001    /* ===========================================================
002     * JFreeChart : a free chart library for the Java(tm) platform
003     * ===========================================================
004     *
005     * (C) Copyright 2000-2005, by Object Refinery Limited 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     * [Java is a trademark or registered trademark of Sun Microsystems, Inc. 
025     * in the United States and other countries.]
026     *
027     * -------------------
028     * TickUnitSource.java
029     * -------------------
030     * (C) Copyright 2003, 2004, by Object Refinery Limited.
031     *
032     * Original Author:  David Gilbert (for Object Refinery Limited);
033     * Contributor(s):   -;
034     *
035     * $Id: TickUnitSource.java,v 1.2.2.1 2005/10/25 20:37:34 mungady Exp $
036     *
037     * Changes
038     * -------
039     * 23-Sep-2003 : Version 1 (DG);
040     *
041     */
042    
043    package org.jfree.chart.axis;
044    
045    /**
046     * An interface used by the {@link DateAxis} and {@link NumberAxis} classes to 
047     * obtain a suitable {@link TickUnit}.
048     */
049    public interface TickUnitSource {
050    
051        /**
052         * Returns a tick unit that is larger than the supplied unit.
053         *
054         * @param unit   the unit.
055         *
056         * @return A tick unit that is larger than the supplied unit.
057         */
058        public TickUnit getLargerTickUnit(TickUnit unit);
059    
060        /**
061         * Returns the tick unit in the collection that is greater than or equal
062         * to (in size) the specified unit.
063         *
064         * @param unit  the unit.
065         *
066         * @return A unit from the collection.
067         */
068        public TickUnit getCeilingTickUnit(TickUnit unit);
069    
070        /**
071         * Returns the tick unit in the collection that is greater than or equal
072         * to the specified size.
073         *
074         * @param size  the size.
075         *
076         * @return A unit from the collection.
077         */
078        public TickUnit getCeilingTickUnit(double size);
079        
080    }