import ChecksumException from '../../ChecksumException' ; import BitMatrix from '../../common/BitMatrix' ; import DecoderResult from '../../common/DecoderResult' ; import GenericGF from '../../common/reedsolomon/GenericGF' ; import ReedSolomonDecoder from '../../common/reedsolomon/ReedSolomonDecoder' ; import DecodeHintType from '../../DecodeHintType' ; import BitMatrixParser from './BitMatrixParser' ; import DataBlock from './DataBlock' ; import DecodedBitStreamParser from './DecodedBitStreamParser' ; import QRCodeDecoderMetaData from './QRCodeDecoderMetaData' ; author Sean Owen
  export default class Decoder { private rsDecoder : ReedSolomonDecoder ; public constructor ( ) { this . rsDecoder = new ReedSolomonDecoder ( GenericGF . QR_CODE_FIELD_256 ) ; } param image param hints return throws throws public decodeBooleanArray ( image , hints ? ) { return this . decodeBitMatrix ( BitMatrix . parseFromBooleanArray ( image ) , hints ) ; } /**
     * <p>Decodes a QR Code represented as a  BitMatrix . A 1 or "true" is taken to mean a black module.</p>
     *
     *  param bits param hints return throws throws public decodeBitMatrix ( bits , hints ? ) { const parser = new BitMatrixParser ( bits ) ; let ex = null ; try { return this . decodeBitMatrixParser ( parser , hints ) ; } catch ( e ) { ex = e ; } try { parser . remask ( ) ; parser . setMirror ( true ) ; parser . readVersion ( ) ; parser . readFormatInformation ( ) ; parser . mirror ( ) ; const result = this . decodeBitMatrixParser ( parser , hints ) ; result . setOther ( new QRCodeDecoderMetaData ( true ) ) ; return result ; } catch ( e ) { if ( ex !== null ) { throw ex ; } throw e ; } } private decodeBitMatrixParser ( parser , hints ) { const version = parser . readVersion ( ) ; const ecLevel = parser . readFormatInformation ( ) . getErrorCorrectionLevel ( ) ; const codewords = parser . readCodewords ( ) ; const dataBlocks = DataBlock . getDataBlocks ( codewords , version , ecLevel ) ; let totalBytes = 0 ; for ( const dataBlock of dataBlocks ) { totalBytes += dataBlock . getNumDataCodewords ( ) ; } const resultBytes = new Uint8Array ( totalBytes ) ; let resultOffset = 0 ; for ( const dataBlock of dataBlocks ) { const codewordBytes = dataBlock . getCodewords ( ) ; const numDataCodewords = dataBlock . getNumDataCodewords ( ) ; this . correctErrors ( codewordBytes , numDataCodewords ) ; for ( let i = 0 ; i < numDataCodewords ; i ++ ) { resultBytes [ resultOffset ++ ] = codewordBytes [ i ] ; } } return DecodedBitStreamParser . decode ( resultBytes , version , ecLevel , hints ) ; } param codewordBytes param numDataCodewords throws private correctErrors ( codewordBytes , numDataCodewords ) { const codewordsInts = new Int32Array ( codewordBytes ) ; try { this . rsDecoder . decode ( codewordsInts , codewordBytes . length - numDataCodewords ) ; } catch ( ignored ) { throw new ChecksumException ( ) ; } for ( let i = 0 ; i < numDataCodewords ; i ++ ) { codewordBytes [ i ] = codewordsInts [ i ] ; } } }