001    /**
002     *   GRANITE DATA SERVICES
003     *   Copyright (C) 2006-2013 GRANITE DATA SERVICES S.A.S.
004     *
005     *   This file is part of the Granite Data Services Platform.
006     *
007     *   Granite Data Services is free software; you can redistribute it and/or
008     *   modify it under the terms of the GNU Lesser General Public
009     *   License as published by the Free Software Foundation; either
010     *   version 2.1 of the License, or (at your option) any later version.
011     *
012     *   Granite Data Services is distributed in the hope that it will be useful,
013     *   but WITHOUT ANY WARRANTY; without even the implied warranty of
014     *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
015     *   General Public License for more details.
016     *
017     *   You should have received a copy of the GNU Lesser General Public
018     *   License along with this library; if not, write to the Free Software
019     *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
020     *   USA, or see <http://www.gnu.org/licenses/>.
021     */
022    package org.granite.spring.data;
023    
024    import java.lang.reflect.Field;
025    import java.lang.reflect.Type;
026    import java.util.ArrayList;
027    import java.util.List;
028    
029    import org.granite.messaging.amf.io.convert.Converter;
030    import org.granite.messaging.amf.io.convert.Converters;
031    import org.granite.messaging.amf.io.convert.Reverter;
032    import org.granite.tide.data.model.PageInfo;
033    import org.granite.tide.data.model.SortInfo;
034    import org.springframework.data.domain.Page;
035    import org.springframework.data.domain.Pageable;
036    import org.springframework.data.domain.Sort;
037    import org.springframework.data.domain.Sort.Direction;
038    import org.springframework.data.domain.Sort.Order;
039    
040    
041    public class PageableConverter extends Converter implements Reverter {
042            
043            public PageableConverter(Converters converters) {
044                    super(converters);
045            }
046    
047            @Override
048            protected boolean internalCanConvert(Object value, Type targetType) {
049                    return (value instanceof PageInfo && targetType.equals(Pageable.class))
050                            || (value instanceof SortInfo && targetType.equals(Sort.class));
051            }
052    
053            @Override
054            protected Object internalConvert(Object value, Type targetType) {
055                    if (targetType.equals(Pageable.class)) {
056                            PageInfo pageInfo = (PageInfo)value;
057                            Sort sort = null;
058                            if (pageInfo.getSortInfo() != null && pageInfo.getSortInfo().getOrder() != null && pageInfo.getSortInfo().getOrder().length > 0) {
059                                    List<Order> orders = new ArrayList<Order>(pageInfo.getSortInfo().getOrder().length);
060                                    for (int i = 0; i < pageInfo.getSortInfo().getOrder().length; i++)
061                                            orders.add(new Order(pageInfo.getSortInfo().getDesc()[i] ? Direction.DESC : Direction.ASC, pageInfo.getSortInfo().getOrder()[i]));                      
062                                    sort = new Sort(orders);                        
063                            }
064                            return new OffsetPageRequest(pageInfo.getFirstResult(), pageInfo.getMaxResults(), sort);
065                    }
066                    return null;
067            }
068    
069            public boolean canRevert(Object value) {
070                    return value instanceof Page;
071            }
072    
073            public Object revert(Object value) {
074                    @SuppressWarnings("unchecked")
075                    Page<Object> page = (Page<Object>)value;
076                    int offset = page.getNumber() * page.getSize();
077                    try {
078                            Field f = page.getClass().getDeclaredField("pageable");
079                            f.setAccessible(true);
080                            Pageable pageable = (Pageable)f.get(page);
081                            offset = pageable.getOffset();
082                    }
083                    catch (Exception e) {
084                    }
085                    return new org.granite.tide.data.model.Page<Object>(offset, page.getSize(), Long.valueOf(page.getTotalElements()).intValue(), page.getContent());
086            }
087    }