Android FM模塊學習之二 FM搜索頻率流程
上一篇大概分析了一下FM啓動流程，若不瞭解Fm啓動流程的，能夠去打開前面的連接先了解FM啓動流程，接下來咱們簡單分析一下FM的搜索頻率流程。java
在瞭解源碼以前，咱們先看一下流程圖：android
其實從圖中能夠看到，實現搜索頻率的功能是在底層CPP文件，java層只操做和更新一些界面（GUI），Java調用JNI實現功能。Java app基本核心，經過方法回調實現a類和b類方法，b類調a類方法信息交互相互控制融爲一體。App實現一些JNI接口最終實現核心功能是cpp文件，最後經過Service類（耗時操做）調用New一個線程循環不斷的獲取cpp裏的信息，去更新UI界面活動狀態。app
搜索流程簡單分析：點擊搜索按鈕，經過互調方法，最後調到FMReceiverJNI類中的方法實現功能。經過FMRxEventListner類不斷獲取cpp變頻的頻率，每獲取一次頻率(直到頻率搜索完成中止調用)就回調FMRadioService內部FmRxEvCallbacksAdaptor的方法在回調到FMRadio類中方法，將頻率存入FmSharedPreferences類xml文檔中，發送Handler更新UI，即刻度盤，對話框，左右箭頭中間顯示的頻率一致跳動。ide
接下來詳細代碼分析：函數
FMRadio中的菜單搜索功能，onOptionsItemSelected(MenuItem item)監聽中走initiateSearch(mScanPtyIndex);方法。post
調用FMRadioService的scan()方法（mService.scan(pty)）進行掃描頻率ui
updateSearchProgress()里加了同步方法對象鎖this
調用了private Dialog createProgressDialog(int id)對話框進行搜索信息線程
標準耳機FmSharedPreferences.isRBDSStd()xml
private Dialog createProgressDialog(int id) {
String msgStr = "";
String titleStr = "";
String []items;
double frequency = mTunedStation.getFrequency() / 1000.0;
boolean bSearchActive = false;
if (isSeekActive()) {
msgStr = getString(R.string.msg_seeking);
bSearchActive = true;
}else if (isScanActive()) {
if(FmSharedPreferences.isRBDSStd()) {//標準耳機
items = getResources().
getStringArray(R.array.search_category_rbds_entries);
}else { // if(FmSharedPreferences.isRDSStd())
items = getResources().
getStringArray(R.array.search_category_rds_entries);
}String ptyStr = "";
if (items.length > mScanPtyIndex)
ptyStr = items[mScanPtyIndex];
if (!TextUtils.isEmpty(ptyStr)) {
msgStr = getString(R.string.msg_scanning_pty, ptyStr);
}else {
Log.d(LOGTAG, "pty is null\n");
msgStr = getString(R.string.msg_scanning);
}
titleStr = getString(R.string.msg_search_title, ("" + frequency));
bSearchActive=true;
}else if (isSearchActive()) {
msgStr = getString(R.string.msg_searching);
titleStr = getString(R.string.msg_searching_title);
bSearchActive = true;
}
if (bSearchActive) {mProgressDialog = new ProgressDialog(FMRadio.this);
if (mProgressDialog != null) {
mProgressDialog.setTitle(titleStr);
mProgressDialog.setMessage(msgStr);
mProgressDialog.setIcon(R.drawable.ic_launcher_fmradio);
mProgressDialog.setProgressStyle(ProgressDialog.STYLE_SPINNER);
mProgressDialog.setCanceledOnTouchOutside(false);
mProgressDialog.setButton(DialogInterface.BUTTON_POSITIVE,
getText(R.string.button_text_stop),
new DialogInterface.OnClickListener() {
public void onClick(DialogInterface dialog, int whichButton) {
cancelSearch();
}
});
mProgressDialog.setOnCancelListener(new DialogInterface.OnCancelListener() { public void onCancel(DialogInterface dialog) {
cancelSearch();
}
});
mProgressDialog.setOnKeyListener(new OnKeyListener() {
public boolean onKey(DialogInterface dialog, int keyCode, KeyEvent event) {
Log.d(LOGTAG, "OnKeyListener event received in ProgressDialog" + keyCode);
switch (keyCode) {
case KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:
case 126: //KeyEvent.KEYCODE_MEDIA_PLAY:
case 127: //KeyEvent.KEYCODE_MEDIA_PAUSE:
case KeyEvent.KEYCODE_MEDIA_FAST_FORWARD:
case KeyEvent.KEYCODE_MEDIA_NEXT:
