/*
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* Copyright 2007 ZXing authors
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*
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* Licensed under the Apache License, Version 2.0 (the "License");
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* you may not use this file except in compliance with the License.
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* You may obtain a copy of the License at
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS,
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* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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* See the License for the specific language governing permissions and
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* limitations under the License.
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*/
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/*namespace com.google.zxing.qrcode.decoder {*/
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import BitSource from '../../common/BitSource';
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import CharacterSetECI from '../../common/CharacterSetECI';
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import DecoderResult from '../../common/DecoderResult';
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import StringUtils from '../../common/StringUtils';
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import FormatException from '../../FormatException';
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import StringBuilder from '../../util/StringBuilder';
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import StringEncoding from '../../util/StringEncoding';
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import Mode from './Mode';
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/*import java.io.UnsupportedEncodingException;*/
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/*import java.util.ArrayList;*/
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/*import java.util.Collection;*/
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/*import java.util.List;*/
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/*import java.util.Map;*/
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/**
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* <p>QR Codes can encode text as bits in one of several modes, and can use multiple modes
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* in one QR Code. This class decodes the bits back into text.</p>
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*
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* <p>See ISO 18004:2006, 6.4.3 - 6.4.7</p>
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*
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* @author Sean Owen
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*/
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export default class DecodedBitStreamParser {
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static decode(bytes, version, ecLevel, hints) {
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const bits = new BitSource(bytes);
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let result = new StringBuilder();
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const byteSegments = new Array(); // 1
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// TYPESCRIPTPORT: I do not use constructor with size 1 as in original Java means capacity and the array length is checked below
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let symbolSequence = -1;
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let parityData = -1;
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try {
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let currentCharacterSetECI = null;
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let fc1InEffect = false;
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let mode;
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do {
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// While still another segment to read...
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if (bits.available() < 4) {
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// OK, assume we're done. Really, a TERMINATOR mode should have been recorded here
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mode = Mode.TERMINATOR;
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}
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else {
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const modeBits = bits.readBits(4);
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mode = Mode.forBits(modeBits); // mode is encoded by 4 bits
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}
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switch (mode) {
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case Mode.TERMINATOR:
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break;
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case Mode.FNC1_FIRST_POSITION:
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case Mode.FNC1_SECOND_POSITION:
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// We do little with FNC1 except alter the parsed result a bit according to the spec
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fc1InEffect = true;
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break;
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case Mode.STRUCTURED_APPEND:
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if (bits.available() < 16) {
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throw new FormatException();
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}
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// sequence number and parity is added later to the result metadata
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// Read next 8 bits (symbol sequence #) and 8 bits (data: parity), then continue
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symbolSequence = bits.readBits(8);
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parityData = bits.readBits(8);
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break;
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case Mode.ECI:
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// Count doesn't apply to ECI
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const value = DecodedBitStreamParser.parseECIValue(bits);
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currentCharacterSetECI = CharacterSetECI.getCharacterSetECIByValue(value);
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if (currentCharacterSetECI === null) {
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throw new FormatException();
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}
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break;
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case Mode.HANZI:
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// First handle Hanzi mode which does not start with character count
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// Chinese mode contains a sub set indicator right after mode indicator
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const subset = bits.readBits(4);
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const countHanzi = bits.readBits(mode.getCharacterCountBits(version));
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if (subset === DecodedBitStreamParser.GB2312_SUBSET) {
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DecodedBitStreamParser.decodeHanziSegment(bits, result, countHanzi);
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}
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break;
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default:
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// "Normal" QR code modes:
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// How many characters will follow, encoded in this mode?
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const count = bits.readBits(mode.getCharacterCountBits(version));
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switch (mode) {
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case Mode.NUMERIC:
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DecodedBitStreamParser.decodeNumericSegment(bits, result, count);
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break;
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case Mode.ALPHANUMERIC:
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DecodedBitStreamParser.decodeAlphanumericSegment(bits, result, count, fc1InEffect);
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break;
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case Mode.BYTE:
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DecodedBitStreamParser.decodeByteSegment(bits, result, count, currentCharacterSetECI, byteSegments, hints);
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break;
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case Mode.KANJI:
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DecodedBitStreamParser.decodeKanjiSegment(bits, result, count);
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break;
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default:
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throw new FormatException();
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}
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break;
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}
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} while (mode !== Mode.TERMINATOR);
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}
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catch (iae /*: IllegalArgumentException*/) {
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// from readBits() calls
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throw new FormatException();
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}
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return new DecoderResult(bytes, result.toString(), byteSegments.length === 0 ? null : byteSegments, ecLevel === null ? null : ecLevel.toString(), symbolSequence, parityData);
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}
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/**
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* See specification GBT 18284-2000
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*/
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static decodeHanziSegment(bits, result, count /*int*/) {
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// Don't crash trying to read more bits than we have available.
