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 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER
 *
 * Copyright 2008, 2010 Oracle and/or its affiliates. All rights reserved.
 *
 * Use is subject to license terms.
 *
 * 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. You can also
 * obtain a copy of the License at http://odftoolkit.org/docs/license.txt
 *
 * 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
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package org.odftoolkit.odfdom.type;

import java.util.regex.Pattern;

/**
 * This class represents the in OpenDocument format used data type {@odf.datatype nonNegativeLength}
 */
public class NonNegativeLength extends Length {


	private static final Pattern nonNegativeLengthPattern = Pattern.compile("^?([0-9]+(\\.[0-9]*)?|\\.[0-9]+)((cm)|(mm)|(in)|(pt)|(pc)|(px))$");
	/**
	 * Construct NonNegativeLength by the parsing the given string
	 *
	 * @param length
	 *            The String to be parsed into NonNegativeLength
	 * @throws NumberFormatException if the given argument is not a valid NonNegativeLength
	 */
	public NonNegativeLength(String length) throws NumberFormatException {
		super(length);
		if (!isValid(length)){
			throw new NumberFormatException(
					"parameter is invalid for datatype NonNegativeLength");
		}
	}

	/**
	 * Returns a NonNegativeLength instance representing the specified String
	 * value
	 *
	 * @param stringValue
	 *            a String value
	 * @return return a NonNegativeLength instance representing stringValue
	 * @throws NumberFormatException if the given argument is not a valid NonNegativeLength
	 */
	public static NonNegativeLength valueOf(String stringValue)
			throws NumberFormatException {
		return new NonNegativeLength(stringValue);
	}

	/**
	 * check if the specified String instance is a valid {@odf.datatype nonNegativeLength} data
	 * type
	 *
	 * @param stringValue
	 *            the value to be tested
	 * @return true if the value of argument is valid for {@odf.datatype nonNegativeLength} data
	 *         type false otherwise
	 */
	public static boolean isValid(String stringValue) {
		if ((stringValue == null) || (!nonNegativeLengthPattern.matcher(stringValue).matches())) {
			return false;
		} else {
			return true;
		}
	}
}
