4 静音与振动
4.1 设置静音和振动
静音和振动都属于来电后的动作.所以在设置静音和振动时都只是设置一些标识,并往数据库写入相应标识.

文件：packages/apps/settings/src/com/android/settings/SoundAndDisplaySettings.java

private CheckBoxPreference mSilent;

private CheckBoxPreference mVibrate;

 

private void setRingerMode(boolean silent, boolean vibrate) {

        if (silent) {

            mAudioManager.setRingerMode(vibrate ? AudioManager.RINGER_MODE_VIBRATE :

                AudioManager.RINGER_MODE_SILENT);

        } else {

            mAudioManager.setRingerMode(AudioManager.RINGER_MODE_NORMAL);

            mAudioManager.setVibrateSetting(AudioManager.VIBRATE_TYPE_RINGER,

                    vibrate ? AudioManager.VIBRATE_SETTING_ON

                            : AudioManager.VIBRATE_SETTING_OFF);

        }

    }

 

public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {

        if (preference == mSilent || preference == mVibrate) {

            setRingerMode(mSilent.isChecked(), mVibrate.isChecked());

            if (preference == mSilent) updateState(false);

        }

...

静音和振动是复选框按钮,两个中有一个发生变化时调用setRingerMode对状态进行设置;如下状态描术:

RINGER_MODE_SILENT 静音,且无振动

RINGER_MODE_VIBRATE 静音,但有振动

RINGER_MODE_NORMAL 正常声音,振动开关由setVibrateSetting决定.

铃响模式的设置是通过mAudioManager(音频管理器)来实现的.

4.2 音频管理器服务
mAudioManager所在服务如下:

文件: frameworks/base/media/java/android/media/AudioManager.java

       public static final int RINGER_MODE_SILENT = 0;

    public static final int RINGER_MODE_VIBRATE = 1;

    public static final int RINGER_MODE_NORMAL = 2;

public void setRingerMode(int ringerMode) {

        IAudioService service = getService();

        try {

            service.setRingerMode(ringerMode);

        } catch (RemoteException e) {

            Log.e(TAG, "Dead object in setRingerMode", e);

        }

}

将铃响模式值传给音频接口服务IaudioService

public static final int VIBRATE_TYPE_RINGER = 0;

    public static final int VIBRATE_TYPE_NOTIFICATION = 1;

    public static final int VIBRATE_SETTING_OFF = 0;

    public static final int VIBRATE_SETTING_ON = 1;

    public static final int VIBRATE_SETTING_ONLY_SILENT = 2;

public void setVibrateSetting(int vibrateTyp  , int vibrateSetting) {

        IAudioService service = getService();

        try {

            service.setVibrateSetting(vibrateType, vibrateSetting);

        } catch (RemoteException e) {

            Log.e(TAG, "Dead object in setVibrateSetting", e);

        }

}

将振动类型和振动设置传给音频接口服务IaudioService,IaudioService的定义如下:

frameworks/base/media/java/android/media/IAudioService.aidl

frameworks/base/media/java/android/media/AudioService.java

文件: frameworks/base/media/java/android/media/AudioService.java

文件: frameworks/base/core/java/android/provider/Settings.java

public void setRingerMode(int ringerMode) {

        synchronized (mSettingsLock) {

            if (ringerMode != mRingerMode) {

                setRingerModeInt(ringerMode, true);

                // Send sticky broadcast

                broadcastRingerMode();

            }

        }

}

将对应模式下的音量写入数据库,并将该模式广播.

public void setVibrateSetting(int vibrateType, int vibrateSetting) {

 

        mVibrateSetting = getValueForVibrateSetting(mVibrateSetting, vibrateType, vibrateSetting);

 

        // Broadcast change

        broadcastVibrateSetting(vibrateType);

 

        // Post message to set ringer mode (it in turn will post a message

        // to persist)

        sendMsg(mAudioHandler, MSG_PERSIST_VIBRATE_SETTING, SHARED_MSG, SENDMSG_NOOP, 0, 0,

                null, 0);

}

同样将振动模式写入数据库,并广播该模式.

