android源码第一季（mars）

package mars.mp3player; import java.io.File; import java.io.FileInputStream; import java.io.FileNotFoundException; import java.io.InputStream; import java.util.ArrayList; import java.util.Queue; import mars.lrc.LrcProcessor; import mars.model.Mp3Info; import mars.mp3player.service.PlayerService; import android.app.Activity; import android.content.Intent; import android.media.MediaPlayer; import android.os.Bundle; import android.os.Environment; import android.os.Handler; import android.view.View; import android.view.View.OnClickListener; import android.widget.ImageButton; import android.widget.TextView; public class PlayerActivity extends Activity { ImageButton beginButton = null; ImageButton pauseButton = null; ImageButton stopButton = null; MediaPlayer mediaPlayer = null; private ArrayList<Queue> queues = null; private TextView lrcTextView = null; private Mp3Info mp3Info = null; private Handler handler = new Handler(); private UpdateTimeCallback updateTimeCallback = null; private long begin = 0; private long nextTimeMill = 0; private long currentTimeMill = 0; private String message = null; private long pauseTimeMills = 0; private boolean isPlaying = false; @Override protected void onCreate(Bundle savedInstanceState) { // TODO Auto-generated method stub super.onCreate(savedInstanceState); setContentView(R.layout.player); Intent intent = getIntent(); mp3Info = (Mp3Info) intent.getSerializableExtra("mp3Info"); beginButton = (ImageButton) findViewById(R.id.begin); pauseButton = (ImageButton) findViewById(R.id.pause); stopButton = (ImageButton) findViewById(R.id.stop); beginButton.setOnClickListener(new BeginButtonListener()); pauseButton.setOnClickListener(new PauseButtonListener()); stopButton.setOnClickListener(new StopButtonListener()); lrcTextView = (TextView)findViewById(R.id.lrcText); } /** * 根据歌词文件的名字，来读取歌词文件当中的信息 * @param lrcName */ private void prepareLrc(String lrcName){ try { InputStream inputStream = new FileInputStream(Environment.getExternalStorageDirectory().getAbsoluteFile() +File.separator + "mp3/" + mp3Info.getLrcName()); LrcProcessor lrcProcessor = new LrcProcessor(); queues = lrcProcessor.process(inputStream); //创建一个UpdateTimeCallback对象 updateTimeCallback = new UpdateTimeCallback(queues); begin = 0 ; currentTimeMill = 0 ; nextTimeMill = 0 ; } catch (FileNotFoundException e) { e.printStackTrace(); } } class BeginButtonListener implements OnClickListener { @Override public void onClick(View v) { //创建一个Intent对象，用于同时Service开始播放MP3 Intent intent = new Intent(); intent.setClass(PlayerActivity.this, PlayerService.class); intent.putExtra("mp3Info", mp3Info); intent.putExtra("MSG", AppConstant.PlayerMsg.PLAY_MSG); //读取LRC文件 prepareLrc(mp3Info.getLrcName()); //启动Service startService(intent); //将begin的值置为当前毫秒数 begin = System.currentTimeMillis(); //执行updateTimeCallback handler.postDelayed(updateTimeCallback, 5); isPlaying = true; } } class PauseButtonListener implements OnClickListener { @Override public void onClick(View v) { //通知Service暂停播放MP3 Intent intent = new Intent(); intent.setClass(PlayerActivity.this, PlayerService.class); intent.putExtra("MSG", AppConstant.PlayerMsg.PAUSE_MSG); startService(intent); // if(isPlaying){ handler.removeCallbacks(updateTimeCallback); pauseTimeMills = System.currentTimeMillis(); } else{ handler.postDelayed(updateTimeCallback, 5); begin = System.currentTimeMillis() - pauseTimeMills + begin; } isPlaying = isPlaying ? false : true; } } class StopButtonListener implements OnClickListener { @Override public void onClick(View v) { //通知Service停止播放MP3文件 Intent intent = new Intent(); intent.setClass(PlayerActivity.this, PlayerService.class); intent.putExtra("MSG", AppConstant.PlayerMsg.STOP_MSG); startService(intent); //从Handler当中移除updateTimeCallback handler.removeCallbacks(updateTimeCallback); } } class UpdateTimeCallback implements Runnable{ Queue times = null; Queue messages = null; public UpdateTimeCallback(ArrayList<Queue> queues) { //从ArrayList当中取出相应的对象对象 times = queues.get(0); messages = queues.get(1); } @Override public void run() { //计算偏移量，也就是说从开始播放MP3到现在为止，共消耗了多少时间，以毫秒为单位 long offset = System.currentTimeMillis() - begin; if(currentTimeMill == 0){ nextTimeMill = (Long)times.poll(); message = (String)messages.poll(); } if(offset >= nextTimeMill){ lrcTextView.setText(message); message = (String)messages.poll(); nextTimeMill = (Long)times.poll(); } currentTimeMill = currentTimeMill + 10; handler.postDelayed(updateTimeCallback, 10); } } }