1. 程式人生 > >和菜鳥一起學android4.0.3原始碼之touchscreen配置+除錯記錄

和菜鳥一起學android4.0.3原始碼之touchscreen配置+除錯記錄

        記得應該是上上週了,終於畢業了,離開了學校,就得面對現實的社會,以前學校實驗室裡,老師給了鑰匙,那電腦隨便用,那元器件隨便玩,什麼51微控制器啊,PIC微控制器啊,FPGA啊,arm11啊什麼的。想著做什麼就直接萬用版+電烙鐵什麼的一起搞定。除錯,寫程式,焊板子都是自己一手操辦啊,多麼自由啊。到了公司,可不依你,對於上市公司來說,管理什麼的總歸還是有些規範化的。
        對於嵌入式,雖然早有所耳聞,大三也玩過arm7,編了幾個基於GUI的貪吃蛇啊,黑白棋啊,連連看啊什麼的。自己也買來arm11,燒寫linux系統,搭建環境,最終也成功完成了hello world驅動模組。待以後有時間再好好整理整理。廢話不多說了,既然是anrdroid下的touchscreen的配置,那就專心點,不東扯西扯了。
     都說android4.0.3的touchscreen有了很大的變化,菜鳥也不知道這麼龐大的程式碼,各個功能模組式幹嘛的。只能找找資料,瞎折騰了。公司的任務,觸控式螢幕得上了,android的東西,只用滑鼠可不好玩啊。開始除錯SPI模式的ads7846的電阻屏,板子沒有SPI介面,於是就用GPIO模擬SPI的方式來實現SPI的功能,在此要說明下,這個嵌入式的板子就是和51,PIC的板子用起來不一樣啊,什麼工作佇列,什麼中斷下半部分工作,什麼匯流排啊,I2C啊,SPI啊,I2S啊,USB啊,都這麼糾結,頓時覺得學得好少啊,自己又有點懶,什麼都想學,至於什麼也沒學好。除錯好驅動後,總算是完成了一半的工作,接著,是否要直接上android去跑呢?android裡什麼機制都不知道額,雖然一開始android中實現滑鼠的時候小研究過android下的input那個框架,不過只是模模糊糊的概念,根本就沒有弄清楚。看來得下點功夫啊,要不然怎麼混啊。又偏題了,額,正題,正題。。
         直接上android了,突然發現出現了一個小圈圈。向滑鼠一樣的。貌似觸控式螢幕變成了滑鼠了。覺得太怪了,怎麼可以這樣?肯定那裡有問題的,找了好久的資料,終於找到了,原來是android4.0.3,他的touchscreen是需要配置檔案的。只要直接建立一個“裝置名.idc”的檔案,直接放到/system/usr/idc/目錄下,就可以了,裝置名是驅動中定義的,在android中的Eventhub中也是可以加列印在logcat中看出來的。

 # Basic Parameters
   touch.deviceType = touchScreen
   touch.orientationAware = 1

   # Size
   touch.size.calibration = diameter
   touch.size.scale = 10
   touch.size.bias = 0
   touch.size.isSummed = 0

   # Pressure
   # Driver reports signal strength as pressure.
   #
   # A normal thumb touch typically registers about 200 signal strength
   # units although we don't expect these values to be accurate.
   touch.pressure.calibration = amplitude
   touch.pressure.scale = 0.005

   # Orientation
   touch.orientation.calibration = none


        但是就知道了這個配置檔案,具體那裡實現的呢?怎麼配置進去的呢?怎麼看著你個是touch.deviceType = touchScreen這個決定的。不多說來程式碼
frameworks/base/services/input/InputReader.cpp

void TouchInputMapper::configureParameters() {
    // Use the pointer presentation mode for devices that do not support distinct
    // multitouch.  The spot-based presentation relies on being able to accurately
    // locate two or more fingers on the touch pad.
    mParameters.gestureMode = getEventHub()->hasInputProperty(getDeviceId(), INPUT_PROP_SEMI_MT)
            ? Parameters::GESTURE_MODE_POINTER : Parameters::GESTURE_MODE_SPOTS;

    String8 gestureModeString;
    if (getDevice()->getConfiguration().tryGetProperty(String8("touch.gestureMode"),
            gestureModeString)) {
        if (gestureModeString == "pointer") {
            mParameters.gestureMode = Parameters::GESTURE_MODE_POINTER;
        } else if (gestureModeString == "spots") {
            mParameters.gestureMode = Parameters::GESTURE_MODE_SPOTS;
        } else if (gestureModeString != "default") {
            LOGW("Invalid value for touch.gestureMode: '%s'", gestureModeString.string());
        }
    }

    if (getEventHub()->hasInputProperty(getDeviceId(), INPUT_PROP_DIRECT)) {
        // The device is a touch screen.
        mParameters.deviceType = Parameters::DEVICE_TYPE_TOUCH_SCREEN;
    } else if (getEventHub()->hasInputProperty(getDeviceId(), INPUT_PROP_POINTER)) {
        // The device is a pointing device like a track pad.
        mParameters.deviceType = Parameters::DEVICE_TYPE_POINTER;
    } else if (getEventHub()->hasRelativeAxis(getDeviceId(), REL_X)
            || getEventHub()->hasRelativeAxis(getDeviceId(), REL_Y)) {
        // The device is a cursor device with a touch pad attached.
        // By default don't use the touch pad to move the pointer.
        mParameters.deviceType = Parameters::DEVICE_TYPE_TOUCH_PAD;
    } else {
        // The device is a touch pad of unknown purpose.
        mParameters.deviceType = Parameters::DEVICE_TYPE_POINTER;
    }