case KeyEvent.KEYCODE_MEDIA_PREVIOUS:
case KeyEvent.KEYCODE_MEDIA_REWIND:
case KeyEvent.KEYCODE_MEDIA_STOP:
return true;
} return false;
}
});
}
Message msg = new Message();
msg.what = TIMEOUT_PROGRESS_DLG;
mSearchProgressHandler.sendMessageDelayed(msg, SHOWBUSY_TIMEOUT);
}
return mProgressDialog;
}
調用FMRadioService類中的Scan()方法掃描
調用 FMReceiver的searchStations()方法進行掃描
public boolean scan(int pty)
{
boolean bCommandSent=false;
if (mReceiver != null)
{
Log.d(LOGTAG, "scan: PTY: " + pty);
if(FmSharedPreferences.isRBDSStd())
{
/* RBDS : Validate PTY value?? */
if( ((pty > 0) && (pty <= 23)) || ((pty >= 29) && (pty <= 31)) )
{bCommandSent = mReceiver.searchStations(FmReceiver.FM_RX_SRCHRDS_MODE_SCAN_PTY,
FmReceiver.FM_RX_DWELL_PERIOD_2S,
FmReceiver.FM_RX_SEARCHDIR_UP,
pty,
0);
}
else
{
bCommandSent = mReceiver.searchStations(FmReceiver.FM_RX_SRCH_MODE_SCAN,
FmReceiver.FM_RX_DWELL_PERIOD_2S,
FmReceiver.FM_RX_SEARCHDIR_UP);
}}
else
{
/* RDS : Validate PTY value?? */
if( (pty > 0) && (pty <= 31) )
{
bCommandSent = mReceiver.searchStations(FmReceiver.FM_RX_SRCHRDS_MODE_SCAN_PTY,
FmReceiver.FM_RX_DWELL_PERIOD_2S,
FmReceiver.FM_RX_SEARCHDIR_UP,
pty,
0);
}
else{
bCommandSent = mReceiver.searchStations(FmReceiver.FM_RX_SRCH_MODE_SCAN,
FmReceiver.FM_RX_DWELL_PERIOD_2S,
FmReceiver.FM_RX_SEARCHDIR_UP);
}
}
}
return bCommandSent;
}
FmReceiver類的public boolean searchStations (int mode,int dwellPeriod,intdirection,int pty,Int pi) 方法
得到FMState狀態
int state = getFMState();
/ * 驗證參數* /
調用setSearchState(subSrchLevel_ScanInProg);
re = mControl.searchStations(sFd, mode,dwellPeriod, direction, pty, pi);
public boolean searchStations (int mode,
int dwellPeriod,
int direction){
int state = getFMState();//得到FMState狀態
boolean bStatus = true;
int re;
/* Check current state of FM device */
if (state == FMState_Turned_Off || state == FMState_Srch_InProg) {
Log.d(TAG, "searchStations: Device currently busy in executing another command.");
return false;
}
Log.d (TAG, "Basic search...");
/* Validate the arguments */
if ( (mode != FM_RX_SRCH_MODE_SEEK) &&
(mode != FM_RX_SRCH_MODE_SCAN))
{
Log.d (TAG, "Invalid search mode: " + mode );
bStatus = false;
}
if ( (dwellPeriod < FM_RX_DWELL_PERIOD_0S ) ||
(dwellPeriod > FM_RX_DWELL_PERIOD_7S))
{
Log.d (TAG, "Invalid dwelling time: " + dwellPeriod);
bStatus = false;
}
if ( (direction != FM_RX_SEARCHDIR_DOWN) &&
(direction != FM_RX_SEARCHDIR_UP))
{
Log.d (TAG, "Invalid search direction: " + direction);
bStatus = false;
}
if (bStatus)
{
Log.d (TAG, "searchStations: mode " + mode + "direction: " + direction);
if (mode == FM_RX_SRCH_MODE_SEEK)
setSearchState(subSrchLevel_SeekInPrg);
else if (mode == FM_RX_SRCH_MODE_SCAN)
setSearchState(subSrchLevel_ScanInProg);
Log.v(TAG, "searchStations: CURRENT-STATE : FMRxOn ---> NEW-STATE : SearchInProg");
re = mControl.searchStations(sFd, mode, dwellPeriod, direction, 0, 0);
if (re != 0) {
Log.e(TAG, "search station failed");
if (getFMState() == FMState_Srch_InProg)
setSearchState(subSrchLevel_SrchComplete);
return false;
} state = getFMState();
