/*
* Copyright (C) 2015 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;
import java.util.List;
/**
* A {@link List} that notifies when changes are made. An ObservableList bound to the UI
* will keep the it up-to-date when changes occur.
* <p>
* The ObservableList must notify its callbacks whenever a change to the list occurs, using
* {@link OnListChangedCallback}.
* <p>
* ObservableArrayList implements ObservableList with an underlying ArrayList.
* ListChangeRegistry can help in maintaining the callbacks of other implementations.
*
* @see Observable
* @see ObservableMap
*/
public interface ObservableList<T> extends List<T> {
/**
* Adds a callback to be notified when changes to the list occur.
* @param callback The callback to be notified on list changes
*/
void addOnListChangedCallback(OnListChangedCallback<? extends ObservableList<T>> callback);
/**
* Removes a callback previously added.
* @param callback The callback to remove.
*/
void removeOnListChangedCallback(OnListChangedCallback<? extends ObservableList<T>> callback);
/**
* The callback that is called by ObservableList when the list has changed.
*/
abstract class OnListChangedCallback<T extends ObservableList> {
/**
* Called whenever a change of unknown type has occurred, such as the entire list being
* set to new values.
*
* @param sender The changing list.
*/
public abstract void onChanged(T sender);
/**
* Called whenever one or more items in the list have changed.
* @param sender The changing list.
* @param positionStart The starting index that has changed.
* @param itemCount The number of items that have changed.
*/
public abstract void onItemRangeChanged(T sender, int positionStart, int itemCount);
/**
* Called whenever items have been inserted into the list.
* @param sender The changing list.
* @param positionStart The insertion index
* @param itemCount The number of items that have been inserted
*/
public abstract void onItemRangeInserted(T sender, int positionStart, int itemCount);
/**
* Called whenever items in the list have been moved.
* @param sender The changing list.
* @param fromPosition The position from which the items were moved
* @param toPosition The destination position of the items
* @param itemCount The number of items moved
*/
public abstract void onItemRangeMoved(T sender, int fromPosition, int toPosition,
int itemCount);
/**
* Called whenever items in the list have been deleted.
* @param sender The changing list.
* @param positionStart The starting index of the deleted items.
* @param itemCount The number of items removed.
*/
public abstract void onItemRangeRemoved(T sender, int positionStart, int itemCount);
}
}