content: /*
   * Copyright (C) 2018 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.chunk;
  
  import com.google.android.exoplayer2.upstream.DataSpec;
  import java.util.NoSuchElementException;
  
  /**
   * Iterator for media chunk sequences.
   *
   * <p>The iterator initially points in front of the first available element. The first call to
   * {@link #next()} moves the iterator to the first element. Check the return value of {@link
   * #next()} or {@link #isEnded()} to determine whether the iterator reached the end of the available
   * data.
   */
  public interface MediaChunkIterator {
  
    /** An empty media chunk iterator without available data. */
    MediaChunkIterator EMPTY =
        new MediaChunkIterator() {
          @Override
          public boolean isEnded() {
            return true;
          }
  
          @Override
          public boolean next() {
            return false;
          }
  
          @Override
          public DataSpec getDataSpec() {
            throw new NoSuchElementException();
          }
  
          @Override
          public long getChunkStartTimeUs() {
            throw new NoSuchElementException();
          }
  
          @Override
          public long getChunkEndTimeUs() {
            throw new NoSuchElementException();
          }
  
          @Override
          public void reset() {
            // Do nothing.
          }
        };
  
    /** Returns whether the iteration has reached the end of the available data. */
    boolean isEnded();
  
    /**
     * Moves the iterator to the next media chunk.
     *
     * <p>Check the return value or {@link #isEnded()} to determine whether the iterator reached the
     * end of the available data.
     *
     * @return Whether the iterator points to a media chunk with available data.
     */
    boolean next();
  
    /**
     * Returns the {@link DataSpec} used to load the media chunk.
     *
     * @throws java.util.NoSuchElementException If the method is called before the first call to
     *     {@link #next()} or when {@link #isEnded()} is true.
     */
    DataSpec getDataSpec();
  
    /**
     * Returns the media start time of the chunk, in microseconds.
     *
     * @throws java.util.NoSuchElementException If the method is called before the first call to
     *     {@link #next()} or when {@link #isEnded()} is true.
     */
    long getChunkStartTimeUs();
  
    /**
     * Returns the media end time of the chunk, in microseconds.
     *
     * @throws java.util.NoSuchElementException If the method is called before the first call to
     *     {@link #next()} or when {@link #isEnded()} is true.
     */
    long getChunkEndTimeUs();
  
    /** Resets the iterator to the initial position. */
    void reset();
  }
  