| /* |
| * Copyright (C) 2014 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.databinding; |
| |
| /** |
| * Observable classes provide a way in which data bound UI can be notified of changes. |
| * {@link ObservableList} and {@link ObservableMap} also provide the ability to notify when |
| * changes occur. ObservableField, ObservableParcelable, ObservableBoolean, ObservableByte, |
| * ObservableShort, ObservableInt, ObservableLong, ObservableFloat, and ObservableDouble provide |
| * a means by which properties may be notified without implementing Observable. |
| * <p> |
| * An Observable object should notify the {@link OnPropertyChangedCallback} whenever |
| * an observed property of the class changes. |
| * <p> |
| * The getter for an observable property should be annotated with {@link Bindable}. |
| * <p> |
| * Convenience class BaseObservable implements this interface and PropertyChangeRegistry |
| * can help classes that don't extend BaseObservable to implement the listener registry. |
| */ |
| public interface Observable { |
| |
| /** |
| * Adds a callback to listen for changes to the Observable. |
| * @param callback The callback to start listening. |
| */ |
| void addOnPropertyChangedCallback(OnPropertyChangedCallback callback); |
| |
| /** |
| * Removes a callback from those listening for changes. |
| * @param callback The callback that should stop listening. |
| */ |
| void removeOnPropertyChangedCallback(OnPropertyChangedCallback callback); |
| |
| /** |
| * The callback that is called by Observable when an observable property has changed. |
| */ |
| abstract class OnPropertyChangedCallback { |
| |
| /** |
| * Called by an Observable whenever an observable property changes. |
| * @param sender The Observable that is changing. |
| * @param propertyId The BR identifier of the property that has changed. The getter |
| * for this property should be annotated with {@link Bindable}. |
| */ |
| public abstract void onPropertyChanged(Observable sender, int propertyId); |
| } |
| } |