if (state == FMState_Turned_Off) {
Log.d(TAG, "searchStations: CURRENT-STATE : FMState_Off (unexpected)");
return false;
}
}
return bStatus;
}
設置FM搜索電源狀態
static void setSearchState(int state)
{
mSearchState = state;
switch(mSearchState) {
case subSrchLevel_SeekInPrg:
case subSrchLevel_ScanInProg:
case subSrchLevel_SrchListInProg:
setFMPowerState(FMState_Srch_InProg);
break;
case subSrchLevel_SrchComplete:
/* Update the state of the FM device */
mSearchState = subSrchLevel_NoSearch;
setFMPowerState(FMState_Rx_Turned_On);
break;
case subSrchLevel_SrchAbort:
break;
default:
mSearchState = subSrchLevel_NoSearch;
break;
}
}
setFMPowerState(FMState_Rx_Turned_On); 是調用FmTransceiver類發射的器類，FM電源狀態
/*==============================================================
FUNCTION: setFMPowerState
==============================================================*/
/**
* Sets the FM power state
*
* <p>
* This method sets the FM power state.
*
* <p>
*/
static void setFMPowerState(int state)
{
FMState = state;
}
調用FMRxControls.java類的
/ * 配置各類搜索參數,開始搜索* /
public int searchStations (int fd, int mode,int dwell, int dir, int pty, int pi)
設置一些參數
FmReceiverJNI.setControlNative();
設置的搜索模式
設置掃描居住的時間
設置的企業
設置PI
/* configure various search parameters and start search */
public int searchStations (int fd, int mode, int dwell,
int dir, int pty, int pi){
int re = 0;
Log.d(TAG, "Mode is " + mode + " Dwell is " + dwell);
Log.d(TAG, "dir is " + dir + " PTY is " + pty);
Log.d(TAG, "pi is " + pi + " id " + V4L2_CID_PRIVATE_TAVARUA_SRCHMODE);
re = FmReceiverJNI.setControlNative (fd, V4L2_CID_PRIVATE_TAVARUA_SRCHMODE, mode);
if (re != 0) {
Log.e(TAG, "setting of search mode failed");
return re;
}
re = FmReceiverJNI.setControlNative (fd, V4L2_CID_PRIVATE_TAVARUA_SCANDWELL, dwell);
if (re != 0) {
Log.e(TAG, "setting of scan dwell time failed");
return re;
}
if (pty != 0)
{ re = FmReceiverJNI.setControlNative (fd, V4L2_CID_PRIVATE_TAVARUA_SRCH_PTY, pty);
if (re != 0) {
Log.e(TAG, "setting of PTY failed");
return re;
}
}
if (pi != 0)
{
re = FmReceiverJNI.setControlNative (fd, V4L2_CID_PRIVATE_TAVARUA_SRCH_PI, pi);
if (re != 0) {
Log.e(TAG, "setting of PI failed");
return re;
}
}
re = FmReceiverJNI.startSearchNative (fd, dir );
return re;
}
啓動搜索 FmReceiverJNI.startSearchNative (fd, dir );
關閉搜索
FMRadio 調用 FMRadioService 的CancelSearch()方法
public boolean cancelSearch()
public boolean cancelSearch()
{
boolean bCommandSent=false;
if (mReceiver != null)
{
Log.d(LOGTAG, "cancelSearch");
bCommandSent = mReceiver.cancelSearch();
}
return bCommandSent;
}
調用FRReceiver的cancelSearch()
mReceiver.cancelSearch()
更新搜索 FMRadio.java中
updateSearchProgress();
private void updateSearchProgress() {
boolean searchActive = isScanActive() || isSeekActive() || isSearchActive();
if (searchActive) {
synchronized (this) {
if(mProgressDialog == null) {
showDialog(DIALOG_PROGRESS_PROGRESS);
}else {
Message msg = new Message();
msg.what = UPDATE_PROGRESS_DLG;
mSearchProgressHandler.sendMessage(msg);
}
}
}else {
Message msg = new Message();
msg.what = END_PROGRESS_DLG;
mSearchProgressHandler.sendMessage(msg);
