Android4.2中Phone的P-sensor的应用的分析。
2024-06-07 04:53:13
先说现象，现象就是来电话，接通电话，把手机屏幕靠近脸部，遮挡住P-sensor，屏幕变黑了，不遮挡住P-sensor,屏幕就点亮了。接着我们来看看代码流程。
先来说说靠近P-sensor，不灭屏的正常的现象：
- 插入耳机
- 打开扬声器
- 打开蓝牙耳机
- 链接蓝牙键盘
步骤一：在PhoneGlobals.java文件中onCreate()方法中：
。。。 。。。
// lock used to keep the processor awake, when we don't care for the display.mPartialWakeLock = mPowerManager.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK| PowerManager.ON_AFTER_RELEASE, LOG_TAG);// Wake lock used to control proximity sensor behavior.if (mPowerManager.isWakeLockLevelSupported(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK)) {mProximityWakeLock = mPowerManager.newWakeLock(PowerManager.PROXIMITY_SCREEN_OFF_WAKE_LOCK, LOG_TAG);}。。。 。。。
注意这个private PowerManager.WakeLock mProximityWakeLock;这个初始化变量，
这个mProximityWakeLock就是所说的P-Sensor锁，它是用来唤醒屏幕和使屏幕睡眠的锁。
步骤二：在PhoneGlobals.java文件中的onCreate()方法中：
// create mAccelerometerListener only if we are using the proximity sensorif (proximitySensorModeEnabled()) {mAccelerometerListener = new AccelerometerListener(this, this);}
创建加速度感应器。
步骤三：在更新Phone的状态的时候确定这个加速度的P-sensor感应器起作用；
/*** Notifies the phone app when the phone state changes.** This method will updates various states inside Phone app (e.g. proximity sensor mode,* accelerometer listener state, update-lock state, etc.)*//* package */ void updatePhoneState(PhoneConstants.State state) {if (state != mLastPhoneState) {mLastPhoneState = state;if (state == PhoneConstants.State.IDLE)PhoneGlobals.getInstance().pokeUserActivity();updateProximitySensorMode(state);// Try to acquire or release UpdateLock.//// Watch out: we don't release the lock here when the screen is still in foreground.// At that time InCallScreen will release it on onPause().if (state != PhoneConstants.State.IDLE) {// UpdateLock is a recursive lock, while we may get "acquire" request twice and// "release" request once for a single call (RINGING + OFFHOOK and IDLE).// We need to manually ensure the lock is just acquired once for each (and this// will prevent other possible buggy situations too).if (!mUpdateLock.isHeld()) {mUpdateLock.acquire();}} else {if (!isShowingCallScreen()) {if (!mUpdateLock.isHeld()) {mUpdateLock.release();}} else {// For this case InCallScreen will take care of the release() call.}}if (mAccelerometerListener != null) {// use accelerometer to augment proximity sensor when in callmOrientation = AccelerometerListener.ORIENTATION_UNKNOWN; mAccelerometerListener.enable(state == PhoneConstants.State.OFFHOOK);}// clear our beginning call flagmBeginningCall = false;// While we are in call, the in-call screen should dismiss the keyguard.// This allows the user to press Home to go directly home without going through// an insecure lock screen.// But we do not want to do this if there is no active call so we do not// bypass the keyguard if the call is not answered or declined.if (mInCallScreen != null) {if (VDBG) Log.d(LOG_TAG, "updatePhoneState: state = " + state);if (!PhoneUtils.isDMLocked())mInCallScreen.updateKeyguardPolicy(state == PhoneConstants.State.OFFHOOK);}}}步骤四：用AccelerometerListener.java类中的监听事件来处理一些这个覆盖的改变，一共有2个状态，一个是
horizontal，一个是vertical的状态。在上述步骤三红色的调用部分注册这个监听事件:
public void enable(boolean enable) {if (DEBUG) Log.d(TAG, "enable(" + enable + ")");synchronized (this) {if (enable) {mOrientation = ORIENTATION_UNKNOWN;mPendingOrientation = ORIENTATION_UNKNOWN;mSensorManager.registerListener(mSensorListener, mSensor,SensorManager.SENSOR_DELAY_NORMAL);} else {mSensorManager.unregisterListener(mSensorListener);mHandler.removeMessages(ORIENTATION_CHANGED);}}}步骤五：监听事件的相应的过程如下：