    String8 deviceTypeString;
    if (getDevice()->getConfiguration().tryGetProperty(String8("touch.deviceType"),
            deviceTypeString)) {
        if (deviceTypeString == "touchScreen") {
            mParameters.deviceType = Parameters::DEVICE_TYPE_TOUCH_SCREEN;
        } else if (deviceTypeString == "touchPad") {
            mParameters.deviceType = Parameters::DEVICE_TYPE_TOUCH_PAD;
        } else if (deviceTypeString == "pointer") {
            mParameters.deviceType = Parameters::DEVICE_TYPE_POINTER;
        } else if (deviceTypeString != "default") {
            LOGW("Invalid value for touch.deviceType: '%s'", deviceTypeString.string());
        }
    }

    mParameters.orientationAware = mParameters.deviceType == Parameters::DEVICE_TYPE_TOUCH_SCREEN;
    getDevice()->getConfiguration().tryGetProperty(String8("touch.orientationAware"),
            mParameters.orientationAware);

    mParameters.associatedDisplayId = -1;
    mParameters.associatedDisplayIsExternal = false;
    if (mParameters.orientationAware
            || mParameters.deviceType == Parameters::DEVICE_TYPE_TOUCH_SCREEN
            || mParameters.deviceType == Parameters::DEVICE_TYPE_POINTER) {
        mParameters.associatedDisplayIsExternal =
                mParameters.deviceType == Parameters::DEVICE_TYPE_TOUCH_SCREEN
                        && getDevice()->isExternal();
        mParameters.associatedDisplayId = 0;
    }
}


     還是英文呢,看到第一行,如果沒有配置的話,那就是pointer,pointer不就是滑鼠嗎?只有定義deviceType為touchScreen,那才是我們要的啊。看來英文真的好重要好重

要啊。那到底是那裡去獲取配置檔案的呢?不是一般都是EventHub下開啟什麼檔案嗎?走,咱們去seesee。
frameworks/base/services/input/EventHub.cpp

void EventHub::loadConfigurationLocked(Device* device) {
    device->configurationFile = getInputDeviceConfigurationFilePathByDeviceIdentifier(
            device->identifier, INPUT_DEVICE_CONFIGURATION_FILE_TYPE_CONFIGURATION);
    if (device->configurationFile.isEmpty()) {
        LOGD("No input device configuration file found for device '%s'.",
                device->identifier.name.string());
    } else {
        status_t status = PropertyMap::load(device->configurationFile,
                &device->configuration);
        if (status) {
            LOGE("Error loading input device configuration file for device '%s'.  "
                    "Using default configuration.",
                    device->identifier.name.string());
        }
    }
}


     原來就是這裡去載入配置檔案的。然後再進行配置的,接著我們看看那些配置是什麼功能?上面的deviceType就不用說了,就是型別是觸控式螢幕而不是touchPad和pointer。

pointer是滑鼠類似的游標,touchPad還沒試過,板子上的觸控式螢幕也拆了,也沒法跳了。不知道是什麼,下次有機會去試試。差不多應該和touchScreen差不多。那麼

touch.size.calibration等一些配置是什麼?有什麼作用呢?還是程式碼看起
frameworks/base/services/input/InputReader.cpp

void TouchInputMapper::parseCalibration() {
    const PropertyMap& in = getDevice()->getConfiguration();
    Calibration& out = mCalibration;

    // Size
    out.sizeCalibration = Calibration::SIZE_CALIBRATION_DEFAULT;
    String8 sizeCalibrationString;
    if (in.tryGetProperty(String8("touch.size.calibration"), sizeCalibrationString)) {
        if (sizeCalibrationString == "none") {
            out.sizeCalibration = Calibration::SIZE_CALIBRATION_NONE;
        } else if (sizeCalibrationString == "geometric") {
            out.sizeCalibration = Calibration::SIZE_CALIBRATION_GEOMETRIC;
        } else if (sizeCalibrationString == "diameter") {
            out.sizeCalibration = Calibration::SIZE_CALIBRATION_DIAMETER;
        } else if (sizeCalibrationString == "area") {
            out.sizeCalibration = Calibration::SIZE_CALIBRATION_AREA;
        } else if (sizeCalibrationString != "default") {
            LOGW("Invalid value for touch.size.calibration: '%s'",
                    sizeCalibrationString.string());
        }
    }

    out.haveSizeScale = in.tryGetProperty(String8("touch.size.scale"),
            out.sizeScale);
    out.haveSizeBias = in.tryGetProperty(String8("touch.size.bias"),
            out.sizeBias);
    out.haveSizeIsSummed = in.tryGetProperty(String8("touch.size.isSummed"),
            out.sizeIsSummed);

    // Pressure
    out.pressureCalibration = Calibration::PRESSURE_CALIBRATION_DEFAULT;
    String8 pressureCalibrationString;
    if (in.tryGetProperty(String8("touch.pressure.calibration"), pressureCalibrationString)) {
        if (pressureCalibrationString == "none") {
            out.pressureCalibration = Calibration::PRESSURE_CALIBRATION_NONE;
        } else if (pressureCalibrationString == "physical") {
            out.pressureCalibration = Calibration::PRESSURE_CALIBRATION_PHYSICAL;
        } else if (pressureCalibrationString == "amplitude") {
            out.pressureCalibration = Calibration::PRESSURE_CALIBRATION_AMPLITUDE;
        } else if (pressureCalibrationString != "default") {
            LOGW("Invalid value for touch.pressure.calibration: '%s'",
                    pressureCalibrationString.string());
        }
    }

    out.havePressureScale = in.tryGetProperty(String8("touch.pressure.scale"),
            out.pressureScale);

