001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-present, by David Gilbert and Contributors.
006 *
007 * Project Info:  http://www.jfree.org/jfreechart/index.html
008 *
009 * This library is free software; you can redistribute it and/or modify it
010 * under the terms of the GNU Lesser General Public License as published by
011 * the Free Software Foundation; either version 2.1 of the License, or
012 * (at your option) any later version.
013 *
014 * This library is distributed in the hope that it will be useful, but
015 * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
016 * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
017 * License for more details.
018 *
019 * You should have received a copy of the GNU Lesser General Public
020 * License along with this library; if not, write to the Free Software
021 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
022 * USA.
023 *
024 * [Oracle and Java are registered trademarks of Oracle and/or its affiliates. 
025 * Other names may be trademarks of their respective owners.]
026 *
027 * -------------------
028 * TickUnitSource.java
029 * -------------------
030 * (C) Copyright 2003-present, by David Gilbert.
031 *
032 * Original Author:  David Gilbert;
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart.axis;
038
039/**
040 * An interface used by the {@link DateAxis} and {@link NumberAxis} classes to
041 * obtain a suitable {@link TickUnit}.
042 */
043public interface TickUnitSource {
044
045    /**
046     * Returns the smallest tick unit available in the source that is larger
047     * than {@code unit} or, if there is no larger unit, returns {@code unit}.
048     *
049     * @param unit  the unit ({@code null} not permitted).
050     *
051     * @return A tick unit that is larger than the supplied unit.
052     */
053    TickUnit getLargerTickUnit(TickUnit unit);
054
055    /**
056     * Returns the tick unit in the collection that is greater than or equal
057     * to (in size) the specified unit.
058     *
059     * @param unit  the unit.
060     *
061     * @return A unit from the collection.
062     */
063    TickUnit getCeilingTickUnit(TickUnit unit);
064
065    /**
066     * Returns the smallest tick unit available in the source that is greater 
067     * than or equal to the specified size.  If there is no such tick unit,
068     * the method should return the largest available tick in the source.
069     *
070     * @param size  the size.
071     *
072     * @return A unit from the collection (never {@code null}).
073     */
074    TickUnit getCeilingTickUnit(double size);
075
076}