src/java/org/apache/commons/cli/avalon/CLUtil.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 * 
 */

package org.apache.commons.cli.avalon;
//Renamed from org.apache.avalon.excalibur.cli

/**
 * CLUtil offers basic utility operations for use both internal and external to package.
 *
 * @see CLOptionDescriptor
 */
public final class CLUtil
{
    private static final int MAX_DESCRIPTION_COLUMN_LENGTH = 60;

    /**
     * Format options into StringBuffer and return. This is typically used to
     * print "Usage" text in response to a "--help" or invalid option.
     *
     * @param options the option descriptors
     * @return the formatted description/help for options
     */
    public static final StringBuffer describeOptions( final CLOptionDescriptor[] options )
    {
        final String lSep = System.getProperty( "line.separator" ); // $NON-NLS-1$
        final StringBuffer sb = new StringBuffer();

        for( int i = 0; i < options.length; i++ )
        {
            final char ch = (char)options[i].getId();
            final String name = options[i].getName();
            String description = options[i].getDescription();
            int flags = options[i].getFlags();
            boolean argumentOptional = 
                    ((flags & CLOptionDescriptor.ARGUMENT_OPTIONAL) == 
                              CLOptionDescriptor.ARGUMENT_OPTIONAL);
            boolean argumentRequired =
                    ((flags & CLOptionDescriptor.ARGUMENT_REQUIRED) ==
                              CLOptionDescriptor.ARGUMENT_REQUIRED);
            boolean twoArgumentsRequired =
                    ((flags & CLOptionDescriptor.ARGUMENTS_REQUIRED_2) ==
                              CLOptionDescriptor.ARGUMENTS_REQUIRED_2);
            boolean needComma = false;
            if( twoArgumentsRequired )
            {
                argumentRequired = true;
            }

            sb.append( '\t' ); // $NON-NLS-1$

            if( Character.isLetter( ch ) )
            {
                sb.append( "-" ); // $NON-NLS-1$
                sb.append( ch );
                needComma = true;
            }

            if( null != name )
            {
                if( needComma )
                {
                    sb.append( ", " ); // $NON-NLS-1$
                }

                sb.append( "--" ); // $NON-NLS-1$
                sb.append( name );
            }

            if (argumentOptional)
            {
                sb.append(" [[=]<argument>]");
            }
            if( argumentRequired )
            {
                sb.append( " <argument>" );
            }
            if( twoArgumentsRequired )
            {
                sb.append( "=<value>" );
            }
            sb.append( lSep );

            if( null != description )
            {
                while( description.length() > MAX_DESCRIPTION_COLUMN_LENGTH )
                {
                    final String descriptionPart =
                            description.substring( 0, MAX_DESCRIPTION_COLUMN_LENGTH );
                    description =
                            description.substring( MAX_DESCRIPTION_COLUMN_LENGTH );
                    sb.append( "\t\t" ); // $NON-NLS-1$
                    sb.append( descriptionPart );
                    sb.append( lSep );
                }

                sb.append( "\t\t" ); // $NON-NLS-1$
                sb.append( description );
                sb.append( lSep );
            }
        }
        return sb;
    }

    /**
     * Private Constructor so that no instance can ever be created.
     *
     */
    private CLUtil()
    {
    }
}