zxing-js/library

/*
 * Copyright 2008 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 BitArray from '../common/BitArray';
import DecodeHintType from '../DecodeHintType';

import Result from '../Result';
import OneDReader from './OneDReader';
import UPCEANReader from './UPCEANReader';
import EAN13Reader from './EAN13Reader';
import EAN8Reader from './EAN8Reader';
import UPCAReader from './UPCAReader';
import NotFoundException from '../NotFoundException';
import UPCEReader from './UPCEReader';
import { Collection } from 'src/customTypings';

/**
 * <p>A reader that can read all available UPC/EAN formats. If a caller wants to try to
 * read all such formats, it is most efficient to use this implementation rather than invoke
 * individual readers.</p>
 *
 * @author Sean Owen
 */
export default class MultiFormatUPCEANReader extends OneDReader {
  private readers: UPCEANReader[];

  public constructor(hints?: Map<DecodeHintType, any>) {
    super();
    let possibleFormats = hints == null ? null : <BarcodeFormat[]>hints.get(DecodeHintType.POSSIBLE_FORMATS);
    let readers: Collection<UPCEANReader> = [];
    if (possibleFormats != null) {

      if (possibleFormats.indexOf(BarcodeFormat.EAN_13) > -1) {
        readers.push(new EAN13Reader());
      }

      if (possibleFormats.indexOf(BarcodeFormat.UPC_A) > -1) {
        readers.push(new UPCAReader());
      }

      if (possibleFormats.indexOf(BarcodeFormat.EAN_8) > -1) {
        readers.push(new EAN8Reader());
      }

      if (possibleFormats.indexOf(BarcodeFormat.UPC_E) > -1) {
        readers.push(new UPCEReader());
      }
    }

    if (readers.length === 0) {
      readers.push(new EAN13Reader());
      readers.push(new UPCAReader());
      readers.push(new EAN8Reader());
      readers.push(new UPCEReader());
    }

    this.readers = readers;
  }

  public decodeRow(rowNumber: number, row: BitArray, hints?: Map<DecodeHintType, any>): Result {
    for (let reader of this.readers) {
      try {
        // const result: Result = reader.decodeRow(rowNumber, row, startGuardPattern, hints);
        const result = reader.decodeRow(rowNumber, row, hints);
        // Special case: a 12-digit code encoded in UPC-A is identical to a "0"
        // followed by those 12 digits encoded as EAN-13. Each will recognize such a code,
        // UPC-A as a 12-digit string and EAN-13 as a 13-digit string starting with "0".
        // Individually these are correct and their readers will both read such a code
        // and correctly call it EAN-13, or UPC-A, respectively.
        //
        // In this case, if we've been looking for both types, we'd like to call it
        // a UPC-A code. But for efficiency we only run the EAN-13 decoder to also read
        // UPC-A. So we special case it here, and convert an EAN-13 result to a UPC-A
        // result if appropriate.
        //
        // But, don't return UPC-A if UPC-A was not a requested format!
        const ean13MayBeUPCA: boolean =
          result.getBarcodeFormat() === BarcodeFormat.EAN_13 &&
          result.getText().charAt(0) === '0';
        // @SuppressWarnings("unchecked")
        const possibleFormats: Collection<BarcodeFormat> =
          hints == null ? null : hints.get(DecodeHintType.POSSIBLE_FORMATS) as Collection<BarcodeFormat>;
        const canReturnUPCA: boolean = possibleFormats == null || possibleFormats.includes(BarcodeFormat.UPC_A);

        if (ean13MayBeUPCA && canReturnUPCA) {
          const rawBytes = result.getRawBytes();
          // Transfer the metadata across
          const resultUPCA: Result = new Result(
            result.getText().substring(1),
            rawBytes,
            (rawBytes ? rawBytes.length : null),
            result.getResultPoints(),
            BarcodeFormat.UPC_A
          );
          resultUPCA.putAllMetadata(result.getResultMetadata());
          return resultUPCA;
        }
        return result;
      } catch (err) {
        // continue;
      }
    }
    throw new NotFoundException();
  }

  public reset() {
    for (let reader of this.readers) {
      reader.reset();
    }
  }
}