}
}
初始化菜單 invalidateOptionsMenu();
調用FMRxControls類的public void cancelSearch (int fd)方法
最後調用FMReceiver類的cancelSearchNative()
/* cancel search in progress */
public void cancelSearch (int fd){
FmReceiverJNI.cancelSearchNative(fd);
}
最後發送一個mSearchProgressHandler
msg.what = END_PROGRESS_DLG;
mSearchProgressHandler.sendMessage(msg)
刪除handler發送消息關閉對話框
private Handler mSearchProgressHandler = new Handler() {
public void handleMessage(Message msg) {
if (msg.what == UPDATE_PROGRESS_DLG) {
if(mProgressDialog != null) {
double frequency = mTunedStation.getFrequency() / 1000.0;
String titleStr = getString(R.string.msg_search_title, ("" + frequency));
mProgressDialog.setTitle(titleStr);
}
}else if (msg.what == END_PROGRESS_DLG) {
mSearchProgressHandler.removeMessages(END_PROGRESS_DLG);
mSearchProgressHandler.removeMessages(UPDATE_PROGRESS_DLG);
mSearchProgressHandler.removeMessages(TIMEOUT_PROGRESS_DLG);
removeDialog(DIALOG_PROGRESS_PROGRESS);
mProgressDialog = null;
}else if (msg.what == TIMEOUT_PROGRESS_DLG) {
cancelSearch();
}
}
};
在搜索中更新FMRadioUI界面的監聽類FmRxEventListner.java
public void startListner (final int fd, final FmRxEvCallbacks cb) {
/* start a thread and listen for messages */
mThread = new Thread(){
public void run(){
byte [] buff = new byte[STD_BUF_SIZE];
Log.d(TAG, "Starting listener " + fd);
while ((!Thread.currentThread().isInterrupted())) {
try {
int index = 0;
int state = 0;
Arrays.fill(buff, (byte)0x00);
int freq = 0;
int eventCount = FmReceiverJNI.getBufferNative (fd, buff, EVENT_LISTEN);
if (eventCount >= 0)
Log.d(TAG, "Received event. Count: " + eventCount);
for ( index = 0; index < eventCount; index++ ) {
Log.d(TAG, "Received <" +buff[index]+ ">" );
switch(buff[index]){
case 0:Log.d(TAG, "Got READY_EVENT");
if(FmTransceiver.getFMPowerState() == FmTransceiver.subPwrLevel_FMRx_Starting) {
/*Set the state as FMRxOn */
FmTransceiver.setFMPowerState(FmTransceiver.FMState_Rx_Turned_On);
Log.v(TAG, "RxEvtList: CURRENT-STATE : FMRxStarting ---> NEW-STATE : FMRxOn");
cb.FmRxEvEnableReceiver();
}
else if (FmTransceiver.getFMPowerState() == FmTransceiver.subPwrLevel_FMTurning_Off) {
/*Set the state as FMOff */
FmTransceiver.setFMPowerState(FmTransceiver.FMState_Turned_Off);
Log.v(TAG, "RxEvtList: CURRENT-STATE : FMTurningOff ---> NEW-STATE : FMOff");
FmTransceiver.release("/dev/radio0");
cb.FmRxEvDisableReceiver();
Thread.currentThread().interrupt();
}
break;case 1:
Log.d(TAG, "Got TUNE_EVENT");
freq = FmReceiverJNI.getFreqNative(fd);
state = FmReceiver.getSearchState();
switch(state) {
case FmTransceiver.subSrchLevel_SeekInPrg :
Log.v(TAG, "Current state is " + state);
FmReceiver.setSearchState(FmTransceiver.subSrchLevel_SrchComplete);
Log.v(TAG, "RxEvtList: CURRENT-STATE : Search ---> NEW-STATE : FMRxOn");
cb.FmRxEvSearchComplete(freq);
break;
default:
if (freq > 0)
cb.FmRxEvRadioTuneStatus(freq);
else
Log.e(TAG, "get frequency command failed");
break;
}
break;
case 2:Log.d(TAG, "Got SEEK_COMPLETE_EVENT");
state = FmReceiver.getSearchState();
switch(state) {
case FmTransceiver.subSrchLevel_ScanInProg:
