plugins/org.eclipse.ocl.xtext.markup/src/org/eclipse/ocl/xtext/markup/services/MarkupValueConverterService.java

/*******************************************************************************
 * Copyright (c) 2011, 2018 Willink Transformations and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v2.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v20.html
 *
 * Contributors:
 *     E.D.Willink - initial API and implementation
 *******************************************************************************/
package org.eclipse.ocl.xtext.markup.services;

import org.eclipse.xtext.conversion.IValueConverter;
import org.eclipse.xtext.conversion.ValueConverter;
import org.eclipse.xtext.conversion.ValueConverterException;
import org.eclipse.xtext.conversion.impl.AbstractDeclarativeValueConverterService;
import org.eclipse.xtext.conversion.impl.AbstractNullSafeConverter;
import org.eclipse.xtext.nodemodel.INode;
import org.eclipse.xtext.util.Strings;

public class MarkupValueConverterService extends AbstractDeclarativeValueConverterService
{
	/**
	 * Mostly copied from {@link java.util.Properties#loadConvert}
	 */
	public static String convertFromJavaString(String javaString, boolean useUnicode) {
		char[] in = javaString.toCharArray();
		int off = 0;
		int len = javaString.length();
		char[] convtBuf = new char[len];
		char aChar;
		char[] out = convtBuf;
		int outLen = 0;
		int end = off + len;

		while (off < end) {
			aChar = in[off++];
			if (aChar == '\\') {
				aChar = in[off++];
				if (useUnicode && aChar == 'u') {
					// Read the xxxx
					int value = 0;
					for (int i = 0; i < 4; i++) {
						aChar = in[off++];
						switch (aChar) {
							case '0':
							case '1':
							case '2':
							case '3':
							case '4':
							case '5':
							case '6':
							case '7':
							case '8':
							case '9':
								value = (value << 4) + aChar - '0';
								break;
							case 'a':
							case 'b':
							case 'c':
							case 'd':
							case 'e':
							case 'f':
								value = (value << 4) + 10 + aChar - 'a';
								break;
							case 'A':
							case 'B':
							case 'C':
							case 'D':
							case 'E':
							case 'F':
								value = (value << 4) + 10 + aChar - 'A';
								break;
							default:
								throw new IllegalArgumentException("Malformed \\uxxxx encoding.");
						}
					}
					out[outLen++] = (char) value;
				} else {
					if (aChar == 't')
						aChar = '\t';
					else if (aChar == 'r')
						aChar = '\r';
					else if (aChar == 'n')
						aChar = '\n';
					else if (aChar == 'f')
						aChar = '\f';
					else if (aChar == 'b')
						aChar = '\b';
					else if (aChar == '<')
						aChar = '<';
					else if (aChar == '>')
						aChar = '>';
					else if (aChar == '"')
						aChar = '\"';
					else if (aChar == '\'')
						aChar = '\'';
					else if (aChar == '\\')
						aChar = '\\';
					else
						throw new IllegalArgumentException("Illegal escape character \\" + aChar);
					out[outLen++] = aChar;
				}
			} else {
				out[outLen++] = aChar;
			}
		}
		return new String(out, 0, outLen);
	}

	@ValueConverter(rule = "STRING")
	public IValueConverter<String> STRING() {
		return new AbstractNullSafeConverter<String>() {
			@Override
			protected String internalToValue(String string, INode node) {
				try {
					return convertFromJavaString(string.substring(1, string.length() - 1), false);
				} catch(IllegalArgumentException e) {
					throw new ValueConverterException(e.getMessage(), node, e);
				}
			}

			@Override
			protected String internalToString(String value) {
				return '\'' + Strings.convertToJavaString(value, false) + '\'';
			}
		};
	}
	
	@ValueConverter(rule = "TEXT")
	public IValueConverter<String> TEXT() {
		return new AbstractNullSafeConverter<String>() {
			@Override
			protected String internalToValue(String string, INode node) {
				try {
					return convertFromJavaString(string.substring(1, string.length() - 1), false);
				} catch(IllegalArgumentException e) {
					throw new ValueConverterException(e.getMessage(), node, e);
				}
			}

			@Override
			protected String internalToString(String value) {
				return '\'' + Strings.convertToJavaString(value, false) + '\'';
			}
		};
	}
}