    // Orientation
    out.orientationCalibration = Calibration::ORIENTATION_CALIBRATION_DEFAULT;
    String8 orientationCalibrationString;
    if (in.tryGetProperty(String8("touch.orientation.calibration"), orientationCalibrationString)) {
        if (orientationCalibrationString == "none") {
            out.orientationCalibration = Calibration::ORIENTATION_CALIBRATION_NONE;
        } else if (orientationCalibrationString == "interpolated") {
            out.orientationCalibration = Calibration::ORIENTATION_CALIBRATION_INTERPOLATED;
        } else if (orientationCalibrationString == "vector") {
            out.orientationCalibration = Calibration::ORIENTATION_CALIBRATION_VECTOR;
        } else if (orientationCalibrationString != "default") {
            LOGW("Invalid value for touch.orientation.calibration: '%s'",
                    orientationCalibrationString.string());
        }
    }

    // Distance
    out.distanceCalibration = Calibration::DISTANCE_CALIBRATION_DEFAULT;
    String8 distanceCalibrationString;
    if (in.tryGetProperty(String8("touch.distance.calibration"), distanceCalibrationString)) {
        if (distanceCalibrationString == "none") {
            out.distanceCalibration = Calibration::DISTANCE_CALIBRATION_NONE;
        } else if (distanceCalibrationString == "scaled") {
            out.distanceCalibration = Calibration::DISTANCE_CALIBRATION_SCALED;
        } else if (distanceCalibrationString != "default") {
            LOGW("Invalid value for touch.distance.calibration: '%s'",
                    distanceCalibrationString.string());
        }
    }

    out.haveDistanceScale = in.tryGetProperty(String8("touch.distance.scale"),
            out.distanceScale);
}


        touch.size.calibration分為了1、geometric 2、diameter 3、area,老師說不懂的單詞要查字典,現在都什麼年代了,隨便谷歌一下,手機也行。什麼牛津字典啊的,那都是浮雲了。geometric:幾何圖形?怪怪的,是不是代表不同的觸控的形狀?不懂,diameter倒是還好,直徑嘛應該是一個觸控的點是以這個為直徑的一個圓,至於area嘛,區域,難道是多點的時候?也許吧。touch.pressure.calibration分為了1、physical 2、amplitude 。physical:物理的,是不是理論上的?amplitude是不是幅度就是壓力的大小?不懂額。要不再來看看程式碼?那些配置之後肯定有執行的。不可能簡簡單單的就是賦值了。找找看
frameworks/base/services/input/InputReader.cpp

void TouchInputMapper::cookPointerData() {
    uint32_t currentPointerCount = mCurrentRawPointerData.pointerCount;

    mCurrentCookedPointerData.clear();
    mCurrentCookedPointerData.pointerCount = currentPointerCount;
    mCurrentCookedPointerData.hoveringIdBits = mCurrentRawPointerData.hoveringIdBits;
    mCurrentCookedPointerData.touchingIdBits = mCurrentRawPointerData.touchingIdBits;

    // Walk through the the active pointers and map device coordinates onto
    // surface coordinates and adjust for display orientation.
    for (uint32_t i = 0; i < currentPointerCount; i++) {
        const RawPointerData::Pointer& in = mCurrentRawPointerData.pointers[i];

        // Size
        float touchMajor, touchMinor, toolMajor, toolMinor, size;
        switch (mCalibration.sizeCalibration) {
        case Calibration::SIZE_CALIBRATION_GEOMETRIC:
        case Calibration::SIZE_CALIBRATION_DIAMETER:
        case Calibration::SIZE_CALIBRATION_AREA:
            if (mRawPointerAxes.touchMajor.valid && mRawPointerAxes.toolMajor.valid) {
                touchMajor = in.touchMajor;
                touchMinor = mRawPointerAxes.touchMinor.valid ? in.touchMinor : in.touchMajor;
                toolMajor = in.toolMajor;
                toolMinor = mRawPointerAxes.toolMinor.valid ? in.toolMinor : in.toolMajor;
                size = mRawPointerAxes.touchMinor.valid
                        ? avg(in.touchMajor, in.touchMinor) : in.touchMajor;
            } else if (mRawPointerAxes.touchMajor.valid) {
                toolMajor = touchMajor = in.touchMajor;
                toolMinor = touchMinor = mRawPointerAxes.touchMinor.valid
                        ? in.touchMinor : in.touchMajor;
                size = mRawPointerAxes.touchMinor.valid
                        ? avg(in.touchMajor, in.touchMinor) : in.touchMajor;
            } else if (mRawPointerAxes.toolMajor.valid) {
                touchMajor = toolMajor = in.toolMajor;
                touchMinor = toolMinor = mRawPointerAxes.toolMinor.valid
                        ? in.toolMinor : in.toolMajor;
                size = mRawPointerAxes.toolMinor.valid
                        ? avg(in.toolMajor, in.toolMinor) : in.toolMajor;
            } else {
                LOG_ASSERT(false, "No touch or tool axes.  "
                        "Size calibration should have been resolved to NONE.");
                touchMajor = 0;
                touchMinor = 0;
                toolMajor = 0;
                toolMinor = 0;
                size = 0;
            }

