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.io.Serializable; 19 20 /** 21 * An object wrapper to make it observable. 22 * <p> 23 * Observable field classes may be used instead of creating an Observable object: 24 * <pre><code>public class MyDataObject { 25 * public final ObservableField<String> name = new ObservableField<String>(); 26 * public final ObservableInt age = new ObservableInt(); 27 * }</code></pre> 28 * Fields of this type should be declared final because bindings only detect changes in the 29 * field's value, not of the field itself. 30 * 31 * @param <T> The type parameter for the actual object. 32 * @see android.databinding.ObservableParcelable 33 */ 34 public class ObservableField<T> extends BaseObservable implements Serializable { 35 static final long serialVersionUID = 1L; 36 private T mValue; 37 38 /** 39 * Wraps the given object and creates an observable object 40 * 41 * @param value The value to be wrapped as an observable. 42 */ 43 public ObservableField(T value) { 44 mValue = value; 45 } 46 47 /** 48 * Creates an empty observable object 49 */ 50 public ObservableField() { 51 } 52 53 /** 54 * @return the stored value. 55 */ 56 public T get() { 57 return mValue; 58 } 59 60 /** 61 * Set the stored value. 62 */ 63 public void set(T value) { 64 if (value != mValue) { 65 mValue = value; 66 notifyChange(); 67 } 68 } 69 } 70
