@zxing/library
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TypeScript port of ZXing multi-format 1D/2D barcode image processing library.
175 lines (174 loc) • 7.01 kB
JavaScript
/*
* 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 BarcodeFormat from './BarcodeFormat';
import QRCodeReader from './qrcode/QRCodeReader';
import AztecReader from './aztec/AztecReader';
import MultiFormatOneDReader from './oned/MultiFormatOneDReader';
import DataMatrixReader from './datamatrix/DataMatrixReader';
import NotFoundException from './NotFoundException';
import PDF417Reader from './pdf417/PDF417Reader';
import ReaderException from './ReaderException';
/*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 {
/**
* 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 {
// 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*/
decode(image, hints) {
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
*/
decodeWithState(image) {
// 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)
*/
setHints(hints) {
this.hints = hints;
const tryHarder = 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();
if (formats !== null && formats !== undefined) {
const addOneDReader = formats.some(f => f === BarcodeFormat.UPC_A ||
f === BarcodeFormat.UPC_E ||
f === BarcodeFormat.EAN_13 ||
f === BarcodeFormat.EAN_8 ||
f === BarcodeFormat.CODABAR ||
f === BarcodeFormat.CODE_39 ||
f === BarcodeFormat.CODE_93 ||
f === BarcodeFormat.CODE_128 ||
f === BarcodeFormat.ITF ||
f === BarcodeFormat.RSS_14 ||
f === 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.includes(BarcodeFormat.QR_CODE)) {
readers.push(new QRCodeReader());
}
if (formats.includes(BarcodeFormat.DATA_MATRIX)) {
readers.push(new DataMatrixReader());
}
if (formats.includes(BarcodeFormat.AZTEC)) {
readers.push(new AztecReader());
}
if (formats.includes(BarcodeFormat.PDF_417)) {
readers.push(new PDF417Reader());
}
// if (formats.includes(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*/
reset() {
if (this.readers !== null) {
for (const reader of this.readers) {
reader.reset();
}
}
}
/**
* @throws NotFoundException
*/
decodeInternal(image) {
if (this.readers === null) {
throw new ReaderException('No readers where selected, nothing can be read.');
}
for (const reader of this.readers) {
// Trying to decode with ${reader} reader.
try {
return reader.decode(image, this.hints);
}
catch (ex) {
if (ex instanceof ReaderException) {
continue;
}
// Bad Exception.
}
}
throw new NotFoundException('No MultiFormat Readers were able to detect the code.');
}
}