001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2013, 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 * [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 * DialScale.java
029 * --------------
030 * (C) Copyright 2006-2008, by Object Refinery Limited.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 * Changes
036 * -------
037 * 03-Nov-2006 : Version 1 (DG);
038 * 17-Oct-2007 : Made this an extension of the DialLayer interface (DG);
039 *
040 */
041
042package org.jfree.chart.plot.dial;
043
044/**
045 * A dial scale is a specialised layer that has the ability to convert data
046 * values into angles.
047 *
048 * @since 1.0.7
049 */
050public interface DialScale extends DialLayer {
051
052    /**
053     * Converts a data value to an angle (in degrees, using the same
054     * specification as Java's Arc2D class).
055     *
056     * @param value  the data value.
057     *
058     * @return The angle in degrees.
059     *
060     * @see #angleToValue(double)
061     */
062    public double valueToAngle(double value);
063
064    /**
065     * Converts an angle (in degrees) to a data value.
066     *
067     * @param angle  the angle (in degrees).
068     *
069     * @return The data value.
070     *
071     * @see #valueToAngle(double)
072     */
073    public double angleToValue(double angle);
074
075}