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QR Code generator only, fork of ZXing barcode scanning library for Java, this is minified version
There is a newer version: 1.0.1
/*
 * Copyright 2007 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 org.javastack.qr;

/**
 * 
 * See ISO 18004:2006, 6.4.1, Tables 2 and 3. This enum encapsulates the various
 * modes in which data can be encoded to bits in the QR code standard.
 * 
 *
 * @author Sean Owen
 */
public enum Mode {
	// @formatter:off
	TERMINATOR(new int[] { 0, 0, 0 }, 0x00), // Not really a mode...
	NUMERIC(new int[] { 10, 12, 14 }, 0x01), //
	ALPHANUMERIC(new int[] { 9, 11, 13 }, 0x02), //
	STRUCTURED_APPEND(new int[] { 0, 0, 0 }, 0x03), // Not supported
	BYTE(new int[] { 8, 16, 16 }, 0x04), //
	ECI(new int[] { 0, 0, 0 }, 0x07), // character counts don't apply
	KANJI(new int[] { 8, 10, 12 }, 0x08), //
	FNC1_FIRST_POSITION(new int[] { 0, 0, 0 }, 0x05), //
	FNC1_SECOND_POSITION(new int[] { 0, 0, 0 }, 0x09),
	/** See GBT 18284-2000; "Hanzi" is a transliteration of this mode name. */
	HANZI(new int[] { 8, 10, 12 }, 0x0D);
	// @formatter:on

	private final int[] characterCountBitsForVersions;
	private final int bits;

	Mode(int[] characterCountBitsForVersions, int bits) {
		this.characterCountBitsForVersions = characterCountBitsForVersions;
		this.bits = bits;
	}

	/**
	 * @param bits four bits encoding a QR Code data mode
	 * @return Mode encoded by these bits
	 * @throws IllegalArgumentException if bits do not correspond to a known mode
	 */
	public static Mode forBits(int bits) {
		switch (bits) {
			case 0x0:
				return TERMINATOR;
			case 0x1:
				return NUMERIC;
			case 0x2:
				return ALPHANUMERIC;
			case 0x3:
				return STRUCTURED_APPEND;
			case 0x4:
				return BYTE;
			case 0x5:
				return FNC1_FIRST_POSITION;
			case 0x7:
				return ECI;
			case 0x8:
				return KANJI;
			case 0x9:
				return FNC1_SECOND_POSITION;
			case 0xD:
				// 0xD is defined in GBT 18284-2000, may not be supported in foreign country
				return HANZI;
			default:
				throw new IllegalArgumentException();
		}
	}

	/**
	 * @param version version in question
	 * @return number of bits used, in this QR Code symbol {@link Version}, to
	 *         encode the count of characters that will follow encoded in this Mode
	 */
	public int getCharacterCountBits(Version version) {
		int number = version.getVersionNumber();
		int offset;
		if (number <= 9) {
			offset = 0;
		} else if (number <= 26) {
			offset = 1;
		} else {
			offset = 2;
		}
		return characterCountBitsForVersions[offset];
	}

	public int getBits() {
		return bits;
	}
}