DispatchVirtualKey;
        } else {
            if (mCurrentTouch.pointerCount >= 1 && mLastTouch.pointerCount == 0) {
                // Pointer just went down.  Handle off-screen touches, if needed.
                int32_t x = mCurrentTouch.pointers[0].x;
                int32_t y = mCurrentTouch.pointers[0].y;
                if (! isPointInsideSurface(x, y)) {
                    // If exactly one pointer went down, check for virtual key hit.
                    // Otherwise we will drop the entire stroke.
                    if (mCurrentTouch.pointerCount == 1) {
                        const VirtualKey* virtualKey = findVirtualKeyHitLvk(x, y);
                        if (virtualKey) {
                            mCurrentVirtualKey.down = true;
                            mCurrentVirtualKey.downTime = when;
                            mCurrentVirtualKey.keyCode = virtualKey->keyCode;
                            mCurrentVirtualKey.scanCode = virtualKey->scanCode;
#if DEBUG_VIRTUAL_KEYS
                            LOGD("VirtualKeys: Generating key down: keyCode=%d, scanCode=%d",
                                    mCurrentVirtualKey.keyCode, mCurrentVirtualKey.scanCode);
#endif
                            keyEventAction = AKEY_EVENT_ACTION_DOWN;
                            keyEventFlags = AKEY_EVENT_FLAG_FROM_SYSTEM
                                    | AKEY_EVENT_FLAG_VIRTUAL_HARD_KEY;
                            touchResult = SKIP_TOUCH;
                            goto DispatchVirtualKey;
                        }
                    }
                    return DROP_STROKE;
                }
            }
            return DISPATCH_TOUCH;
        }

    DispatchVirtualKey:
        // Collect remaining state needed to dispatch virtual key.
        keyCode = mCurrentVirtualKey.keyCode;
        scanCode = mCurrentVirtualKey.scanCode;
        downTime = mCurrentVirtualKey.downTime;
    } // release virtual key lock

    // Dispatch virtual key.
    int32_t metaState = mContext->getGlobalMetaState();

    if (keyEventAction == AKEY_EVENT_ACTION_DOWN) {
        getPolicy()->virtualKeyDownFeedback();
    }

    int32_t policyActions = getPolicy()->interceptKey(when, getDeviceId(),
            keyEventAction == AKEY_EVENT_ACTION_DOWN, keyCode, scanCode, policyFlags);

    if (applyStandardPolicyActions(when, policyActions)) {
        getDispatcher()->notifyKey(when, getDeviceId(), AINPUT_SOURCE_KEYBOARD, policyFlags,
                keyEventAction, keyEventFlags, keyCode, scanCode, metaState, downTime);
    }
    return touchResult;
}

void TouchInputMapper::dispatchTouches(nsecs_t when, uint32_t policyFlags) {
    uint32_t currentPointerCount = mCurrentTouch.pointerCount;
    uint32_t lastPointerCount = mLastTouch.pointerCount;
    if (currentPointerCount == 0 && lastPointerCount == 0) {
        return; // nothing to do!
    }

    BitSet32 currentIdBits = mCurrentTouch.idBits;
    BitSet32 lastIdBits = mLastTouch.idBits;

    if (currentIdBits == lastIdBits) {
        // No pointer id changes so this is a move event.
        // The dispatcher takes care of batching moves so we don't have to deal with that here.
        int32_t motionEventAction = AMOTION_EVENT_ACTION_MOVE;
        dispatchTouch(when, policyFlags, & mCurrentTouch,
                currentIdBits, -1, motionEventAction);
    } else {
        // There may be pointers going up and pointers going down at the same time when pointer
        // ids are reported by the device driver.
        BitSet32 upIdBits(lastIdBits.value & ~ currentIdBits.value);
        BitSet32 downIdBits(currentIdBits.value & ~ lastIdBits.value);
        BitSet32 activeIdBits(lastIdBits.value);

        while (! upIdBits.isEmpty()) {
            uint32_t upId = upIdBits.firstMarkedBit();
            upIdBits.clearBit(upId);
            BitSet32 oldActiveIdBits = activeIdBits;
            activeIdBits.clearBit(upId);

            int32_t motionEventAction;
            if (activeIdBits.isEmpty()) {
                motionEventAction = AMOTION_EVENT_ACTION_UP;
            } else {
                motionEventAction = AMOTION_EVENT_ACTION_POINTER_UP;
            }

            dispatchTouch(when, policyFlags, & mLastTouch,
                    oldActiveIdBits, upId, motionEventAction);
        }

        while (! downIdBits.isEmpty()) {
            uint32_t downId = downIdBits.firstMarkedBit();
            downIdBits.clearBit(downId);
            BitSet32 oldActiveIdBits = activeIdBits;
            activeIdBits.markBit(downId);

            int32_t motionEventAction;
            if (oldActiveIdBits.isEmpty()) {
                motionEventAction = AMOTION_EVENT_ACTION_DOWN;
                mDownTime = when;
            } else {
                motionEventAction = AMOTION_EVENT_ACTION_POINTER_DOWN;
            }

            dispatchTouch(when, policyFlags, & mCurrentTouch,
                    activeIdBits, downId, motionEventAction);
        }
    }
}

void TouchInputMapper::dispatchTouch(nsecs_t when, uint32_t policyFlags,
        TouchData* touch, BitSet32 idBits, uint32_t changedId,
        int32_t motionEventAction) {
    uint32_t pointerCount = 0;
    int32_t pointerIds[MAX_POINTERS];
    PointerCoords pointerCoords[MAX_POINTERS];

