trunk/odfdom/src/main/java/org/odftoolkit/odfdom/type/NonNegativePixelLength.java

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* 
*  Licensed to the Apache Software Foundation (ASF) under one
*  or more contributor license agreements.  See the NOTICE file
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*  to you under the Apache License, Version 2.0 (the
*  "License"); you may not use this file except in compliance
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*
*   http://www.apache.org/licenses/LICENSE-2.0
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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 nonNegativePixelLength}
 */
public class NonNegativePixelLength extends Length {

	private String mLength;
	private static final Pattern pixelLengthPattern = Pattern.compile("^([0-9]+(\\.[0-9]*)?|\\.[0-9]+)(px)$");

	/**
	 * Construct NonNegativePixelLength by the parsing the given string
	 *
	 * @param pixelLength
	 *            The String to be parsed into NonNegativePixelLength
	 * @throws NumberFormatException if the given argument is not a valid NonNegativePixelLength
	 */
	public NonNegativePixelLength(String pixelLength) throws NumberFormatException {
		super(pixelLength);
		if (!isValid(pixelLength)) {
			throw new NumberFormatException("parameter is invalid for datatype NonNegativePixelLength");
		}
	}

	/**
	 * Returns a String Object representing this NonNegativePixelLength's value
	 *
	 * @return return a string representation of the value of this
	 *         NonNegativePixelLength object
	 */
	@Override
	public String toString() {
		return mLength;
	}

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

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