Android FM模塊學習之四源碼解析（二）

上一章咱們瞭解了FM主activity：FMRadio.java，若沒查看的，請打開連接Android FM模塊學習之四源碼解析（一）

查看fmradio.java源碼註釋。接下來咱們來看看FM重要的一個類：FMRadioService.java

由上一章咱們已經知道，打開FM時，在OnStart函數中會bindToService來開啓服務，

    public  boolean bindToService(Context context, ServiceConnection callback) {
          Log.e(LOGTAG, "bindToService: Context with serviceconnection callback");
          context.startService(new Intent(context, FMRadioService.class));
          ServiceBinder sb = new ServiceBinder(callback);
          sConnectionMap.put(context, sb);
          return context.bindService((new Intent()).setClass(context,
                                                             FMRadioService.class), sb, 0);
       }

開啓了服務，就會去作一些FM的操做和響應。咱們進入到類FMRadioSerivce.java中

在publicvoid onCreate() 方法裏初始化數據

mPrefs = new FmSharedPreferences(this);初始化存取數據

 

電話監聽
TelephonyManager tmgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
      tmgr.listen(mPhoneStateListener, PhoneStateListener.LISTEN_CALL_STATE |
                                       PhoneStateListener.LISTEN_DATA_ACTIVITY);

保持CPU 運轉，屏幕和鍵盤燈有多是關閉的

    PowerManager pm = (PowerManager)getSystemService(Context.POWER_SERVICE);
          mWakeLock = pm.newWakeLock(PowerManager.PARTIAL_WAKE_LOCK, this.getClass().getName());
          mWakeLock.setReferenceCounted(false);

註冊屏幕是否開啓

     registerScreenOnOffListener();

      註冊耳機

     registerHeadsetListener();

     registerSleepExpired();

     registerRecordTimeout();

     registerDelayedServiceStop();

     registerFMRecordingStatus();

 

Activity銷燬界面方法

public void onDestroy()

在onDestroy方法裏mDelayedStopHandler.removeCallbacksAndMessages(null); 移除回調handler信息

關閉警鈴cancelAlarms()

將聲音設爲音樂焦點
 //release the audio focus listener
      AudioManager audioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);
      if (isMuted()) {
          mMuted = false;
          audioManager.setStreamMute(AudioManager.STREAM_MUSIC,false);
      }
      audioManager.abandonAudioFocus(mAudioFocusListener);

遺棄音頻管理監聽

audioManager.abandonAudioFocus(mAudioFocusListener);

 

在onDestroy方法裏卸載註冊

    /* Remove the Screen On/off listener */
          if (mScreenOnOffReceiver != null) {
              unregisterReceiver(mScreenOnOffReceiver);
              mScreenOnOffReceiver = null;
          }
          /* Unregister the headset Broadcase receiver */
          
           if (mAirplaneModeReceiver != null) {
              unregisterReceiver(mAirplaneModeReceiver);
              mAirplaneModeReceiver = null;
          }
          
          if (mHeadsetReceiver != null) {unregisterReceiver(mHeadsetReceiver);
              mHeadsetReceiver = null;
          }
          if( mMusicCommandListener != null ) {
              unregisterReceiver(mMusicCommandListener);
              mMusicCommandListener = null;
          }
          if( mFmMediaButtonListener != null ) {
              unregisterReceiver(mFmMediaButtonListener);
              mFmMediaButtonListener = null;
          } if (mAudioBecomeNoisyListener != null) {
              unregisterReceiver(mAudioBecomeNoisyListener);
              mAudioBecomeNoisyListener = null;
          }
          if (mSleepExpiredListener != null ) {
              unregisterReceiver(mSleepExpiredListener);
              mSleepExpiredListener = null;
          }
          if (mRecordTimeoutListener != null) {
              unregisterReceiver(mRecordTimeoutListener);
              mRecordTimeoutListener = null;
          } if (mDelayedServiceStopListener != null) {
              unregisterReceiver(mDelayedServiceStopListener);
              mDelayedServiceStopListener = null;
          }
          if (mFmRecordingStatus != null ) {
              unregisterReceiver(mFmRecordingStatus);
              mFmRecordingStatus = null;
          }

關閉收音機fmOff();關掉調頻:禁用調頻主機和硬件。

    TelephonyManager tmgr = (TelephonyManager) getSystemService(Context.TELEPHONY_SERVICE);
          tmgr.listen(mPhoneStateListener, 0);
     
