com.liferay.portal.kernel.dao.search.SearchPaginationUtil.java Source code

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Here is the source code for com.liferay.portal.kernel.dao.search.SearchPaginationUtil.java

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/**
 * 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.portal.kernel.dao.search;

/**
 * @author Roberto Daz
 */
public class SearchPaginationUtil {

    public static int[] calculateStartAndEnd(int cur, int delta) {
        int start = 0;

        if (cur > 0) {
            start = (cur - 1) * delta;
        }

        int end = start + delta;

        return new int[] { start, end };
    }

    public static int[] calculateStartAndEnd(int start, int end, int total) {
        if (total <= 0) {
            return new int[] { 0, 0 };
        }

        int[] startAndEnd = { start, end };

        int delta = end - start;

        if (delta < 0) {
            return new int[] { 0, 0 };
        }

        while ((start > 0) && (start >= total)) {
            int cur = start / delta;

            startAndEnd = calculateStartAndEnd(cur, delta);

            start = startAndEnd[0];
        }

        end = startAndEnd[1];

        if (end > total) {
            startAndEnd[1] = total;
        }

        return startAndEnd;
    }

}