4.3 硬件服务
文件：frameworks/base/services/java/com/android/server/HardwareService.java

开始振动：

public void vibrate(long milliseconds, IBinder token) {

        if (mContext.checkCallingOrSelfPermission(android.Manifest.permission.VIBRATE)

                != PackageManager.PERMISSION_GRANTED) {

            throw new SecurityException("Requires VIBRATE permission");

        }

        // We're running in the system server so we cannot crash. Check for a

        // timeout of 0 or negative. This will ensure that a vibration has

        // either a timeout of > 0 or a non-null pattern.

        if (milliseconds <= 0 || (mCurrentVibration != null

                && mCurrentVibration.hasLongerTimeout(milliseconds))) {

            // Ignore this vibration since the current vibration will play for

            // longer than milliseconds.

            return;

        }

        Vibration vib = new Vibration(token, milliseconds);

        synchronized (mVibrations) {

            removeVibrationLocked(token);

            doCancelVibrateLocked();

            mCurrentVibration = vib;

            startVibrationLocked(vib);

        }

}

private void startVibrationLocked(final Vibration vib) {

        if (vib.mTimeout != 0) {

            vibratorOn(vib.mTimeout);

            mH.postDelayed(mVibrationRunnable, vib.mTimeout);

        } else {

            // mThread better be null here. doCancelVibrate should always be

            // called before startNextVibrationLocked or startVibrationLocked.

            mThread = new VibrateThread(vib);

            mThread.start();

        }

    }

该接口允许设置振动的时间长度，通过调用vibratorOn(vib.mTimeout);实现对底层硬件的操作。

取消振动：

public void cancelVibrate(IBinder token) {

        mContext.enforceCallingOrSelfPermission(

                android.Manifest.permission.VIBRATE,

                "cancelVibrate");

 

        // so wakelock calls will succeed

        long identity = Binder.clearCallingIdentity();

        try {

            synchronized (mVibrations) {

                final Vibration vib = removeVibrationLocked(token);

                if (vib == mCurrentVibration) {

                    doCancelVibrateLocked();

                    startNextVibrationLocked();

                }

            }

        }

        finally {

            Binder.restoreCallingIdentity(identity);

        }

}

private void doCancelVibrateLocked() {

        if (mThread != null) {

            synchronized (mThread) {

                mThread.mDone = true;

                mThread.notify();

            }

            mThread = null;

        }

        vibratorOff ();

        mH.removeCallbacks(mVibrationRunnable);

}

该接口允许停止振动，通过调用vibratorOff();实现对底层硬件的操作。

4.4 硬件调用
vibratorOn、vibratorOff对应的jni代码如下：

文件：frameworks/base/services/jni/com_android_server_HardwareService.cpp

static void vibratorOn(JNIEnv *env, jobject clazz, jlong timeout_ms)

{

    // LOGI("vibratorOn/n");

    vibrator_on(timeout_ms);

}

static void vibratorOff(JNIEnv *env, jobject clazz)

{

    // LOGI("vibratorOff/n");

    vibrator_off();

}

vibrator_on、vibrator_off 接口的提供者为如下硬件原型。

4.5 硬件原型
文件：hardware/libhardware_legacy/vibrator/vibrator.c

#define THE_DEVICE "/sys/class/timed_output/vibrator/enable"

 

static int sendit(int timeout_ms)

{

    int nwr, ret, fd;

    char value[20];

 

#ifdef QEMU_HARDWARE

    if (qemu_check()) {

        return qemu_control_command( "vibrator:%d", timeout_ms );

    }

#endif

 

    fd = open(THE_DEVICE, O_RDWR);

    if(fd < 0)

        return errno;

 

    nwr = sprintf(value, "%d/n", timeout_ms);

    ret = write(fd, value, nwr);

 

    close(fd);

 

    return (ret == nwr) ? 0 : -1;

}

 

int vibrator_on(int timeout_ms)

{

    /* constant on, up to maximum allowed time */

    return sendit(timeout_ms);

}

 

int vibrator_off()

{

    return sendit(0);

}

由以上代码可知，开启振动时是往文件/sys/class/timed_output/vibrator/enable写入振动的时间长度；关闭振动时，其时间长度为0。/sys/class/timed_output/vibrator/enable 的真实路径根据实际作修改。

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