          Log.d(LOGTAG, "onDestroy: unbindFromService completed");
     
          //unregisterReceiver(mIntentReceiver);
          mWakeLock.release();

 

mWakeLock.release();//釋放喚醒鎖

在onDestroy方法裏設置電話監聽參數0失去監聽來電狀態

      tmgr.listen(mPhoneStateListener, 0);

public void registerFMRecordingStatus()控制

private void stop() 卸載FMMediaButtonIntentReceiver類的註冊

mAudioManager = (AudioManager) getSystemService(Context.AUDIO_SERVICE);

         ComponentName fmRadio = new ComponentName(this.getPackageName(),

                                 FMMediaButtonIntentReceiver.class.getName());

         mAudioManager.unregisterMediaButtonEventReceiver(fmRadio);

stop()方法調用gotoIdleState()方法刪除mDelayedStopHandler空消息，關閉警鈴

    private void gotoIdleState()
     
    mDelayedStopHandler.removeCallbacksAndMessages(null);
     
         cancelAlarms();
     
         setAlarmDelayedServiceStop();
     
         stopForeground(true);
     
      

public IBinder onBind(Intent intent)綁定service

mDelayedStopHandler.removeCallbacksAndMessages(null);

     cancelAlarms();關閉，警鈴

     mServiceInUse = true; 服務可使用

     /* Application/UI is attached, so get out of lower power mode */

     setLowPowerMode(false);

 

public void onRebind(Intent intent)從新捆綁service

 

public void onStart(Intent intent, intstartId) StartService啓動方法

 

public boolean onUnbind(Intent intent) 解綁service

 

得到進程名字方法private String getProcessName()

private void sendRecordIntent(int action) 發送錄音無序廣播在註冊錄音廣播接收方法中

 

private void sendRecordServiceIntent(intaction) 發送錄音狀態無序廣播

 

private void startFM()啓動FM方法：

    if(true == mAppShutdown) { // not to sendintent to AudioManager in Shutdown
     
    if (isCallActive()) { // when Call is activenever let audio playback
     
    if ( true == mPlaybackInProgress ) // no needto resend event

 

請求音頻聲音焦點

    AudioManager audioManager = (AudioManager)getSystemService(Context.AUDIO_SERVICE);
     
          int granted = audioManager.requestAudioFocus(mAudioFocusListener,AudioManager.STREAM_MUSIC,
     
                 AudioManager.AUDIOFOCUS_GAIN_TRANSIENT);

 

判斷是否請求聲音焦點成功

    if(granted !=AudioManager.AUDIOFOCUS_REQUEST_GRANTED) {
     
             Log.d(LOGTAG, "audio focuss couldnot be granted");
     
             return;
     
          }

 

    /**

     *請求改變焦點失敗

     */

    public static final int AUDIOFOCUS_REQUEST_FAILED = 0;

    /**

     *請求改變焦點成功     */

    public static final intAUDIOFOCUS_REQUEST_GRANTED = 1;

 

實現audioManager類的焦點監聽接口

     private OnAudioFocusChangeListener mAudioFocusListener = new OnAudioFocusChangeListener() {
           public void onAudioFocusChange(int focusChange) {
               mDelayedStopHandler.obtainMessage(FOCUSCHANGE, focusChange, 0).sendToTarget();
           }
       };

 

 

請求聲音焦點當music響起fm短期暫停，music關閉後fm繼續播放private void requestFocus()

 

mAudioManager.registerMediaButtonEventReceiver(fmRadio);註冊多媒體按鈕事件監聽

mStoppedOnFocusLoss = false;中止聲音焦值爲false

中止fm使用

    private void stopFM(){
     
    AudioSystem.setDeviceConnectionState(AudioSystem.DEVICE_OUT_FM,AudioSystem.DEVICE_STATE_UNAVAILABLE,"");
     
    }

從新設置fm

    private void resetFM() {
     
           AudioSystem.setDeviceConnectionState(AudioSystem.DEVICE_OUT_FM,
     
       AudioSystem.DEVICE_STATE_UNAVAILABLE, "")
     
