DirectorySelectItemComparator.java

/*
 * (C) Copyright 2006-2007 Nuxeo SAS (http://nuxeo.com/) and contributors.
 *
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the GNU Lesser General Public License
 * (LGPL) version 2.1 which accompanies this distribution, and is available at
 * http://www.gnu.org/licenses/lgpl.html
 *
 * This library is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 * Lesser General Public License for more details.
 *
 * Contributors:
 *     Nuxeo - initial API and implementation
 *
 * $Id$
 */

package org.nuxeo.ecm.platform.ui.web.directory;

import java.io.Serializable;
import java.text.Collator;
import java.util.Comparator;
import java.util.Locale;

import javax.faces.context.FacesContext;

import org.apache.commons.lang.StringUtils;

/**
 * @author <a href="mailto:glefter@nuxeo.com">George Lefter</a>
 */
public class DirectorySelectItemComparator implements
        Comparator<DirectorySelectItem>, Serializable {

    private static final long serialVersionUID = 1L;

    private final String[] ordering;

    private Boolean caseSensitive;

    private Collator collator;

    private Locale locale;

    public DirectorySelectItemComparator(String ordering,
            Boolean caseSensitive, Locale locale) {
        this.ordering = StringUtils.split(ordering, ",");
        this.caseSensitive = caseSensitive;
        if (locale == null) {
            FacesContext context = FacesContext.getCurrentInstance();
            this.locale = context.getViewRoot().getLocale();
        } else {
            this.locale = locale;
        }
        collator = Collator.getInstance(this.locale);
        if (Boolean.TRUE.equals(this.caseSensitive)) {
            collator.setStrength(Collator.TERTIARY); // TERTIARY will make a
                                                     // difference between 'a'
                                                     // and 'A'
        } else {
            collator.setStrength(Collator.SECONDARY);
        }
    }

    public DirectorySelectItemComparator(String ordering, Boolean caseSentitive) {
        this(ordering, caseSentitive, null);
    }

    public DirectorySelectItemComparator(String ordering) {
        this(ordering, Boolean.FALSE);
    }

    protected int compareField(String field, DirectorySelectItem item1,
            DirectorySelectItem item2) {
        if ("label".equals(field)) {
            String label1 = item1.getLabel();
            String label2 = item2.getLabel();
            return collator.compare(label1, label2);
        } else if ("id".equals(field)) {
            String value1 = String.valueOf(item1.getValue());
            String value2 = String.valueOf(item2.getValue());
            // TODO: maybe deal with numbers comparisons (?)
            return collator.compare(value1, value2);
        } else if ("ordering".equals(field)) {
            long orderItem1 = item1.getOrdering();
            long orderItem2 = item2.getOrdering();
            return Long.valueOf(orderItem1).compareTo(Long.valueOf(orderItem2));
        } else {
            throw new RuntimeException("Invalid sort criteria " + field);
        }
    }

    public int compare(DirectorySelectItem item1, DirectorySelectItem item2) {
        for (String field : ordering) {
            int compare = compareField(field, item1, item2);
            if (compare != 0) {
                return compare;
            }
        }
        return 0;
    }

}