@zxing/library
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TypeScript port of ZXing multi-format 1D/2D barcode image processing library.
93 lines (92 loc) • 4.6 kB
JavaScript
/*
* 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.
*/
/*namespace com.google.zxing.qrcode {*/
import BarcodeFormat from '../BarcodeFormat';
import EncodeHintType from '../EncodeHintType';
import BitMatrix from '../common/BitMatrix';
import ErrorCorrectionLevel from './decoder/ErrorCorrectionLevel';
import Encoder from './encoder/Encoder';
import IllegalArgumentException from '../IllegalArgumentException';
import IllegalStateException from '../IllegalStateException';
/*import java.util.Map;*/
/**
* This object renders a QR Code as a BitMatrix 2D array of greyscale values.
*
* @author dswitkin@google.com (Daniel Switkin)
*/
export default class QRCodeWriter {
/*@Override*/
// public encode(contents: string, format: BarcodeFormat, width: number /*int*/, height: number /*int*/): BitMatrix
// /*throws WriterException */ {
// return encode(contents, format, width, height, null)
// }
/*@Override*/
encode(contents, format, width /*int*/, height /*int*/, hints) {
if (contents.length === 0) {
throw new IllegalArgumentException('Found empty contents');
}
if (format !== BarcodeFormat.QR_CODE) {
throw new IllegalArgumentException('Can only encode QR_CODE, but got ' + format);
}
if (width < 0 || height < 0) {
throw new IllegalArgumentException(`Requested dimensions are too small: ${width}x${height}`);
}
let errorCorrectionLevel = ErrorCorrectionLevel.L;
let quietZone = QRCodeWriter.QUIET_ZONE_SIZE;
if (hints !== null) {
if (undefined !== hints.get(EncodeHintType.ERROR_CORRECTION)) {
errorCorrectionLevel = ErrorCorrectionLevel.fromString(hints.get(EncodeHintType.ERROR_CORRECTION).toString());
}
if (undefined !== hints.get(EncodeHintType.MARGIN)) {
quietZone = Number.parseInt(hints.get(EncodeHintType.MARGIN).toString(), 10);
}
}
const code = Encoder.encode(contents, errorCorrectionLevel, hints);
return QRCodeWriter.renderResult(code, width, height, quietZone);
}
// Note that the input matrix uses 0 == white, 1 == black, while the output matrix uses
// 0 == black, 255 == white (i.e. an 8 bit greyscale bitmap).
static renderResult(code, width /*int*/, height /*int*/, quietZone /*int*/) {
const input = code.getMatrix();
if (input === null) {
throw new IllegalStateException();
}
const inputWidth = input.getWidth();
const inputHeight = input.getHeight();
const qrWidth = inputWidth + (quietZone * 2);
const qrHeight = inputHeight + (quietZone * 2);
const outputWidth = Math.max(width, qrWidth);
const outputHeight = Math.max(height, qrHeight);
const multiple = Math.min(Math.floor(outputWidth / qrWidth), Math.floor(outputHeight / qrHeight));
// Padding includes both the quiet zone and the extra white pixels to accommodate the requested
// dimensions. For example, if input is 25x25 the QR will be 33x33 including the quiet zone.
// If the requested size is 200x160, the multiple will be 4, for a QR of 132x132. These will
// handle all the padding from 100x100 (the actual QR) up to 200x160.
const leftPadding = Math.floor((outputWidth - (inputWidth * multiple)) / 2);
const topPadding = Math.floor((outputHeight - (inputHeight * multiple)) / 2);
const output = new BitMatrix(outputWidth, outputHeight);
for (let inputY = 0, outputY = topPadding; inputY < inputHeight; inputY++, outputY += multiple) {
// Write the contents of this row of the barcode
for (let inputX = 0, outputX = leftPadding; inputX < inputWidth; inputX++, outputX += multiple) {
if (input.get(inputX, inputY) === 1) {
output.setRegion(outputX, outputY, multiple, multiple);
}
}
}
return output;
}
}
QRCodeWriter.QUIET_ZONE_SIZE = 4;