/*
 * Copyright (c) 2002-2004 Widespace, OU 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:
 *     Igor Malinin - initial contribution
 *
 * $Id: EntityRule.java,v 1.1 2004-09-02 18:28:03 jsurfer Exp $
 */

package net.sourceforge.phpeclipse.xml.ui.internal.text;

import org.eclipse.jface.text.rules.ICharacterScanner;
import org.eclipse.jface.text.rules.IRule;
import org.eclipse.jface.text.rules.IToken;
import org.eclipse.jface.text.rules.Token;

/**
 * Rule detecting XML or DTD entities.
 * 
 * @author Igor Malinin
 */
public class EntityRule implements IRule {

	private static NameDetector detector = new NameDetector();

	private char start;

	private IToken token;

	public EntityRule(char start, IToken token) {
		this.start = start;
		this.token = token;
	}

	public IToken evaluate(ICharacterScanner scanner) {
		int ch = scanner.read();

		if (ch == start) {
			ch = scanner.read();
			if (ch == ICharacterScanner.EOF) {
				scanner.unread();
				return token;
			}
			if (ch == ';') {
				return token;
			}
			if (!detector.isWordStart((char) ch)) {
				scanner.unread();
				return token;
			}

			while (true) {
				ch = scanner.read();
				if (ch == ICharacterScanner.EOF) {
					scanner.unread();
					return token;
				}
				if (ch == ';') {
					return token;
				}
				if (!detector.isWordPart((char) ch)) {
					scanner.unread();
					return token;
				}
			}
		}
		scanner.unread();

		return Token.UNDEFINED;
	}
}