1 // Copyright 2021 The Android Open Source Project 2 // 3 // Licensed under the Apache License, Version 2.0 (the "License"); 4 // you may not use this file except in compliance with the License. 5 // You may obtain a copy of the License at 6 // 7 // http://www.apache.org/licenses/LICENSE-2.0 8 // 9 // Unless required by applicable law or agreed to in writing, software 10 // distributed under the License is distributed on an "AS IS" BASIS, 11 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 // See the License for the specific language governing permissions and 13 // limitations under the License. 14 15 package com.google.android.downloader; 16 17 import com.google.common.util.concurrent.ListenableFuture; 18 19 /** Interface for dealing with connectivity checking and handling in the downloader. */ 20 public interface ConnectivityHandler { 21 /** 22 * Handles the checking connectivity for the given {@link DownloadConstraints}. This method must 23 * return a {@link ListenableFuture} that resolves when the constraints are satisfied. 24 * 25 * <p>The returned future may be resolved in failure state with a {@link 26 * java.util.concurrent.TimeoutException} if too much time without sufficient connectivity has 27 * been observed. The future may also be cancelled (resulting in a {@link 28 * java.util.concurrent.CancellationException}) if observing connectivity changes is no longer 29 * necessary. Either state will be given special treatment to retry downloads. Any other failure 30 * state will be considered fatal and will fail ongoing downloads. 31 */ checkConnectivity(DownloadConstraints constraints)32 ListenableFuture<Void> checkConnectivity(DownloadConstraints constraints); 33 } 34