    // Walk through the the active pointers and map touch screen coordinates (TouchData) into
    // display coordinates (PointerCoords) and adjust for display orientation.
    while (! idBits.isEmpty()) {
        uint32_t id = idBits.firstMarkedBit();
        idBits.clearBit(id);
        uint32_t index = touch->idToIndex[id];

        float x = float(touch->pointers[index].x - mXOrigin) * mXScale;
        float y = float(touch->pointers[index].y - mYOrigin) * mYScale;
        float pressure = float(touch->pointers[index].pressure - mPressureOrigin) * mPressureScale;
        float size = float(touch->pointers[index].size - mSizeOrigin) * mSizeScale;

        float orientation = float(touch->pointers[index].orientation) * mOrientationScale;

        float touchMajor, touchMinor, toolMajor, toolMinor;
        if (abs(orientation) <= M_PI_4) {
            // Nominally vertical orientation: scale major axis by Y, and scale minor axis by X.
            touchMajor = float(touch->pointers[index].touchMajor) * mYScale;
            touchMinor = float(touch->pointers[index].touchMinor) * mXScale;
            toolMajor = float(touch->pointers[index].toolMajor) * mYScale;
            toolMinor = float(touch->pointers[index].toolMinor) * mXScale;
        } else {
            // Nominally horizontal orientation: scale major axis by X, and scale minor axis by Y.
            touchMajor = float(touch->pointers[index].touchMajor) * mXScale;
            touchMinor = float(touch->pointers[index].touchMinor) * mYScale;
            toolMajor = float(touch->pointers[index].toolMajor) * mXScale;
            toolMinor = float(touch->pointers[index].toolMinor) * mYScale;
        }

        switch (mSurfaceOrientation) {
        case InputReaderPolicyInterface::ROTATION_90: {
            float xTemp = x;
            x = y;
            y = mOrientedSurfaceWidth - xTemp;
            orientation -= M_PI_2;
            if (orientation < - M_PI_2) {
                orientation += M_PI;
            }
            break;
        }
        case InputReaderPolicyInterface::ROTATION_180: {
            x = mOrientedSurfaceWidth - x;
            y = mOrientedSurfaceHeight - y;
            orientation = - orientation;
            break;
        }
        case InputReaderPolicyInterface::ROTATION_270: {
            float xTemp = x;
            x = mOrientedSurfaceHeight - y;
            y = xTemp;
            orientation += M_PI_2;
            if (orientation > M_PI_2) {
                orientation -= M_PI;
            }
            break;
        }
        }

        pointerIds[pointerCount] = int32_t(id);

        pointerCoords[pointerCount].x = x;
        pointerCoords[pointerCount].y = y;
        pointerCoords[pointerCount].pressure = pressure;
        pointerCoords[pointerCount].size = size;
        pointerCoords[pointerCount].touchMajor = touchMajor;
        pointerCoords[pointerCount].touchMinor = touchMinor;
        pointerCoords[pointerCount].toolMajor = toolMajor;
        pointerCoords[pointerCount].toolMinor = toolMinor;
        pointerCoords[pointerCount].orientation = orientation;

        if (id == changedId) {
            motionEventAction |= pointerCount << AMOTION_EVENT_ACTION_POINTER_INDEX_SHIFT;
        }

        pointerCount += 1;
    }

    // Check edge flags by looking only at the first pointer since the flags are
    // global to the event.
    int32_t motionEventEdgeFlags = 0;
    if (motionEventAction == AMOTION_EVENT_ACTION_DOWN) {
        if (pointerCoords[0].x <= 0) {
            motionEventEdgeFlags |= AMOTION_EVENT_EDGE_FLAG_LEFT;
        } else if (pointerCoords[0].x >= mOrientedSurfaceWidth) {
            motionEventEdgeFlags |= AMOTION_EVENT_EDGE_FLAG_RIGHT;
        }
        if (pointerCoords[0].y <= 0) {
            motionEventEdgeFlags |= AMOTION_EVENT_EDGE_FLAG_TOP;
        } else if (pointerCoords[0].y >= mOrientedSurfaceHeight) {
            motionEventEdgeFlags |= AMOTION_EVENT_EDGE_FLAG_BOTTOM;
        }
    }

    getDispatcher()->notifyMotion(when, getDeviceId(), AINPUT_SOURCE_TOUCHSCREEN, policyFlags,
            motionEventAction, getContext()->getGlobalMetaState(), motionEventEdgeFlags,
            pointerCount, pointerIds, pointerCoords,
            mOrientedXPrecision, mOrientedYPrecision, mDownTime);
}

bool TouchInputMapper::isPointInsideSurface(int32_t x, int32_t y) {
    if (mAxes.x.valid && mAxes.y.valid) {
        return x >= mAxes.x.minValue && x <= mAxes.x.maxValue
                && y >= mAxes.y.minValue && y <= mAxes.y.maxValue;
    }
    return true;
}

const TouchInputMapper::VirtualKey* TouchInputMapper::findVirtualKeyHitLvk(int32_t x, int32_t y) {
    for (size_t i = 0; i < mVirtualKeys.size(); i++) {
        const VirtualKey& virtualKey = mVirtualKeys[i];

#if DEBUG_VIRTUAL_KEYS
        LOGD("VirtualKeys: Hit test (%d, %d): keyCode=%d, scanCode=%d, "
                "left=%d, top=%d, right=%d, bottom=%d",
                x, y,
                virtualKey.keyCode, virtualKey.scanCode,
                virtualKey.hitLeft, virtualKey.hitTop,
                virtualKey.hitRight, virtualKey.hitBottom);
#endif

        if (virtualKey.isHit(x, y)) {
            return & virtualKey;
        }
    }

    return NULL;
}

void TouchInputMapper::calculatePointerIds() {
    uint32_t currentPointerCount = mCurrentTouch.pointerCount;
    uint32_t lastPointerCount = mLastTouch.pointerCount;

