/*
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* Copyright 2008 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.oned {*/
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import BarcodeFormat from '../BarcodeFormat';
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import ChecksumException from '../ChecksumException';
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import FormatException from '../FormatException';
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import NotFoundException from '../NotFoundException';
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import OneDReader from './OneDReader';
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import Result from '../Result';
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import ResultPoint from '../ResultPoint';
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/**
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* <p>Decodes Code 39 barcodes. Supports "Full ASCII Code 39" if USE_CODE_39_EXTENDED_MODE is set.</p>
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*
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* @author Sean Owen
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* @see Code93Reader
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*/
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export default class Code39Reader extends OneDReader {
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/**
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* Creates a reader that assumes all encoded data is data, and does not treat the final
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* character as a check digit. It will not decoded "extended Code 39" sequences.
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*/
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// public Code39Reader() {
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// this(false);
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// }
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/**
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* Creates a reader that can be configured to check the last character as a check digit.
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* It will not decoded "extended Code 39" sequences.
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*
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* @param usingCheckDigit if true, treat the last data character as a check digit, not
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* data, and verify that the checksum passes.
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*/
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// public Code39Reader(boolean usingCheckDigit) {
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// this(usingCheckDigit, false);
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// }
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/**
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* Creates a reader that can be configured to check the last character as a check digit,
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* or optionally attempt to decode "extended Code 39" sequences that are used to encode
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* the full ASCII character set.
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*
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* @param usingCheckDigit if true, treat the last data character as a check digit, not
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* data, and verify that the checksum passes.
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* @param extendedMode if true, will attempt to decode extended Code 39 sequences in the
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* text.
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*/
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constructor(usingCheckDigit = false, extendedMode = false) {
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super();
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this.usingCheckDigit = usingCheckDigit;
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this.extendedMode = extendedMode;
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this.decodeRowResult = '';
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this.counters = new Int32Array(9);
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}
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decodeRow(rowNumber, row, hints) {
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let theCounters = this.counters;
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theCounters.fill(0);
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this.decodeRowResult = '';
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let start = Code39Reader.findAsteriskPattern(row, theCounters);
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// Read off white space
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let nextStart = row.getNextSet(start[1]);
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let end = row.getSize();
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let decodedChar;
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let lastStart;
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do {
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Code39Reader.recordPattern(row, nextStart, theCounters);
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let pattern = Code39Reader.toNarrowWidePattern(theCounters);
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if (pattern < 0) {
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throw new NotFoundException();
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}
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decodedChar = Code39Reader.patternToChar(pattern);
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this.decodeRowResult += decodedChar;
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lastStart = nextStart;
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for (let counter of theCounters) {
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nextStart += counter;
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}
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// Read off white space
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nextStart = row.getNextSet(nextStart);
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} while (decodedChar !== '*');
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this.decodeRowResult = this.decodeRowResult.substring(0, this.decodeRowResult.length - 1); // remove asterisk
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// Look for whitespace after pattern:
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let lastPatternSize = 0;
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for (let counter of theCounters) {
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lastPatternSize += counter;
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}
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let whiteSpaceAfterEnd = nextStart - lastStart - lastPatternSize;
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// If 50% of last pattern size, following last pattern, is not whitespace, fail
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// (but if it's whitespace to the very end of the image, that's OK)
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if (nextStart !== end && (whiteSpaceAfterEnd * 2) < lastPatternSize) {
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throw new NotFoundException();
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}
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if (this.usingCheckDigit) {
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let max = this.decodeRowResult.length - 1;
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let total = 0;
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for (let i = 0; i < max; i++) {
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total += Code39Reader.ALPHABET_STRING.indexOf(this.decodeRowResult.charAt(i));
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}
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if (this.decodeRowResult.charAt(max) !== Code39Reader.ALPHABET_STRING.charAt(total % 43)) {
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throw new ChecksumException();
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}
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this.decodeRowResult = this.decodeRowResult.substring(0, max);
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}
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if (this.decodeRowResult.length === 0) {
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// false positive
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throw new NotFoundException();
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}
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let resultString;
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if (this.extendedMode) {
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resultString = Code39Reader.decodeExtended(this.decodeRowResult);
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}
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else {
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resultString = this.decodeRowResult;
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}
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let left = (start[1] + start[0]) / 2.0;
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let right = lastStart + lastPatternSize / 2.0;
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return new Result(resultString, null, 0, [new ResultPoint(left, rowNumber), new ResultPoint(right, rowNumber)], BarcodeFormat.CODE_39, new Date().getTime());
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}
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static findAsteriskPattern(row, counters) {
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let width = row.getSize();
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let rowOffset = row.getNextSet(0);
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let counterPosition = 0;
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let patternStart = rowOffset;
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let isWhite = false;
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let patternLength = counters.length;
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for (let i = rowOffset; i < width; i++) {
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if (row.get(i) !== isWhite) {
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counters[counterPosition]++;
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}
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else {
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if (counterPosition === patternLength - 1) {
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// Look for whitespace before start pattern, >= 50% of width of start pattern
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if (this.toNarrowWidePattern(counters) === Code39Reader.ASTERISK_ENCODING &&
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row.isRange(Math.max(0, patternStart - Math.floor((i - patternStart) / 2)), patternStart, false)) {
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return [patternStart, i];
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}
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patternStart += counters[0] + counters[1];
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counters.copyWithin(0, 2, 2 + counterPosition - 1);
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counters[counterPosition - 1] = 0;
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counters[counterPosition] = 0;
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counterPosition--;
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}
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else {
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counterPosition++;
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}
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counters[counterPosition] = 1;
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isWhite = !isWhite;
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}
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}
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throw new NotFoundException();
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}
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// For efficiency, returns -1 on failure. Not throwing here saved as many as 700 exceptions
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// per image when using some of our blackbox images.
