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1   /*
2    * Copyright (c) 2002-2025 Gargoyle Software Inc.
3    *
4    * Licensed under the Apache License, Version 2.0 (the "License");
5    * you may not use this file except in compliance with the License.
6    * You may obtain a copy of the License at
7    * https://www.apache.org/licenses/LICENSE-2.0
8    *
9    * Unless required by applicable law or agreed to in writing, software
10   * distributed under the License is distributed on an "AS IS" BASIS,
11   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12   * See the License for the specific language governing permissions and
13   * limitations under the License.
14   */
15  package org.htmlunit.css;
16  
17  import java.util.Locale;
18  import java.util.Map;
19  import java.util.concurrent.ConcurrentHashMap;
20  
21  /**
22   * Helper to work with colors.
23   *
24   * @author Ronald Brill
25   */
26  public final class CssColors {
27  
28      private static final Map<String, String> CSS_COLORS = new ConcurrentHashMap<>();
29  
30      static {
31          CSS_COLORS.put("aqua", "rgb(0, 255, 255)");
32          CSS_COLORS.put("black", "rgb(0, 0, 0)");
33          CSS_COLORS.put("blue", "rgb(0, 0, 255)");
34          CSS_COLORS.put("fuchsia", "rgb(255, 0, 255)");
35          CSS_COLORS.put("gray", "rgb(128, 128, 128)");
36          CSS_COLORS.put("green", "rgb(0, 128, 0)");
37          CSS_COLORS.put("lime", "rgb(0, 255, 0)");
38          CSS_COLORS.put("maroon", "rgb(128, 0, 0)");
39          CSS_COLORS.put("navy", "rgb(0, 0, 128)");
40          CSS_COLORS.put("olive", "rgb(128, 128, 0)");
41          CSS_COLORS.put("purple", "rgb(128, 0, 128)");
42          CSS_COLORS.put("red", "rgb(255, 0, 0)");
43          CSS_COLORS.put("silver", "rgb(192, 192, 192)");
44          CSS_COLORS.put("teal", "rgb(0, 128, 128)");
45          CSS_COLORS.put("white", "rgb(255, 255, 255)");
46          CSS_COLORS.put("yellow", "rgb(255, 255, 0)");
47      }
48  
49      private CssColors() {
50          // util class
51      }
52  
53      /**
54       * Returns if the specified token is a reserved color keyword.
55       * @param token the token to check
56       * @return whether the token is a reserved color keyword or not
57       */
58      public static boolean isColorKeyword(final String token) {
59          return CSS_COLORS.containsKey(token.toLowerCase(Locale.ROOT));
60      }
61  
62      /**
63       * Gets the RGB equivalent of a CSS color if the provided color is recognized.
64       * @param color the color
65       * @return the provided color if this is not a recognized color keyword, the RGB value
66       *         in the form "rgb(x, y, z)" otherwise
67       */
68      public static String toRGBColor(final String color) {
69          final String rgbValue = CSS_COLORS.get(color.toLowerCase(Locale.ROOT));
70          if (rgbValue != null) {
71              return rgbValue;
72          }
73          return color;
74      }
75  }