    if (currentPointerCount == 0) {
        // No pointers to assign.
        mCurrentTouch.idBits.clear();
    } else if (lastPointerCount == 0) {
        // All pointers are new.
        mCurrentTouch.idBits.clear();
        for (uint32_t i = 0; i < currentPointerCount; i++) {
            mCurrentTouch.pointers[i].id = i;
            mCurrentTouch.idToIndex[i] = i;
            mCurrentTouch.idBits.markBit(i);
        }
    } else if (currentPointerCount == 1 && lastPointerCount == 1) {
        // Only one pointer and no change in count so it must have the same id as before.
        uint32_t id = mLastTouch.pointers[0].id;
        mCurrentTouch.pointers[0].id = id;
        mCurrentTouch.idToIndex[id] = 0;
        mCurrentTouch.idBits.value = BitSet32::valueForBit(id);
    } else {
        // General case.
        // We build a heap of squared euclidean distances between current and last pointers
        // associated with the current and last pointer indices.  Then, we find the best
        // match (by distance) for each current pointer.
        PointerDistanceHeapElement heap[MAX_POINTERS * MAX_POINTERS];

        uint32_t heapSize = 0;
        for (uint32_t currentPointerIndex = 0; currentPointerIndex < currentPointerCount;
                currentPointerIndex++) {
            for (uint32_t lastPointerIndex = 0; lastPointerIndex < lastPointerCount;
                    lastPointerIndex++) {
                int64_t deltaX = mCurrentTouch.pointers[currentPointerIndex].x
                        - mLastTouch.pointers[lastPointerIndex].x;
                int64_t deltaY = mCurrentTouch.pointers[currentPointerIndex].y
                        - mLastTouch.pointers[lastPointerIndex].y;

                uint64_t distance = uint64_t(deltaX * deltaX + deltaY * deltaY);

                // Insert new element into the heap (sift up).
                heap[heapSize].currentPointerIndex = currentPointerIndex;
                heap[heapSize].lastPointerIndex = lastPointerIndex;
                heap[heapSize].distance = distance;
                heapSize += 1;
            }
        }

        // Heapify
        for (uint32_t startIndex = heapSize / 2; startIndex != 0; ) {
            startIndex -= 1;
            for (uint32_t parentIndex = startIndex; ;) {
                uint32_t childIndex = parentIndex * 2 + 1;
                if (childIndex >= heapSize) {
                    break;
                }

                if (childIndex + 1 < heapSize
                        && heap[childIndex + 1].distance < heap[childIndex].distance) {
                    childIndex += 1;
                }

                if (heap[parentIndex].distance <= heap[childIndex].distance) {
                    break;
                }

                swap(heap[parentIndex], heap[childIndex]);
                parentIndex = childIndex;
            }
        }

#if DEBUG_POINTER_ASSIGNMENT
        LOGD("calculatePointerIds - initial distance min-heap: size=%d", heapSize);
        for (size_t i = 0; i < heapSize; i++) {
            LOGD("  heap[%d]: cur=%d, last=%d, distance=%lld",
                    i, heap[i].currentPointerIndex, heap[i].lastPointerIndex,
                    heap[i].distance);
        }
#endif

        // Pull matches out by increasing order of distance.
        // To avoid reassigning pointers that have already been matched, the loop keeps track
        // of which last and current pointers have been matched using the matchedXXXBits variables.
        // It also tracks the used pointer id bits.
        BitSet32 matchedLastBits(0);
        BitSet32 matchedCurrentBits(0);
        BitSet32 usedIdBits(0);
        bool first = true;
        for (uint32_t i = min(currentPointerCount, lastPointerCount); i > 0; i--) {
            for (;;) {
                if (first) {
                    // The first time through the loop, we just consume the root element of
                    // the heap (the one with smallest distance).
                    first = false;
                } else {
                    // Previous iterations consumed the root element of the heap.
                    // Pop root element off of the heap (sift down).
                    heapSize -= 1;
                    assert(heapSize > 0);

                    // Sift down.
                    heap[0] = heap[heapSize];
                    for (uint32_t parentIndex = 0; ;) {
                        uint32_t childIndex = parentIndex * 2 + 1;
                        if (childIndex >= heapSize) {
                            break;
                        }

                        if (childIndex + 1 < heapSize
                                && heap[childIndex + 1].distance < heap[childIndex].distance) {
                            childIndex += 1;
                        }

                        if (heap[parentIndex].distance <= heap[childIndex].distance) {
                            break;
                        }

                        swap(heap[parentIndex], heap[childIndex]);
                        parentIndex = childIndex;
                    }

#if DEBUG_POINTER_ASSIGNMENT
                    LOGD("calculatePointerIds - reduced distance min-heap: size=%d", heapSize);
                    for (size_t i = 0; i < heapSize; i++) {
                        LOGD("  heap[%d]: cur=%d, last=%d, distance=%lld",
                                i, heap[i].currentPointerIndex, heap[i].lastPointerIndex,
                                heap[i].distance);
                    }
#endif
                }

                uint32_t currentPointerIndex = heap[0].currentPointerIndex;
                if (matchedCurrentBits.hasBit(currentPointerIndex)) continue; // already matched

                uint32_t lastPointerIndex = heap[0].lastPointerIndex;
                if (matchedLastBits.hasBit(lastPointerIndex)) continue; // already matched

                matchedCurrentBits.markBit(currentPointerIndex);
                matchedLastBits.markBit(lastPointerIndex);

                uint32_t id = mLastTouch.pointers[lastPointerIndex].id;
                mCurrentTouch.pointers[currentPointerIndex].id = id;
                mCurrentTouch.idToIndex[id] = currentPointerIndex;
                usedIdBits.markBit(id);

#if DEBUG_POINTER_ASSIGNMENT
                LOGD("calculatePointerIds - matched: cur=%d, last=%d, id=%d, distance=%lld",
                        lastPointerIndex, currentPointerIndex, id, heap[0].distance);
#endif
                break;
            }
        }

