001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements. See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership. The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License. You may obtain a copy of the License at
009 *
010 * https://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied. See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.commons.beanutils2.converters;
020
021import java.awt.Color;
022import java.util.Objects;
023import java.util.regex.Matcher;
024import java.util.regex.Pattern;
025
026/**
027 * {@link org.apache.commons.beanutils2.Converter} implementation that handles conversion to and from {@link Color}.
028 *
029 * <p>
030 * Will interpret hexadecimal colors similar to CSS engines, for example #RGB is interpreted as #RRGGBB. If using the literal hexadecimal value is desired, the
031 * value should be prefixed with {@code 0x} instead of {@link #HEX_COLOR_PREFIX #}.
032 * </p>
033 *
034 * @since 2.0.0
035 */
036public class ColorConverter extends AbstractConverter<Color> {
037
038    /** Prefix for hexadecimal color notation. */
039    private static final String HEX_COLOR_PREFIX = "#";
040
041    /** Regular expression matching the output of {@link Color#toString()}. */
042    private static final Pattern JAVA_COLOR_PATTERN = Pattern.compile("^(?:[A-Za-z\\d._]+)??\\[?(?:r=)?(\\d{1,3}),(?:g=)?(\\d{1,3}),(?:b=)?(\\d{1,3})\\]?$");
043
044    /**
045     * Construct a <strong>{@link Color}</strong> <em>Converter</em> that throws a {@code ConversionException} if an error occurs.
046     */
047    public ColorConverter() {
048    }
049
050    /**
051     * Constructs a {@link org.apache.commons.beanutils2.Converter} that will return the specified default value if a conversion error occurs.
052     *
053     * @param defaultValue The default value to be returned if the value to be converted is missing or an error occurs converting the value.
054     */
055    public ColorConverter(final Color defaultValue) {
056        super(defaultValue);
057    }
058
059    /**
060     * Converts a {@link Color} into a {@link String}.
061     *
062     * <p>
063     * Supports hexadecimal colors like #RGB, #RRGGBB, #RGBA, and #RRGGBBAA, and interprets raw color names based on the colors defined in Java, such as:
064     * </p>
065     *
066     * <ul>
067     * <li>{@link Color#BLACK}</li>
068     * <li>{@link Color#BLUE}</li>
069     * <li>{@link Color#CYAN}</li>
070     * <li>{@link Color#DARK_GRAY}</li>
071     * <li>{@link Color#GRAY}</li>
072     * <li>{@link Color#GREEN}</li>
073     * <li>{@link Color#LIGHT_GRAY}</li>
074     * <li>{@link Color#MAGENTA}</li>
075     * <li>{@link Color#ORANGE}</li>
076     * <li>{@link Color#PINK}</li>
077     * <li>{@link Color#RED}</li>
078     * <li>{@link Color#WHITE}</li>
079     * <li>{@link Color#YELLOW}</li>
080     * </ul>
081     *
082     * @param type  Data type to which this value should be converted.
083     * @param value The String property value to convert.
084     * @return A {@link Color} which represents the compiled configuration property.
085     * @throws NullPointerException  If the value is null.
086     * @throws NumberFormatException If an invalid number is provided.
087     */
088    @Override
089    protected <T> T convertToType(final Class<T> type, final Object value) throws Throwable {
090        if (Color.class.isAssignableFrom(type)) {
091            final String stringValue = toString(value);
092
093            switch (toLowerCase(stringValue)) {
094            case "black":
095                return type.cast(Color.BLACK);
096            case "blue":
097                return type.cast(Color.BLUE);
098            case "cyan":
099                return type.cast(Color.CYAN);
100            case "darkgray":
101            case "darkgrey":
102            case "dark_gray":
103            case "dark_grey":
104                return type.cast(Color.DARK_GRAY);
105            case "gray":
106            case "grey":
107                return type.cast(Color.GRAY);
108            case "green":
109                return type.cast(Color.GREEN);
110            case "lightgray":
111            case "lightgrey":
112            case "light_gray":
113            case "light_grey":
114                return type.cast(Color.LIGHT_GRAY);
115            case "magenta":
116                return type.cast(Color.MAGENTA);
117            case "orange":
118                return type.cast(Color.ORANGE);
119            case "pink":
120                return type.cast(Color.PINK);
121            case "red":
122                return type.cast(Color.RED);
123            case "white":
124                return type.cast(Color.WHITE);
125            case "yellow":
126                return type.cast(Color.YELLOW);
127            default:
128                // Do nothing.
