ADROID 2.1 架构解析 4 静音与振动
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。