        // Assign fresh ids to new pointers.
        if (currentPointerCount > lastPointerCount) {
            for (uint32_t i = currentPointerCount - lastPointerCount; ;) {
                uint32_t currentPointerIndex = matchedCurrentBits.firstUnmarkedBit();
                uint32_t id = usedIdBits.firstUnmarkedBit();

                mCurrentTouch.pointers[currentPointerIndex].id = id;
                mCurrentTouch.idToIndex[id] = currentPointerIndex;
                usedIdBits.markBit(id);

#if DEBUG_POINTER_ASSIGNMENT
                LOGD("calculatePointerIds - assigned: cur=%d, id=%d",
                        currentPointerIndex, id);
#endif

                if (--i == 0) break; // done
                matchedCurrentBits.markBit(currentPointerIndex);
            }
        }

        // Fix id bits.
        mCurrentTouch.idBits = usedIdBits;
    }
}

/* Special hack for devices that have bad screen data: if one of the
 * points has moved more than a screen height from the last position,
 * then drop it. */
bool TouchInputMapper::applyBadTouchFilter() {
    // This hack requires valid axis parameters.
    if (! mAxes.y.valid) {
        return false;
    }

    uint32_t pointerCount = mCurrentTouch.pointerCount;

    // Nothing to do if there are no points.
    if (pointerCount == 0) {
        return false;
    }

    // Don't do anything if a finger is going down or up.  We run
    // here before assigning pointer IDs, so there isn't a good
    // way to do per-finger matching.
    if (pointerCount != mLastTouch.pointerCount) {
        return false;
    }

    // We consider a single movement across more than a 7/16 of
    // the long size of the screen to be bad.  This was a magic value
    // determined by looking at the maximum distance it is feasible
    // to actually move in one sample.
    int32_t maxDeltaY = mAxes.y.getRange() * 7 / 16;

    // XXX The original code in InputDevice.java included commented out
    //     code for testing the X axis.  Note that when we drop a point
    //     we don't actually restore the old X either.  Strange.
    //     The old code also tries to track when bad points were previously
    //     detected but it turns out that due to the placement of a "break"
    //     at the end of the loop, we never set mDroppedBadPoint to true
    //     so it is effectively dead code.
    // Need to figure out if the old code is busted or just overcomplicated
    // but working as intended.

    // Look through all new points and see if any are farther than
    // acceptable from all previous points.
    for (uint32_t i = pointerCount; i-- > 0; ) {
        int32_t y = mCurrentTouch.pointers[i].y;
        int32_t closestY = INT_MAX;
        int32_t closestDeltaY = 0;

#if DEBUG_HACKS
        LOGD("BadTouchFilter: Looking at next point #%d: y=%d", i, y);
#endif

        for (uint32_t j = pointerCount; j-- > 0; ) {
            int32_t lastY = mLastTouch.pointers[j].y;
            int32_t deltaY = abs(y - lastY);

#if DEBUG_HACKS
            LOGD("BadTouchFilter: Comparing with last point #%d: y=%d deltaY=%d",
                    j, lastY, deltaY);
#endif

            if (deltaY < maxDeltaY) {
                goto SkipSufficientlyClosePoint;
            }
            if (deltaY < closestDeltaY) {
                closestDeltaY = deltaY;
                closestY = lastY;
            }
        }

        // Must not have found a close enough match.
#if DEBUG_HACKS
        LOGD("BadTouchFilter: Dropping bad point #%d: newY=%d oldY=%d deltaY=%d maxDeltaY=%d",
                i, y, closestY, closestDeltaY, maxDeltaY);
#endif

        mCurrentTouch.pointers[i].y = closestY;
        return true; // XXX original code only corrects one point

    SkipSufficientlyClosePoint: ;
    }

    // No change.
    return false;
}

/* Special hack for devices that have bad screen data: drop points where
 * the coordinate value for one axis has jumped to the other pointer's location.
 */
bool TouchInputMapper::applyJumpyTouchFilter() {
    // This hack requires valid axis parameters.
    if (! mAxes.y.valid) {
        return false;
    }

    uint32_t pointerCount = mCurrentTouch.pointerCount;
    if (mLastTouch.pointerCount != pointerCount) {
#if DEBUG_HACKS
        LOGD("JumpyTouchFilter: Different pointer count %d -> %d",
                mLastTouch.pointerCount, pointerCount);
        for (uint32_t i = 0; i < pointerCount; i++) {
            LOGD("  Pointer %d (%d, %d)", i,
                    mCurrentTouch.pointers[i].x, mCurrentTouch.pointers[i].y);
        }
#endif

        if (mJumpyTouchFilter.jumpyPointsDropped < JUMPY_TRANSITION_DROPS) {
            if (mLastTouch.pointerCount == 1 && pointerCount == 2) {
                // Just drop the first few events going from 1 to 2 pointers.
                // They're bad often enough that they're not worth considering.
                mCurrentTouch.pointerCount = 1;
                mJumpyTouchFilter.jumpyPointsDropped += 1;

#if DEBUG_HACKS
                LOGD("JumpyTouchFilter: Pointer 2 dropped");
#endif
                return true;
            } else if (mLastTouch.pointerCount == 2 && pointerCount == 1) {
                // The event when we go from 2 -> 1 tends to be messed up too
                mCurrentTouch.pointerCount = 2;
                mCurrentTouch.pointers[0] = mLastTouch.pointers[0];
                mCurrentTouch.pointers[1] = mLastTouch.pointers[1];
                mJumpyTouchFilter.jumpyPointsDropped += 1;

