001    /**
002     * Licensed to the Apache Software Foundation (ASF) under one or more
003     * contributor license agreements.  See the NOTICE file distributed with
004     * this work for additional information regarding copyright ownership.
005     * The ASF licenses this file to You under the Apache License, Version 2.0
006     * (the "License"); you may not use this file except in compliance with
007     * the License.  You may obtain a copy of the License at
008     *
009     *     http://www.apache.org/licenses/LICENSE-2.0
010     *
011     * Unless required by applicable law or agreed to in writing, software
012     * distributed under the License is distributed on an "AS IS" BASIS,
013     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014     * See the License for the specific language governing permissions and
015     * limitations under the License.
016     */
017    package org.apache.commons.cli2;
018    
019    import java.util.Comparator;
020    import java.util.Set;
021    
022    /**
023     * An Option representing a choice or group of Options in the form "-a|-b|-c".
024     */
025    public interface Group extends Option {
026    
027        /**
028         * Appends usage information to the specified StringBuffer
029         *
030         * @param buffer the buffer to append to
031         * @param helpSettings a set of display settings @see DisplaySetting
032         * @param comp a comparator used to sort the Options
033         * @param separator the String used to separate member Options
034         */
035        void appendUsage(
036            final StringBuffer buffer,
037            final Set helpSettings,
038            final Comparator comp,
039            final String separator);
040    
041        /**
042         * Indicates whether group members must be present for the CommandLine to be
043         * valid.
044         *
045         * @see #getMinimum()
046         * @see #getMaximum()
047         * @return true iff the CommandLine will be invalid without at least one
048         *         member option
049         */
050        boolean isRequired();
051    
052        /**
053         * Retrieves the minimum number of members required for a valid Group
054         *
055         * @return the minimum number of members
056         */
057        int getMinimum();
058    
059        /**
060         * Retrieves the maximum number of members acceptable for a valid Group
061         *
062         * @return the maximum number of members
063         */
064        int getMaximum();
065    }