Log.v(TAG, "Current state is " + state);
FmReceiver.setSearchState(FmTransceiver.subSrchLevel_SrchComplete);
Log.v(TAG, "RxEvtList: CURRENT-STATE : Search ---> NEW-STATE : FMRxOn");
cb.FmRxEvSearchComplete(FmReceiverJNI.getFreqNative(fd));
break;
case FmTransceiver.subSrchLevel_SrchAbort:
Log.v(TAG, "Current state is SRCH_ABORTED");
Log.v(TAG, "Aborting on-going search command...");
FmReceiver.setSearchState(FmTransceiver.subSrchLevel_SrchComplete);
Log.v(TAG, "RxEvtList: CURRENT-STATE : Search ---> NEW-STATE : FMRxOn");
cb.FmRxEvSearchComplete(FmReceiverJNI.getFreqNative(fd));
break;
}
break;
case 3:Log.d(TAG, "Got SCAN_NEXT_EVENT");
cb.FmRxEvSearchInProgress();
break;
case 4:
Log.d(TAG, "Got RAW_RDS_EVENT");
cb.FmRxEvRdsGroupData();
break;
case 5:
Log.d(TAG, "Got RT_EVENT");
cb.FmRxEvRdsRtInfo();
break;
case 6:
Log.d(TAG, "Got PS_EVENT");
cb.FmRxEvRdsPsInfo();
break;
case 7:
Log.d(TAG, "Got ERROR_EVENT");
break;
case 8:
Log.d(TAG, "Got BELOW_TH_EVENT");
cb.FmRxEvServiceAvailable (false);
break;
case 9:Log.d(TAG, "Got ABOVE_TH_EVENT");
cb.FmRxEvServiceAvailable(true);
break;
case 10:
Log.d(TAG, "Got STEREO_EVENT");
cb.FmRxEvStereoStatus (true);
break;
case 11:
Log.d(TAG, "Got MONO_EVENT");
cb.FmRxEvStereoStatus (false);
break;
case 12:
Log.d(TAG, "Got RDS_AVAL_EVENT");
cb.FmRxEvRdsLockStatus (true);
break;
case 13:
Log.d(TAG, "Got RDS_NOT_AVAL_EVENT");
cb.FmRxEvRdsLockStatus (false);
break;
case 14:Log.d(TAG, "Got NEW_SRCH_LIST");
state = FmReceiver.getSearchState();
switch(state) {
case FmTransceiver.subSrchLevel_SrchListInProg:
Log.v(TAG, "FmRxEventListener: Current state is AUTO_PRESET_INPROGRESS");
FmReceiver.setSearchState(FmTransceiver.subSrchLevel_SrchComplete);
Log.v(TAG, "RxEvtList: CURRENT-STATE : Search ---> NEW-STATE : FMRxOn");
cb.FmRxEvSearchListComplete ();
break;
case FmTransceiver.subSrchLevel_SrchAbort:
Log.v(TAG, "Current state is SRCH_ABORTED");
Log.v(TAG, "Aborting on-going SearchList command...");
FmReceiver.setSearchState(FmTransceiver.subSrchLevel_SrchComplete);
Log.v(TAG, "RxEvtList: CURRENT-STATE : Search ---> NEW-STATE : FMRxOn");
cb.FmRxEvSearchCancelled();
break;
}
break;
case 15:Log.d(TAG, "Got NEW_AF_LIST");
cb.FmRxEvRdsAfInfo();
break;
case 18:
Log.d(TAG, "Got RADIO_DISABLED");
if (FmTransceiver.getFMPowerState() == FmTransceiver.subPwrLevel_FMTurning_Off) {
/*Set the state as FMOff */
FmTransceiver.setFMPowerState(FmTransceiver.FMState_Turned_Off);
Log.v(TAG, "RxEvtList: CURRENT-STATE : FMTurningOff ---> NEW-STATE : FMOff");
FmTransceiver.release("/dev/radio0");
cb.FmRxEvDisableReceiver();
Thread.currentThread().interrupt();
} else {
Log.d(TAG, "Unexpected RADIO_DISABLED recvd");
cb.FmRxEvRadioReset();
}
break;
case 19:FmTransceiver.setRDSGrpMask(0);
break;
case 20:
Log.d(TAG, "got RT plus event");
cb.FmRxEvRTPlus();
break;
case 21:
Log.d(TAG, "got eRT event");
cb.FmRxEvERTInfo();
break;
default:
Log.d(TAG, "Unknown event");
break;
}
}//end of for
} catch ( Exception ex ) {
Log.d( TAG, "RunningThread InterruptedException");
ex.printStackTrace();
Thread.currentThread().interrupt();