#if DEBUG_HACKS
                for (int32_t i = 0; i < 2; i++) {
                    LOGD("JumpyTouchFilter: Pointer %d replaced (%d, %d)", i,
                            mCurrentTouch.pointers[i].x, mCurrentTouch.pointers[i].y);
                }
#endif
                return true;
            }
        }
        // Reset jumpy points dropped on other transitions or if limit exceeded.
        mJumpyTouchFilter.jumpyPointsDropped = 0;

#if DEBUG_HACKS
        LOGD("JumpyTouchFilter: Transition - drop limit reset");
#endif
        return false;
    }

    // We have the same number of pointers as last time.
    // A 'jumpy' point is one where the coordinate value for one axis
    // has jumped to the other pointer's location. No need to do anything
    // else if we only have one pointer.
    if (pointerCount < 2) {
        return false;
    }

    if (mJumpyTouchFilter.jumpyPointsDropped < JUMPY_DROP_LIMIT) {
        int jumpyEpsilon = mAxes.y.getRange() / JUMPY_EPSILON_DIVISOR;

        // We only replace the single worst jumpy point as characterized by pointer distance
        // in a single axis.
        int32_t badPointerIndex = -1;
        int32_t badPointerReplacementIndex = -1;
        int32_t badPointerDistance = INT_MIN; // distance to be corrected

        for (uint32_t i = pointerCount; i-- > 0; ) {
            int32_t x = mCurrentTouch.pointers[i].x;
            int32_t y = mCurrentTouch.pointers[i].y;

#if DEBUG_HACKS
            LOGD("JumpyTouchFilter: Point %d (%d, %d)", i, x, y);
#endif

            // Check if a touch point is too close to another's coordinates
            bool dropX = false, dropY = false;
            for (uint32_t j = 0; j < pointerCount; j++) {
                if (i == j) {
                    continue;
                }

                if (abs(x - mCurrentTouch.pointers[j].x) <= jumpyEpsilon) {
                    dropX = true;
                    break;
                }

                if (abs(y - mCurrentTouch.pointers[j].y) <= jumpyEpsilon) {
                    dropY = true;
                    break;
                }
            }
            if (! dropX && ! dropY) {
                continue; // not jumpy
            }

            // Find a replacement candidate by comparing with older points on the
            // complementary (non-jumpy) axis.
            int32_t distance = INT_MIN; // distance to be corrected
            int32_t replacementIndex = -1;

            if (dropX) {
                // X looks too close.  Find an older replacement point with a close Y.
                int32_t smallestDeltaY = INT_MAX;
                for (uint32_t j = 0; j < pointerCount; j++) {
                    int32_t deltaY = abs(y - mLastTouch.pointers[j].y);
                    if (deltaY < smallestDeltaY) {
                        smallestDeltaY = deltaY;
                        replacementIndex = j;
                    }
                }
                distance = abs(x - mLastTouch.pointers[replacementIndex].x);
            } else {
                // Y looks too close.  Find an older replacement point with a close X.
                int32_t smallestDeltaX = INT_MAX;
                for (uint32_t j = 0; j < pointerCount; j++) {
                    int32_t deltaX = abs(x - mLastTouch.pointers[j].x);
                    if (deltaX < smallestDeltaX) {
                        smallestDeltaX = deltaX;
                        replacementIndex = j;
                    }
                }
                distance = abs(y - mLastTouch.pointers[replacementIndex].y);
            }

            // If replacing this pointer would correct a worse error than the previous ones
            // considered, then use this replacement instead.
            if (distance > badPointerDistance) {
                badPointerIndex = i;
                badPointerReplacementIndex = replacementIndex;
                badPointerDistance = distance;
            }
        }

        // Correct the jumpy pointer if one was found.
        if (badPointerIndex >= 0) {
#if DEBUG_HACKS
            LOGD("JumpyTouchFilter: Replacing bad pointer %d with (%d, %d)",
                    badPointerIndex,
                    mLastTouch.pointers[badPointerReplacementIndex].x,
                    mLastTouch.pointers[badPointerReplacementIndex].y);
#endif

            mCurrentTouch.pointers[badPointerIndex].x =
                    mLastTouch.pointers[badPointerReplacementIndex].x;
            mCurrentTouch.pointers[badPointerIndex].y =
                    mLastTouch.pointers[badPointerReplacementIndex].y;
            mJumpyTouchFilter.jumpyPointsDropped += 1;
            return true;
        }
    }

    mJumpyTouchFilter.jumpyPointsDropped = 0;
    return false;
}

/* Special hack for devices that have bad screen data: aggregate and
 * compute averages of the coordinate data, to reduce the amount of
 * jitter seen by applications. */
void TouchInputMapper::applyAveragingTouchFilter() {
    for (uint32_t currentIndex = 0; currentIndex < mCurrentTouch.pointerCount; currentIndex++) {
        uint32_t id = mCurrentTouch.pointers[currentIndex].id;
        int32_t x = mCurrentTouch.pointers[currentIndex].x;
        int32_t y = mCurrentTouch.pointers[currentIndex].y;
        int32_t pressure = mCurrentTouch.pointers[currentIndex].pressure;

        if (mLastTouch.idBits.hasBit(id)) {
            // Pointer was down before and is still down now.
            // Compute average over history trace.
            uint32_t start = mAveragingTouchFilter.historyStart[id];
            uint32_t end = mAveragingTouchFilter.historyEnd[id];

            int64_t deltaX = x - mAveragingTouchFilter.historyData[end].pointers[id].x;
            int64_t deltaY = y - mAveragingTouchFilter.historyData[end].pointers[id].y;
            uint64_t distance = uint64_t(deltaX * deltaX + deltaY * deltaY);

#if DEBUG_HACKS
            LOGD("AveragingTouchFilter: Pointer id %d - Distance from last sample: %lld",
                    id, distance);
#endif

            if (distance < AVERAGING_DISTANCE_LIMIT) {
                // Increment end index in preparation for recording new historical data.
                end += 1;
                if (end > AVERAGING_HISTORY_SIZE) {
                    end = 0;
                }

