content: /*
   * Copyright (C) 2019 The Android Open Source Project
   *
   * 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.exoplayer2;
  
  import android.content.BroadcastReceiver;
  import android.content.Context;
  import android.content.Intent;
  import android.content.IntentFilter;
  import android.media.AudioManager;
  import android.os.Handler;
  
  /* package */ final class AudioBecomingNoisyManager {
  
    private final Context context;
    private final AudioBecomingNoisyReceiver receiver;
    private boolean receiverRegistered;
  
    public interface EventListener {
      void onAudioBecomingNoisy();
    }
  
    public AudioBecomingNoisyManager(Context context, Handler eventHandler, EventListener listener) {
      this.context = context.getApplicationContext();
      this.receiver = new AudioBecomingNoisyReceiver(eventHandler, listener);
    }
  
    /**
     * Enables the {@link AudioBecomingNoisyManager} which calls {@link
     * EventListener#onAudioBecomingNoisy()} upon receiving an intent of {@link
     * AudioManager#ACTION_AUDIO_BECOMING_NOISY}.
     *
     * @param enabled True if the listener should be notified when audio is becoming noisy.
     */
    public void setEnabled(boolean enabled) {
      if (enabled && !receiverRegistered) {
        context.registerReceiver(
            receiver, new IntentFilter(AudioManager.ACTION_AUDIO_BECOMING_NOISY));
        receiverRegistered = true;
      } else if (!enabled && receiverRegistered) {
        context.unregisterReceiver(receiver);
        receiverRegistered = false;
      }
    }
  
    private final class AudioBecomingNoisyReceiver extends BroadcastReceiver implements Runnable {
      private final EventListener listener;
      private final Handler eventHandler;
  
      public AudioBecomingNoisyReceiver(Handler eventHandler, EventListener listener) {
        this.eventHandler = eventHandler;
        this.listener = listener;
      }
  
      @Override
      public void onReceive(Context context, Intent intent) {
        if (AudioManager.ACTION_AUDIO_BECOMING_NOISY.equals(intent.getAction())) {
          eventHandler.post(this);
        }
      }
  
      @Override
      public void run() {
        if (receiverRegistered) {
          listener.onAudioBecomingNoisy();
        }
      }
    }
  }
  