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      1 /*
      2  * Copyright (C) 2007 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 
     17 package android.database;
     18 
     19 import android.net.Uri;
     20 
     21 /**
     22  * A specialization of {@link Observable} for {@link ContentObserver}
     23  * that provides methods for sending notifications to a list of
     24  * {@link ContentObserver} objects.
     25  */
     26 public class ContentObservable extends Observable<ContentObserver> {
     27     // Even though the generic method defined in Observable would be perfectly
     28     // fine on its own, we can't delete this overridden method because it would
     29     // potentially break binary compatibility with existing applications.
     30     @Override
     31     public void registerObserver(ContentObserver observer) {
     32         super.registerObserver(observer);
     33     }
     34 
     35     /**
     36      * Invokes {@link ContentObserver#dispatchChange(boolean)} on each observer.
     37      * <p>
     38      * If <code>selfChange</code> is true, only delivers the notification
     39      * to the observer if it has indicated that it wants to receive self-change
     40      * notifications by implementing {@link ContentObserver#deliverSelfNotifications}
     41      * to return true.
     42      * </p>
     43      *
     44      * @param selfChange True if this is a self-change notification.
     45      *
     46      * @deprecated Use {@link #dispatchChange(boolean, Uri)} instead.
     47      */
     48     @Deprecated
     49     public void dispatchChange(boolean selfChange) {
     50         dispatchChange(selfChange, null);
     51     }
     52 
     53     /**
     54      * Invokes {@link ContentObserver#dispatchChange(boolean, Uri)} on each observer.
     55      * Includes the changed content Uri when available.
     56      * <p>
     57      * If <code>selfChange</code> is true, only delivers the notification
     58      * to the observer if it has indicated that it wants to receive self-change
     59      * notifications by implementing {@link ContentObserver#deliverSelfNotifications}
     60      * to return true.
     61      * </p>
     62      *
     63      * @param selfChange True if this is a self-change notification.
     64      * @param uri The Uri of the changed content, or null if unknown.
     65      */
     66     public void dispatchChange(boolean selfChange, Uri uri) {
     67         synchronized(mObservers) {
     68             for (ContentObserver observer : mObservers) {
     69                 if (!selfChange || observer.deliverSelfNotifications()) {
     70                     observer.dispatchChange(selfChange, uri);
     71                 }
     72             }
     73         }
     74     }
     75 
     76     /**
     77      * Invokes {@link ContentObserver#onChange} on each observer.
     78      *
     79      * @param selfChange True if this is a self-change notification.
     80      *
     81      * @deprecated Use {@link #dispatchChange} instead.
     82      */
     83     @Deprecated
     84     public void notifyChange(boolean selfChange) {
     85         synchronized(mObservers) {
     86             for (ContentObserver observer : mObservers) {
     87                 observer.onChange(selfChange, null);
     88             }
     89         }
     90     }
     91 }
     92