                // If the end index has looped back to the start index then we have filled
                // the historical trace up to the desired size so we drop the historical
                // data at the start of the trace.
                if (end == start) {
                    start += 1;
                    if (start > AVERAGING_HISTORY_SIZE) {
                        start = 0;
                    }
                }

                // Add the raw data to the historical trace.
                mAveragingTouchFilter.historyStart[id] = start;
                mAveragingTouchFilter.historyEnd[id] = end;
                mAveragingTouchFilter.historyData[end].pointers[id].x = x;
                mAveragingTouchFilter.historyData[end].pointers[id].y = y;
                mAveragingTouchFilter.historyData[end].pointers[id].pressure = pressure;

                // Average over all historical positions in the trace by total pressure.
                int32_t averagedX = 0;
                int32_t averagedY = 0;
                int32_t totalPressure = 0;
                for (;;) {
                    int32_t historicalX = mAveragingTouchFilter.historyData[start].pointers[id].x;
                    int32_t historicalY = mAveragingTouchFilter.historyData[start].pointers[id].y;
                    int32_t historicalPressure = mAveragingTouchFilter.historyData[start]
                            .pointers[id].pressure;

                    averagedX += historicalX * historicalPressure;
                    averagedY += historicalY * historicalPressure;
                    totalPressure += historicalPressure;

                    if (start == end) {
                        break;
                    }

                    start += 1;
                    if (start > AVERAGING_HISTORY_SIZE) {
                        start = 0;
                    }
                }

                averagedX /= totalPressure;
                averagedY /= totalPressure;

#if DEBUG_HACKS
                LOGD("AveragingTouchFilter: Pointer id %d - "
                        "totalPressure=%d, averagedX=%d, averagedY=%d", id, totalPressure,
                        averagedX, averagedY);
#endif

                mCurrentTouch.pointers[currentIndex].x = averagedX;
                mCurrentTouch.pointers[currentIndex].y = averagedY;
            } else {
#if DEBUG_HACKS
                LOGD("AveragingTouchFilter: Pointer id %d - Exceeded max distance", id);
#endif
            }
        } else {
#if DEBUG_HACKS
            LOGD("AveragingTouchFilter: Pointer id %d - Pointer went up", id);
#endif
        }

        // Reset pointer history.
        mAveragingTouchFilter.historyStart[id] = 0;
        mAveragingTouchFilter.historyEnd[id] = 0;
        mAveragingTouchFilter.historyData[0].pointers[id].x = x;
        mAveragingTouchFilter.historyData[0].pointers[id].y = y;
        mAveragingTouchFilter.historyData[0].pointers[id].pressure = pressure;
    }
}

int32_t TouchInputMapper::getKeyCodeState(uint32_t sourceMask, int32_t keyCode) {
    { // acquire virtual key lock
        AutoMutex _l(mVirtualKeyLock);

        if (mCurrentVirtualKey.down && mCurrentVirtualKey.keyCode == keyCode) {
            return AKEY_STATE_VIRTUAL;
        }

        for (size_t i = 0; i < mVirtualKeys.size(); i++) {
            const VirtualKey& virtualKey = mVirtualKeys[i];
            if (virtualKey.keyCode == keyCode) {
                return AKEY_STATE_UP;
            }
        }
    } // release virtual key lock

    return AKEY_STATE_UNKNOWN;
}

int32_t TouchInputMapper::getScanCodeState(uint32_t sourceMask, int32_t scanCode) {
    { // acquire virtual key lock
        AutoMutex _l(mVirtualKeyLock);

        if (mCurrentVirtualKey.down && mCurrentVirtualKey.scanCode == scanCode) {
            return AKEY_STATE_VIRTUAL;
        }

        for (size_t i = 0; i < mVirtualKeys.size(); i++) {
            const VirtualKey& virtualKey = mVirtualKeys[i];
            if (virtualKey.scanCode == scanCode) {
                return AKEY_STATE_UP;
            }
        }
    } // release virtual key lock

    return AKEY_STATE_UNKNOWN;
}

bool TouchInputMapper::markSupportedKeyCodes(uint32_t sourceMask, size_t numCodes,
        const int32_t* keyCodes, uint8_t* outFlags) {
    { // acquire virtual key lock
        AutoMutex _l(mVirtualKeyLock);

        for (size_t i = 0; i < mVirtualKeys.size(); i++) {
            const VirtualKey& virtualKey = mVirtualKeys[i];

            for (size_t i = 0; i < numCodes; i++) {
                if (virtualKey.keyCode == keyCodes[i]) {
                    outFlags[i] = 1;
                }
            }
        }
    } // release virtual key lock

    return true;
}


// --- SingleTouchInputMapper ---

SingleTouchInputMapper::SingleTouchInputMapper(InputDevice* device, int32_t associatedDisplayId) :
        TouchInputMapper(device, associatedDisplayId) {
    initialize();
}

SingleTouchInputMapper::~SingleTouchInputMapper() {
}

void SingleTouchInputMapper::initialize() {
    mAccumulator.clear();

    mDown = false;
    mX = 0;
    mY = 0;
    mPressure = 0;
    mSize = 0;
}

void SingleTouchInputMapper::reset() {
    TouchInputMapper::reset();