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if (count * 13 > bits.available()) {
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throw new FormatException();
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}
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// Each character will require 2 bytes. Read the characters as 2-byte pairs
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// and decode as GB2312 afterwards
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const buffer = new Uint8Array(2 * count);
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let offset = 0;
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while (count > 0) {
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// Each 13 bits encodes a 2-byte character
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const twoBytes = bits.readBits(13);
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let assembledTwoBytes = (((twoBytes / 0x060) << 8) & 0xFFFFFFFF) | (twoBytes % 0x060);
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if (assembledTwoBytes < 0x003BF) {
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// In the 0xA1A1 to 0xAAFE range
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assembledTwoBytes += 0x0A1A1;
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}
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else {
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// In the 0xB0A1 to 0xFAFE range
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assembledTwoBytes += 0x0A6A1;
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}
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buffer[offset] = /*(byte) */ ((assembledTwoBytes >> 8) & 0xFF);
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buffer[offset + 1] = /*(byte) */ (assembledTwoBytes & 0xFF);
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offset += 2;
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count--;
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}
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try {
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result.append(StringEncoding.decode(buffer, StringUtils.GB2312));
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// TYPESCRIPTPORT: TODO: implement GB2312 decode. StringView from MDN could be a starting point
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}
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catch (ignored /*: UnsupportedEncodingException*/) {
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throw new FormatException(ignored);
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}
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}
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static decodeKanjiSegment(bits, result, count /*int*/) {
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// Don't crash trying to read more bits than we have available.
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if (count * 13 > bits.available()) {
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throw new FormatException();
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}
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// Each character will require 2 bytes. Read the characters as 2-byte pairs
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// and decode as Shift_JIS afterwards
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const buffer = new Uint8Array(2 * count);
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let offset = 0;
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while (count > 0) {
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// Each 13 bits encodes a 2-byte character
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const twoBytes = bits.readBits(13);
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let assembledTwoBytes = (((twoBytes / 0x0C0) << 8) & 0xFFFFFFFF) | (twoBytes % 0x0C0);
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if (assembledTwoBytes < 0x01F00) {
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// In the 0x8140 to 0x9FFC range
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assembledTwoBytes += 0x08140;
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}
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else {
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// In the 0xE040 to 0xEBBF range
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assembledTwoBytes += 0x0C140;
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}
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buffer[offset] = /*(byte) */ (assembledTwoBytes >> 8);
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buffer[offset + 1] = /*(byte) */ assembledTwoBytes;
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offset += 2;
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count--;
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}
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// Shift_JIS may not be supported in some environments:
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try {
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result.append(StringEncoding.decode(buffer, StringUtils.SHIFT_JIS));
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// TYPESCRIPTPORT: TODO: implement SHIFT_JIS decode. StringView from MDN could be a starting point
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}
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catch (ignored /*: UnsupportedEncodingException*/) {
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throw new FormatException(ignored);
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}
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}
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static decodeByteSegment(bits, result, count /*int*/, currentCharacterSetECI, byteSegments, hints) {
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// Don't crash trying to read more bits than we have available.
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if (8 * count > bits.available()) {
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throw new FormatException();
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}
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const readBytes = new Uint8Array(count);
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for (let i = 0; i < count; i++) {
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readBytes[i] = /*(byte) */ bits.readBits(8);
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}
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let encoding;
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if (currentCharacterSetECI === null) {
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// The spec isn't clear on this mode; see
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// section 6.4.5: t does not say which encoding to assuming
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// upon decoding. I have seen ISO-8859-1 used as well as
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// Shift_JIS -- without anything like an ECI designator to
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// give a hint.
