1 /* 2 * Copyright (C) 2016 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 package com.google.android.exoplayer2.upstream; 17 18 /** 19 * A listener of data transfer events. 20 * 21 * <p>A transfer usually progresses through multiple steps: 22 * 23 * <ol> 24 * <li>Initializing the underlying resource (e.g. opening a HTTP connection). {@link 25 * #onTransferInitializing(DataSource, DataSpec, boolean)} is called before the initialization 26 * starts. 27 * <li>Starting the transfer after successfully initializing the resource. {@link 28 * #onTransferStart(DataSource, DataSpec, boolean)} is called. Note that this only happens if 29 * the initialization was successful. 30 * <li>Transferring data. {@link #onBytesTransferred(DataSource, DataSpec, boolean, int)} is 31 * called frequently during the transfer to indicate progress. 32 * <li>Closing the transfer and the underlying resource. {@link #onTransferEnd(DataSource, 33 * DataSpec, boolean)} is called. Note that each {@link #onTransferStart(DataSource, DataSpec, 34 * boolean)} will have exactly one corresponding call to {@link #onTransferEnd(DataSource, 35 * DataSpec, boolean)}. 36 * </ol> 37 */ 38 public interface TransferListener { 39 40 /** 41 * Called when a transfer is being initialized. 42 * 43 * @param source The source performing the transfer. 44 * @param dataSpec Describes the data for which the transfer is initialized. 45 * @param isNetwork Whether the data is transferred through a network. 46 */ onTransferInitializing(DataSource source, DataSpec dataSpec, boolean isNetwork)47 void onTransferInitializing(DataSource source, DataSpec dataSpec, boolean isNetwork); 48 49 /** 50 * Called when a transfer starts. 51 * 52 * @param source The source performing the transfer. 53 * @param dataSpec Describes the data being transferred. 54 * @param isNetwork Whether the data is transferred through a network. 55 */ onTransferStart(DataSource source, DataSpec dataSpec, boolean isNetwork)56 void onTransferStart(DataSource source, DataSpec dataSpec, boolean isNetwork); 57 58 /** 59 * Called incrementally during a transfer. 60 * 61 * @param source The source performing the transfer. 62 * @param dataSpec Describes the data being transferred. 63 * @param isNetwork Whether the data is transferred through a network. 64 * @param bytesTransferred The number of bytes transferred since the previous call to this method 65 */ onBytesTransferred( DataSource source, DataSpec dataSpec, boolean isNetwork, int bytesTransferred)66 void onBytesTransferred( 67 DataSource source, DataSpec dataSpec, boolean isNetwork, int bytesTransferred); 68 69 /** 70 * Called when a transfer ends. 71 * 72 * @param source The source performing the transfer. 73 * @param dataSpec Describes the data being transferred. 74 * @param isNetwork Whether the data is transferred through a network. 75 */ onTransferEnd(DataSource source, DataSpec dataSpec, boolean isNetwork)76 void onTransferEnd(DataSource source, DataSpec dataSpec, boolean isNetwork); 77 } 78