MediaPlayer API more and more

I used MediaPlayer class API.
getAudioSessionId(), getCurrentPosition(), and pause().
and I try any Listener interface implement.
onCompletion(), onError(), onInfo(), onVideoSizeChanged(),

• when app  play clip, onVideoSizeChanged() is called soon.
• when app run clip end, onCompletion() is called.
• If setLoop(true), onCompletion() isn't call. but onInfo() is called by what = 1 and extra = 44.

I used getAudioSessionId(), getCurrentPosition().

Log.d("player", "getAudioSessionId = " + _mediaplayer.getAudioSessionId());
Log.d("player", "getCurrentPosition = " + _mediaplayer.getCurrentPosition());

I designed as if app play clip, app call pause and if app pause, app play clip.

boolean isPause = false;
・・・・
if (isPause == false) {
 isPause = true;
 _mediaplayer.pause();
} else {
 isPause = false;
 _mediaplayer.start();
}

Implements Listeners:

@Override
public void onCompletion(MediaPlayer mp) {
 Log.d("player", "onCompletion");
 
}
@Override
public boolean onError(MediaPlayer mp, int what, int extra) {
 Log.d("player", "onError what = " + what + "extra = " + extra);
 return false;
}
@Override
public boolean onInfo(MediaPlayer mp, int what, int extra) {
 Log.d("player", "onInfo what = " + what + "extra = " + extra);
 return false;
}
@Override
public void onVideoSizeChanged(MediaPlayer mp, int width, int height) {
 Log.d("player", "onVideoSizeChanged width = " + width + " height = " + height);
 
}
@Override
public void onPrepared(MediaPlayer mp) {
 Log.d("player", "onPrepared");
}

Must Register listener before MediaPlayer.start():

_mediaplayer.setOnCompletionListener(this);
_mediaplayer.setOnErrorListener(this);
_mediaplayer.setOnInfoListener(this);
_mediaplayer.setOnPreparedListener(this);
_mediaplayer.setOnVideoSizeChangedListener(this);

My source code is here.