@tjieco/library/src/core/MultiFormatReader.ts

TypeScript port of ZXing multi-format 1D/2D barcode image processing library, with Code128 and ITF support.

/*
 * Copyright 2009 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 DecodeHintType from './DecodeHintType';
import Reader from './Reader';
import Result from './Result';
import BinaryBitmap from './BinaryBitmap';
import BarcodeFormat from './BarcodeFormat';
import QRCodeReader from './qrcode/QRCodeReader';
import Exception from './Exception';
import MultiFormatOneDReader from './oned/MultiFormatOneDReader';

/*namespace com.google.zxing {*/

/**
 * MultiFormatReader is a convenience class and the main entry point into the library for most uses.
 * By default it attempts to decode all barcode formats that the library supports. Optionally, you
 * can provide a hints object to request different behavior, for example only decoding QR codes.
 *
 * @author Sean Owen
 * @author dswitkin@google.com (Daniel Switkin)
 */
export default class MultiFormatReader implements Reader {

    private hints: Map<DecodeHintType, any> | null;
    private readers: Reader[];

    /**
     * This version of decode honors the intent of Reader.decode(BinaryBitmap) in that it
     * passes null as a hint to the decoders. However, that makes it inefficient to call repeatedly.
     * Use setHints() followed by decodeWithState() for continuous scan applications.
     *
     * @param image The pixel data to decode
     * @return The contents of the image
     * @throws NotFoundException Any errors which occurred
     */
    /*@Override*/
    // public decode(image: BinaryBitmap): Result /*throws NotFoundException */ {
    //   setHints(null)
    //   return decodeInternal(image)
    // }

    /**
     * Decode an image using the hints provided. Does not honor existing state.
     *
     * @param image The pixel data to decode
     * @param hints The hints to use, clearing the previous state.
     * @return The contents of the image
     * @throws NotFoundException Any errors which occurred
     */
    /*@Override*/
    public decode(image: BinaryBitmap, hints?: Map<DecodeHintType, any>): Result /*throws NotFoundException */ {
        this.setHints(hints);
        return this.decodeInternal(image);
    }

    /**
     * Decode an image using the state set up by calling setHints() previously. Continuous scan
     * clients will get a <b>large</b> speed increase by using this instead of decode().
     *
     * @param image The pixel data to decode
     * @return The contents of the image
     * @throws NotFoundException Any errors which occurred
     */
    public decodeWithState(image: BinaryBitmap): Result /*throws NotFoundException */ {
        // Make sure to set up the default state so we don't crash
        if (this.readers === null || this.readers === undefined) {
            this.setHints(null);
        }
        return this.decodeInternal(image);
    }

    /**
     * This method adds state to the MultiFormatReader. By setting the hints once, subsequent calls
     * to decodeWithState(image) can reuse the same set of readers without reallocating memory. This
     * is important for performance in continuous scan clients.
     *
     * @param hints The set of hints to use for subsequent calls to decode(image)
     */
    public setHints(hints?: Map<DecodeHintType, any> | null): void {
        this.hints = hints;

        const tryHarder: boolean = hints !== null && hints !== undefined && undefined !== hints.get(DecodeHintType.TRY_HARDER);
        /*@SuppressWarnings("unchecked")*/
        const formats = hints === null || hints === undefined ? null : hints.get(DecodeHintType.POSSIBLE_FORMATS);
        const readers = new Array<Reader>();
        if (formats !== null && formats !== undefined) {
            const addOneDReader: boolean =
                formats.contains(BarcodeFormat.UPC_A) ||
                formats.contains(BarcodeFormat.UPC_E) ||
                formats.contains(BarcodeFormat.EAN_13) ||
                formats.contains(BarcodeFormat.EAN_8) ||
                formats.contains(BarcodeFormat.CODABAR) ||
                formats.contains(BarcodeFormat.CODE_39) ||
                formats.contains(BarcodeFormat.CODE_93) ||
                formats.contains(BarcodeFormat.CODE_128) ||
                formats.contains(BarcodeFormat.ITF) ||
                formats.contains(BarcodeFormat.RSS_14) ||
                formats.contains(BarcodeFormat.RSS_EXPANDED);
            // Put 1D readers upfront in "normal" mode

            // TYPESCRIPTPORT: TODO: uncomment below as they are ported

            if (addOneDReader && !tryHarder) {
               readers.push(new MultiFormatOneDReader(hints));
            }
            if (formats.contains(BarcodeFormat.QR_CODE)) {
                readers.push(new QRCodeReader());
            }
            // if (formats.contains(BarcodeFormat.DATA_MATRIX)) {
            //   readers.push(new DataMatrixReader())
            // }
            // if (formats.contains(BarcodeFormat.AZTEC)) {
            //   readers.push(new AztecReader())
            // }
            // if (formats.contains(BarcodeFormat.PDF_417)) {
            //    readers.push(new PDF417Reader())
            // }
            // if (formats.contains(BarcodeFormat.MAXICODE)) {
            //    readers.push(new MaxiCodeReader())
            // }
            // At end in "try harder" mode
            if (addOneDReader && tryHarder) {
              readers.push(new MultiFormatOneDReader(hints));
            }
        }
        if (readers.length === 0) {
            if (!tryHarder) {
              readers.push(new MultiFormatOneDReader(hints));
            }

            readers.push(new QRCodeReader());
            // readers.push(new DataMatrixReader())
            // readers.push(new AztecReader())
            // readers.push(new PDF417Reader())
            // readers.push(new MaxiCodeReader())

            if (tryHarder) {
               readers.push(new MultiFormatOneDReader(hints));
            }
        }
        this.readers = readers; // .toArray(new Reader[readers.size()])
    }

    /*@Override*/
    public reset(): void {
        if (this.readers !== null) {
            for (let i = 0, length = this.readers.length; i !== length; i++) {
                const reader = this.readers[i];
                reader.reset();
            }
        }
    }

    private decodeInternal(image: BinaryBitmap): Result /*throws NotFoundException */ {
        if (this.readers !== null) {
            for (let i = 0, length = this.readers.length; i !== length; i++) {
                const reader = this.readers[i];
                try {
                    return reader.decode(image, this.hints);
                } catch (re/*ReaderException*/) {
                    // console.log(`Exception ${re.type} ${re.message}`)
                    if (re.type === 'ReaderException') {
                        continue;
                    }
                }
            }
        }
        throw new Exception(Exception.NotFoundException);
    }

}