android二维码zxing源代码

/* * 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.google.zxing.qrcode.decoder; import com.google.zxing.FormatException; import com.google.zxing.common.BitMatrix; /** * See ISO 18004:2006 Annex D * * @author Sean Owen */ public final class Version { /** * See ISO 18004:2006 Annex D. * Element i represents the raw version bits that specify version i + 7 */ private static final int[] VERSION_DECODE_INFO = { 0x07C94, 0x085BC, 0x09A99, 0x0A4D3, 0x0BBF6, 0x0C762, 0x0D847, 0x0E60D, 0x0F928, 0x10B78, 0x1145D, 0x12A17, 0x13532, 0x149A6, 0x15683, 0x168C9, 0x177EC, 0x18EC4, 0x191E1, 0x1AFAB, 0x1B08E, 0x1CC1A, 0x1D33F, 0x1ED75, 0x1F250, 0x209D5, 0x216F0, 0x228BA, 0x2379F, 0x24B0B, 0x2542E, 0x26A64, 0x27541, 0x28C69 }; private static final Version[] VERSIONS = buildVersions(); private final int versionNumber; private final int[] alignmentPatternCenters; private final ECBlocks[] ecBlocks; private final int totalCodewords; private Version(int versionNumber, int[] alignmentPatternCenters, ECBlocks ecBlocks1, ECBlocks ecBlocks2, ECBlocks ecBlocks3, ECBlocks ecBlocks4) { this.versionNumber = versionNumber; this.alignmentPatternCenters = alignmentPatternCenters; this.ecBlocks = new ECBlocks[]{ecBlocks1, ecBlocks2, ecBlocks3, ecBlocks4}; int total = 0; int ecCodewords = ecBlocks1.getECCodewordsPerBlock(); ECB[] ecbArray = ecBlocks1.getECBlocks(); for (int i = 0; i < ecbArray.length; i++) { ECB ecBlock = ecbArray[i]; total += ecBlock.getCount() * (ecBlock.getDataCodewords() + ecCodewords); } this.totalCodewords = total; } public int getVersionNumber() { return versionNumber; } public int[] getAlignmentPatternCenters() { return alignmentPatternCenters; } public int getTotalCodewords() { return totalCodewords; } public int getDimensionForVersion() { return 17 + 4 * versionNumber; } public ECBlocks getECBlocksForLevel(ErrorCorrectionLevel ecLevel) { return ecBlocks[ecLevel.ordinal()]; } /** * <p>Deduces version information purely from QR Code dimensions.</p> * * @param dimension dimension in modules * @return {@link Version} for a QR Code of that dimension * @throws FormatException if dimension is not 1 mod 4 */ public static Version getProvisionalVersionForDimension(int dimension) throws FormatException { if (dimension % 4 != 1) { throw FormatException.getFormatInstance(); } try { return getVersionForNumber((dimension - 17) >> 2); } catch (IllegalArgumentException iae) { throw FormatException.getFormatInstance(); } } public static Version getVersionForNumber(int versionNumber) { if (versionNumber < 1 || versionNumber > 40) { throw new IllegalArgumentException(); } return VERSIONS[versionNumber - 1]; } static Version decodeVersionInformation(int versionBits) { int bestDifference = Integer.MAX_VALUE; int bestVersion = 0; for (int i = 0; i < VERSION_DECODE_INFO.length; i++) { int targetVersion = VERSION_DECODE_INFO[i]; // Do the version info bits match exactly? done. if (targetVersion == versionBits) { return getVersionForNumber(i + 7); } // Otherwise see if this is the closest to a real version info bit string // we have seen so far int bitsDifference = FormatInformation.numBitsDiffering(versionBits, targetVersion); if (bitsDifference < bestDifference) { bestVersion = i + 7; bestDifference = bitsDifference; } } // We can tolerate up to 3 bits of error since no two version info codewords will // differ in less than 8 bits. if (bestDifference <= 3) { return getVersionForNumber(bestVersion); } // If we didn't find a close enough match, fail return null; } /** * See ISO 18004:2006 Annex E */ BitMatrix buildFunctionPattern() { int dimension = getDimensionForVersion(); BitMatrix bitMatrix = new BitMatrix(dimension); // Top left finder pattern + separator + format bitMatrix.setRegion(0, 0, 9, 9); // Top right finder pattern + separator + format bitMatrix.setRegion(dimension - 8, 0, 8, 9); // Bottom left finder pattern + separator + format bitMatrix.setRegion(0, dimension - 8, 9, 8); // Alignment patterns int max = alignmentPatternCenters.length; for (int x = 0; x < max; x++) { int i = alignmentPatternCenters[x] - 2; for (int y = 0; y < max; y++) { if ((x == 0 && (y == 0 || y == max - 1)) || (x == max - 1 && y == 0)) { // No alignment patterns near the three finder paterns continue; } bitMatrix.setRegion(alignmentPatternCenters[y] - 2, i, 5, 5); } } // Vertical timing pattern bitMatrix.setRegion(6, 9, 1, dimension - 17); // Horizontal timing pattern bitMatrix.setRegion(9, 6, dimension - 17, 1); if (versionNumber > 6) { // Version info, top right bitMatrix.setRegion(dimension - 11, 0, 3, 6); // Version info, bottom left bitMatrix.setRegion(0, dimension - 11, 6, 3); } return bitMatrix; } /** * <p>Encapsulates a set of error-correction blocks in one symbol version. Most versions will * use blocks of differing sizes within one version, so, this encapsulates the parameters for * each set of blocks. It also holds the number of error-correction codewords per block since it * will be the same across all blocks within one version.</p> */ public static final class ECBlocks { private final int ecCodewordsPerBlock; private final ECB[] ecBlocks; ECBlocks(int ecCodewordsPerBlock, ECB ecBlocks) { this.ecCodewordsPerBlock = ecCodewordsPerBlock; this.ecBlocks = new ECB[]{ecBlocks}; } ECBlocks(int ecCodewordsPerBlock, ECB ecBlocks1, ECB ecBlocks2) { this.ecCodewordsPerBlock = ecCodewordsPerBlock; this.ecBlocks = new ECB[]{ecBlocks1, ecBlocks2}; } public int getECCodewordsPerBlock() { return ecCodewordsPerBlock; } public int getNumBlocks() { int total = 0; for (int i = 0; i < ecBlocks.length; i++) { total += ecBlocks[i].getCount(); } return total; } public int getTotalECCodewords() { return ecCodewordsPerBlock * getNumBlocks(); } public ECB[] getECBlocks() { return ecBlocks; } } /** * <p>Encapsualtes the parameters for one error-correction block in one symbol version. * This includes the number of data codewords, and the number of times a block with these * parameters is used consecutively in the QR code version's format.</p> */ public static final class ECB { private final int count; private final int dataCodewords; ECB(int count, int dataCodewords) { this.count = count; this.dataCodewords = dataCodewords; } public int getCount() { return count; } public int getDataCodewords() { return dataCodewords; } } public String toString()