@zxing/library
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TypeScript port of ZXing multi-format 1D/2D barcode image processing library.
146 lines (145 loc) • 5.51 kB
JavaScript
/*
* Copyright (C) 2010 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.
*/
import BarcodeFormat from '../BarcodeFormat';
// import UPCEANReader from './UPCEANReader';
import AbstractUPCEANReader from './AbstractUPCEANReader';
import Result from '../Result';
import ResultPoint from '../ResultPoint';
import ResultMetadataType from '../ResultMetadataType';
import NotFoundException from '../NotFoundException';
/**
* @see UPCEANExtension2Support
*/
export default class UPCEANExtension5Support {
constructor() {
this.CHECK_DIGIT_ENCODINGS = [0x18, 0x14, 0x12, 0x11, 0x0C, 0x06, 0x03, 0x0A, 0x09, 0x05];
this.decodeMiddleCounters = Int32Array.from([0, 0, 0, 0]);
this.decodeRowStringBuffer = '';
}
decodeRow(rowNumber, row, extensionStartRange) {
let result = this.decodeRowStringBuffer;
let end = this.decodeMiddle(row, extensionStartRange, result);
let resultString = result.toString();
let extensionData = UPCEANExtension5Support.parseExtensionString(resultString);
let resultPoints = [
new ResultPoint((extensionStartRange[0] + extensionStartRange[1]) / 2.0, rowNumber),
new ResultPoint(end, rowNumber)
];
let extensionResult = new Result(resultString, null, 0, resultPoints, BarcodeFormat.UPC_EAN_EXTENSION, new Date().getTime());
if (extensionData != null) {
extensionResult.putAllMetadata(extensionData);
}
return extensionResult;
}
decodeMiddle(row, startRange, resultString) {
let counters = this.decodeMiddleCounters;
counters[0] = 0;
counters[1] = 0;
counters[2] = 0;
counters[3] = 0;
let end = row.getSize();
let rowOffset = startRange[1];
let lgPatternFound = 0;
for (let x = 0; x < 5 && rowOffset < end; x++) {
let bestMatch = AbstractUPCEANReader.decodeDigit(row, counters, rowOffset, AbstractUPCEANReader.L_AND_G_PATTERNS);
resultString += String.fromCharCode(('0'.charCodeAt(0) + bestMatch % 10));
for (let counter of counters) {
rowOffset += counter;
}
if (bestMatch >= 10) {
lgPatternFound |= 1 << (4 - x);
}
if (x !== 4) {
// Read off separator if not last
rowOffset = row.getNextSet(rowOffset);
rowOffset = row.getNextUnset(rowOffset);
}
}
if (resultString.length !== 5) {
throw new NotFoundException();
}
let checkDigit = this.determineCheckDigit(lgPatternFound);
if (UPCEANExtension5Support.extensionChecksum(resultString.toString()) !== checkDigit) {
throw new NotFoundException();
}
return rowOffset;
}
static extensionChecksum(s) {
let length = s.length;
let sum = 0;
for (let i = length - 2; i >= 0; i -= 2) {
sum += s.charAt(i).charCodeAt(0) - '0'.charCodeAt(0);
}
sum *= 3;
for (let i = length - 1; i >= 0; i -= 2) {
sum += s.charAt(i).charCodeAt(0) - '0'.charCodeAt(0);
}
sum *= 3;
return sum % 10;
}
determineCheckDigit(lgPatternFound) {
for (let d = 0; d < 10; d++) {
if (lgPatternFound === this.CHECK_DIGIT_ENCODINGS[d]) {
return d;
}
}
throw new NotFoundException();
}
static parseExtensionString(raw) {
if (raw.length !== 5) {
return null;
}
let value = UPCEANExtension5Support.parseExtension5String(raw);
if (value == null) {
return null;
}
return new Map([[ResultMetadataType.SUGGESTED_PRICE, value]]);
}
static parseExtension5String(raw) {
let currency;
switch (raw.charAt(0)) {
case '0':
currency = '£';
break;
case '5':
currency = '$';
break;
case '9':
// Reference: http://www.jollytech.com
switch (raw) {
case '90000':
// No suggested retail price
return null;
case '99991':
// Complementary
return '0.00';
case '99990':
return 'Used';
}
// Otherwise... unknown currency?
currency = '';
break;
default:
currency = '';
break;
}
let rawAmount = parseInt(raw.substring(1));
let unitsString = (rawAmount / 100).toString();
let hundredths = rawAmount % 100;
let hundredthsString = hundredths < 10 ? '0' + hundredths : hundredths.toString(); // fixme
return currency + unitsString + '.' + hundredthsString;
}
}