processtreerowscallback.java

exTreme taglib的使用

/*
 * Copyright 2004 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.extremecomponents.table.callback;

import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Iterator;
import java.util.List;

import org.apache.commons.beanutils.BeanComparator;
import org.apache.commons.collections.CollectionUtils;
import org.apache.commons.collections.comparators.NullComparator;
import org.apache.commons.collections.comparators.ReverseComparator;
import org.extremecomponents.table.bean.TreeNode;
import org.extremecomponents.table.core.BaseModel;
import org.extremecomponents.table.core.TableConstants;
import org.extremecomponents.table.core.TreeModelUtils;
import org.extremecomponents.table.limit.Sort;

/**
 * @author phorn
 */
public final class ProcessTreeRowsCallback implements FilterRowsCallback, SortRowsCallback {
    public Collection filterRows(BaseModel model, Collection rows)
            throws Exception {
        List results = new ArrayList();
        FilterPredicate filterPredicate = new FilterPredicate(model);
        CollectionUtils.select(rows, filterPredicate, results);

        // Add back the parents
        for (int i = 0; i < results.size(); i++) {
            Object bean = results.get(i);
            TreeModelUtils.findBeanParents(model, rows, results, bean);
        }

        return results;
    }

    public Collection sortRows(BaseModel model, Collection rows)
            throws Exception {
        List parents = new ArrayList();
        for (Iterator iter = rows.iterator(); iter.hasNext();) {
            TreeNode node = (TreeNode) iter.next();
            if (node.getParent() == null)
                parents.add(node);
        }

        List output = new ArrayList();
        Sort sort = model.getLimit().getSort();
        String property = sort.getProperty();
        String sortOrder = sort.getSortOrder();
        subSort(parents, property, sortOrder); // First sort the parents
        recursiveSort(output, parents, property, sortOrder);

        output.retainAll(rows); // Only keep the original nodes
        rows.clear();
        rows.addAll(output);

        return rows;
    }

    private void recursiveSort(List output, List rows, String property, String sortOrder) {
        for (Iterator iter = rows.iterator(); iter.hasNext();) {
            TreeNode node = (TreeNode) iter.next();

            output.add(node);

            if (node.getChildren() != null && node.getChildren().size() > 0) {
                subSort(node.getChildren(), property, sortOrder);
                recursiveSort(output, node.getChildren(), property, sortOrder);
            }
        }
    }

    private void subSort(List rows, String property, String sortOrder) {
        if (sortOrder.equals(TableConstants.SORT_ASC)) {
            BeanComparator comparator = new BeanComparator(property, new NullComparator());
            Collections.sort(rows, comparator);
        } else if (sortOrder.equals(TableConstants.SORT_DESC)) {
            BeanComparator reversedNaturalOrderBeanComparator = new BeanComparator(property, new ReverseComparator(
                    new NullComparator()));
            Collections.sort(rows, reversedNaturalOrderBeanComparator);
        }
    }
}