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.upstream;
  
  /**
   * A listener of data transfer events.
   */
  public interface TransferListener<S> {
  
    /**
     * Called when a transfer starts.
     *
     * @param source The source performing the transfer.
     * @param dataSpec Describes the data being transferred.
     */
    void onTransferStart(S source, DataSpec dataSpec);
  
    /**
     * Called incrementally during a transfer.
     *
     * @param source The source performing the transfer.
     * @param bytesTransferred The number of bytes transferred since the previous call to this
     *     method (or if the first call, since the transfer was started).
     */
    void onBytesTransferred(S source, int bytesTransferred);
  
    /**
     * Called when a transfer ends.
     *
     * @param source The source performing the transfer.
     */
    void onTransferEnd(S source);
  
  }
  