/*

   Copyright 2000  The Apache Software Foundation 

   Licensed 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.batik.parser;

/**
 * This class encapsulates a general parse error or warning.
 *
 * <p>This class can contain basic error or warning information from
 * either the parser or the application.
 *
 * <p>If the application needs to pass through other types of
 * exceptions, it must wrap those exceptions in a ParseException.
 *
 * @author <a href="mailto:stephane@hillion.org">Stephane Hillion</a>
 * @version $Id$
 */
public class ParseException extends RuntimeException {

    /**
     * @serial The embedded exception if tunnelling, or null.
     */    
    protected Exception exception;
    
    /**
     * @serial The line number.
     */
    protected int lineNumber;

    /**
     * @serial The column number.
     */
    protected int columnNumber;

    /**
     * Creates a new ParseException.
     * @param message The error or warning message.
     * @param line The line of the last parsed character.
     * @param column The column of the last parsed character.
     */
    public ParseException (String message, int line, int column) {
	super(message);
	exception = null;
	lineNumber = line;
	columnNumber = column;
    }
    
    /**
     * Creates a new ParseException wrapping an existing exception.
     *
     * <p>The existing exception will be embedded in the new
     * one, and its message will become the default message for
     * the ParseException.
     * @param e The exception to be wrapped in a ParseException.
     */
    public ParseException (Exception e) {
	exception = e;
	lineNumber = -1;
	columnNumber = -1;
    }
    
    /**
     * Creates a new ParseException from an existing exception.
     *
     * <p>The existing exception will be embedded in the new
     * one, but the new exception will have its own message.
     * @param message The detail message.
     * @param e The exception to be wrapped in a SAXException.
     */
    public ParseException (String message, Exception e) {
	super(message);
	this.exception = e;
    }
    
    /**
     * Return a detail message for this exception.
     *
     * <p>If there is a embedded exception, and if the ParseException
     * has no detail message of its own, this method will return
     * the detail message from the embedded exception.
     * @return The error or warning message.
     */
    public String getMessage () {
	String message = super.getMessage();
	
	if (message == null && exception != null) {
	    return exception.getMessage();
	} else {
	    return message;
	}
    }
    
    /**
     * Return the embedded exception, if any.
     * @return The embedded exception, or null if there is none.
     */
    public Exception getException () {
	return exception;
    }

    /**
     * Returns the line of the last parsed character.
     */
    public int getLineNumber() {
	return lineNumber;
    }

    /**
     * Returns the column of the last parsed character.
     */
    public int getColumnNumber() {
	return columnNumber;
    }
}