AndroidFm模块学习之四源码解析（十一）

接上一篇，接下来看看android\vendor\qcom\opensource\fm\fmapp2\src\com\caf\fmradio\FmTags.java

当点击FMRadio.java菜单的全部频道选项，跳转到FmTags.java类
定义了一个ListView控件和一个简单适配器
private ListView la;
private ArrayAdapter<String> adapter;
 
使用Handler刷新UI界面
private final Handler mHandler = newHandler();
 
使用迭代器private Iterator itr;
将FmSharedPreferences类取出数据迭代化，再使用循环添加到字符数组里，使用适配器显示。

final Runnable mDisplayTagList = new Runnable() {
public void run() {
String[] tags;
int l = 0;

tags = new String[FmSharedPreferences.num_tags];
for(int i = 0; i < FmSharedPreferences.MAX_NUM_TAG_TYPES; i++) {
if (FmSharedPreferences.tagList[i] != null) {
itr = FmSharedPreferences.tagList[i].iterator();
while(itr.hasNext())
tags[l++] = ((FmSharedPreferences.TAG_NAMES[i]) + "\n" +
"\t" + (String)itr.next());
}
}
adapter = new ArrayAdapter(la.getContext(), android.R.layout.simple_list_item_1, tags);
la.setAdapter(adapter);
}
};

再分析一个FM耳机按键的类 android\vendor\qcom\opensource\fm\fmapp2\src\com\caf\fmradio\FMMediaButtonIntentReceiver.java
手机耳机控制音量或者其它，通过静态注册接收action（“android.intent.action.MEDIA_BUTTON”）

按键监听事件

KeyEvent event =(KeyEvent)intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);

监听是否是头戴式耳机和点击按下去的监听

 intkeycode = event.getKeyCode();

 intkey_action = event.getAction();

 

发送一个附带Intent.EXTRA_KEY_EVENT广播去FMRadioService实现接听实现一些功能。

 

KeyEvent.KEYCODE_HEADSETHOOK:监听是否是头戴式耳机

KeyEvent.ACTION_DOWN:监听是否按下键

KeyEvent.KEYCODE_MEDIA_PLAY_PAUSE:暂停 

KeyEvent.KEYCODE_MEDIA_PLAY 播放键

KeyEvent.KEYCODE_MEDIA_NEXT:短按=播放下一首音乐，长按=当前音乐快进

KeyEvent.KEYCODE_MEDIA_PREVIOUS:短按=播放上一首音乐，长按=当前音乐快退

 

欧标耳机才能测试出监听事件

public class FMMediaButtonIntentReceiver extends BroadcastReceiver {

private static final String TAG = "FMMediaButtonIntentReceiver";
public static final String FM_MEDIA_BUTTON = "com.caf.fmradio.action.MEDIA_BUTTON";
public static final String AUDIO_BECOMING_NOISY = "com.caf.fmradio.action.AUDIO_BECOMING_NOISY";
public void onReceive(Context context, Intent intent) {
String action = intent.getAction();
if ((action != null) && action.equals(AudioManager.ACTION_AUDIO_BECOMING_NOISY)) {
Log.d(TAG, "ACTION_AUDIO_BECOMING_NOISY intent received for ACTION_HEADSET_PLUG");
Intent i = new Intent(AUDIO_BECOMING_NOISY); context.sendBroadcast(i);
} else if ((action != null) && action.equals("android.intent.action.MEDIA_BUTTON")) {
KeyEvent event = (KeyEvent)
intent.getParcelableExtra(Intent.EXTRA_KEY_EVENT);

if (event == null) {
return;
}
int keycode = event.getKeyCode();
int key_action = event.getAction();
if (((KeyEvent.KEYCODE_HEADSETHOOK == keycode) &&
(key_action == KeyEvent.ACTION_DOWN)) ||
(KeyEvent.KEYCODE_MEDIA_PAUSE == keycode) ||
(KeyEvent.KEYCODE_MEDIA_PLAY == keycode)) {

Log.d(TAG, "ACTION_MEDIA_BUTTON intent received for ACTION_DOWN");
Intent i = new Intent(FM_MEDIA_BUTTON);
i.putExtra(Intent.EXTRA_KEY_EVENT, event);
context.sendBroadcast(i);
}
}
}