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 * ChartHints.java
029 * ---------------
030 * (C) Copyright 2014-present, by David Gilbert and Contributors.
031 *
032 * Original Author:  David Gilbert;
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 */
048public final class ChartHints {
049
050    private ChartHints() {
051        // no need to instantiate this    
052    }
053    
054    /**
055     * The key for a hint to signal the beginning of an element.  The value
056     * should be a string containing the element id or, alternatively, a Map 
057     * containing the 'id' (String) and 'ref' (String in JSON format).
058     */
059    public static final Key KEY_BEGIN_ELEMENT = new ChartHints.Key(0);
060    
061    /**
062     * The key for a hint that ends an element.
063     */
064    public static final Key KEY_END_ELEMENT = new ChartHints.Key(1);
065    
066    /**
067     * A key for rendering hints that can be used with JFreeChart (in 
068     * addition to the regular Java2D rendering hints).
069     */
070    public static class Key extends java.awt.RenderingHints.Key {
071
072        /**
073         * Creates a new key.
074         * 
075         * @param privateKey  the private key. 
076         */
077        public Key(int privateKey) {
078            super(privateKey);    
079        }
080    
081        /**
082         * Returns {@code true} if {@code val} is a value that is
083         * compatible with this key, and {@code false} otherwise.
084         * 
085         * @param val  the value.
086         * 
087         * @return A boolean. 
088         */
089        @Override
090        public boolean isCompatibleValue(Object val) {
091            switch (intKey()) {
092                case 0:
093                    return val == null || val instanceof String 
094                            || val instanceof Map;
095                case 1:
096                    return val == null || val instanceof Object;
097                default:
098                    throw new RuntimeException("Not possible!");
099            }
100        }
101    }
102    
103}