/*
 * Copyright (c) 2003-2004 Christopher Lenz and others.
 * 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:
 *     Christopher Lenz - initial API and implementation
 * 
 * $Id: MutableRegion.java,v 1.1 2004-09-02 18:07:13 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.css.core.internal.parser;

import org.eclipse.jface.text.IRegion;

/**
 * 
 */
public class MutableRegion implements IRegion {

	// Instance Variables ------------------------------------------------------

	/**
	 * The offset of the region.
	 */
	private int offset = 0;

	/**
	 * The length of the region.
	 */
	private int length = 0;

	// Constructors ------------------------------------------------------------

	/**
	 * Default constructor.
	 */
	public MutableRegion() {
		this(0);
	}

	/**
	 * Constructor with partial initialization.
	 * 
	 * @param offset the offset of the region
	 */
	public MutableRegion(int offset) {
		this.offset = offset;
	}

	/**
	 * Constructor with initialization.
	 * 
	 * @param offset the offset of the region
	 * @param length the length of the region
	 */
	public MutableRegion(int offset, int length) {
		this.offset = offset;
		this.length = length;
	}

	/**
	 * Constructor with initialization.
	 * 
	 * @param region another region to initialize this region with
	 */
	public MutableRegion(IRegion region) {
		this.offset = region.getOffset();
		this.length = region.getLength();
	}

	// IRegion Implementation --------------------------------------------------

	/*
	 * @see org.eclipse.jface.text.IRegion#getLength()
	 */
	public int getLength() {
		return length;
	}

	/*
	 * @see org.eclipse.jface.text.IRegion#getOffset()
	 */
	public int getOffset() {
		return offset;
	}

	// Public Methods ----------------------------------------------------------

	/**
	 * Adds another region to this region, which will be enlarged so that the
	 * added region completely fits into this region.
	 * 
	 * @param region the region to add 
	 */
	public void add(IRegion region) {
		int start1 = offset;
		int end1 = offset + length;
		int start2 = region.getOffset();
		int end2 = start2 + region.getLength();
		offset = (start1 < start2) ? start1 : start2;
		length = (end1 > end2) ? (end1 - offset) : (end2 - offset);
	}

	/**
	 * Sets the length of the region.
	 * 
	 * @param length the length to set
	 */
	public void setLength(int length) {
		this.length = length;
	}

	/**
	 * Sets the offset of the region.
	 * 
	 * @param offset the offset to set
	 */
	public void setOffset(int offset) {
		this.offset = offset;
	}

}