core/src/org/apache/pivot/util/ObservableMap.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to you 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 org.apache.pivot.util;

import java.util.Map;

/**
 * A map that fires events when its content changes.
 */
public interface ObservableMap<K, V> extends Map<K, V> {
    /**
     * Observable map listener list.
     */
    public static class ObservableMapListenerList<K, V>
        extends ListenerList<ObservableMapListener<K, V>>
        implements ObservableMapListener<K, V> {
        @Override
        public void valueAdded(ObservableMap<K, V> map, K key) {
            for (ObservableMapListener<K, V> listener : listeners()) {
                listener.valueAdded(map, key);
            }
        }

        @Override
        public void valueUpdated(ObservableMap<K, V> map, K key, V previousValue) {
            for (ObservableMapListener<K, V> listener : listeners()) {
                listener.valueUpdated(map, key, previousValue);
            }
        }

        @Override
        public void valueRemoved(ObservableMap<K, V> map, Object key, V value) {
            for (ObservableMapListener<K, V> listener : listeners()) {
                listener.valueRemoved(map, key, value);
            }
        }
    }

    public ListenerList<ObservableMapListener<K, V>> getObservableMapListeners();
}