/*
* Copyright 2002-2010 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 org.jdal.dao;
import java.io.Serializable;
import java.util.ArrayList;
import java.util.List;
import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
/**
* A Page of Objects as result of query on PaginableDataSource
* Holds results for a page and info of Page definition page size and order.
*
* @author Jose Luis Martin - (jlm@joseluismartin.info)
*/
@SuppressWarnings("unchecked")
public class Page<T> implements Paginator, Cloneable, Serializable {
private static final Log log = LogFactory.getLog(Page.class);
public static enum Order { ASC, DESC };
/** List of results */
private List<T> data = new ArrayList<T>();
/** Result count, Not the page size, the count of all result if not paginated */
private int count;
/** the page size */
private int pageSize;
/** sort by this property name */
private String sortName;
/** sort order */
private Order order;
/** a Object used as filter */
private Object filter;
/** page number */
private int page = 1;
/** PageableDataSource that loads the page */
private transient PageableDataSource<?> pageableDataSource;
/** Paginator Listeners */
private ArrayList<PaginatorListener> listeners = new ArrayList<PaginatorListener>();
public Page(int pageSize, int page, String sortName, Order order) {
this.pageSize = pageSize;
if (page > 0)
this.page = page;
this.sortName = sortName;
this.order = order;
}
public Page(int pageSize, int page, String sortName) {
this(pageSize, page, sortName, Order.ASC);
}
public Page(int pageSize, int page) {
this(pageSize, page, null);
}
public Page(int pageSize) {
this (pageSize, 1);
}
public Page() {
this (10);
}
/**
* @return list of data objects
*/
public List<T> getData() {
return data;
}
/**
* @return the count
*/
public int getCount() {
return count;
}
/**
* @param count the count to set
*/
public void setCount(int count) {
this.count = count;
}
/**
* @return the sortName
*/
public String getSortName() {
return sortName;
}
/**
* @param sortName the sortName to set
*/
public void setSortName(String sortName) {
this.sortName = sortName;
}
/**
* @return the order
*/
public Order getOrder() {
return order;
}
/**
* @param order the order to set
*/
public void setOrder(Order order) {
this.order = order;
}
/**
* @param data the data to set
*/
public void setData(List<T> data) {
this.data = data;
}
public void setOrderAsc() {
setOrder(Order.ASC);
}
public void setOrderDesc() {
setOrder(Order.DESC);
}
/**
* @return the filter
*/
public Object getFilter() {
return filter;
}
/**
* @param filter the filter to set
*/
public void setFilter(Object filter) {
this.filter = filter;
}
public Page<T> clone() {
try {
return (Page<T>) super.clone();
} catch (CloneNotSupportedException e) {
log.error(e);
return null;
}
}
/**
* @return the pageableDataSource
*/
public PageableDataSource<?> getPageableDataSource() {
return pageableDataSource;
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#hasNext()
*/
public boolean hasNext() {
return page < getTotalPages();
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#hasPage(int)
*/
public boolean hasPage(int indexPage) {
return indexPage <= getTotalPages() && indexPage > 0;
}
/**
* {@inheritDoc}
*/
public boolean hasPrevious() {
return page > 1;
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#setPage(int)
*/
public void setPage(int indexPage) {
if (indexPage > 0) {
page = indexPage;
load();
firePageChangedEvent();
}
else {
log.warn("Try to set a page < 1");
}
}
/**
* {@inheritDoc}
*/
public int getStartIndex() {
return (page - 1) * pageSize;
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#getTotalPages()
*/
public int getTotalPages() {
if (pageSize > 0)
return (int) Math.ceil(count/pageSize) + (count % pageSize == 0 ? 0 : 1);
return 1;
}
/**
* {@inheritDoc}
*/
public void addPaginatorListener(PaginatorListener listener) {
if (!listeners.contains(listener))
listeners.add(listener);
}
/**
* {@inheritDoc}
*/
public void removePaginatorListener(PaginatorListener listener) {
listeners.remove(listener);
}
/**
* @return the pageSize
*/
public int getPageSize() {
return pageSize;
}
/**
* @param pageSize the pageSize to set
*/
public void setPageSize(int pageSize) {
if (pageSize > 0) {
// need to recalculate current page
page = (int) Math.ceil(getStartIndex()/pageSize) + 1;
this.pageSize = pageSize;
load();
firePageChangedEvent();
}
}
/**
* @return the page
*/
public int getPage() {
return page;
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#firstPage()
*/
public void firstPage() {
setPage(1);
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#lastPage()
*/
public void lastPage() {
setPage(getTotalPages());
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#nextPage()
*/
public void nextPage() {
setPage(page + 1);
}
/**
* {@inheritDoc}
* @see org.jdal.dao.Paginator#previousPage()
*/
public void previousPage() {
setPage(page - 1);
}
/**
* Notify Listener that current page changed
*/
private void firePageChangedEvent() {
for (PaginatorListener listener : listeners) {
listener.pageChanged(new PageChangedEvent(this, page, getStartIndex(), getTotalPages(), pageSize));
}
}
public void load() {
if (pageableDataSource != null) {
Page<T> newPage = pageableDataSource.getPage(this);
this.data = newPage.data;
}
}
/**
* @param pageableDataSource the pageableDataSource to set
*/
public void setPageableDataSource(PageableDataSource<?> pageableDataSource) {
this.pageableDataSource = pageableDataSource;
}
}