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.source;
  
  import android.os.Bundle;
  import androidx.annotation.Nullable;
  import com.google.android.exoplayer2.Bundleable;
  import com.google.android.exoplayer2.C;
  import com.google.android.exoplayer2.util.BundleableUtil;
  import com.google.android.exoplayer2.util.Log;
  import com.google.android.exoplayer2.util.Util;
  import com.google.common.collect.ImmutableList;
  import java.util.List;
  
  /**
   * An immutable array of {@link TrackGroup}s.
   *
   * <p>This class is typically used to represent all of the tracks available in a piece of media.
   * Tracks that are known to present the same content are grouped together (e.g., the same video feed
   * provided at different resolutions in an adaptive stream). Tracks that are known to present
   * different content are in separate track groups (e.g., an audio track will not be in the same
   * group as a video track, and an audio track in one language will be in a different group to an
   * audio track in another language).
   */
  public final class TrackGroupArray implements Bundleable {
  
    private static final String TAG = "TrackGroupArray";
  
    /** The empty array. */
    public static final TrackGroupArray EMPTY = new TrackGroupArray();
  
    /** The number of groups in the array. Greater than or equal to zero. */
    public final int length;
  
    private final ImmutableList<TrackGroup> trackGroups;
  
    // Lazily initialized hashcode.
    private int hashCode;
  
    /**
     * Construct a {@code TrackGroupArray} from an array of {@link TrackGroup TrackGroups}.
     *
     * <p>The groups must not contain duplicates.
     */
    public TrackGroupArray(TrackGroup... trackGroups) {
      this.trackGroups = ImmutableList.copyOf(trackGroups);
      this.length = trackGroups.length;
      verifyCorrectness();
    }
  
    /**
     * Returns the group at a given index.
     *
     * @param index The index of the group.
     * @return The group.
     */
    public TrackGroup get(int index) {
      return trackGroups.get(index);
    }
  
    /**
     * Returns the index of a group within the array.
     *
     * @param group The group.
     * @return The index of the group, or {@link C#INDEX_UNSET} if no such group exists.
     */
    public int indexOf(TrackGroup group) {
      int index = trackGroups.indexOf(group);
      return index >= 0 ? index : C.INDEX_UNSET;
    }
  
    /** Returns whether this track group array is empty. */
    public boolean isEmpty() {
      return length == 0;
    }
  
    @Override
    public int hashCode() {
      if (hashCode == 0) {
        hashCode = trackGroups.hashCode();
      }
      return hashCode;
    }
  
    @Override
    public boolean equals(@Nullable Object obj) {
      if (this == obj) {
        return true;
      }
      if (obj == null || getClass() != obj.getClass()) {
        return false;
      }
      TrackGroupArray other = (TrackGroupArray) obj;
      return length == other.length && trackGroups.equals(other.trackGroups);
    }
  
    // Bundleable implementation.
  
    private static final String FIELD_TRACK_GROUPS = Util.intToStringMaxRadix(0);
  
    @Override
    public Bundle toBundle() {
      Bundle bundle = new Bundle();
      bundle.putParcelableArrayList(
          FIELD_TRACK_GROUPS, BundleableUtil.toBundleArrayList(trackGroups));
      return bundle;
    }
  
    /** Object that can restores a TrackGroupArray from a {@link Bundle}. */
    public static final Creator<TrackGroupArray> CREATOR =
        bundle -> {
          @Nullable
          List<Bundle> trackGroupBundles = bundle.getParcelableArrayList(FIELD_TRACK_GROUPS);
          if (trackGroupBundles == null) {
            return new TrackGroupArray();
          }
          return new TrackGroupArray(
              BundleableUtil.fromBundleList(TrackGroup.CREATOR, trackGroupBundles)
                  .toArray(new TrackGroup[0]));
        };
  
    private void verifyCorrectness() {
      for (int i = 0; i < trackGroups.size(); i++) {
        for (int j = i + 1; j < trackGroups.size(); j++) {
          if (trackGroups.get(i).equals(trackGroups.get(j))) {
            Log.e(
                TAG,
                "",
                new IllegalArgumentException(
                    "Multiple identical TrackGroups added to one TrackGroupArray."));
          }
        }
      }
    }
  }
  