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;
021    
022    import org.crsh.cmdline.spi.Completer;
023    
024    import java.util.Collections;
025    import java.util.Map;
026    
027    /**
028     * A {@link Completer} implementation that returns no completion results.
029     *
030     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
031     * @version $Revision$
032     */
033    public class EmptyCompleter implements Completer {
034    
035      /** . */
036      private static final EmptyCompleter instance = new EmptyCompleter();
037    
038      /**
039       * Returns the empty completer instance.
040       *
041       * @return the instance
042       */
043      public static EmptyCompleter getInstance() {
044        return instance;
045      }
046    
047      /**
048       * Returns the value returned by {@link java.util.Collections#emptyList()}.
049       */
050      public Map<String, Boolean> complete(ParameterDescriptor<?> parameter, String prefix) {
051        return Collections.emptyMap();
052      }
053    }