/* *******************************************************************
 * Copyright (c) 1999-2001 Xerox Corporation, 
 *               2002 Palo Alto Research Center, Incorporated (PARC).
 * All rights reserved. 
 * This program and the accompanying materials are made available 
 * under the terms of the Common Public License v1.0 
 * which accompanies this distribution and is available at 
 * http://www.eclipse.org/legal/cpl-v10.html 
 *  
 * Contributors: 
 *     Xerox/PARC     initial implementation 
 * ******************************************************************/


package org.aspectj.bridge;

import java.io.File;

/**
 * Represent source location as a starting line/column and ending
 * line in a source file.
 * Implementations should be immutable. XXX why?
 * @see org.aspectj.lang.reflect.SourceLocation
 * @see org.aspectj.compiler.base.parser.SourceInfo
 * @see org.aspectj.tools.ide.SourceLine
 * @see org.aspectj.testing.harness.ErrorLine
 */
public interface ISourceLocation  {
    static final int MAX_LINE = Integer.MAX_VALUE / 2;
    static final int MAX_COLUMN = MAX_LINE;
    
    /** non-null but empty (nonexisting) File constant */
    static final File NO_FILE = new File("ISourceLocation.NO_FILE");

    /** signal that column is not known */
    static final int NO_COLUMN = Integer.MIN_VALUE +1;

    /** non-null but empty constant source location */
    static final ISourceLocation EMPTY = new SourceLocation(NO_FILE, 0, 0, 0);
    
    /** 
     * @return File source or NO_FILE if the implementation requires
     * a non-null result or null otherwise
     */
    File getSourceFile();
    
    /** @return 0..MAX_LINE */
    int getLine();
    
    /**
     * @return int 0..MAX_COLUMN actual column 
     *        or 0 if column input was ISourceLocation.NO_COLUMN 
     */
    int getColumn();    
    
    /** @return getLine()..MAX_LINE */
    int getEndLine();
    
    /** @return String application-specific context for source */
    String getContext();
    
}
