/*
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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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import BarcodeFormat from '../BarcodeFormat';
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import UPCEANReader from './UPCEANReader';
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/**
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* <p>Implements decoding of the EAN-8 format.</p>
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*
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* @author Sean Owen
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*/
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export default class EAN8Reader extends UPCEANReader {
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constructor() {
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super();
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this.decodeMiddleCounters = Int32Array.from([0, 0, 0, 0]);
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}
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decodeMiddle(row, startRange, resultString) {
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const counters = this.decodeMiddleCounters;
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counters[0] = 0;
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counters[1] = 0;
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counters[2] = 0;
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counters[3] = 0;
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let end = row.getSize();
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let rowOffset = startRange[1];
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for (let x = 0; x < 4 && rowOffset < end; x++) {
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let bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_PATTERNS);
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resultString += String.fromCharCode(('0'.charCodeAt(0) + bestMatch));
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for (let counter of counters) {
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rowOffset += counter;
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}
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}
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let middleRange = UPCEANReader.findGuardPattern(row, rowOffset, true, UPCEANReader.MIDDLE_PATTERN, new Int32Array(UPCEANReader.MIDDLE_PATTERN.length).fill(0));
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rowOffset = middleRange[1];
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for (let x = 0; x < 4 && rowOffset < end; x++) {
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let bestMatch = UPCEANReader.decodeDigit(row, counters, rowOffset, UPCEANReader.L_PATTERNS);
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resultString += String.fromCharCode(('0'.charCodeAt(0) + bestMatch));
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for (let counter of counters) {
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rowOffset += counter;
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}
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}
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return { rowOffset, resultString };
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}
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getBarcodeFormat() {
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return BarcodeFormat.EAN_8;
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}
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}
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