            if (mCalibration.haveSizeIsSummed && mCalibration.sizeIsSummed) {
                uint32_t touchingCount = mCurrentRawPointerData.touchingIdBits.count();
                if (touchingCount > 1) {
                    touchMajor /= touchingCount;
                    touchMinor /= touchingCount;
                    toolMajor /= touchingCount;
                    toolMinor /= touchingCount;
                    size /= touchingCount;
                }
            }

            if (mCalibration.sizeCalibration == Calibration::SIZE_CALIBRATION_GEOMETRIC) {
                touchMajor *= mGeometricScale;
                touchMinor *= mGeometricScale;
                toolMajor *= mGeometricScale;
                toolMinor *= mGeometricScale;
            } else if (mCalibration.sizeCalibration == Calibration::SIZE_CALIBRATION_AREA) {
                touchMajor = touchMajor > 0 ? sqrtf(touchMajor) : 0;
                touchMinor = touchMajor;
                toolMajor = toolMajor > 0 ? sqrtf(toolMajor) : 0;
                toolMinor = toolMajor;
            } else if (mCalibration.sizeCalibration == Calibration::SIZE_CALIBRATION_DIAMETER) {
                touchMinor = touchMajor;
                toolMinor = toolMajor;
            }

            mCalibration.applySizeScaleAndBias(&touchMajor);
            mCalibration.applySizeScaleAndBias(&touchMinor);
            mCalibration.applySizeScaleAndBias(&toolMajor);
            mCalibration.applySizeScaleAndBias(&toolMinor);
            size *= mSizeScale;
            break;
        default:
            touchMajor = 0;
            touchMinor = 0;
            toolMajor = 0;
            toolMinor = 0;
            size = 0;
            break;
        }

        // Pressure
        float pressure;
        switch (mCalibration.pressureCalibration) {
        case Calibration::PRESSURE_CALIBRATION_PHYSICAL:
        case Calibration::PRESSURE_CALIBRATION_AMPLITUDE:
            pressure = in.pressure * mPressureScale;
            break;
        default:
            pressure = in.isHovering ? 0 : 1;
            break;
        }

        // Tilt and Orientation
        float tilt;
        float orientation;
        if (mHaveTilt) {
            float tiltXAngle = (in.tiltX - mTiltXCenter) * mTiltXScale;
            float tiltYAngle = (in.tiltY - mTiltYCenter) * mTiltYScale;
            orientation = atan2f(-sinf(tiltXAngle), sinf(tiltYAngle));
            tilt = acosf(cosf(tiltXAngle) * cosf(tiltYAngle));
        } else {
            tilt = 0;

            switch (mCalibration.orientationCalibration) {
            case Calibration::ORIENTATION_CALIBRATION_INTERPOLATED:
                orientation = (in.orientation - mOrientationCenter) * mOrientationScale;
                break;
            case Calibration::ORIENTATION_CALIBRATION_VECTOR: {
                int32_t c1 = signExtendNybble((in.orientation & 0xf0) >> 4);
                int32_t c2 = signExtendNybble(in.orientation & 0x0f);
                if (c1 != 0 || c2 != 0) {
                    orientation = atan2f(c1, c2) * 0.5f;
                    float confidence = hypotf(c1, c2);
                    float scale = 1.0f + confidence / 16.0f;
                    touchMajor *= scale;
                    touchMinor /= scale;
                    toolMajor *= scale;
                    toolMinor /= scale;
                } else {
                    orientation = 0;
                }
                break;
            }
            default:
                orientation = 0;
            }
        }

        // Distance
        float distance;
        switch (mCalibration.distanceCalibration) {
        case Calibration::DISTANCE_CALIBRATION_SCALED:
            distance = in.distance * mDistanceScale;
            break;
        default:
            distance = 0;
        }

        // X and Y
        // Adjust coords for surface orientation.
        float x, y;
        switch (mSurfaceOrientation) {
        case DISPLAY_ORIENTATION_90:
            x = float(in.y - mRawPointerAxes.y.minValue) * mYScale;
            y = float(mRawPointerAxes.x.maxValue - in.x) * mXScale;
            orientation -= M_PI_2;
            if (orientation < - M_PI_2) {
                orientation += M_PI;
            }
            break;
        case DISPLAY_ORIENTATION_180:
            x = float(mRawPointerAxes.x.maxValue - in.x) * mXScale;
            y = float(mRawPointerAxes.y.maxValue - in.y) * mYScale;
            break;
        case DISPLAY_ORIENTATION_270:
            x = float(mRawPointerAxes.y.maxValue - in.y) * mYScale;
            y = float(in.x - mRawPointerAxes.x.minValue) * mXScale;
            orientation += M_PI_2;
            if (orientation > M_PI_2) {
                orientation -= M_PI;
            }
            break;
        default:
            x = float(in.x - mRawPointerAxes.x.minValue) * mXScale;
            y = float(in.y - mRawPointerAxes.y.minValue) * mYScale;
            break;
        }