    // Reinitialize.
    initialize();
 }

void SingleTouchInputMapper::process(const RawEvent* rawEvent) {
    switch (rawEvent->type) {
    case EV_KEY:
        switch (rawEvent->scanCode) {
        case BTN_TOUCH:
            mAccumulator.fields |= Accumulator::FIELD_BTN_TOUCH;
            mAccumulator.btnTouch = rawEvent->value != 0;

            sync(rawEvent->when);
            mAccumulator.clear();
            break;
        }
        break;

    case EV_ABS:
        switch (rawEvent->scanCode) {
        case ABS_X:
            mAccumulator.fields |= Accumulator::FIELD_ABS_X;
            mAccumulator.absX = rawEvent->value;
            break;
        case ABS_Y:
            mAccumulator.fields |= Accumulator::FIELD_ABS_Y;
            mAccumulator.absY = rawEvent->value;
            break;
        case ABS_PRESSURE:
            mAccumulator.fields |= Accumulator::FIELD_ABS_PRESSURE;
            mAccumulator.absPressure = rawEvent->value;
            break;
        case ABS_TOOL_WIDTH:
            mAccumulator.fields |= Accumulator::FIELD_ABS_TOOL_WIDTH;
            mAccumulator.absToolWidth = rawEvent->value;
            break;
        }
        break;

    case EV_SYN:
        switch (rawEvent->scanCode) {
        case SYN_REPORT:
            if (mAccumulator.isDirty()) {
                sync(rawEvent->when);
                mAccumulator.clear();
            }
            break;
        }
        break;
    }
}

void SingleTouchInputMapper::sync(nsecs_t when) {
    /* Update device state */

    uint32_t fields = mAccumulator.fields;

    if (fields & Accumulator::FIELD_BTN_TOUCH) {
        mDown = mAccumulator.btnTouch;
    }

    if (fields & Accumulator::FIELD_ABS_X) {
        mX = mAccumulator.absX;
    }

    if (fields & Accumulator::FIELD_ABS_Y) {
        mY = mAccumulator.absY;
    }

    if (fields & Accumulator::FIELD_ABS_PRESSURE) {
        mPressure = mAccumulator.absPressure;
    }

    if (fields & Accumulator::FIELD_ABS_TOOL_WIDTH) {
        mSize = mAccumulator.absToolWidth;
    }

    mCurrentTouch.clear();

    if (mDown) {
        mCurrentTouch.pointerCount = 1;
        mCurrentTouch.pointers[0].id = 0;
        mCurrentTouch.pointers[0].x = mX;
        mCurrentTouch.pointers[0].y = mY;
        mCurrentTouch.pointers[0].pressure = mPressure;
        mCurrentTouch.pointers[0].size = mSize;
        mCurrentTouch.pointers[0].touchMajor = mPressure;
        mCurrentTouch.pointers[0].touchMinor = mPressure;
        mCurrentTouch.pointers[0].toolMajor = mSize;
        mCurrentTouch.pointers[0].toolMinor = mSize;
        mCurrentTouch.pointers[0].orientation = 0;
        mCurrentTouch.idToIndex[0] = 0;
        mCurrentTouch.idBits.markBit(0);
    }

    syncTouch(when, true);
}

void SingleTouchInputMapper::configureAxes() {
    TouchInputMapper::configureAxes();

    // The axes are aliased to take into account the manner in which they are presented
    // as part of the TouchData during the sync.
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_X, & mAxes.x);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_Y, & mAxes.y);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_PRESSURE, & mAxes.pressure);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_TOOL_WIDTH, & mAxes.size);

    mAxes.touchMajor = mAxes.pressure;
    mAxes.touchMinor = mAxes.pressure;
    mAxes.toolMajor = mAxes.size;
    mAxes.toolMinor = mAxes.size;
}


// --- MultiTouchInputMapper ---

MultiTouchInputMapper::MultiTouchInputMapper(InputDevice* device, int32_t associatedDisplayId) :
        TouchInputMapper(device, associatedDisplayId) {
    initialize();
}

MultiTouchInputMapper::~MultiTouchInputMapper() {
}

void MultiTouchInputMapper::initialize() {
    mAccumulator.clear();
}

void MultiTouchInputMapper::reset() {
    TouchInputMapper::reset();

    // Reinitialize.
    initialize();
}

void MultiTouchInputMapper::process(const RawEvent* rawEvent) {
    switch (rawEvent->type) {
    case EV_ABS: {
        uint32_t pointerIndex = mAccumulator.pointerCount;
        Accumulator::Pointer* pointer = & mAccumulator.pointers[pointerIndex];

        switch (rawEvent->scanCode) {
        case ABS_MT_POSITION_X:
            pointer->fields |= Accumulator::FIELD_ABS_MT_POSITION_X;
            pointer->absMTPositionX = rawEvent->value;
            break;
        case ABS_MT_POSITION_Y:
            pointer->fields |= Accumulator::FIELD_ABS_MT_POSITION_Y;
            pointer->absMTPositionY = rawEvent->value;
            break;
        case ABS_MT_TOUCH_MAJOR:
            pointer->fields |= Accumulator::FIELD_ABS_MT_TOUCH_MAJOR;
            pointer->absMTTouchMajor = rawEvent->value;
            break;
        case ABS_MT_TOUCH_MINOR:
            pointer->fields |= Accumulator::FIELD_ABS_MT_TOUCH_MINOR;
            pointer->absMTTouchMinor = rawEvent->value;
            break;
        case ABS_MT_WIDTH_MAJOR:
            pointer->fields |= Accumulator::FIELD_ABS_MT_WIDTH_MAJOR;
            pointer->absMTWidthMajor = rawEvent->value;
            break;
        case ABS_MT_WIDTH_MINOR:
            pointer->fields |= Accumulator::FIELD_ABS_MT_WIDTH_MINOR;
            pointer->absMTWidthMinor = rawEvent->value;
            break;
        case ABS_MT_ORIENTATION:
            pointer->fields |= Accumulator::FIELD_ABS_MT_ORIENTATION;
            pointer->absMTOrientation = rawEvent->value;
            break;
        case ABS_MT_TRACKING_ID:
            pointer->fields |= Accumulator::FIELD_ABS_MT_TRACKING_ID;
            pointer->absMTTrackingId = rawEvent->value;
            break;
        }
        break;
    }

