content: /*
   * Copyright (C) 2016 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.audio;
  
  import android.content.BroadcastReceiver;
  import android.content.ContentResolver;
  import android.content.Context;
  import android.content.Intent;
  import android.content.IntentFilter;
  import android.database.ContentObserver;
  import android.media.AudioManager;
  import android.net.Uri;
  import android.os.Handler;
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.util.Assertions;
  import com.google.android.exoplayer2.util.Util;
  
  /**
   * Receives broadcast events indicating changes to the device's audio capabilities, notifying a
   * {@link Listener} when audio capability changes occur.
   */
  public final class AudioCapabilitiesReceiver {
  
    /** Listener notified when audio capabilities change. */
    public interface Listener {
  
      /**
       * Called when the audio capabilities change.
       *
       * @param audioCapabilities The current audio capabilities for the device.
       */
      void onAudioCapabilitiesChanged(AudioCapabilities audioCapabilities);
    }
  
    private final Context context;
    private final Listener listener;
    private final Handler handler;
    @Nullable private final BroadcastReceiver receiver;
    @Nullable private final ExternalSurroundSoundSettingObserver externalSurroundSoundSettingObserver;
  
    // AMZN_CHANGE_BEGIN
    private final ContentResolver resolver;
    // AMZN_CHANGE_END
    /* package */ @Nullable AudioCapabilities audioCapabilities;
    private boolean registered;
  
    /**
     * @param context A context for registering the receiver.
     * @param listener The listener to notify when audio capabilities change.
     */
    public AudioCapabilitiesReceiver(Context context, Listener listener) {
      context = context.getApplicationContext();
      this.context = context;
      this.listener = Assertions.checkNotNull(listener);
      handler = Util.createHandlerForCurrentOrMainLooper();
      Uri externalSurroundSoundUri = AudioCapabilities.getExternalSurroundSoundGlobalSettingUri();
      externalSurroundSoundSettingObserver =
          externalSurroundSoundUri != null
              ? new ExternalSurroundSoundSettingObserver(
                  handler, context.getContentResolver(), externalSurroundSoundUri)
              : null;
      // AMZN_CHANGE_BEGIN
      boolean useSurroundSoundFlag = false;
      if (Util.SDK_INT >= 17) {
        this.resolver = context.getContentResolver();
        useSurroundSoundFlag = AudioCapabilities.useSurroundSoundFlagV17(
              resolver);
      } else {
        this.resolver = null;
      }
      // Don't listen for audio plug encodings if useSurroundSoundFlag is set.
      // If useSurroundSoundFlag is set then the platform controls what the
      // audio output is by using the iSurroundSoundEnabled setting.
      this.receiver = (Util.SDK_INT >= 21 && !useSurroundSoundFlag) ?
              new HdmiAudioPlugBroadcastReceiver() : null;
      // AMZN_CHANGE_END
    }
  
    /**
     * Registers the receiver, meaning it will notify the listener when audio capability changes
     * occur. The current audio capabilities will be returned. It is important to call {@link
     * #unregister} when the receiver is no longer required.
     *
     * @return The current audio capabilities for the device.
     */
    @SuppressWarnings("InlinedApi")
    public AudioCapabilities register() {
      if (registered) {
        return Assertions.checkNotNull(audioCapabilities);
      }
      registered = true;
      if (externalSurroundSoundSettingObserver != null) {
        externalSurroundSoundSettingObserver.register();
      }
      @Nullable Intent stickyIntent = null;
      if (receiver != null) {
        IntentFilter intentFilter = new IntentFilter(AudioManager.ACTION_HDMI_AUDIO_PLUG);
        stickyIntent =
            context.registerReceiver(
                receiver, intentFilter, /* broadcastPermission= */ null, handler);
      }
      audioCapabilities = AudioCapabilities.getCapabilities(context, stickyIntent);
      return audioCapabilities;
    }
  
    /**
     * Unregisters the receiver, meaning it will no longer notify the listener when audio capability
     * changes occur.
     */
    public void unregister() {
      if (!registered) {
        return;
      }
      audioCapabilities = null;
      if (receiver != null) {
        context.unregisterReceiver(receiver);
      }
      if (externalSurroundSoundSettingObserver != null) {
        externalSurroundSoundSettingObserver.unregister();
      }
      registered = false;
    }
  
    private void onNewAudioCapabilities(AudioCapabilities newAudioCapabilities) {
      if (registered && !newAudioCapabilities.equals(audioCapabilities)) {
        audioCapabilities = newAudioCapabilities;
        listener.onAudioCapabilitiesChanged(newAudioCapabilities);
      }
    }
  
    private final class HdmiAudioPlugBroadcastReceiver extends BroadcastReceiver {
  
      @Override
      public void onReceive(Context context, Intent intent) {
        if (!isInitialStickyBroadcast()) {
          onNewAudioCapabilities(AudioCapabilities.getCapabilities(context, intent));
        }
      }
    }
  
    private final class ExternalSurroundSoundSettingObserver extends ContentObserver {
  
      private final ContentResolver resolver;
      private final Uri settingUri;
  
      public ExternalSurroundSoundSettingObserver(
          Handler handler, ContentResolver resolver, Uri settingUri) {
        super(handler);
        this.resolver = resolver;
        this.settingUri = settingUri;
      }
  
      public void register() {
        resolver.registerContentObserver(settingUri, /* notifyForDescendants= */ false, this);
      }
  
      public void unregister() {
        resolver.unregisterContentObserver(this);
      }
  
      @Override
      public void onChange(boolean selfChange) {
        super.onChange(selfChange); // AMZN_CHANGE_ONELINE
        onNewAudioCapabilities(AudioCapabilities.getCapabilities(context));
      }
    }
  }
  