| /* |
| * Copyright (C) 2009 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 android.app.backup; |
| |
| import android.os.ParcelFileDescriptor; |
| |
| import java.io.IOException; |
| |
| /** |
| * A convenient {@link BackupAgent} wrapper class that automatically manages |
| * heterogeneous data sets within the backup data, each identified by a unique |
| * key prefix. When processing a backup or restore operation, the BackupAgentHelper |
| * dispatches to one or more installed {@link BackupHelper} objects, each |
| * of which is responsible for a defined subset of the data being processed. |
| * <p> |
| * An application will typically extend this class in its own |
| * backup agent. Then, within the agent's {@link BackupAgent#onCreate() onCreate()} |
| * method, it will call {@link #addHelper(String, BackupHelper) addHelper()} one or more times to |
| * install the handlers for each kind of data it wishes to manage within its backups. |
| * <p> |
| * The Android framework currently provides two predefined {@link BackupHelper} classes:</p> |
| * <ul><li>{@link FileBackupHelper} - Manages the backup and restore of entire files |
| * within an application's data directory hierarchy.</li> |
| * <li>{@link SharedPreferencesBackupHelper} - Manages the backup and restore of an |
| * application's {@link android.content.SharedPreferences} data.</li></ul> |
| * <p> |
| * An application can also implement its own helper classes to work within the |
| * {@link BackupAgentHelper} framework. See the {@link BackupHelper} interface |
| * documentation for details. |
| * |
| * <div class="special reference"> |
| * <h3>Developer Guides</h3> |
| * <p>For more information about using BackupAgentHelper, read the |
| * <a href="{@docRoot}guide/topics/data/backup.html">Data Backup</a> developer guide.</p> |
| * </div> |
| * |
| * @see BackupHelper |
| * @see FileBackupHelper |
| * @see SharedPreferencesBackupHelper |
| */ |
| public class BackupAgentHelper extends BackupAgent { |
| static final String TAG = "BackupAgentHelper"; |
| |
| BackupHelperDispatcher mDispatcher = new BackupHelperDispatcher(); |
| |
| /** |
| * Run the backup process on each of the configured handlers. |
| */ |
| @Override |
| public void onBackup(ParcelFileDescriptor oldState, BackupDataOutput data, |
| ParcelFileDescriptor newState) throws IOException { |
| mDispatcher.performBackup(oldState, data, newState); |
| } |
| |
| /** |
| * Run the restore process on each of the configured handlers. |
| */ |
| @Override |
| public void onRestore(BackupDataInput data, int appVersionCode, ParcelFileDescriptor newState) |
| throws IOException { |
| mDispatcher.performRestore(data, appVersionCode, newState); |
| } |
| |
| /** @hide */ |
| public BackupHelperDispatcher getDispatcher() { |
| return mDispatcher; |
| } |
| |
| /** |
| * Add a helper for a given data subset to the agent's configuration. Each helper |
| * must have a prefix string that is unique within this backup agent's set of |
| * helpers. |
| * |
| * @param keyPrefix A string used to disambiguate the various helpers within this agent |
| * @param helper A backup/restore helper object to be invoked during backup and restore |
| * operations. |
| */ |
| public void addHelper(String keyPrefix, BackupHelper helper) { |
| mDispatcher.addHelper(keyPrefix, helper); |
| } |
| } |
| |
| |