From 05cc2023daa57bfdb813e478ddb61c1b2f3156c4 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Dominik=20Sch=C3=BCrmann?= Date: Sat, 5 Oct 2013 20:43:42 +0200 Subject: Add parts of zxing library to generate qr codes --- .../zxing/qrcode/decoder/BitMatrixParser.java | 203 +++++++++++++++++++++ 1 file changed, 203 insertions(+) create mode 100644 OpenPGP-Keychain/src/com/google/zxing/qrcode/decoder/BitMatrixParser.java (limited to 'OpenPGP-Keychain/src/com/google/zxing/qrcode/decoder/BitMatrixParser.java') diff --git a/OpenPGP-Keychain/src/com/google/zxing/qrcode/decoder/BitMatrixParser.java b/OpenPGP-Keychain/src/com/google/zxing/qrcode/decoder/BitMatrixParser.java new file mode 100644 index 000000000..9d131a554 --- /dev/null +++ b/OpenPGP-Keychain/src/com/google/zxing/qrcode/decoder/BitMatrixParser.java @@ -0,0 +1,203 @@ +/* + * 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; + +/** + * @author Sean Owen + */ +final class BitMatrixParser { + + private final BitMatrix bitMatrix; + private Version parsedVersion; + private FormatInformation parsedFormatInfo; + + /** + * @param bitMatrix {@link BitMatrix} to parse + * @throws FormatException if dimension is not >= 21 and 1 mod 4 + */ + BitMatrixParser(BitMatrix bitMatrix) throws FormatException { + int dimension = bitMatrix.getHeight(); + if (dimension < 21 || (dimension & 0x03) != 1) { + throw FormatException.getFormatInstance(); + } + this.bitMatrix = bitMatrix; + } + + /** + *

Reads format information from one of its two locations within the QR Code.

+ * + * @return {@link FormatInformation} encapsulating the QR Code's format info + * @throws FormatException if both format information locations cannot be parsed as + * the valid encoding of format information + */ + FormatInformation readFormatInformation() throws FormatException { + + if (parsedFormatInfo != null) { + return parsedFormatInfo; + } + + // Read top-left format info bits + int formatInfoBits1 = 0; + for (int i = 0; i < 6; i++) { + formatInfoBits1 = copyBit(i, 8, formatInfoBits1); + } + // .. and skip a bit in the timing pattern ... + formatInfoBits1 = copyBit(7, 8, formatInfoBits1); + formatInfoBits1 = copyBit(8, 8, formatInfoBits1); + formatInfoBits1 = copyBit(8, 7, formatInfoBits1); + // .. and skip a bit in the timing pattern ... + for (int j = 5; j >= 0; j--) { + formatInfoBits1 = copyBit(8, j, formatInfoBits1); + } + + // Read the top-right/bottom-left pattern too + int dimension = bitMatrix.getHeight(); + int formatInfoBits2 = 0; + int jMin = dimension - 7; + for (int j = dimension - 1; j >= jMin; j--) { + formatInfoBits2 = copyBit(8, j, formatInfoBits2); + } + for (int i = dimension - 8; i < dimension; i++) { + formatInfoBits2 = copyBit(i, 8, formatInfoBits2); + } + + parsedFormatInfo = FormatInformation.decodeFormatInformation(formatInfoBits1, formatInfoBits2); + if (parsedFormatInfo != null) { + return parsedFormatInfo; + } + throw FormatException.getFormatInstance(); + } + + /** + *

Reads version information from one of its two locations within the QR Code.

+ * + * @return {@link Version} encapsulating the QR Code's version + * @throws FormatException if both version information locations cannot be parsed as + * the valid encoding of version information + */ + Version readVersion() throws FormatException { + + if (parsedVersion != null) { + return parsedVersion; + } + + int dimension = bitMatrix.getHeight(); + + int provisionalVersion = (dimension - 17) >> 2; + if (provisionalVersion <= 6) { + return Version.getVersionForNumber(provisionalVersion); + } + + // Read top-right version info: 3 wide by 6 tall + int versionBits = 0; + int ijMin = dimension - 11; + for (int j = 5; j >= 0; j--) { + for (int i = dimension - 9; i >= ijMin; i--) { + versionBits = copyBit(i, j, versionBits); + } + } + + parsedVersion = Version.decodeVersionInformation(versionBits); + if (parsedVersion != null && parsedVersion.getDimensionForVersion() == dimension) { + return parsedVersion; + } + + // Hmm, failed. Try bottom left: 6 wide by 3 tall + versionBits = 0; + for (int i = 5; i >= 0; i--) { + for (int j = dimension - 9; j >= ijMin; j--) { + versionBits = copyBit(i, j, versionBits); + } + } + + parsedVersion = Version.decodeVersionInformation(versionBits); + if (parsedVersion != null && parsedVersion.getDimensionForVersion() == dimension) { + return parsedVersion; + } + throw FormatException.getFormatInstance(); + } + + private int copyBit(int i, int j, int versionBits) { + return bitMatrix.get(i, j) ? (versionBits << 1) | 0x1 : versionBits << 1; + } + + /** + *

Reads the bits in the {@link BitMatrix} representing the finder pattern in the + * correct order in order to reconstitute the codewords bytes contained within the + * QR Code.

+ * + * @return bytes encoded within the QR Code + * @throws FormatException if the exact number of bytes expected is not read + */ + byte[] readCodewords() throws FormatException { + + FormatInformation formatInfo = readFormatInformation(); + Version version = readVersion(); + + // Get the data mask for the format used in this QR Code. This will exclude + // some bits from reading as we wind through the bit matrix. + DataMask dataMask = DataMask.forReference((int) formatInfo.getDataMask()); + int dimension = bitMatrix.getHeight(); + dataMask.unmaskBitMatrix(bitMatrix, dimension); + + BitMatrix functionPattern = version.buildFunctionPattern(); + + boolean readingUp = true; + byte[] result = new byte[version.getTotalCodewords()]; + int resultOffset = 0; + int currentByte = 0; + int bitsRead = 0; + // Read columns in pairs, from right to left + for (int j = dimension - 1; j > 0; j -= 2) { + if (j == 6) { + // Skip whole column with vertical alignment pattern; + // saves time and makes the other code proceed more cleanly + j--; + } + // Read alternatingly from bottom to top then top to bottom + for (int count = 0; count < dimension; count++) { + int i = readingUp ? dimension - 1 - count : count; + for (int col = 0; col < 2; col++) { + // Ignore bits covered by the function pattern + if (!functionPattern.get(j - col, i)) { + // Read a bit + bitsRead++; + currentByte <<= 1; + if (bitMatrix.get(j - col, i)) { + currentByte |= 1; + } + // If we've made a whole byte, save it off + if (bitsRead == 8) { + result[resultOffset++] = (byte) currentByte; + bitsRead = 0; + currentByte = 0; + } + } + } + } + readingUp ^= true; // readingUp = !readingUp; // switch directions + } + if (resultOffset != version.getTotalCodewords()) { + throw FormatException.getFormatInstance(); + } + return result; + } + +} \ No newline at end of file -- cgit v1.2.3