001    /*
002     * Copyright 2006 Sun Microsystems, Inc.  All Rights Reserved.
003     * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
004     *
005     * This code is free software; you can redistribute it and/or modify it
006     * under the terms of the GNU General Public License version 2 only, as
007     * published by the Free Software Foundation.  Sun designates this
008     * particular file as subject to the "Classpath" exception as provided
009     * by Sun in the LICENSE file that accompanied this code.
010     *
011     * This code is distributed in the hope that it will be useful, but WITHOUT
012     * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
013     * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
014     * version 2 for more details (a copy is included in the LICENSE file that
015     * accompanied this code).
016     *
017     * You should have received a copy of the GNU General Public License version
018     * 2 along with this work; if not, write to the Free Software Foundation,
019     * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
020     *
021     * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
022     * CA 95054 USA or visit www.sun.com if you need additional information or
023     * have any questions.
024     */
025    
026    package com.sun.source.tree;
027    
028    /**
029     * Provides methods to convert between character positions and line numbers
030     * for a compilation unit.
031     *
032     * @since 1.6
033     */
034    public interface LineMap {
035        /**
036         * Find the start position of a line.
037         *
038         * @param line line number (beginning at 1)
039         * @return     position of first character in line
040         * @throws  IndexOutOfBoundsException
041         *           if <tt>lineNumber < 1</tt>
042         *           if <tt>lineNumber > no. of lines</tt>
043         */
044        long getStartPosition(long line);
045    
046        /**
047         * Find the position corresponding to a (line,column).
048         *
049         * @param   line    line number (beginning at 1)
050         * @param   column  tab-expanded column number (beginning 1)
051         *
052         * @return  position of character
053         * @throws  IndexOutOfBoundsException
054         *           if {@code line < 1}
055         *           if {@code line > no. of lines}
056         */
057        long getPosition(long line, long column);
058    
059        /**
060         * Find the line containing a position; a line termination
061         * character is on the line it terminates.
062         *
063         * @param   pos  character offset of the position
064         * @return the line number of pos (first line is 1)
065         */
066        long getLineNumber(long pos);
067    
068        /**
069         * Find the column for a character position.
070         * Tab characters preceding the position on the same line
071         * will be expanded when calculating the column number.
072         *
073         * @param  pos   character offset of the position
074         * @return       the tab-expanded column number of pos (first column is 1)
075         */
076        long getColumnNumber(long pos);
077    
078    }