SensorEventListener mSensorListener = new SensorEventListener() {public void onSensorChanged(SensorEvent event) {onSensorEvent(event.values[0], event.values[1], event.values[2]);}public void onAccuracyChanged(Sensor sensor, int accuracy) {// ignore}};private void onSensorEvent(double x, double y, double z) {if (VDEBUG) Log.d(TAG, "onSensorEvent(" + x + ", " + y + ", " + z + ")");// If some values are exactly zero, then likely the sensor is not powered up yet.// ignore these events to avoid false horizontal positives.if (x == 0.0 || y == 0.0 || z == 0.0) return;// magnitude of the acceleration vector projected onto XY planedouble xy = Math.sqrt(x*x + y*y);// compute the vertical angledouble angle = Math.atan2(xy, z);// convert to degreesangle = angle * 180.0 / Math.PI;int orientation = (angle > VERTICAL_ANGLE ? ORIENTATION_VERTICAL : ORIENTATION_HORIZONTAL);if (VDEBUG) Log.d(TAG, "angle: " + angle + " orientation: " + orientation);setOrientation(orientation);}private void setOrientation(int orientation) {synchronized (this) {if (mPendingOrientation == orientation) {// Pending orientation has not changed, so do nothing.return;}// Cancel any pending messages.// We will either start a new timer or cancel alltogether// if the orientation has not changed.mHandler.removeMessages(ORIENTATION_CHANGED);if (mOrientation != orientation) {// Set timer to send an event if the orientation has changed since its// previously reported value.mPendingOrientation = orientation;Message m = mHandler.obtainMessage(ORIENTATION_CHANGED);// set delay to our debounce timeoutint delay = (orientation == ORIENTATION_VERTICAL ? VERTICAL_DEBOUNCE: HORIZONTAL_DEBOUNCE);mHandler.sendMessageDelayed(m, delay);} else {// no message is pendingmPendingOrientation = ORIENTATION_UNKNOWN;}}}然后发送消息ORIENTATION_CHANGED这个改变的消息;这个消息会调用一个回调函数，然后根据状态判断，调用acquire和release（）方法；
Handler mHandler = new Handler() {public void handleMessage(Message msg) {switch (msg.what) {case ORIENTATION_CHANGED:synchronized (this) {mOrientation = mPendingOrientation;if (DEBUG) {Log.d(TAG, "orientation: " +(mOrientation == ORIENTATION_HORIZONTAL ? "horizontal": (mOrientation == ORIENTATION_VERTICAL ? "vertical": "unknown")));}mListener.orientationChanged(mOrientation);}break;}}};步骤五：回调到PhoneGlobals.java这个类的 orientationChanged（）
@Overridepublic void orientationChanged(int orientation) {mOrientation = orientation;updateProximitySensorMode(mCM.getState());}/*** Updates the wake lock used to control proximity sensor behavior,* based on the current state of the phone. This method is called* from the CallNotifier on any phone state change.** On devices that have a proximity sensor, to avoid false touches* during a call, we hold a PROXIMITY_SCREEN_OFF_WAKE_LOCK wake lock* whenever the phone is off hook. (When held, that wake lock causes* the screen to turn off automatically when the sensor detects an* object close to the screen.)** This method is a no-op for devices that don't have a proximity* sensor.** Note this method doesn't care if the InCallScreen is the foreground* activity or not. That's because we want the proximity sensor to be* enabled any time the phone is in use, to avoid false cheek events* for whatever app you happen to be running.** Proximity wake lock will *not* be held if any one of the* conditions is true while on a call:* 1) If the audio is routed via Bluetooth* 2) If a wired headset is connected* 3) if the speaker is ON* 4) If the slider is open(i.e. the hardkeyboard is *not* hidden)** @param state current state of the phone (see {@link Phone#State})*//* package */ void updateProximitySensorMode(PhoneConstants.State state) {boolean isRingingWhenActive = false;//MTK81281 add isRingingWhenActive for Cr:ALPS00117091if (VDBG) Log.d(LOG_TAG, "updateProximitySensorMode: state = " + state);if (proximitySensorModeEnabled()) {synchronized (mProximityWakeLock) {// turn proximity sensor off and turn screen on immediately if// we are using a headset, the keyboard is open, or the device// is being held in a horizontal position.boolean screenOnImmediately = (isHeadsetPlugged()|| PhoneUtils.isSpeakerOn(this)|| isBluetoothHeadsetAudioOn()|| mIsHardKeyboardOpen);if (FeatureOption.MTK_VT3G324M_SUPPORT) {screenOnImmediately = screenOnImmediately ||((!VTCallUtils.isVTIdle()) && (!VTCallUtils.isVTRinging()));}// We do not keep the screen off when the user is outside in-call screen and we are// horizontal, but we do not force it on when we become horizontal until the// proximity sensor goes negative.