KBObjectsPriorityComparator.java

/**
 * Copyright (c) 2000-present Liferay, Inc. All rights reserved.
 *
 * This library is free software; you can redistribute it and/or modify it under
 * the terms of the GNU Lesser General Public License as published by the Free
 * Software Foundation; either version 2.1 of the License, or (at your option)
 * any later version.
 *
 * 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.
 */

package com.liferay.knowledge.base.util.comparator;

import com.liferay.knowledge.base.model.KBArticle;
import com.liferay.knowledge.base.model.KBFolder;
import com.liferay.portal.kernel.util.OrderByComparator;

/**
 * @author Roberto Díaz
 */
public class KBObjectsPriorityComparator<T> extends OrderByComparator<T> {

	public static final String ORDER_BY_ASC =
		"modelFolder DESC, priority ASC, title ASC";

	public static final String ORDER_BY_DESC =
		"modelFolder DESC, priority DESC, title ASC";

	public static final String[] ORDER_BY_FIELDS = {"priority", "title"};

	public KBObjectsPriorityComparator() {
		this(false);
	}

	public KBObjectsPriorityComparator(boolean ascending) {
		_ascending = ascending;
	}

	@Override
	public int compare(T t1, T t2) {
		int value = 0;

		double priority1 = getPriority(t1);
		double priority2 = getPriority(t2);

		String title1 = getTitle(t1);
		String title2 = getTitle(t1);

		if ((t1 instanceof KBFolder) && (t2 instanceof KBFolder)) {
			value = title1.compareToIgnoreCase(title2);
		}
		else if (t1 instanceof KBFolder) {
			value = -1;
		}
		else if (t2 instanceof KBFolder) {
			value = 1;
		}
		else {
			if (priority1 < priority2) {
				value = -1;
			}
			else if (priority1 > priority2) {
				value = 1;
			}
			else {
				value = title1.compareToIgnoreCase(title2);
			}
		}

		if (_ascending) {
			return value;
		}
		else {
			return -value;
		}
	}

	@Override
	public String getOrderBy() {
		if (_ascending) {
			return ORDER_BY_ASC;
		}
		else {
			return ORDER_BY_DESC;
		}
	}

	@Override
	public String[] getOrderByFields() {
		return ORDER_BY_FIELDS;
	}

	@Override
	public boolean isAscending() {
		return _ascending;
	}

	protected double getPriority(Object obj) {
		if (obj instanceof KBArticle) {
			KBArticle kbArticle = (KBArticle)obj;

			return kbArticle.getPriority();
		}
		else {
			return 0.0;
		}
	}

	protected String getTitle(Object obj) {
		if (obj instanceof KBArticle) {
			KBArticle kbArticle = (KBArticle)obj;

			return kbArticle.getTitle();
		}
		else {
			KBFolder kbFolder = (KBFolder)obj;

			return kbFolder.getName();
		}
	}

	private final boolean _ascending;

}