129            }
130
131            if (stringValue.startsWith(HEX_COLOR_PREFIX)) {
132                return type.cast(parseHexadecimalColor(stringValue));
133            }
134
135            if (stringValue.contains(",")) {
136                return type.cast(parseToStringColor(stringValue));
137            }
138
139            return type.cast(Color.decode(stringValue));
140        }
141
142        throw conversionException(type, value);
143    }
144
145    /**
146     * Gets the default type this {@code Converter} handles.
147     *
148     * @return The default type this {@code Converter} handles.
149     * @since 2.0.0
150     */
151    @Override
152    protected Class<Color> getDefaultType() {
153        return Color.class;
154    }
155
156    /**
157     * Returns a {@link Color} for hexadecimal colors.
158     *
159     * @param value Hexadecimal representation of a color.
160     * @return The converted value.
161     * @throws NumberFormatException If the hexadecimal input contains non parsable characters.
162     */
163    private Color parseHexadecimalColor(final String value) {
164        Objects.requireNonNull(value);
165
166        switch (value.length()) {
167        case 4:
168            return new Color(Integer.parseInt(value.substring(1, 2), 16) * 17, Integer.parseInt(value.substring(2, 3), 16) * 17,
169                    Integer.parseInt(value.substring(3, 4), 16) * 17);
170        case 5:
171            return new Color(Integer.parseInt(value.substring(1, 2), 16) * 17, Integer.parseInt(value.substring(2, 3), 16) * 17,
172                    Integer.parseInt(value.substring(3, 4), 16) * 17, Integer.parseInt(value.substring(4, 5), 16) * 17);
173        case 7:
174            return new Color(Integer.parseInt(value.substring(1, 3), 16), Integer.parseInt(value.substring(3, 5), 16),
175                    Integer.parseInt(value.substring(5, 7), 16));
176        case 9:
177            return new Color(Integer.parseInt(value.substring(1, 3), 16), Integer.parseInt(value.substring(3, 5), 16),
178                    Integer.parseInt(value.substring(5, 7), 16), Integer.parseInt(value.substring(7, 9), 16));
179        default:
180            throw new IllegalArgumentException("Value is an malformed hexadecimal color, if literal value decoding "
181                    + "is required, prefix with 0x instead of #, otherwise expecting 3, 4, 6, or 8 characters only.");
182        }
183    }
184
185    /**
186     * Parses the Color based on the result of the {@link Color#toString()} method.
187     *
188     * Accepts the following values:
189     * <ul>
190     * <li>{@code java.awt.Color[r=255,g=255,b=255]}</li>
191     * <li>{@code [r=255,g=255,b=255]}</li>
192     * <li>{@code r=255,g=255,b=255}</li>
193     * <li>{@code 255,255,255}</li>
194     * </ul>
195     *
196     * @param value A color as represented by {@link Color#toString()}.
197     * @return The Java friendly {@link Color} this color represents.
198     * @throws IllegalArgumentException If the input can't be matches by the {@link #JAVA_COLOR_PATTERN} or a {@link Color} component specified is over 255.
199     */
200    private Color parseToStringColor(final String value) {
201        Objects.requireNonNull(value);
202
203        final Matcher matcher = JAVA_COLOR_PATTERN.matcher(value);
204
205        if (!matcher.matches()) {
206            throw new IllegalArgumentException("Invalid Color String provided. Could not parse.");
207        }
208
209        final int red = Integer.parseInt(matcher.group(1));
210        final int green = Integer.parseInt(matcher.group(2));
211        final int blue = Integer.parseInt(matcher.group(3));
212
213        if (red > 255 || green > 255 || blue > 255) {
214            throw new IllegalArgumentException("Color component integers must be between 0 and 255.");
215        }
216
217        return new Color(red, green, blue);
218    }
219}