}
}
}
};
mThread.start();
}
Switch case取1的時候就FMReceiverJNI類中獲取頻率，調FmRxEvRadioTuneStatus接收讀取頻率
freq= FmReceiverJNI.getFreqNative(fd);
cb.FmRxEvRadioTuneStatus(freq);
將頻率保存起來
FmSharedPreferences.setTunedFrequency(frequency);
mPrefs.Save();
清除狀態信息 clearStationInfo();
調用改變界面狀態 mCallbacks.onTuneStatusChanged();
可用存儲，設置可用模擬器 enableStereo(FmSharedPreferences.getAudioOutputMode());
public void FmRxEvRadioTuneStatus(int frequency)
{
Log.d(LOGTAG, "FmRxEvRadioTuneStatus: Tuned Frequency: " +frequency);
try
{
FmSharedPreferences.setTunedFrequency(frequency);
mPrefs.Save();
//Log.d(LOGTAG, "Call mCallbacks.onTuneStatusChanged");
/* Since the Tuned Status changed, clear out the RDSData cached */
if(mReceiver != null) {
clearStationInfo();
}
if(mCallbacks != null)
{
mCallbacks.onTuneStatusChanged();
}
/* Update the frequency in the StatusBar's Notification */
startNotification();
enableStereo(FmSharedPreferences.getAudioOutputMode());
}
catch (RemoteException e)
{
e.printStackTrace();
}
}
最後調到底層
FmReceiverJNI.setMonoStereoNative (fd, 1)
/* force mono/stereo mode */
public int stereoControl(int fd, boolean stereo) {
if (stereo){
return FmReceiverJNI.setMonoStereoNative (fd, 1);
}
else {
return FmReceiverJNI.setMonoStereoNative (fd, 0);
}
}
經過mCallbacks.onTuneStatusChanged();調用到FMRadio.java的內部存根類IFMRadioServiceCallbacks.stub類的public void onTuneStatusChanged()方法進行存入fm頻率，數據最後調用FMRadio的resetFMStationInfoUI()刷新UI
public void onTuneStatusChanged() {
Log.d(LOGTAG, "mServiceCallbacks.onTuneStatusChanged: ");
if (mIsScaning) {
Log.d(LOGTAG, "isScanning....................");
SharedPreferences sp = getSharedPreferences(SCAN_STATION_PREFS_NAME, 0);
SharedPreferences.Editor editor = sp.edit();
int station_number = sp.getInt(NUM_OF_STATIONS, 0);
station_number++;
editor.putInt(NUM_OF_STATIONS, station_number);
editor.putString(STATION_NAME + station_number, station_number + "");
editor.putInt(STATION_FREQUENCY + station_number,
FmSharedPreferences.getTunedFrequency());
editor.commit();
}
cleanupTimeoutHandler();
mHandler.post(mUpdateStationInfo);
mHandler.post(mOnStereo);
}
發送一handler跟新UI,調用此回調方法Runnable mUpdateStationInfo = new Runnable()
Runnable mUpdateStationInfo = new Runnable() {
public void run() {
cleanupTimeoutHandler();
PresetStation station = new PresetStation("", FmSharedPreferences.getTunedFrequency());
if (station != null) {
mTunedStation.Copy(station);
}
updateSearchProgress();
resetFMStationInfoUI();
}
};
updateStationInfoToUI()；
private void updateStationInfoToUI() {
double frequency = mTunedStation.getFrequency() / 1000.0;
mTuneStationFrequencyTV.setText("" + frequency + "MHz");
if ((mPicker != null) && mUpdatePickerValue) {
mPicker.setValue(((mTunedStation.getFrequency() - mPrefs.getLowerLimit())
/ mPrefs.getFrequencyStepSize()));
}
mStationCallSignTV.setText(mTunedStation.getPIString());
mProgramTypeTV.setText(mTunedStation.getPtyString());
mRadioTextTV.setText("");
mERadioTextTV.setText("");
mRadioTextScroller.mOriginalString = "";
mRadioTextScroller.mStringlength = 0;
mRadioTextScroller.mIteration = 0;