    }

mA2dpDeviceState.isDeviceAvailable()藍牙耳機設備可用是否可用

mOverA2DP全局變量是用來表示藍牙是否可用

 

public boolean mute()靜音模式 mMute 全局變量做爲是否開啓靜音模式作判斷

AudioManager audioManager =(AudioManager) getSystemService(Context.AUDIO_SERVICE);

設置靜音audioManager.setStreamMute(AudioManager.STREAM_MUSIC,false);

public booleanisWiredHeadsetAvailable()耳機可用

public boolean isCallActive()通話中，調用getCallState()方法返回0爲空閒沒有通話，返回1是通話狀態。

public void stopRecording()中止錄音

private void fmActionOnCallState(int state ) 通話活動狀態在進入fm方法privateboolean fmOn()中調用此方法，會用到通話監聽獲取state值。

public boolean startA2dpPlayback()啓動藍牙播放方法，

 

final Runnable mHeadsetPluginHandler= new Runnable()方法當耳機被拔出就關閉fm

     final Runnable    mHeadsetPluginHandler = new Runnable() {
            public void run() {
                /* Update the UI based on the state change of the headset/antenna*/
                if(!isAntennaAvailable())
                {
                   // if (!isFmOn())
                   //     return;       
                    /* Disable FM and let the UI know */
                    fmOff();
                    try
                    {
                        /* Notify the UI/Activity, only if the service is "bound"
                      by an activity and if Callbacks are registered
                         */
                        if((mServiceInUse) && (mCallbacks != null) )
                        {
                            mCallbacks.onDisabled();
                        }
                    } catch (RemoteException e)
                    {
                        e.printStackTrace();
                    }
                }else
                {
                    /* headset is plugged back in,
                   So turn on FM if:
                   - FM is not already ON.
                   - If the FM UI/Activity is in the foreground
                     (the service is "bound" by an activity
                      and if Callbacks are registered)
                     */
                    if ((!isFmOn()) && (mServiceInUse)
                            && (mCallbacks != null))
                    {
                        if( true != fmOn() ) {
                            return;
                        }
                        try
                        {
                            mCallbacks.onEnabled();
                        } catch (RemoteException e)
                        {
                            e.printStackTrace();
                        }
                    }
                }
            }
        };

public void clearStationInfo()清除fm狀態信息

FmRxEvCallbacksAdaptor fmCallbacks= new FmRxEvCallbacksAdaptor() 廣播接收類詳解

public void FmRxEvEnableReceiver()可用接收

public voidFmRxEvDisableReceiver() 失去接收功能

public void FmRxEvRadioReset()收音機重新設置

調整fm頻率並保持

FmSharedPreferences.setTunedFrequency(frequency);

mPrefs.Save();

enableStereo(FmSharedPreferences.getAudioOutputMode());獲取立體聲音是否可用

更新狀態欄的通知信息

startNotification();設計fm在後臺播放，service不被殺死，掛一個前臺通知，在中止FMRadioService中止前臺通知:

startForeground(FMRADIOSERVICE_STATUS,status);

在gotoIdleState()轉到fm空閒狀態的時候就中止前警鈴，後警鈴後臺服務，前臺通知欄等關閉。

mDelayedStopHandler.removeCallbacksAndMessages(null);

      cancelAlarms();

      setAlarmDelayedServiceStop();

      stopForeground(true);

 

readInternalAntennaAvailable() 讀的調頻的內部天線可用狀態

private booleansetAudioPath(boolean analogMode) 安裝判斷鈴聲路徑

/*
*打開調頻:調頻硬件啓動,並初始化調頻模塊
* @return返回值爲真：若是調頻使api調用成功, 假：若是api失敗了。
* /

private boolean fmOn()

mReceiver = newFmReceiver(FMRADIO_DEVICE_FD_STRING, fmCallbacks);

從調頻堆棧接收回調函數

FmRxEvCallbacksAdaptor fmCallbacks = newFmRxEvCallbacksAdaptor()

 

mReceiver.setRawRdsGrpMask();

FmSharedPreferences.clearTags();清除Tag

Fm從新設置

public void FmRxEvRadioReset()

fmRadioReset();

調整屏幕狀態

public void FmRxEvRadioTuneStatus(intfrequency)

FmSharedPreferences.setTunedFrequency(frequency);

           mPrefs.Save();

清除狀態信息

if(mReceiver != null) {

    clearStationInfo();

}

更新狀態欄通知

startNotification();

