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.spi;
021    
022    import org.crsh.cmdline.ParameterDescriptor;
023    
024    import java.util.Map;
025    
026    /**
027     * A completer provides completion suffixes for a given prefix. The cmdline framework uses it when
028     * computing a completion.
029     *
030     * @author <a href="mailto:julien.viet@exoplatform.com">Julien Viet</a>
031     * @version $Revision$
032     */
033    public interface Completer {
034    
035      /**
036       * <p>Query the completer for a set of completion for the given prefix. The returned Map
037       * should provide the possible suffixes matching the prefix argument. Each map entry maps
038       * to a possible completion: an entry key is the possible completion, its corresponding
039       * boolean value indicates wether the value can be further more completed or not.
040       *
041       * The following guidelines
042       * should be respected:
043       *
044       * <ul>
045       * <li>An empty map means no completion can be determined, the framework will not do anything.</li>
046       * <li>A singleton map means the match was entire and the framework will complete it with the sole map entry.</li>
047       * <li>A map containing string sharing a common prefix instruct the framework to insert this common prefix.</li>
048       * <li>A list containing strings with no common prefix (other than the empty string) instruct the framework to display
049       * the list of possible completions.</li>
050       * </ul>
051       * <ul>When a match is considered as full (the entry value is set to true), the completion should contain a trailing value
052       * that is usually a white space (but it could be a quote for quoted values).</ul>
053       * </p>
054       *
055       * <p>Example: a completer that would complete colors could
056       * <ul>
057       * <li>return the map ["lack ":true,"lue ":true] for the prefix "b".</li>
058       * <li>return the amp ["e ":true] for the prefix "blu".</li>
059       * <li>return the map [] for the prefix "z".</li>
060       * </ul>
061       * </p>
062       *
063       * <p>Example: a completer that would complete java packages could
064       * <ul>
065       * <li>return the map ["ext":true,"ext.spi":false] for the prefix "java.t"</li>
066       * </ul>
067       * </p>
068       *
069       * @param parameter the completed parameter
070       * @param prefix the prefix to complete
071       * @return the possible suffix map
072       * @throws Exception any exception that would prevent completion to perform correctly
073       */
074      Map<String, Boolean> complete(ParameterDescriptor<?> parameter, String prefix) throws Exception;
075    
076    }