mERadioTextScroller.mOriginalString = "";
mERadioTextScroller.mStringlength = 0;
mERadioTextScroller.mIteration = 0;
mProgramServiceTV.setText("");
mStereoTV.setText("");
setupPresetLayout();
}
FM啓動和關閉搜索都是經過JNI調到底層實現，代碼路徑是：vendor\qcom\opensource\fm\jni
android_hardware_fm.cpp
/*
* JNI registration.
*/
static JNINativeMethod gMethods[] = {
/* name, signature, funcPtr */
{ "acquireFdNative", "(Ljava/lang/String;)I",
(void*)android_hardware_fmradio_FmReceiverJNI_acquireFdNative},
{ "closeFdNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_closeFdNative},
{ "getFreqNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getFreqNative},
{ "setFreqNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setFreqNative},
{ "getControlNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getControlNative},
{ "setControlNative", "(III)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setControlNative},
{ "startSearchNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_startSearchNative},
{ "cancelSearchNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_cancelSearchNative}, { "getRSSINative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getRSSINative},
{ "setBandNative", "(III)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setBandNative},
{ "getLowerBandNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getLowerBandNative},
{ "getUpperBandNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getUpperBandNative},
{ "getBufferNative", "(I[BI)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getBufferNative},
{ "setMonoStereoNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setMonoStereoNative},
{ "getRawRdsNative", "(I[BI)I",
(void*)android_hardware_fmradio_FmReceiverJNI_getRawRdsNative},
{ "setNotchFilterNative", "(IIZ)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setNotchFilterNative},
{ "startRTNative", "(ILjava/lang/String;I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_startRTNative},
{ "stopRTNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_stopRTNative},
{ "startPSNative", "(ILjava/lang/String;I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_startPSNative}, { "stopPSNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_stopPSNative},
{ "setPTYNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setPTYNative},
{ "setPINative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setPINative},
{ "setPSRepeatCountNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setPSRepeatCountNative},
{ "setTxPowerLevelNative", "(II)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setTxPowerLevelNative},
{ "setAnalogModeNative", "(Z)I",
(void*)android_hardware_fmradio_FmReceiverJNI_setAnalogModeNative},
{ "SetCalibrationNative", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_SetCalibrationNative},
{ "configureSpurTable", "(I)I",
(void*)android_hardware_fmradio_FmReceiverJNI_configureSpurTable},
};
上面寫明瞭從jni的調用關係。具體的函數實現，請到Android_hardware_fm.cpp中去查看。我就不一一寫出來了。以上就是FM搜索頻率與取消搜索頻率的操做與實現。搜索到頻率後就能夠聽FM了。
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