CharacterSetECI.java

/*
 * Copyright 2008 ZXing authors
 *
 * 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
 *
 * 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
 * limitations under the License.
 */

package com.google.zxing.common;

import com.google.zxing.FormatException;

import java.util.HashMap;
import java.util.Map;

/**
 * Encapsulates a Character Set ECI, according to
 * "Extended Channel Interpretations" 5.3.1.1 of ISO 18004.
 * 
 * @author Sean Owen
 */
public enum CharacterSetECI {

	// Enum name is a Java encoding valid for java.lang and java.io
	Cp437(new int[] { 0, 2 }), ISO8859_1(new int[] { 1, 3 }, "ISO-8859-1"), ISO8859_2(
			4, "ISO-8859-2"), ISO8859_3(5, "ISO-8859-3"), ISO8859_4(6,
			"ISO-8859-4"), ISO8859_5(7, "ISO-8859-5"), ISO8859_6(8,
			"ISO-8859-6"), ISO8859_7(9, "ISO-8859-7"), ISO8859_8(10,
			"ISO-8859-8"), ISO8859_9(11, "ISO-8859-9"), ISO8859_10(12,
			"ISO-8859-10"), ISO8859_11(13, "ISO-8859-11"), ISO8859_13(15,
			"ISO-8859-13"), ISO8859_14(16, "ISO-8859-14"), ISO8859_15(17,
			"ISO-8859-15"), ISO8859_16(18, "ISO-8859-16"), SJIS(20, "Shift_JIS"), Cp1250(
			21, "windows-1250"), Cp1251(22, "windows-1251"), Cp1252(23,
			"windows-1252"), Cp1256(24, "windows-1256"), UnicodeBigUnmarked(25,
			"UTF-16BE", "UnicodeBig"), UTF8(26, "UTF-8"), ASCII(new int[] { 27,
			170 }, "US-ASCII"), Big5(28), GB18030(29, "GB2312", "EUC_CN", "GBK"), EUC_KR(
			30, "EUC-KR");

	private static final Map<Integer, CharacterSetECI> VALUE_TO_ECI = new HashMap<>();
	private static final Map<String, CharacterSetECI> NAME_TO_ECI = new HashMap<>();
	static {
		for (CharacterSetECI eci : values()) {
			for (int value : eci.values) {
				VALUE_TO_ECI.put(value, eci);
			}
			NAME_TO_ECI.put(eci.name(), eci);
			for (String name : eci.otherEncodingNames) {
				NAME_TO_ECI.put(name, eci);
			}
		}
	}

	private final int[] values;
	private final String[] otherEncodingNames;

	CharacterSetECI(int value) {
		this(new int[] { value });
	}

	CharacterSetECI(int value, String... otherEncodingNames) {
		this.values = new int[] { value };
		this.otherEncodingNames = otherEncodingNames;
	}

	CharacterSetECI(int[] values, String... otherEncodingNames) {
		this.values = values;
		this.otherEncodingNames = otherEncodingNames;
	}

	public int getValue() {
		return values[0];
	}

	/**
	 * @param value
	 *            character set ECI value
	 * @return {@link CharacterSetECI} representing ECI of given value, or null
	 *         if it is legal but unsupported
	 * @throws FormatException
	 *             if ECI value is invalid
	 */
	public static CharacterSetECI getCharacterSetECIByValue(int value)
			throws FormatException {
		if (value < 0 || value >= 900) {
			throw FormatException.getFormatInstance();
		}
		return VALUE_TO_ECI.get(value);
	}

	/**
	 * @param name
	 *            character set ECI encoding name
	 * @return CharacterSetECI representing ECI for character encoding, or null
	 *         if it is legal but unsupported
	 */
	public static CharacterSetECI getCharacterSetECIByName(String name) {
		return NAME_TO_ECI.get(name);
	}

}