// this horizontal is not the same portrait.boolean horizontal =(mOrientation == AccelerometerListener.ORIENTATION_HORIZONTAL);screenOnImmediately |= !isShowingCallScreenForProximity() && horizontal;if (VDBG) Log.d(LOG_TAG, "updateProximitySensorMode: mBeginningCall = " + mBeginningCall);if (VDBG) Log.d(LOG_TAG, "updateProximitySensorMode: screenOnImmediately = " + screenOnImmediately);//MTK81281 add isRingingWhenActive for Cr:ALPS00117091 start //when a call is activeand p-sensor turn off the screen, //another call or vtcall in we don't release the lock and acquire again//(the prowermanagerservice will turn on and off the screen and it's a problem)//instead ,we don't release the lock(prowermanagerservice will not turn on and off the screen)isRingingWhenActive = (state == PhoneConstants.State.RINGING)&& (mCM.getActiveFgCallState() == Call.State.ACTIVE)&& (mCM.getFirstActiveRingingCall().getState() == Call.State.WAITING);if (VDBG) Log.d(LOG_TAG, "updateProximitySensorMode: isRingingWhenActive = " + isRingingWhenActive);//MTK81281 add isRingingWhenActive for Cr:ALPS00117091 end//MTK81281 add isRingingWhenActive for Cr:ALPS00117091if (((state == PhoneConstants.State.OFFHOOK) || mBeginningCall || isRingingWhenActive)&& !screenOnImmediately) {// Phone is in use! Arrange for the screen to turn off// automatically when the sensor detects a close object.if (!mProximityWakeLock.isHeld()) {if (DBG) Log.d(LOG_TAG, "updateProximitySensorMode: acquiring...");mProximityWakeLock.acquire();} else {if (VDBG) Log.d(LOG_TAG, "updateProximitySensorMode: lock already held.");}} else {// Phone is either idle, or ringing. We don't want any// special proximity sensor behavior in either case.if (mProximityWakeLock.isHeld()) {if (DBG) Log.d(LOG_TAG, "updateProximitySensorMode: releasing...");// Wait until user has moved the phone away from his head if we are// releasing due to the phone call ending.// Qtherwise, turn screen on immediatelyint flags =(screenOnImmediately ? 0 : PowerManager.WAIT_FOR_PROXIMITY_NEGATIVE);mProximityWakeLock.release(flags);} else {if (VDBG) {Log.d(LOG_TAG, "updateProximitySensorMode: lock already released.");}}}}}}到这已经把Phone层的P-sensor的亮屏和灭屏说完了，回头再来屡屡这个mProximityWakeLock在framework层怎么具体实现的亮屏和灭屏的；敬请期待。。。 。。。
更正：上述的讲解是不正确的，后来经过打log，发现，这个mProximityWakeLock.acquire();和mProximityWakeLock.release(flags);只是申请这个锁，和释放这个锁，防止其他的调用，
其实，在4.2以前Phone模块的P-Sensor在PowerManagerServer.java中处理的，而Android4.2的时候，谷歌对代码进行了一些调整，所以Phone的模块的P-Sensor的控制的类在DisplayPowerController.java
路径:framework/base/services/java/com/android/server/power/DisplayPowerController.java中的：
private final SensorEventListener mProximitySensorListener = new SensorEventListener() {@Overridepublic void onSensorChanged(SensorEvent event) {if (mProximitySensorEnabled) {final long time = SystemClock.uptimeMillis();final float distance = event.values[0];boolean positive = distance >= 0.0f && distance < mProximityThreshold;if (DEBUG) {Slog.d(TAG, "P-Sensor Changed: " + positive);}handleProximitySensorEvent(time, positive);}}这个onSensorChanged（）就是距离感应器的；这个log：
P-Sensor Changed:true 表示：靠近手机，P-sensor被遮挡住；
P-Sensor Changed:false 表示：离开手机，P-sensor没有被遮挡住；
通过这个log也能帮我们分析一些问题；这个mProximitySensorListener的注册和反注册，大家可以自己在这个类中搜索就可以了；
补充：在PowserManagerServerice.java这个类中， private LightsService.Light mButtonLight;这个变量申请的就是按键灯，像：home，返回键，menu键的灯，申请这个灯的代码：
private LightsService mLightsService;
。。。 。。。mButtonLight = mLightsService.getLight(LightsService.LIGHT_ID_BUTTONS);通过LightService可以获得键盘灯的实例，
打开灯的方法：mButtonLight.setBrightness(120);//120可以是（0～255）任意数字；
关闭灯的方法：mButtonLight.turnOff();
需求：要想使Phone通话界面的P-Sensor亮灭屏幕和按键灯同步，当屏幕灭的时候，按键灯也灭，屏幕亮的时候，按键灯也亮；其实做法很简单了，在onSensorChanged（）的时候处理，扩一些接口，
具体设计的类我列举一下：
- PowerManager.java
- PowerManagerService.java
- BridgetPowerManager.java
- IPowerManager.adil
- DisPlayPowerController.java
具体代码就不详细赘述了，还是“觉知此事要躬行”；
注意在
mLastUserActivityButtonTime = SystemClock.uptimeMillis();mButtonLight.setBrightness(102);在设置打开按键灯的时候，设置一下最后一次用户触摸按钮的时间；至于为什么？？大家自已到时候打log就明白了。。。 。。。
mLastUserActivityButtonTimeAndroid4.2中Phone的P-sensor的应用的分析。相关推荐
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