1 /* 2 * Copyright (C) 2015 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 package android.databinding; 17 18 import java.util.Map; 19 20 /** 21 * A {@link Map} that notifies when items change. This kind of Map may be data bound 22 * and have the UI update as the map changes. 23 * <p> 24 * Implementers must call {@link OnMapChangedCallback#onMapChanged(ObservableMap, Object)} whenever 25 * an item is added, changed, or removed. 26 * <p> 27 * ObservableArrayMap is a convenient implementation of ObservableMap. 28 * MapChangeRegistry may help other implementations manage the callbacks. 29 * @see Observable 30 * @see ObservableList 31 */ 32 public interface ObservableMap<K, V> extends Map<K, V> { 33 34 /** 35 * Adds a callback to listen for changes to the ObservableMap. 36 * @param callback The callback to start listening for events. 37 */ addOnMapChangedCallback( OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> callback)38 void addOnMapChangedCallback( 39 OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> callback); 40 41 /** 42 * Removes a previously added callback. 43 * @param callback The callback that no longer needs to be notified of map changes. 44 */ removeOnMapChangedCallback( OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> callback)45 void removeOnMapChangedCallback( 46 OnMapChangedCallback<? extends ObservableMap<K, V>, K, V> callback); 47 48 /** 49 * A callback receiving notifications when an ObservableMap changes. 50 */ 51 abstract class OnMapChangedCallback<T extends ObservableMap<K, V>, K, V> { 52 53 /** 54 * Called whenever an ObservableMap changes, including values inserted, deleted, 55 * and changed. 56 * @param sender The changing map. 57 * @param key The key of the value inserted, removed, or changed. 58 */ onMapChanged(T sender, K key)59 public abstract void onMapChanged(T sender, K key); 60 } 61 } 62