core/java/android/database/DataSetObservable.java

/*
 * 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;

/**
 * A specialization of Observable for DataSetObserver that provides methods for
 * invoking the various callback methods of DataSetObserver.
 */
public class DataSetObservable extends Observable<DataSetObserver> {
    /**
     * Invokes onChanged on each observer. Called when the data set being observed has
     * changed, and which when read contains the new state of the data.
     */
    public void notifyChanged() {
        synchronized(mObservers) {
            for (DataSetObserver observer : mObservers) {
                observer.onChanged();
            }
        }
    }

    /**
     * Invokes onInvalidated on each observer. Called when the data set being monitored
     * has changed such that it is no longer valid.
     */
    public void notifyInvalidated() {
        synchronized (mObservers) {
            for (DataSetObserver observer : mObservers) {
                observer.onInvalidated();
            }
        }
    }
}