Java tutorial
/* * Copyright (C) 2007 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.database; import android.net.Uri; /** * A specialization of {@link Observable} for {@link ContentObserver} * that provides methods for sending notifications to a list of * {@link ContentObserver} objects. */ public class ContentObservable extends Observable<ContentObserver> { // Even though the generic method defined in Observable would be perfectly // fine on its own, we can't delete this overridden method because it would // potentially break binary compatibility with existing applications. @Override public void registerObserver(ContentObserver observer) { super.registerObserver(observer); } /** * Invokes {@link ContentObserver#dispatchChange(boolean)} on each observer. * <p> * If <code>selfChange</code> is true, only delivers the notification * to the observer if it has indicated that it wants to receive self-change * notifications by implementing {@link ContentObserver#deliverSelfNotifications} * to return true. * </p> * * @param selfChange True if this is a self-change notification. * * @deprecated Use {@link #dispatchChange(boolean, Uri)} instead. */ @Deprecated public void dispatchChange(boolean selfChange) { dispatchChange(selfChange, null); } /** * Invokes {@link ContentObserver#dispatchChange(boolean, Uri)} on each observer. * Includes the changed content Uri when available. * <p> * If <code>selfChange</code> is true, only delivers the notification * to the observer if it has indicated that it wants to receive self-change * notifications by implementing {@link ContentObserver#deliverSelfNotifications} * to return true. * </p> * * @param selfChange True if this is a self-change notification. * @param uri The Uri of the changed content, or null if unknown. */ public void dispatchChange(boolean selfChange, Uri uri) { synchronized (mObservers) { for (ContentObserver observer : mObservers) { if (!selfChange || observer.deliverSelfNotifications()) { observer.dispatchChange(selfChange, uri); } } } } /** * Invokes {@link ContentObserver#onChange} on each observer. * * @param selfChange True if this is a self-change notification. * * @deprecated Use {@link #dispatchChange} instead. */ @Deprecated public void notifyChange(boolean selfChange) { synchronized (mObservers) { for (ContentObserver observer : mObservers) { observer.onChange(selfChange, null); } } } }