info.joseluismartin.vaadin.data.IndexedItemIdStrategy Maven / Gradle / Ivy
/*
* Copyright 2009-2011 the original author or authors.
*
* 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 info.joseluismartin.vaadin.data;
import java.util.Collection;
import java.util.Collections;
import java.util.LinkedList;
import com.vaadin.data.Item;
import com.vaadin.data.Container.ItemSetChangeEvent;
/**
* Indexed ItemIdStragy use the index on the item in container as itemId.
* The itemId of a item will change when filtering, sorting, adding or removing items.
* If this is not a trouble, this is the faster ItemIdStrategy to use.
*
* @author Jose Luis Martin - ([email protected])
*/
public class IndexedItemIdStrategy implements ItemIdStrategy {
private ContainerDataSource containerDataSource;
/**
* {@inheritDoc}
*/
public Object firstItemId() {
return containerDataSource.size() > 0 ? 0 : null;
}
/**
* Test for first itemId
* @param itemId the itemId
* @return true is itemId is the first
*/
public boolean isFirstId(Object itemId) {
if (itemId instanceof Integer && containerDataSource.size() > 0)
return ((Integer) itemId) == 0;
return false;
}
/**
* Test for last itemId
* @param itemId the itemId
* @return true if the itemId is the last
*/
public boolean isLastId(Object itemId) {
if (itemId instanceof Integer && containerDataSource.size() > 0)
return ((Integer) itemId) == containerDataSource.size() - 1;
return false;
}
/**
* {@inheritDoc}
*/
public Object lastItemId() {
return containerDataSource.size() > 0 ? containerDataSource.size() -1 : null;
}
/**
* Return the next itemId
* @param itemId the itemId
* @return the next itemId
*/
public Object nextItemId(Object itemId) {
if (itemId instanceof Integer) {
return ((Integer) itemId) <= containerDataSource.size() ? ((Integer) itemId) + 1 : null;
}
return null;
}
/**
* Gets the previous itemId
* @param itemId
*/
public Object prevItemId(Object itemId) {
if (itemId instanceof Integer) {
return ((Integer) itemId) > 0 ? ((Integer) itemId) - 1 : null;
}
return null;
}
/**
* {@inheritDoc}
*/
public Collection getItemIds() {
LinkedList ids = new LinkedList();
for (int i = 0; i < containerDataSource.size(); i++) {
ids.add(i);
}
return Collections.unmodifiableCollection(ids);
}
/**
* {@inheritDoc}
*/
public int indexOfId(Object itemId) {
return (Integer) itemId;
}
/**
* {@inheritDoc}
*/
public Object getIdByIndex(int index) {
return index;
}
/**
* {@inheritDoc}
*/
public void setContainerDataSource(ContainerDataSource containerDataSource) {
this.containerDataSource = containerDataSource;
}
/**
* {@inheritDoc}
*/
public void itemLoaded(int index, Item item) {
}
/**
* {@inheritDoc}
*/
public void containerItemSetChange(ItemSetChangeEvent event) {
}
}