Java tutorial
/* * 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 com.itextpdf.text.pdf.qrcode; /** * <p>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.</p> * * @author Sean Owen * @since 5.0.2 */ public final class Mode { // No, we can't use an enum here. J2ME doesn't support it. public static final Mode TERMINATOR = new Mode(new int[] { 0, 0, 0 }, 0x00, "TERMINATOR"); // Not really a mode... public static final Mode NUMERIC = new Mode(new int[] { 10, 12, 14 }, 0x01, "NUMERIC"); public static final Mode ALPHANUMERIC = new Mode(new int[] { 9, 11, 13 }, 0x02, "ALPHANUMERIC"); public static final Mode STRUCTURED_APPEND = new Mode(new int[] { 0, 0, 0 }, 0x03, "STRUCTURED_APPEND"); // Not supported public static final Mode BYTE = new Mode(new int[] { 8, 16, 16 }, 0x04, "BYTE"); public static final Mode ECI = new Mode(null, 0x07, "ECI"); // character counts don't apply public static final Mode KANJI = new Mode(new int[] { 8, 10, 12 }, 0x08, "KANJI"); public static final Mode FNC1_FIRST_POSITION = new Mode(null, 0x05, "FNC1_FIRST_POSITION"); public static final Mode FNC1_SECOND_POSITION = new Mode(null, 0x09, "FNC1_SECOND_POSITION"); private final int[] characterCountBitsForVersions; private final int bits; private final String name; private Mode(int[] characterCountBitsForVersions, int bits, String name) { this.characterCountBitsForVersions = characterCountBitsForVersions; this.bits = bits; this.name = name; } /** * @param bits four bits encoding a QR Code data mode * @return {@link 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; 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 {@link Mode} */ public int getCharacterCountBits(Version version) { if (characterCountBitsForVersions == null) { throw new IllegalArgumentException("Character count doesn't apply to this mode"); } 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; } public String getName() { return name; } public String toString() { return name; } }