        // Write output coords.
        PointerCoords& out = mCurrentCookedPointerData.pointerCoords[i];
        out.clear();
        out.setAxisValue(AMOTION_EVENT_AXIS_X, x);
        out.setAxisValue(AMOTION_EVENT_AXIS_Y, y);
        out.setAxisValue(AMOTION_EVENT_AXIS_PRESSURE, pressure);
        out.setAxisValue(AMOTION_EVENT_AXIS_SIZE, size);
        out.setAxisValue(AMOTION_EVENT_AXIS_TOUCH_MAJOR, touchMajor);
        out.setAxisValue(AMOTION_EVENT_AXIS_TOUCH_MINOR, touchMinor);
        out.setAxisValue(AMOTION_EVENT_AXIS_TOOL_MAJOR, toolMajor);
        out.setAxisValue(AMOTION_EVENT_AXIS_TOOL_MINOR, toolMinor);
        out.setAxisValue(AMOTION_EVENT_AXIS_ORIENTATION, orientation);
        out.setAxisValue(AMOTION_EVENT_AXIS_TILT, tilt);
        out.setAxisValue(AMOTION_EVENT_AXIS_DISTANCE, distance);

        // Write output properties.
        PointerProperties& properties = mCurrentCookedPointerData.pointerProperties[i];
        uint32_t id = in.id;
        properties.clear();
        properties.id = id;
        properties.toolType = in.toolType;

        // Write id index.
        mCurrentCookedPointerData.idToIndex[id] = i;
    }
}

    這資料處理的,cookPointerData,哈哈哈,原來都在這裡搞定的啊。TouchMajor and TouchMinor表示了觸控時接觸面積的大小範圍。這個函式會把驅動上傳上來的資料,也就是X、Y座標轉換為android設定的解析度的一個對映。差不多就這樣了。具體,碰到問題了在解決了。
    在此,有時候再講講自己除錯的時候碰到的一個問題,那就是android電源管理中會把背光給關掉,所以點死了觸控式螢幕還是發現沒用。所以除錯的時候可以把其中的一個

policyFlags設定下,不要drop掉,也就是即使背光關掉了也可以有效。
frameworks/base/services/input/InputDispatcher.cpp

 void InputDispatcher::dispatchOnceInnerLocked(nsecs_t* nextWakeupTime) {
    nsecs_t currentTime = now();

    // Reset the key repeat timer whenever we disallow key events, even if the next event
    // is not a key.  This is to ensure that we abort a key repeat if the device is just coming
    // out of sleep.
    if (!mPolicy->isKeyRepeatEnabled()) {
        resetKeyRepeatLocked();
    }

    // If dispatching is frozen, do not process timeouts or try to deliver any new events.
    if (mDispatchFrozen) {
#if DEBUG_FOCUS
        LOGD("Dispatch frozen.  Waiting some more.");
#endif
        return;
    }

    // Optimize latency of app switches.
    // Essentially we start a short timeout when an app switch key (HOME / ENDCALL) has
    // been pressed.  When it expires, we preempt dispatch and drop all other pending events.
    bool isAppSwitchDue = mAppSwitchDueTime <= currentTime;
    if (mAppSwitchDueTime < *nextWakeupTime) {
        *nextWakeupTime = mAppSwitchDueTime;
    }

    // Ready to start a new event.
    // If we don't already have a pending event, go grab one.
    if (! mPendingEvent) {
        if (mInboundQueue.isEmpty()) {
            if (isAppSwitchDue) {
                // The inbound queue is empty so the app switch key we were waiting
                // for will never arrive.  Stop waiting for it.
                resetPendingAppSwitchLocked(false);
                isAppSwitchDue = false;
            }

            // Synthesize a key repeat if appropriate.
            if (mKeyRepeatState.lastKeyEntry) {
                if (currentTime >= mKeyRepeatState.nextRepeatTime) {
                    mPendingEvent = synthesizeKeyRepeatLocked(currentTime);
                } else {
                    if (mKeyRepeatState.nextRepeatTime < *nextWakeupTime) {
                        *nextWakeupTime = mKeyRepeatState.nextRepeatTime;
                    }
                }
            }

            // Nothing to do if there is no pending event.
            if (! mPendingEvent) {
                if (mActiveConnections.isEmpty()) {
                    dispatchIdleLocked();
                }
                return;
            }
        } else {
            // Inbound queue has at least one entry.
            EventEntry* entry = mInboundQueue.head;

            // Throttle the entry if it is a move event and there are no
            // other events behind it in the queue.  Due to movement batching, additional
            // samples may be appended to this event by the time the throttling timeout
            // expires.
            // TODO Make this smarter and consider throttling per device independently.
            if (entry->type == EventEntry::TYPE_MOTION
                    && !isAppSwitchDue
                    && mDispatchEnabled
                    && (entry->policyFlags & POLICY_FLAG_PASS_TO_USER)
                    && !entry->isInjected()) {
                MotionEntry* motionEntry = static_cast<MotionEntry*>(entry);
                int32_t deviceId = motionEntry->deviceId;
                uint32_t source = motionEntry->source;
                if (! isAppSwitchDue
                        && !motionEntry->next // exactly one event, no successors
                        && (motionEntry->action == AMOTION_EVENT_ACTION_MOVE
                                || motionEntry->action == AMOTION_EVENT_ACTION_HOVER_MOVE)
                        && deviceId == mThrottleState.lastDeviceId
                        && source == mThrottleState.lastSource) {
                    nsecs_t nextTime = mThrottleState.lastEventTime
                            + mThrottleState.minTimeBetweenEvents;
                    if (currentTime < nextTime) {
                        // Throttle it!
#if DEBUG_THROTTLING
                        LOGD("Throttling - Delaying motion event for "
                                "device %d, source 0x%08x by up to %0.3fms.",
                                deviceId, source, (nextTime - currentTime) * 0.000001);
#endif
                        if (nextTime < *nextWakeupTime) {
                            *nextWakeupTime = nextTime;
                        }
                        if (mThrottleState.originalSampleCount == 0) {
                            mThrottleState.originalSampleCount =
                                    motionEntry->countSamples();
                        }
                        return;
                    }
                }

