/*
 * Copyright  2000-2004 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.bcel.classfile;

import java.io.DataInputStream;
import java.io.DataOutputStream;
import java.io.IOException;
import java.io.Serializable;
import org.apache.bcel.Constants;

/**
 * This class represents an entry in the exception table of the <em>Code</em>
 * attribute and is used only there. It contains a range in which a particular
 * exception handler is active.
 * 
 * @version $Id: CodeException.java 386056 2006-03-15 11:31:56Z tcurdt $
 * @author <A HREF="mailto:m.dahm@gmx.de">M. Dahm</A>
 * @see Code
 */
public final class CodeException implements Cloneable, Constants, Node,
		Serializable {

	/**
	 * 
	 */
	private static final long serialVersionUID = 1L;
	private int start_pc; // Range in the code the exception handler is
	private int end_pc; // active. start_pc is inclusive, end_pc exclusive
	private int handler_pc; /*
							 * Starting address of exception handler, i.e., an
							 * offset from start of code.
							 */
	private int catch_type; /*
							 * If this is zero the handler catches any
							 * exception, otherwise it points to the exception
							 * class which is to be caught.
							 */

	/**
	 * Initialize from another object.
	 */
	public CodeException(CodeException c) {
		this(c.getStartPC(), c.getEndPC(), c.getHandlerPC(), c.getCatchType());
	}

	/**
	 * Construct object from file stream.
	 * 
	 * @param file
	 *            Input stream
	 * @throws IOException
	 */
	CodeException(DataInputStream file) throws IOException {
		this(file.readUnsignedShort(), file.readUnsignedShort(), file
				.readUnsignedShort(), file.readUnsignedShort());
	}

	/**
	 * @param start_pc
	 *            Range in the code the exception handler is active, start_pc is
	 *            inclusive while
	 * @param end_pc
	 *            is exclusive
	 * @param handler_pc
	 *            Starting address of exception handler, i.e., an offset from
	 *            start of code.
	 * @param catch_type
	 *            If zero the handler catches any exception, otherwise it points
	 *            to the exception class which is to be caught.
	 */
	public CodeException(int start_pc, int end_pc, int handler_pc,
			int catch_type) {
		this.start_pc = start_pc;
		this.end_pc = end_pc;
		this.handler_pc = handler_pc;
		this.catch_type = catch_type;
	}

	/**
	 * Called by objects that are traversing the nodes of the tree implicitely
	 * defined by the contents of a Java class. I.e., the hierarchy of methods,
	 * fields, attributes, etc. spawns a tree of objects.
	 * 
	 * @param v
	 *            Visitor object
	 */
	@Override
	public void accept(Visitor v) {
		v.visitCodeException(this);
	}

	/**
	 * Dump code exception to file stream in binary format.
	 * 
	 * @param file
	 *            Output file stream
	 * @throws IOException
	 */
	public final void dump(DataOutputStream file) throws IOException {
		file.writeShort(start_pc);
		file.writeShort(end_pc);
		file.writeShort(handler_pc);
		file.writeShort(catch_type);
	}

	/**
	 * @return 0, if the handler catches any exception, otherwise it points to
	 *         the exception class which is to be caught.
	 */
	public final int getCatchType() {
		return catch_type;
	}

	/**
	 * @return Exclusive end index of the region where the handler is active.
	 */
	public final int getEndPC() {
		return end_pc;
	}

	/**
	 * @return Starting address of exception handler, relative to the code.
	 */
	public final int getHandlerPC() {
		return handler_pc;
	}

	/**
	 * @return Inclusive start index of the region where the handler is active.
	 */
	public final int getStartPC() {
		return start_pc;
	}

	/**
	 * @param catch_type
	 *            the type of exception that is caught
	 */
	public final void setCatchType(int catch_type) {
		this.catch_type = catch_type;
	}

	/**
	 * @param end_pc
	 *            end of handled block
	 */
	public final void setEndPC(int end_pc) {
		this.end_pc = end_pc;
	}

	/**
	 * @param handler_pc
	 *            where the actual code is
	 */
	public final void setHandlerPC(int handler_pc) {
		this.handler_pc = handler_pc;
	}

	/**
	 * @param start_pc
	 *            start of handled block
	 */
	public final void setStartPC(int start_pc) {
		this.start_pc = start_pc;
	}

	/**
	 * @return String representation.
	 */
	@Override
	public final String toString() {
		return "CodeException(start_pc = " + start_pc + ", end_pc = " + end_pc
				+ ", handler_pc = " + handler_pc + ", catch_type = "
				+ catch_type + ")";
	}

	/**
	 * @return String representation.
	 */
	public final String toString(ConstantPool cp, boolean verbose) {
		String str;
		if (catch_type == 0) {
			str = "<Any exception>(0)";
		} else {
			str = Utility.compactClassName(
					cp.getConstantString(catch_type, CONSTANT_Class), false)
					+ (verbose ? "(" + catch_type + ")" : "");
		}
		return start_pc + "\t" + end_pc + "\t" + handler_pc + "\t" + str;
	}

	public final String toString(ConstantPool cp) {
		return toString(cp, true);
	}

	/**
	 * @return deep copy of this object
	 */
	public CodeException copy() {
		try {
			return (CodeException) clone();
		} catch (CloneNotSupportedException e) {
		}
		return null;
	}
}