判斷RDSS支持

public void FmRxEvRdsLockStatus(booleanbRDSSupported)

mCallbacks.onStationRDSSupported(bRDSSupported);

 

更新警鈴立體聲狀態

public void FmRxEvStereoStatus(booleanstereo)

mCallbacks.onAudioUpdate(stereo);

 

public void FmRxEvServiceAvailable(booleansignal)

fm搜索完成

public void FmRxEvSearchComplete(intfrequency)

FmSharedPreferences.setTunedFrequency(frequency);

clearStationInfo();

startNotification();

mWakeLock.acquire(10*1000);喚醒鎖屏超時10*1000就釋放喚醒對象

電話不是在空閒狀態換回false

if ( TelephonyManager.CALL_STATE_IDLE !=getCallState() ) {

        return bStatus;

}

正常進入fm

    if (isFmOn())
     
    {
     
         /* FM Is already on,*/
     
         bStatus = true;
     
         Log.d(LOGTAG, "mReceiver.already enabled");
     
    }

 獲取fm配置

FmConfig config =FmSharedPreferences.getFMConfiguration();

 

廣播接收穫取FM配置狀態

bStatus =mReceiver.enable(FmSharedPreferences.getFMConfiguration());

 

揚聲器可用設置boolean值

    if (isSpeakerEnabled()) {
     
                    setAudioPath(false);
     
               } else {
     
                    setAudioPath(true);
     
               }

 真正啓動fm播放聲音是AudioSystem.setDeviceConnectionState(); 設置fm設備啓動，設置fm耳機播放仍是揚聲器播放(核心代碼)

    AudioSystem.setDeviceConnectionState(AudioSystem.DEVICE_OUT_FM,
                                   AudioSystem.DEVICE_STATE_AVAILABLE, "");
               if (isSpeakerEnabled()) {
                   mSpeakerPhoneOn = true;
                   Log.d(LOGTAG, "Audio source set it as speaker");
                   AudioSystem.setForceUse(AudioSystem.FOR_MEDIA, AudioSystem.FORCE_SPEAKER);
               } else {
                   Log.d(LOGTAG, "Audio source set it as headset");
                   AudioSystem.setForceUse(AudioSystem.FOR_MEDIA, AudioSystem.FORCE_NONE);
               }

audio焦點監聽事件

AudioManager.OnAudioFocusChangeListener是申請成功以後監聽AudioFocus使用狀況的Listener，後續若是有別的程序要競爭AudioFocus，都是經過這個Listener的onAudioFocusChange()方法來通知這個AudioFocus的使用者的。

請求audio焦點屬性

AUDIOFOCUS_GAIN
指示申請獲得的AudioFocus不知道會持續多久，通常是長期佔有；
AUDIOFOCUS_GAIN_TRANSIENT
指示要申請的AudioFocus是暫時性的，會很快用完釋放的；
AUDIOFOCUS_GAIN_TRANSIENT_MAY_DUCK不但說要申請的AudioFocus是暫時性的，還指示當前正在使用AudioFocus的能夠繼續播放，只是要「duck」一下（下降音量）。

AUDIOFOCUS_REQUEST_GRANTED：申請成功；
AUDIOFOCUS_REQUEST_FAILED：申請失敗。

搶奪焦點
AUDIOFOCUS_GAIN：得到了Audio Focus；
AUDIOFOCUS_LOSS：失去了Audio Focus，並將會持續很長的時間。這裏由於可能會停掉很長時間，因此不單單要中止Audio的播放，最好直接釋放掉Media資源。而由於中止播放Audio的時間會很長，若是程序由於這個緣由而失去AudioFocus，最好不要讓它再次自動得到AudioFocus而繼續播放，否則忽然冒出來的聲音會讓用戶感受莫名其妙，感覺很很差。這裏直接放棄AudioFocus，固然也不用再偵聽遠程播放控制【以下面代碼的處理】。要再次播放，除非用戶再在界面上點擊開始播放，才從新初始化Media，進行播放。
AUDIOFOCUS_LOSS_TRANSIENT：暫時失去Audio Focus，並會很快再次得到。必須中止Audio的播放，可是由於可能會很快再次得到AudioFocus，這裏能夠不釋放Media資源；

AUDIOFOCUS_LOSS_TRANSIENT_CAN_DUCK：暫時失去AudioFocus，可是能夠繼續播放，不過要在下降音量。