001    /*
002     * Copyright (C) 2010 eXo Platform SAS.
003     *
004     * This is free software; you can redistribute it and/or modify it
005     * under the terms of the GNU Lesser General Public License as
006     * published by the Free Software Foundation; either version 2.1 of
007     * the License, or (at your option) any later version.
008     *
009     * This software is distributed in the hope that it will be useful,
010     * but WITHOUT ANY WARRANTY; without even the implied warranty of
011     * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
012     * Lesser General Public License for more details.
013     *
014     * You should have received a copy of the GNU Lesser General Public
015     * License along with this software; if not, write to the Free
016     * Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA
017     * 02110-1301 USA, or see the FSF site: http://www.fsf.org.
018     */
019    
020    package org.crsh.cmdline.completers;
021    
022    import org.crsh.cmdline.ParameterDescriptor;
023    import org.crsh.cmdline.SimpleValueType;
024    import org.crsh.cmdline.spi.Completer;
025    import org.crsh.cmdline.spi.ValueCompletion;
026    
027    import java.lang.reflect.Method;
028    
029    /**
030     * A completer for enums.
031     *
032     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
033     * @version $Revision$
034     */
035    public class EnumCompleter implements Completer {
036    
037      /** . */
038      private static final EnumCompleter instance = new EnumCompleter();
039    
040      /**
041       * Returns the empty completer instance.
042       *
043       * @return the instance
044       */
045      public static EnumCompleter getInstance() {
046        return instance;
047      }
048    
049      public ValueCompletion complete(ParameterDescriptor<?> parameter, String prefix) throws Exception {
050        ValueCompletion completions = ValueCompletion.create();
051        if (parameter.getType() == SimpleValueType.ENUM) {
052          Class<?> vt = parameter.getJavaValueType();
053          Method valuesM = vt.getDeclaredMethod("values");
054          Method nameM = vt.getMethod("name");
055          Enum<?>[] values = (Enum<?>[])valuesM.invoke(null);
056          for (Enum<?> value : values) {
057            String name = (String)nameM.invoke(value);
058            if (name.startsWith(prefix)) {
059              if (completions.isEmpty()) {
060                completions = new ValueCompletion();
061              }
062              completions.put(name.substring(prefix.length()), true);
063            }
064          }
065        }
066        return completions;
067      }
068    }