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encoding = StringUtils.guessEncoding(readBytes, hints);
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}
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else {
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encoding = currentCharacterSetECI.getName();
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}
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try {
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result.append(StringEncoding.decode(readBytes, encoding));
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}
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catch (ignored /*: UnsupportedEncodingException*/) {
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throw new FormatException(ignored);
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}
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byteSegments.push(readBytes);
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}
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static toAlphaNumericChar(value /*int*/) {
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if (value >= DecodedBitStreamParser.ALPHANUMERIC_CHARS.length) {
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throw new FormatException();
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}
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return DecodedBitStreamParser.ALPHANUMERIC_CHARS[value];
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}
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static decodeAlphanumericSegment(bits, result, count /*int*/, fc1InEffect) {
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// Read two characters at a time
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const start = result.length();
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while (count > 1) {
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if (bits.available() < 11) {
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throw new FormatException();
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}
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const nextTwoCharsBits = bits.readBits(11);
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result.append(DecodedBitStreamParser.toAlphaNumericChar(Math.floor(nextTwoCharsBits / 45)));
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result.append(DecodedBitStreamParser.toAlphaNumericChar(nextTwoCharsBits % 45));
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count -= 2;
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}
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if (count === 1) {
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// special case: one character left
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if (bits.available() < 6) {
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throw new FormatException();
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}
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result.append(DecodedBitStreamParser.toAlphaNumericChar(bits.readBits(6)));
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}
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// See section 6.4.8.1, 6.4.8.2
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if (fc1InEffect) {
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// We need to massage the result a bit if in an FNC1 mode:
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for (let i = start; i < result.length(); i++) {
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if (result.charAt(i) === '%') {
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if (i < result.length() - 1 && result.charAt(i + 1) === '%') {
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// %% is rendered as %
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result.deleteCharAt(i + 1);
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}
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else {
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// In alpha mode, % should be converted to FNC1 separator 0x1D
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result.setCharAt(i, String.fromCharCode(0x1D));
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}
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}
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}
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}
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}
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static decodeNumericSegment(bits, result, count /*int*/) {
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// Read three digits at a time
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while (count >= 3) {
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// Each 10 bits encodes three digits
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if (bits.available() < 10) {
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throw new FormatException();
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}
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const threeDigitsBits = bits.readBits(10);
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if (threeDigitsBits >= 1000) {
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throw new FormatException();
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}
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result.append(DecodedBitStreamParser.toAlphaNumericChar(Math.floor(threeDigitsBits / 100)));
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result.append(DecodedBitStreamParser.toAlphaNumericChar(Math.floor(threeDigitsBits / 10) % 10));
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result.append(DecodedBitStreamParser.toAlphaNumericChar(threeDigitsBits % 10));
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count -= 3;
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}
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if (count === 2) {
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// Two digits left over to read, encoded in 7 bits
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if (bits.available() < 7) {
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throw new FormatException();
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}
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const twoDigitsBits = bits.readBits(7);
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if (twoDigitsBits >= 100) {
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throw new FormatException();
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}
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result.append(DecodedBitStreamParser.toAlphaNumericChar(Math.floor(twoDigitsBits / 10)));
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result.append(DecodedBitStreamParser.toAlphaNumericChar(twoDigitsBits % 10));
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}
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else if (count === 1) {
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// One digit left over to read
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if (bits.available() < 4) {
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throw new FormatException();
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}
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const digitBits = bits.readBits(4);
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if (digitBits >= 10) {
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throw new FormatException();
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}
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result.append(DecodedBitStreamParser.toAlphaNumericChar(digitBits));
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}
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}
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static parseECIValue(bits) {
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const firstByte = bits.readBits(8);
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if ((firstByte & 0x80) === 0) {
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// just one byte
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return firstByte & 0x7F;
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}
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if ((firstByte & 0xC0) === 0x80) {
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// two bytes
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const secondByte = bits.readBits(8);
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return (((firstByte & 0x3F) << 8) & 0xFFFFFFFF) | secondByte;
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}
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if ((firstByte & 0xE0) === 0xC0) {
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// three bytes
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const secondThirdBytes = bits.readBits(16);
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return (((firstByte & 0x1F) << 16) & 0xFFFFFFFF) | secondThirdBytes;
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}
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throw new FormatException();
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}
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}
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/**
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* See ISO 18004:2006, 6.4.4 Table 5
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*/
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DecodedBitStreamParser.ALPHANUMERIC_CHARS = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ $%*+-./:';
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DecodedBitStreamParser.GB2312_SUBSET = 1;
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// function Uint8ArrayToString(a: Uint8Array): string {
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// const CHUNK_SZ = 0x8000;
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// const c = new StringBuilder();
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// for (let i = 0, length = a.length; i < length; i += CHUNK_SZ) {
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// c.append(String.fromCharCode.apply(null, a.subarray(i, i + CHUNK_SZ)));
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// }
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// return c.toString();
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// }
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