| /* |
| * Copyright (C) 2012 Google Inc. |
| * Licensed to 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.android.mail.providers; |
| |
| import android.database.DataSetObserver; |
| |
| import com.android.mail.ui.AccountController; |
| import com.android.mail.utils.LogTag; |
| import com.android.mail.utils.LogUtils; |
| |
| /** |
| * A simple extension of {@link DataSetObserver} to provide the updated account in |
| * {@link #onChanged(Account)} when the account changes. Initializing the object registers with |
| * the observer with the {@link AccountController} provided. The object will then begin to |
| * receive {@link #onChanged(Account)} till {@link #unregisterAndDestroy()} is called. |
| * <p> |
| * To implement an {@link AccountObserver}, you need to implement the {@link #onChanged(Account)} |
| * method. |
| */ |
| public abstract class AccountObserver extends DataSetObserver { |
| /** |
| * The AccountController that the observer is registered with. |
| */ |
| private AccountController mController; |
| |
| private static final String LOG_TAG = LogTag.getLogTag(); |
| |
| /** |
| * The no-argument constructor leaves the object unusable till |
| * {@link #initialize(AccountController)} is called. |
| */ |
| public AccountObserver () { |
| } |
| |
| /** |
| * Initializes an {@link AccountObserver} object that receives a call to |
| * {@link #onChanged(Account)} when the controller changes the account. |
| * |
| * @param controller |
| */ |
| public Account initialize(AccountController controller) { |
| if (controller == null) { |
| LogUtils.wtf(LOG_TAG, "AccountObserver initialized with null controller!"); |
| } |
| mController = controller; |
| mController.registerAccountObserver(this); |
| return mController.getAccount(); |
| } |
| |
| @Override |
| public final void onChanged() { |
| if (mController == null) { |
| return; |
| } |
| onChanged(mController.getAccount()); |
| } |
| |
| /** |
| * Callback invoked when the account object is changed. Since {@link Account} objects are |
| * immutable, updates can be received on changes to individual settings (sync on/off) |
| * in addition to changes of accounts: alice@example.com -> bob@example.com. |
| * The updated account is passed as the argument. |
| * @param newAccount |
| */ |
| public abstract void onChanged(Account newAccount); |
| |
| /** |
| * Return the most current account. |
| * @return |
| */ |
| public final Account getAccount() { |
| if (mController == null) { |
| return null; |
| } |
| return mController.getAccount(); |
| } |
| |
| /** |
| * Unregisters for account changes and makes the object unusable. |
| */ |
| public void unregisterAndDestroy() { |
| if (mController == null) { |
| return; |
| } |
| mController.unregisterAccountObserver(this); |
| } |
| } |