001    /*
002     * Created on Apr 15, 2008
003     * 
004     * Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except
005     * in compliance with the License. You may obtain a copy of the License at
006     * 
007     * http://www.apache.org/licenses/LICENSE-2.0
008     * 
009     * Unless required by applicable law or agreed to in writing, software distributed under the License
010     * is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
011     * or implied. See the License for the specific language governing permissions and limitations under
012     * the License.
013     * 
014     * Copyright @2008-2010 the original author or authors.
015     */
016    package org.fest.swing.util;
017    
018    import static org.fest.util.Strings.concat;
019    import static org.fest.util.Strings.quote;
020    
021    import java.awt.Color;
022    
023    import org.fest.util.Strings;
024    
025    /**
026     * Understands utility methods related to colors.
027     *
028     * @author Alex Ruiz
029     */
030    public final class Colors {
031    
032      /**
033       * Returns a <code>{@link Color}</code> from the given <code>String</code> containing the hexadecimal coding of a 
034       * color. 
035       * @param hexString contains the hexadecimal coding of a color.
036       * @return a <code>Color</code> from the given <code>String</code> containing the hexadecimal coding of a color. 
037       * @throws NullPointerException if the hexadecimal code is <code>null</code>.
038       * @throws IllegalArgumentException if the hexadecimal code is empty.
039       * @throws NumberFormatException if the hexadecimal code is empty.
040       */
041      public static Color colorFromHexString(String hexString) {
042        if (hexString == null) throw new NullPointerException("The hexadecimal code should not be null");
043        if (Strings.isEmpty(hexString)) throw new IllegalArgumentException("The hexadecimal code should not be empty");
044        try {
045          return new Color(Integer.parseInt(hexString, 16));
046        } catch (NumberFormatException e) {
047          throw new NumberFormatException(concat("The hexadecimal code ", quote(hexString), " is not a valid color code"));
048        }
049      }
050      
051      private Colors() {}
052    }