add exoplayer listener

app/src/main/java/com/example/android/classicalmusicquiz/QuizActivity.java

@@ -25,28 +25,35 @@
 import android.os.Handler;
 import android.support.v4.content.ContextCompat;
 import android.support.v7.app.AppCompatActivity;
+import android.util.Log;
 import android.view.View;
 import android.widget.Button;
 import android.widget.Toast;
 
 import com.google.android.exoplayer2.DefaultLoadControl;
+import com.google.android.exoplayer2.ExoPlaybackException;
+import com.google.android.exoplayer2.ExoPlayer;
 import com.google.android.exoplayer2.ExoPlayerFactory;
 import com.google.android.exoplayer2.LoadControl;
 import com.google.android.exoplayer2.SimpleExoPlayer;
+import com.google.android.exoplayer2.Timeline;
 import com.google.android.exoplayer2.extractor.DefaultExtractorsFactory;
 import com.google.android.exoplayer2.source.ExtractorMediaSource;
 import com.google.android.exoplayer2.source.MediaSource;
+import com.google.android.exoplayer2.source.TrackGroupArray;
 import com.google.android.exoplayer2.trackselection.DefaultTrackSelector;
+import com.google.android.exoplayer2.trackselection.TrackSelectionArray;
 import com.google.android.exoplayer2.trackselection.TrackSelector;
 import com.google.android.exoplayer2.ui.SimpleExoPlayerView;
 import com.google.android.exoplayer2.upstream.DefaultDataSourceFactory;
 import com.google.android.exoplayer2.util.Util;
 
 import java.util.ArrayList;
 
-// TODO (1): Have this Activity implement ExoPlayer.EventListener and add the required methods.
-public class QuizActivity extends AppCompatActivity implements View.OnClickListener {
+//  (1): Have this Activity implement ExoPlayer.EventListener and add the required methods.
+public class QuizActivity extends AppCompatActivity implements View.OnClickListener , ExoPlayer.EventListener{
 
+    private static final String TAG = "QuizActivity";
     private static final int CORRECT_ANSWER_DELAY_MILLIS = 1000;
     private static final String REMAINING_SONGS_KEY = "remaining_songs";
     private int[] mButtonIDs = {R.id.buttonA, R.id.buttonB, R.id.buttonC, R.id.buttonD};
@@ -149,7 +156,9 @@ private void initializePlayer(Uri mediaUri) {
             mExoPlayer = ExoPlayerFactory.newSimpleInstance(this, trackSelector, loadControl);
             mPlayerView.setPlayer(mExoPlayer);
 
-            // TODO (2): Set the ExoPlayer.EventListener to this activity
+            //  (2): Set the ExoPlayer.EventListener to this activity
+            mExoPlayer.addListener(this);
+
 
             // Prepare the MediaSource.
             String userAgent = Util.getUserAgent(this, "ClassicalMusicQuiz");
@@ -260,5 +269,43 @@ protected void onDestroy() {
         releasePlayer();
     }
 
-    // TODO (3): Add conditional logging statements to the onPlayerStateChanged() method that log when ExoPlayer is playing or paused.
+    @Override
+    public void onTimelineChanged(Timeline timeline, Object manifest) {
+
+    }
+
+    @Override
+    public void onTracksChanged(TrackGroupArray trackGroups, TrackSelectionArray trackSelections) {
+
+    }
+
+    @Override
+    public void onLoadingChanged(boolean isLoading) {
+
+    }
+
+    //  (3): Add conditional logging statements to the onPlayerStateChanged() method that log when ExoPlayer is playing or paused.
+    @Override
+    public void onPlayerStateChanged(boolean playWhenReady, int playbackState) {
+        //每次播放器状态发生变化时都会被调用，因此我们将在该方法中更新媒体会话。
+        if((playbackState == ExoPlayer.STATE_READY) && playWhenReady ){
+            //we are playing
+            Log.e(TAG, "onPlayerStateChanged: playing" );
+        }else if(playbackState == ExoPlayer.STATE_READY){
+            //we are pause
+            Log.e(TAG, "onPlayerStateChanged: pause" );
+        }
+
+    }
+
+    @Override
+    public void onPlayerError(ExoPlaybackException error) {
+
+    }
+
+    @Override
+    public void onPositionDiscontinuity() {
+
+    }
+
 }