    case EV_SYN:
        switch (rawEvent->scanCode) {
        case SYN_MT_REPORT: {
            // MultiTouch Sync: The driver has returned all data for *one* of the pointers.
            uint32_t pointerIndex = mAccumulator.pointerCount;

            if (mAccumulator.pointers[pointerIndex].fields) {
                if (pointerIndex == MAX_POINTERS) {
                    LOGW("MultiTouch device driver returned more than maximum of %d pointers.",
                            MAX_POINTERS);
                } else {
                    pointerIndex += 1;
                    mAccumulator.pointerCount = pointerIndex;
                }
            }

            mAccumulator.pointers[pointerIndex].clear();
            break;
        }

        case SYN_REPORT:
            if (mAccumulator.isDirty()) {
                sync(rawEvent->when);
                mAccumulator.clear();
            }
            break;
        }
        break;
    }
}

void MultiTouchInputMapper::sync(nsecs_t when) {
    static const uint32_t REQUIRED_FIELDS =
            Accumulator::FIELD_ABS_MT_POSITION_X
            | Accumulator::FIELD_ABS_MT_POSITION_Y
            | Accumulator::FIELD_ABS_MT_TOUCH_MAJOR
            | Accumulator::FIELD_ABS_MT_WIDTH_MAJOR;

    /* Update device state */

    uint32_t inCount = mAccumulator.pointerCount;
    uint32_t outCount = 0;
    bool havePointerIds = true;

    mCurrentTouch.clear();

    for (uint32_t inIndex = 0; inIndex < inCount; inIndex++) {
        uint32_t fields = mAccumulator.pointers[inIndex].fields;

        if ((fields & REQUIRED_FIELDS) != REQUIRED_FIELDS) {
#if DEBUG_POINTERS
            LOGD("Pointers: Missing required multitouch pointer fields: index=%d, fields=%d",
                    inIndex, fields);
            continue;
#endif
        }

        if (mAccumulator.pointers[inIndex].absMTTouchMajor <= 0) {
            // Pointer is not down.  Drop it.
            continue;
        }

        mCurrentTouch.pointers[outCount].x = mAccumulator.pointers[inIndex].absMTPositionX;
        mCurrentTouch.pointers[outCount].y = mAccumulator.pointers[inIndex].absMTPositionY;

        mCurrentTouch.pointers[outCount].touchMajor =
                mAccumulator.pointers[inIndex].absMTTouchMajor;
        mCurrentTouch.pointers[outCount].touchMinor =
                (fields & Accumulator::FIELD_ABS_MT_TOUCH_MINOR) != 0
                ? mAccumulator.pointers[inIndex].absMTTouchMinor
                        : mAccumulator.pointers[inIndex].absMTTouchMajor;

        mCurrentTouch.pointers[outCount].toolMajor =
                mAccumulator.pointers[inIndex].absMTWidthMajor;
        mCurrentTouch.pointers[outCount].toolMinor =
                (fields & Accumulator::FIELD_ABS_MT_WIDTH_MINOR) != 0
                ? mAccumulator.pointers[inIndex].absMTWidthMinor
                        : mAccumulator.pointers[inIndex].absMTWidthMajor;

        mCurrentTouch.pointers[outCount].orientation =
                (fields & Accumulator::FIELD_ABS_MT_ORIENTATION) != 0
                ? mAccumulator.pointers[inIndex].absMTOrientation : 0;

        // Derive an approximation of pressure and size.
        // FIXME assignment of pressure may be incorrect, probably better to let
        // pressure = touch / width.  Later on we pass width to MotionEvent as a size, which
        // isn't quite right either.  Should be using touch for that.
        mCurrentTouch.pointers[outCount].pressure = mAccumulator.pointers[inIndex].absMTTouchMajor;
        mCurrentTouch.pointers[outCount].size = mAccumulator.pointers[inIndex].absMTWidthMajor;

        if (havePointerIds) {
            if (fields & Accumulator::
                    FIELD_ABS_MT_TRACKING_ID) {
                uint32_t id = uint32_t(mAccumulator.pointers[inIndex].absMTTrackingId);

                if (id > MAX_POINTER_ID) {
#if DEBUG_POINTERS
                    LOGD("Pointers: Ignoring driver provided pointer id %d because "
                            "it is larger than max supported id %d for optimizations",
                            id, MAX_POINTER_ID);
#endif
                    havePointerIds = false;
                }
                else {
                    mCurrentTouch.pointers[outCount].id = id;
                    mCurrentTouch.idToIndex[id] = outCount;
                    mCurrentTouch.idBits.markBit(id);
                }
            } else {
                havePointerIds = false;
            }
        }

        outCount += 1;
    }

    mCurrentTouch.pointerCount = outCount;

    syncTouch(when, havePointerIds);
}

void MultiTouchInputMapper::configureAxes() {
    TouchInputMapper::configureAxes();

    // The axes are aliased to take into account the manner in which they are presented
    // as part of the TouchData during the sync.
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_POSITION_X, & mAxes.x);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_POSITION_Y, & mAxes.y);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_TOUCH_MAJOR, & mAxes.touchMajor);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_TOUCH_MINOR, & mAxes.touchMinor);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_WIDTH_MAJOR, & mAxes.toolMajor);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_WIDTH_MINOR, & mAxes.toolMinor);
    getEventHub()->getAbsoluteAxisInfo(getDeviceId(), ABS_MT_ORIENTATION, & mAxes.orientation);

    if (! mAxes.touchMinor.valid) {
        mAxes.touchMinor = mAxes.touchMajor;
    }

    if (! mAxes.toolMinor.valid) {
        mAxes.toolMinor = mAxes.toolMajor;
    }

    mAxes.pressure = mAxes.touchMajor;
    mAxes.size = mAxes.toolMajor;
}


} // namespace android