001    /*
002     * Copyright (C) 2012 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    public class EnumCompleter implements Completer {
030    
031      /** . */
032      private static final EnumCompleter instance = new EnumCompleter();
033    
034      /**
035       * Returns the empty completer instance.
036       *
037       * @return the instance
038       */
039      public static EnumCompleter getInstance() {
040        return instance;
041      }
042    
043      public ValueCompletion complete(ParameterDescriptor<?> parameter, String prefix) throws Exception {
044        ValueCompletion completions = ValueCompletion.create();
045        if (parameter.getType() == SimpleValueType.ENUM) {
046          Class<?> vt = parameter.getJavaValueType();
047          Method valuesM = vt.getDeclaredMethod("values");
048          Method nameM = vt.getMethod("name");
049          Enum<?>[] values = (Enum<?>[])valuesM.invoke(null);
050          for (Enum<?> value : values) {
051            String name = (String)nameM.invoke(value);
052            if (name.startsWith(prefix)) {
053              if (completions.isEmpty()) {
054                completions = new ValueCompletion();
055              }
056              completions.put(name.substring(prefix.length()), true);
057            }
058          }
059        }
060        return completions;
061      }
062    }