1 /**
2 * This file Copyright (c) 2009-2016 Magnolia International
3 * Ltd. (http://www.magnolia-cms.com). All rights reserved.
4 *
5 *
6 * This file is dual-licensed under both the Magnolia
7 * Network Agreement and the GNU General Public License.
8 * You may elect to use one or the other of these licenses.
9 *
10 * This file is distributed in the hope that it will be
11 * useful, but AS-IS and WITHOUT ANY WARRANTY; without even the
12 * implied warranty of MERCHANTABILITY or FITNESS FOR A
13 * PARTICULAR PURPOSE, TITLE, or NONINFRINGEMENT.
14 * Redistribution, except as permitted by whichever of the GPL
15 * or MNA you select, is prohibited.
16 *
17 * 1. For the GPL license (GPL), you can redistribute and/or
18 * modify this file under the terms of the GNU General
19 * Public License, Version 3, as published by the Free Software
20 * Foundation. You should have received a copy of the GNU
21 * General Public License, Version 3 along with this program;
22 * if not, write to the Free Software Foundation, Inc., 51
23 * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
24 *
25 * 2. For the Magnolia Network Agreement (MNA), this file
26 * and the accompanying materials are made available under the
27 * terms of the MNA which accompanies this distribution, and
28 * is available at http://www.magnolia-cms.com/mna.html
29 *
30 * Any modifications to this file must keep this entire header
31 * intact.
32 *
33 */
34 package info.magnolia.imaging.util;
35
36 import java.awt.Color;
37 import java.lang.reflect.Field;
38 import java.lang.reflect.Modifier;
39 import java.util.Map;
40 import java.util.TreeMap;
41
42 /**
43 * A class that is able to convert java.lang.String instances to java.awt.Color instances.
44 * It recognizes multiple String representations, such as named colors (using the {@link java.awt.Color} constants),
45 * hexadecimal.
46 *
47 * TODO -- "r:100,g:100,b:100,a:80", "100, 100, 100, 80", ...
48 * TODO - and vice-versa.
49 */
50 public class ColorConverter {
51 private static final Map<String, Color> namedColors = reflectivelyGetNamedColors();
52
53 public static Color toColor(String s) {
54 if (namedColors.containsKey(s)) {
55 return namedColors.get(s);
56 } else if (s.startsWith("#")) {
57 return Color.decode(s);
58 } else {
59 throw new IllegalArgumentException("Can't decode color: " + s + ". Please provide either an #ffffff hexadecimal value or a known named color.");
60 }
61 }
62
63 /**
64 * Using reflection, gather all fields of java.awt.Color that are
65 * static, public, final and of type java.awt.Color, and put them
66 * in them in a case-insensitive Map.
67 * Since we've already loaded the java.awt.Color, there is virtually
68 * no hit on performance or memory usage, except for this very small
69 * map.
70 * Yes, this is a bit ugly, since we're relying on how those constants
71 * are declared ... but it is not very likely to change, is it ?
72 */
73 private static Map<String, Color> reflectivelyGetNamedColors() {
74 try {
75 final Map<String, Color> namedColors = new TreeMap<String, Color>(String.CASE_INSENSITIVE_ORDER);
76 final Field[] fields = Color.class.getFields();
77 for (final Field field : fields) {
78 int mod = field.getModifiers();
79 if (Modifier.isStatic(mod) && Modifier.isPublic(mod) && Modifier.isFinal(mod)) {
80 if (Color.class.equals(field.getType())) {
81 namedColors.put(field.getName(), (Color) field.get(null));
82 }
83 }
84 }
85 return namedColors;
86 } catch (IllegalAccessException e) {
87 throw new RuntimeException("Can't access field values of java.awt.Color, is this system too secure?", e);
88 }
89 }
90 }