#if DEBUG_THROTTLING
                if (mThrottleState.originalSampleCount != 0) {
                    uint32_t count = motionEntry->countSamples();
                    LOGD("Throttling - Motion event sample count grew by %d from %d to %d.",
                            count - mThrottleState.originalSampleCount,
                            mThrottleState.originalSampleCount, count);
                    mThrottleState.originalSampleCount = 0;
                }
#endif

                mThrottleState.lastEventTime = currentTime;
                mThrottleState.lastDeviceId = deviceId;
                mThrottleState.lastSource = source;
            }

            mInboundQueue.dequeue(entry);
            mPendingEvent = entry;
        }

        // Poke user activity for this event.
        if (mPendingEvent->policyFlags & POLICY_FLAG_PASS_TO_USER) {
            pokeUserActivityLocked(mPendingEvent);
        }
    }

    // Now we have an event to dispatch.
    // All events are eventually dequeued and processed this way, even if we intend to drop them.
    LOG_ASSERT(mPendingEvent != NULL);
    bool done = false;
    DropReason dropReason = DROP_REASON_NOT_DROPPED;
    if (!(mPendingEvent->policyFlags & POLICY_FLAG_PASS_TO_USER)) {
        dropReason = DROP_REASON_POLICY;
    } else if (!mDispatchEnabled) {
        dropReason = DROP_REASON_DISABLED;
    }

    if (mNextUnblockedEvent == mPendingEvent) {
        mNextUnblockedEvent = NULL;
    }

    switch (mPendingEvent->type) {
    case EventEntry::TYPE_CONFIGURATION_CHANGED: {
        ConfigurationChangedEntry* typedEntry =
                static_cast<ConfigurationChangedEntry*>(mPendingEvent);
        done = dispatchConfigurationChangedLocked(currentTime, typedEntry);
        dropReason = DROP_REASON_NOT_DROPPED; // configuration changes are never dropped
        break;
    }

    case EventEntry::TYPE_DEVICE_RESET: {
        DeviceResetEntry* typedEntry =
                static_cast<DeviceResetEntry*>(mPendingEvent);
        done = dispatchDeviceResetLocked(currentTime, typedEntry);
        dropReason = DROP_REASON_NOT_DROPPED; // device resets are never dropped
        break;
    }

    case EventEntry::TYPE_KEY: {
        KeyEntry* typedEntry = static_cast<KeyEntry*>(mPendingEvent);
        if (isAppSwitchDue) {
            if (isAppSwitchKeyEventLocked(typedEntry)) {
                resetPendingAppSwitchLocked(true);
                isAppSwitchDue = false;
            } else if (dropReason == DROP_REASON_NOT_DROPPED) {
                dropReason = DROP_REASON_APP_SWITCH;
            }
        }
        if (dropReason == DROP_REASON_NOT_DROPPED
                && isStaleEventLocked(currentTime, typedEntry)) {
            dropReason = DROP_REASON_STALE;
        }
        if (dropReason == DROP_REASON_NOT_DROPPED && mNextUnblockedEvent) {
            dropReason = DROP_REASON_BLOCKED;
        }
        done = dispatchKeyLocked(currentTime, typedEntry, &dropReason, nextWakeupTime);
        break;
    }

    case EventEntry::TYPE_MOTION: {
        MotionEntry* typedEntry = static_cast<MotionEntry*>(mPendingEvent);
        if (dropReason == DROP_REASON_NOT_DROPPED && isAppSwitchDue) {
            dropReason = DROP_REASON_APP_SWITCH;
        }
        if (dropReason == DROP_REASON_NOT_DROPPED
                && isStaleEventLocked(currentTime, typedEntry)) {
            dropReason = DROP_REASON_STALE;
        }
        if (dropReason == DROP_REASON_NOT_DROPPED && mNextUnblockedEvent) {
            dropReason = DROP_REASON_BLOCKED;
        }
        done = dispatchMotionLocked(currentTime, typedEntry,
                &dropReason, nextWakeupTime);
        break;
    }

    default:
        LOG_ASSERT(false);
        break;
    }

    if (done) {
        if (dropReason != DROP_REASON_NOT_DROPPED) {
            dropInboundEventLocked(mPendingEvent, dropReason);
        }

        releasePendingEventLocked();
        *nextWakeupTime = LONG_LONG_MIN;  // force next poll to wake up immediately
    }
}


