taro-code/lib/common/canvas/qrcode.js

Taro.js barcode & qrcode, Image & Canvas

import Taro from '@tarojs/taro';
import { qrcode } from '../qrcode';
function autoIncreaseTypeNumber(text, options) {
    var _a, _b, _c, _d, _e;
    options = options !== null && options !== void 0 ? options : {};
    const typeNumber = (_a = options.typeNumber) !== null && _a !== void 0 ? _a : 4;
    const errorCorrectLevel = (_b = options.errorCorrectLevel) !== null && _b !== void 0 ? _b : 'M';
    const size = (_c = options.size) !== null && _c !== void 0 ? _c : 500;
    const black = (_d = options.black) !== null && _d !== void 0 ? _d : '#000000';
    const white = (_e = options.white) !== null && _e !== void 0 ? _e : '#FFFFFF';
    let qr;
    try {
        qr = qrcode(typeNumber, errorCorrectLevel !== null && errorCorrectLevel !== void 0 ? errorCorrectLevel : 'M');
        qr.addData(text);
        qr.make();
    }
    catch (e) {
        if (typeNumber >= 40) {
            throw new Error('Text too long to encode');
        }
        else {
            return autoIncreaseTypeNumber(text, {
                size: size,
                errorCorrectLevel: errorCorrectLevel,
                typeNumber: typeNumber + 1,
                black,
                white,
            });
        }
    }
    return qr;
}
export function drawCanvasQRCode(text, options) {
    var _a, _b, _c;
    const typeNumber = (_a = options.typeNumber) !== null && _a !== void 0 ? _a : 4;
    const errorCorrectLevel = (_b = options.errorCorrectLevel) !== null && _b !== void 0 ? _b : 'M';
    const size = (_c = options.size) !== null && _c !== void 0 ? _c : 500;
    const qr = autoIncreaseTypeNumber(text, {
        typeNumber,
        errorCorrectLevel,
        size,
        black: options.foregroundColor,
        white: options.backgroundColor,
    });
    const canvas = options.canvas;
    const dpr = Taro.getSystemInfoSync().pixelRatio;
    canvas.width = size * dpr;
    canvas.height = size * dpr;
    const width = canvas.width;
    const ctx = canvas.getContext('2d');
    ctx.fillStyle = options.backgroundColor;
    ctx.fillRect(0, 0, width + options.padding * 2, width + options.padding * 2);
    const tileW = (width - options.padding * 2) / qr.getModuleCount();
    const tileH = (width - options.padding * 2) / qr.getModuleCount();
    for (let row = 0; row < qr.getModuleCount(); row++) {
        for (let col = 0; col < qr.getModuleCount(); col++) {
            ctx.fillStyle = qr.isDark(row, col) ? options.foregroundColor : options.backgroundColor;
            const w = Math.ceil((col + 1) * tileW) - Math.floor(col * tileW);
            const h = Math.ceil((row + 1) * tileW) - Math.floor(row * tileW);
            ctx.fillRect(Math.round(col * tileW) + options.padding, Math.round(row * tileH) + options.padding, w, h);
        }
    }
}
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