001/* ===========================================================
002 * JFreeChart : a free chart library for the Java(tm) platform
003 * ===========================================================
004 *
005 * (C) Copyright 2000-2020, 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 * ChartHints.java
029 * ---------------
030 * (C) Copyright 2014-2020, by Object Refinery Limited and Contributors.
031 *
032 * Original Author:  David Gilbert (for Object Refinery Limited);
033 * Contributor(s):   -;
034 *
035 */
036
037package org.jfree.chart;
038
039import java.util.Map;
040
041/**
042 * Special rendering hints that can be used internally by JFreeChart or by
043 * specialised implementations of the {@code Graphics2D} API.  For example,
044 * JFreeSVG's {@code SVGGraphics2D} class, will use the 
045 * {@code KEY_BEGIN_ELEMENT} and {@code KEY_END_ELEMENT} hints to drive the 
046 * output content.
047 * 
048 * @since 1.0.18
049 */
050public final class ChartHints {
051
052    private ChartHints() {
053        // no need to instantiate this    
054    }
055    
056    /**
057     * The key for a hint to signal the beginning of an element.  The value
058     * should be a string containing the element id or, alternatively, a Map 
059     * containing the 'id' (String) and 'ref' (String in JSON format).
060     */
061    public static final Key KEY_BEGIN_ELEMENT = new ChartHints.Key(0);
062    
063    /**
064     * The key for a hint that ends an element.
065     */
066    public static final Key KEY_END_ELEMENT = new ChartHints.Key(1);
067    
068    /**
069     * A key for rendering hints that can be used with JFreeChart (in 
070     * addition to the regular Java2D rendering hints).
071     */
072    public static class Key extends java.awt.RenderingHints.Key {
073
074        /**
075         * Creates a new key.
076         * 
077         * @param privateKey  the private key. 
078         */
079        public Key(int privateKey) {
080            super(privateKey);    
081        }
082    
083        /**
084         * Returns {@code true} if {@code val} is a value that is
085         * compatible with this key, and {@code false} otherwise.
086         * 
087         * @param val  the value.
088         * 
089         * @return A boolean. 
090         */
091        @Override
092        public boolean isCompatibleValue(Object val) {
093            switch (intKey()) {
094                case 0:
095                    return val == null || val instanceof String 
096                            || val instanceof Map;
097                case 1:
098                    return val == null || val instanceof Object;
099                default:
100                    throw new RuntimeException("Not possible!");
101            }
102        }
103    }
104    
105}