001/*
002 *   Copyright (C) 2005 Christian Schulte <cs@schulte.it>
003 *   All rights reserved.
004 *
005 *   Redistribution and use in source and binary forms, with or without
006 *   modification, are permitted provided that the following conditions
007 *   are met:
008 *
009 *     o Redistributions of source code must retain the above copyright
010 *       notice, this list of conditions and the following disclaimer.
011 *
012 *     o Redistributions in binary form must reproduce the above copyright
013 *       notice, this list of conditions and the following disclaimer in
014 *       the documentation and/or other materials provided with the
015 *       distribution.
016 *
017 *   THIS SOFTWARE IS PROVIDED "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
018 *   INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
019 *   AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
020 *   THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY DIRECT, INDIRECT,
021 *   INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
022 *   NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
023 *   DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
024 *   THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
025 *   (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
026 *   THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
027 *
028 *   $JOMC: TrailingWhitespaceEditor.java 5091 2016-04-04 15:40:17Z schulte $
029 *
030 */
031package org.jomc.util;
032
033/**
034 * {@code LineEditor} removing trailing whitespace.
035 *
036 * @author <a href="mailto:cs@schulte.it">Christian Schulte</a>
037 * @version $JOMC: TrailingWhitespaceEditor.java 5091 2016-04-04 15:40:17Z schulte $
038 *
039 * @see #edit(java.lang.String)
040 */
041public final class TrailingWhitespaceEditor extends LineEditor
042{
043
044    /**
045     * Creates a new {@code TrailingWhitespaceEditor} instance.
046     */
047    public TrailingWhitespaceEditor()
048    {
049        this( null, null );
050    }
051
052    /**
053     * Creates a new {@code TrailingWhitespaceEditor} instance taking a string to use for separating lines.
054     *
055     * @param lineSeparator String to use for separating lines.
056     */
057    public TrailingWhitespaceEditor( final String lineSeparator )
058    {
059        this( null, lineSeparator );
060    }
061
062    /**
063     * Creates a new {@code TrailingWhitespaceEditor} instance taking an editor to chain.
064     *
065     * @param editor The editor to chain.
066     */
067    public TrailingWhitespaceEditor( final LineEditor editor )
068    {
069        this( editor, null );
070    }
071
072    /**
073     * Creates a new {@code TrailingWhitespaceEditor} instance taking an editor to chain and a string to use for
074     * separating lines.
075     *
076     * @param editor The editor to chain.
077     * @param lineSeparator String to use for separating lines.
078     */
079    public TrailingWhitespaceEditor( final LineEditor editor, final String lineSeparator )
080    {
081        super( editor, lineSeparator );
082    }
083
084    /**
085     * {@inheritDoc}
086     * <p>
087     * This method returns {@code line} with any trailing whitespace characters removed.
088     * </p>
089     *
090     * @see Character#isWhitespace(char)
091     */
092    @Override
093    protected String editLine( final String line )
094    {
095        String replacement = line;
096
097        if ( line != null )
098        {
099            StringBuilder whitespace = null;
100            boolean sawWhitespace = false;
101            final StringBuilder buf = new StringBuilder( line.length() );
102            final char[] chars = line.toCharArray();
103
104            for ( int i = 0; i < chars.length; i++ )
105            {
106                if ( Character.isWhitespace( chars[i] ) )
107                {
108                    if ( whitespace == null )
109                    {
110                        whitespace = new StringBuilder( line.length() );
111                    }
112
113                    whitespace.append( chars[i] );
114                    sawWhitespace = true;
115                }
116                else
117                {
118                    if ( sawWhitespace )
119                    {
120                        buf.append( whitespace );
121                        sawWhitespace = false;
122                        whitespace = null;
123                    }
124                    buf.append( chars[i] );
125                }
126            }
127
128            replacement = buf.toString();
129        }
130
131        return replacement;
132    }
133
134}