        只要把下面的東西給註釋掉就好了,那具體的policyflags是哪裡賦值的呢?真心找了我好久的。
frameworks/base/services/input/InputDispatcher.cpp

  if (!(mPendingEvent->policyFlags & POLICY_FLAG_PASS_TO_USER)) {
        dropReason = DROP_REASON_POLICY;
    } else if (!mDispatchEnabled) {
        dropReason = DROP_REASON_DISABLED;
    }


frameworks/base/services/input/InputDispatcher.cpp 

void InputDispatcher::notifyMotion(const NotifyMotionArgs* args) {
#if DEBUG_INBOUND_EVENT_DETAILS
    LOGD("notifyMotion - eventTime=%lld, deviceId=%d, source=0x%x, policyFlags=0x%x, "
            "action=0x%x, flags=0x%x, metaState=0x%x, buttonState=0x%x, edgeFlags=0x%x, "
            "xPrecision=%f, yPrecision=%f, downTime=%lld",
            args->eventTime, args->deviceId, args->source, args->policyFlags,
            args->action, args->flags, args->metaState, args->buttonState,
            args->edgeFlags, args->xPrecision, args->yPrecision, args->downTime);
    for (uint32_t i = 0; i < args->pointerCount; i++) {
        LOGD("  Pointer %d: id=%d, toolType=%d, "
                "x=%f, y=%f, pressure=%f, size=%f, "
                "touchMajor=%f, touchMinor=%f, toolMajor=%f, toolMinor=%f, "
                "orientation=%f",
                i, args->pointerProperties[i].id,
                args->pointerProperties[i].toolType,
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_X),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_Y),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_PRESSURE),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_SIZE),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_TOUCH_MAJOR),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_TOUCH_MINOR),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_TOOL_MAJOR),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_TOOL_MINOR),
                args->pointerCoords[i].getAxisValue(AMOTION_EVENT_AXIS_ORIENTATION));
    }
#endif
    if (!validateMotionEvent(args->action, args->pointerCount, args->pointerProperties)) {
        return;
    }

    uint32_t policyFlags = args->policyFlags;
    policyFlags |= POLICY_FLAG_TRUSTED;
    mPolicy->interceptMotionBeforeQueueing(args->eventTime, /*byref*/ policyFlags);

    bool needWake;
    { // acquire lock
        mLock.lock();

        if (mInputFilterEnabled) {
            mLock.unlock();

            MotionEvent event;
            event.initialize(args->deviceId, args->source, args->action, args->flags,
                    args->edgeFlags, args->metaState, args->buttonState, 0, 0,
                    args->xPrecision, args->yPrecision,
                    args->downTime, args->eventTime,
                    args->pointerCount, args->pointerProperties, args->pointerCoords);

            policyFlags |= POLICY_FLAG_FILTERED;
            if (!mPolicy->filterInputEvent(&event, policyFlags)) {
                return; // event was consumed by the filter
            }

            mLock.lock();
        }

        // Attempt batching and streaming of move events.
        if (args->action == AMOTION_EVENT_ACTION_MOVE
                || args->action == AMOTION_EVENT_ACTION_HOVER_MOVE) {
            // BATCHING CASE
            //
            // Try to append a move sample to the tail of the inbound queue for this device.
            // Give up if we encounter a non-move motion event for this device since that
            // means we cannot append any new samples until a new motion event has started.
            for (EventEntry* entry = mInboundQueue.tail; entry; entry = entry->prev) {
                if (entry->type != EventEntry::TYPE_MOTION) {
                    // Keep looking for motion events.
                    continue;
                }

                MotionEntry* motionEntry = static_cast<MotionEntry*>(entry);
                if (motionEntry->deviceId != args->deviceId
                        || motionEntry->source != args->source) {
                    // Keep looking for this device and source.
                    continue;
                }

                if (!motionEntry->canAppendSamples(args->action,
                        args->pointerCount, args->pointerProperties)) {
                    // Last motion event in the queue for this device and source is
                    // not compatible for appending new samples.  Stop here.
                    goto NoBatchingOrStreaming;
                }

                // Do the batching magic.
                batchMotionLocked(motionEntry, args->eventTime,
                        args->metaState, args->pointerCoords,
                        "most recent motion event for this device and source in the inbound queue");
                mLock.unlock();
                return; // done!
            }

            // BATCHING ONTO PENDING EVENT CASE
            //
            // Try to append a move sample to the currently pending event, if there is one.
            // We can do this as long as we are still waiting to find the targets for the
            // event.  Once the targets are locked-in we can only do streaming.
            if (mPendingEvent
                    && (!mPendingEvent->dispatchInProgress || !mCurrentInputTargetsValid)
                    && mPendingEvent->type == EventEntry::TYPE_MOTION) {
                MotionEntry* motionEntry = static_cast<MotionEntry*>(mPendingEvent);
                if (motionEntry->deviceId == args->deviceId
                        && motionEntry->source == args->source) {
                    if (!motionEntry->canAppendSamples(args->action,
                            args->pointerCount, args->pointerProperties)) {
                        // Pending motion event is for this device and source but it is
                        // not compatible for appending new samples.  Stop here.
                        goto NoBatchingOrStreaming;
                    }

                    // Do the batching magic.
                    batchMotionLocked(motionEntry, args->eventTime,
                            args->metaState, args->pointerCoords,
                            "pending motion event");
                    mLock.unlock();
                    return; // done!
                }
            }

            // STREAMING CASE
            //
            // There is no pending motion event (of any kind) for this device in the inbound queue.
            // Search the outbound queue for the current foreground targets to find a dispatched
            // motion event that is still in progress.  If found, then, appen the new sample to
            // that event and push it out to all current targets.  The logic in
            // prepareDispatchCycleLocked takes care of the case where some targets may
            // already have consumed the motion event by starting a new dispatch cycle if needed.
            if (mCurrentInputTargetsValid) {
                for (size_t i = 0; i < mCurrentInputTargets.size(); i++) {
                    const InputTarget& inputTarget = mCurrentInputTargets[i];
                    if ((inputTarget.flags & InputTarget::FLAG_FOREGROUND) == 0) {
                        // Skip non-foreground targets.  We only want to stream if there is at
                        // least one foreground target whose dispatch is still in progress.
                        continue;
                    }

                    ssize_t connectionIndex = getConnectionIndexLocked(inputTarget.inputChannel);
                    if (connectionIndex < 0) {
                        // Connection must no longer be valid.
                        continue;
                    }

                    sp<Connection> connection = mConnectionsByReceiveFd.valueAt(connectionIndex);
                    if (connection->outboundQueue.isEmpty()) {
                        // This foreground target has an empty outbound queue.
                        continue;
                    }

