LoopingMediaPlayer.java

/*
 * Copyright (C) 2016 Google Inc. All Rights Reserved.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package com.google.android.apps.santatracker.doodles.shared.sound;

import android.content.Context;
import android.content.res.AssetFileDescriptor;
import android.media.MediaPlayer;
import android.media.MediaPlayer.OnCompletionListener;
import android.util.Log;

/**
 * A wrapper around a MediaPlayer which allows for a gapless, looping track.
 */
public class LoopingMediaPlayer implements PineappleMediaPlayer {
  private static final String TAG = LoopingMediaPlayer.class.getSimpleName();

  private MediaPlayer currentPlayer;
  private MediaPlayer nextPlayer;
  private AssetFileDescriptor soundFileDescriptor;
  private float volume;

  public static LoopingMediaPlayer create(Context context, int resId) {
    return new LoopingMediaPlayer(context, resId);
  }

  private LoopingMediaPlayer(Context context, int resId) {
    soundFileDescriptor = context.getResources().openRawResourceFd(resId);

    currentPlayer = MediaPlayer.create(context, resId);
    nextPlayer = MediaPlayer.create(context, resId);
    currentPlayer.setNextMediaPlayer(nextPlayer);

    currentPlayer.setOnCompletionListener(new OnCompletionListener() {
      @Override
      public void onCompletion(MediaPlayer mediaPlayer) {
        try {
          currentPlayer.reset();
          currentPlayer.setDataSource(soundFileDescriptor.getFileDescriptor(),
              soundFileDescriptor.getStartOffset(), soundFileDescriptor.getLength());
          currentPlayer.prepare();
          nextPlayer.setNextMediaPlayer(currentPlayer);
        } catch (Exception e) {
          Log.w(TAG, "onCompletion: unexpected exception", e);
        }
      }
    });
    nextPlayer.setOnCompletionListener(new OnCompletionListener() {
      @Override
      public void onCompletion(MediaPlayer mediaPlayer) {
        try {
          nextPlayer.reset();
          nextPlayer.setDataSource(soundFileDescriptor.getFileDescriptor(),
              soundFileDescriptor.getStartOffset(), soundFileDescriptor.getLength());
          nextPlayer.prepare();
          currentPlayer.setNextMediaPlayer(nextPlayer);
        } catch (Exception e) {
          Log.w(TAG, "onCompletion: unexpected exception", e);
        }
      }
    });
  }

  @Override
  public void start() {
    try {
      currentPlayer.start();
    } catch (IllegalStateException e) {
      Log.w(TAG, "start() failed: " + e.toString());
    }
  }

  @Override
  public boolean isPlaying() {
    return currentPlayer.isPlaying() || nextPlayer.isPlaying();
  }

  @Override
  public void pause() {
    try {
      currentPlayer.pause();
      nextPlayer.pause();
    } catch (Exception e) {
      Log.w(TAG, "pause() failed: " + e.toString());
    }
  }

  @Override
  public MediaPlayer getMediaPlayer() {
    return currentPlayer;
  }

  @Override
  public void setNextMediaPlayer(MediaPlayer mediaPlayer) {
    try {
      currentPlayer.setNextMediaPlayer(mediaPlayer);
    } catch (Exception e) {
      Log.w(TAG, "setNextMediaPlayer() failed: ", e);
    }
  }

  @Override
  public void setVolume(float volume) {
    this.volume = volume;
    try {
      currentPlayer.setVolume(volume, volume);
      nextPlayer.setVolume(volume, volume);
    } catch (Exception e) {
      Log.w(TAG, "setVolume() failed: ", e);
    }
  }

  @Override
  public void mute() {
    try {
      currentPlayer.setVolume(0, 0);
      nextPlayer.setVolume(0, 0);
    } catch (Exception e) {
      Log.w(TAG, "mute() failed: ", e);
    }
  }

  @Override
  public void unmute() {
    try {
      currentPlayer.setVolume(volume, volume);
      nextPlayer.setVolume(volume, volume);
    } catch (Exception e) {
      Log.w(TAG, "unmute() failed: ", e);
    }
  }

  @Override
  public void release() {
    try {
      currentPlayer.release();
      nextPlayer.release();
      soundFileDescriptor.close();
    } catch (Exception e) {
      Log.w(TAG, "release() failed: ", e);
    }
  }
}