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static toNarrowWidePattern(counters) {
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let numCounters = counters.length;
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let maxNarrowCounter = 0;
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let wideCounters;
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do {
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let minCounter = 0x7fffffff;
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for (let counter of counters) {
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if (counter < minCounter && counter > maxNarrowCounter) {
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minCounter = counter;
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}
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}
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maxNarrowCounter = minCounter;
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wideCounters = 0;
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let totalWideCountersWidth = 0;
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let pattern = 0;
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for (let i = 0; i < numCounters; i++) {
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let counter = counters[i];
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if (counter > maxNarrowCounter) {
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pattern |= 1 << (numCounters - 1 - i);
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wideCounters++;
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totalWideCountersWidth += counter;
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}
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}
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if (wideCounters === 3) {
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// Found 3 wide counters, but are they close enough in width?
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// We can perform a cheap, conservative check to see if any individual
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// counter is more than 1.5 times the average:
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for (let i = 0; i < numCounters && wideCounters > 0; i++) {
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let counter = counters[i];
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if (counter > maxNarrowCounter) {
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wideCounters--;
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// totalWideCountersWidth = 3 * average, so this checks if counter >= 3/2 * average
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if ((counter * 2) >= totalWideCountersWidth) {
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return -1;
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}
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}
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}
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return pattern;
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}
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} while (wideCounters > 3);
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return -1;
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}
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static patternToChar(pattern) {
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for (let i = 0; i < Code39Reader.CHARACTER_ENCODINGS.length; i++) {
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if (Code39Reader.CHARACTER_ENCODINGS[i] === pattern) {
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return Code39Reader.ALPHABET_STRING.charAt(i);
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}
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}
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if (pattern === Code39Reader.ASTERISK_ENCODING) {
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return '*';
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}
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throw new NotFoundException();
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}
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static decodeExtended(encoded) {
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let length = encoded.length;
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let decoded = '';
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for (let i = 0; i < length; i++) {
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let c = encoded.charAt(i);
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if (c === '+' || c === '$' || c === '%' || c === '/') {
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let next = encoded.charAt(i + 1);
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let decodedChar = '\0';
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switch (c) {
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case '+':
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// +A to +Z map to a to z
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if (next >= 'A' && next <= 'Z') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) + 32);
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}
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else {
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throw new FormatException();
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}
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break;
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case '$':
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// $A to $Z map to control codes SH to SB
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if (next >= 'A' && next <= 'Z') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) - 64);
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}
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else {
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throw new FormatException();
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}
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break;
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case '%':
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// %A to %E map to control codes ESC to US
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if (next >= 'A' && next <= 'E') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) - 38);
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}
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else if (next >= 'F' && next <= 'J') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) - 11);
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}
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else if (next >= 'K' && next <= 'O') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) + 16);
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}
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else if (next >= 'P' && next <= 'T') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) + 43);
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}
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else if (next === 'U') {
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decodedChar = '\0';
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}
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else if (next === 'V') {
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decodedChar = '@';
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}
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else if (next === 'W') {
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decodedChar = '`';
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}
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else if (next === 'X' || next === 'Y' || next === 'Z') {
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decodedChar = '\x7f';
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}
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else {
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throw new FormatException();
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}
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break;
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case '/':
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// /A to /O map to ! to , and /Z maps to :
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if (next >= 'A' && next <= 'O') {
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decodedChar = String.fromCharCode(next.charCodeAt(0) - 32);
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}
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else if (next === 'Z') {
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decodedChar = ':';
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}
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else {
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throw new FormatException();
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}
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break;
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}
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decoded += decodedChar;
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// bump up i again since we read two characters
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i++;
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}
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else {
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decoded += c;
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}
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}
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return decoded;
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}
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}
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Code39Reader.ALPHABET_STRING = '0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ-. $/+%';
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/**
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* These represent the encodings of characters, as patterns of wide and narrow bars.
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* The 9 least-significant bits of each int correspond to the pattern of wide and narrow,
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* with 1s representing "wide" and 0s representing narrow.
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*/
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Code39Reader.CHARACTER_ENCODINGS = [
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0x034, 0x121, 0x061, 0x160, 0x031, 0x130, 0x070, 0x025, 0x124, 0x064,
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0x109, 0x049, 0x148, 0x019, 0x118, 0x058, 0x00D, 0x10C, 0x04C, 0x01C,
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0x103, 0x043, 0x142, 0x013, 0x112, 0x052, 0x007, 0x106, 0x046, 0x016,
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0x181, 0x0C1, 0x1C0, 0x091, 0x190, 0x0D0, 0x085, 0x184, 0x0C4, 0x0A8,
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0x0A2, 0x08A, 0x02A // /-%
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];
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Code39Reader.ASTERISK_ENCODING = 0x094;
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