                    DispatchEntry* dispatchEntry = connection->outboundQueue.head;
                    if (! dispatchEntry->inProgress
                            || dispatchEntry->eventEntry->type != EventEntry::TYPE_MOTION
                            || dispatchEntry->isSplit()) {
                        // No motion event is being dispatched, or it is being split across
                        // windows in which case we cannot stream.
                        continue;
                    }

                    MotionEntry* motionEntry = static_cast<MotionEntry*>(
                            dispatchEntry->eventEntry);
                    if (motionEntry->action != args->action
                            || motionEntry->deviceId != args->deviceId
                            || motionEntry->source != args->source
                            || motionEntry->pointerCount != args->pointerCount
                            || motionEntry->isInjected()) {
                        // The motion event is not compatible with this move.
                        continue;
                    }

                    if (args->action == AMOTION_EVENT_ACTION_HOVER_MOVE) {
                        if (mLastHoverWindowHandle == NULL) {
#if DEBUG_BATCHING
                            LOGD("Not streaming hover move because there is no "
                                    "last hovered window.");
#endif
                            goto NoBatchingOrStreaming;
                        }

                        sp<InputWindowHandle> hoverWindowHandle = findTouchedWindowAtLocked(
                                args->pointerCoords[0].getAxisValue(AMOTION_EVENT_AXIS_X),
                                args->pointerCoords[0].getAxisValue(AMOTION_EVENT_AXIS_Y));
                        if (mLastHoverWindowHandle != hoverWindowHandle) {
#if DEBUG_BATCHING
                            LOGD("Not streaming hover move because the last hovered window "
                                    "is '%s' but the currently hovered window is '%s'.",
                                    mLastHoverWindowHandle->getName().string(),
                                    hoverWindowHandle != NULL
                                            ? hoverWindowHandle->getName().string() : "<null>");
#endif
                            goto NoBatchingOrStreaming;
                        }
                    }

                    // Hurray!  This foreground target is currently dispatching a move event
                    // that we can stream onto.  Append the motion sample and resume dispatch.
                    motionEntry->appendSample(args->eventTime, args->pointerCoords);
#if DEBUG_BATCHING
                    LOGD("Appended motion sample onto batch for most recently dispatched "
                            "motion event for this device and source in the outbound queues.  "
                            "Attempting to stream the motion sample.");
#endif
                    nsecs_t currentTime = now();
                    dispatchEventToCurrentInputTargetsLocked(currentTime, motionEntry,
                            true /*resumeWithAppendedMotionSample*/);

                    runCommandsLockedInterruptible();
                    mLock.unlock();
                    return; // done!
                }
            }

NoBatchingOrStreaming:;
        }

        // Just enqueue a new motion event.
        MotionEntry* newEntry = new MotionEntry(args->eventTime,
                args->deviceId, args->source, policyFlags,
                args->action, args->flags, args->metaState, args->buttonState,
                args->edgeFlags, args->xPrecision, args->yPrecision, args->downTime,
                args->pointerCount, args->pointerProperties, args->pointerCoords);

        needWake = enqueueInboundEventLocked(newEntry);
        mLock.unlock();
    } // release lock

    if (needWake) {
        mLooper->wake();
    }
}

看到了嗎?就是這裡了,interceptMotionBeforeQueueing()函式,

 uint32_t policyFlags = args->policyFlags;
    policyFlags |= POLICY_FLAG_TRUSTED;
    mPolicy->interceptMotionBeforeQueueing(args->eventTime, /*byref*/ policyFlags);
void NativeInputManager::interceptMotionBeforeQueueing(nsecs_t when, uint32_t& policyFlags) {
    // Policy:
    // - Ignore untrusted events and pass them along.
    // - No special filtering for injected events required at this time.
    // - Filter normal events based on screen state.
    // - For normal events brighten (but do not wake) the screen if currently dim.
    if ((policyFlags & POLICY_FLAG_TRUSTED) && !(policyFlags & POLICY_FLAG_INJECTED)) {
        if (isScreenOn()) {
            policyFlags |= POLICY_FLAG_PASS_TO_USER;

            if (!isScreenBright()) {
                policyFlags |= POLICY_FLAG_BRIGHT_HERE;
            }
        } else {
            JNIEnv* env = jniEnv();
            jint wmActions = env->CallIntMethod(mCallbacksObj,
                        gCallbacksClassInfo.interceptMotionBeforeQueueingWhenScreenOff,
                        policyFlags);
            if (checkAndClearExceptionFromCallback(env,
                    "interceptMotionBeforeQueueingWhenScreenOff")) {
                wmActions = 0;
            }

            policyFlags |= POLICY_FLAG_WOKE_HERE | POLICY_FLAG_BRIGHT_HERE;
            handleInterceptActions(wmActions, when, /*byref*/ policyFlags);
        }
    } else {
        policyFlags |= POLICY_FLAG_PASS_TO_USER;
    }
}


原來如此呢, if (isScreenOn()) 。搞定,收工,回去睡覺了,哈哈。。。