001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.commons.lang3.text.translate;
018
019/**
020 * Translates codepoints to their Unicode escaped value suitable for Java source.
021 * 
022 * @since 3.2
023 */
024public class JavaUnicodeEscaper extends UnicodeEscaper {
025
026    /**
027     * <p>
028     * Constructs a <code>JavaUnicodeEscaper</code> above the specified value (exclusive).
029     * </p>
030     * 
031     * @param codepoint
032     *            above which to escape
033     * @return the newly created {@code UnicodeEscaper} instance
034     */
035    public static JavaUnicodeEscaper above(final int codepoint) {
036        return outsideOf(0, codepoint);
037    }
038
039    /**
040     * <p>
041     * Constructs a <code>JavaUnicodeEscaper</code> below the specified value (exclusive).
042     * </p>
043     * 
044     * @param codepoint
045     *            below which to escape
046     * @return the newly created {@code UnicodeEscaper} instance
047     */
048    public static JavaUnicodeEscaper below(final int codepoint) {
049        return outsideOf(codepoint, Integer.MAX_VALUE);
050    }
051
052    /**
053     * <p>
054     * Constructs a <code>JavaUnicodeEscaper</code> between the specified values (inclusive).
055     * </p>
056     * 
057     * @param codepointLow
058     *            above which to escape
059     * @param codepointHigh
060     *            below which to escape
061     * @return the newly created {@code UnicodeEscaper} instance
062     */
063    public static JavaUnicodeEscaper between(final int codepointLow, final int codepointHigh) {
064        return new JavaUnicodeEscaper(codepointLow, codepointHigh, true);
065    }
066
067    /**
068     * <p>
069     * Constructs a <code>JavaUnicodeEscaper</code> outside of the specified values (exclusive).
070     * </p>
071     * 
072     * @param codepointLow
073     *            below which to escape
074     * @param codepointHigh
075     *            above which to escape
076     * @return the newly created {@code UnicodeEscaper} instance
077     */
078    public static JavaUnicodeEscaper outsideOf(final int codepointLow, final int codepointHigh) {
079        return new JavaUnicodeEscaper(codepointLow, codepointHigh, false);
080    }
081
082    /**
083     * <p>
084     * Constructs a <code>JavaUnicodeEscaper</code> for the specified range. This is the underlying method for the
085     * other constructors/builders. The <code>below</code> and <code>above</code> boundaries are inclusive when
086     * <code>between</code> is <code>true</code> and exclusive when it is <code>false</code>.
087     * </p>
088     * 
089     * @param below
090     *            int value representing the lowest codepoint boundary
091     * @param above
092     *            int value representing the highest codepoint boundary
093     * @param between
094     *            whether to escape between the boundaries or outside them
095     */
096    public JavaUnicodeEscaper(final int below, final int above, final boolean between) {
097        super(below, above, between);
098    }
099
100    /**
101     * Converts the given codepoint to a hex string of the form {@code "\\uXXXX\\uXXXX"}
102     * 
103     * @param codepoint
104     *            a Unicode code point
105     * @return the hex string for the given codepoint
106     */
107    @Override
108    protected String toUtf16Escape(final int codepoint) {
109        final char[] surrogatePair = Character.toChars(codepoint);
110        return "\\u" + hex(surrogatePair[0]) + "\\u" + hex(surrogatePair[1]);
111    }
112
113}