/*
* 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.wicket.markup.repeater.data;
import java.io.Serializable;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;
import org.apache.wicket.model.IModel;
import org.apache.wicket.model.Model;
/**
* Allows the use of lists with {@link DataView}. The only requirement is that either list items
* must be serializable or model(Object) needs to be overridden to provide the proper model
* implementation.
*
* @author Igor Vaynberg ( ivaynberg )
* @param <T>
*
*/
public class ListDataProvider<T extends Serializable> implements IDataProvider<T>
{
private static final long serialVersionUID = 1L;
/** reference to the list used as dataprovider for the dataview */
private final List<T> list;
/**
* Constructs an empty provider. Useful for lazy loading together with {@linkplain #getData()}
*/
public ListDataProvider()
{
this(Collections.<T> emptyList());
}
/**
*
* @param list
* the list used as dataprovider for the dataview
*/
public ListDataProvider(List<T> list)
{
if (list == null)
{
throw new IllegalArgumentException("argument [list] cannot be null");
}
this.list = list;
}
/**
* Subclass to lazy load the list
*
* @return The list
*/
protected List<T> getData()
{
return list;
}
@Override
public Iterator<T> iterator(final long first, final long count)
{
List<T> list = getData();
long toIndex = first + count;
if (toIndex > list.size())
{
toIndex = list.size();
}
return list.subList((int)first, (int)toIndex).listIterator();
}
@Override
public long size()
{
return getData().size();
}
@Override
public IModel<T> model(T object)
{
return new Model<>(object);
}
}