Ziele Untersuchung
mit Columbo Integrität von
Datenbanken Interaktion und
Portierbarkeit Ergonomie der
Schnittstellen

Angebot Produkte Projekt Beratung

Mittel Analytik Modellierung Sprachen Algebra Logik Hardware Denken Kreativität

Zusammenhänge Gesellschaft Wirtschaft Branche Firma


products/sources/formale Sprachen/C/Firefox/devtools/shared/qrcode/ (Browser von der Mozilla Stiftung Version 136.0.1^©) Datei vom 10.2.2025 mit Größe 3 kB

Quelle index.js Sprache: JAVA

/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */

"use strict";

// Lazily require encoder and decoder in case only one is needed
Object.defineProperty(this, "Encoder", {
  get: () =>
    require("resource://devtools/shared/qrcode/encoder/index.js").Encoder,
});
Object.defineProperty(this, "QRRSBlock", {
  get: () =>
    require("resource://devtools/shared/qrcode/encoder/index.js").QRRSBlock,
});
Object.defineProperty(this, "QRErrorCorrectLevel", {
  get: () =>
    require("resource://devtools/shared/qrcode/encoder/index.js")
      .QRErrorCorrectLevel,
});
Object.defineProperty(this, "decoder", {
  get: () => {
    // Some applications don't ship the decoder, see moz.build
    try {
      return require("resource://devtools/shared/qrcode/decoder/index.js");
    } catch (e) {
      return null;
    }
  },
});

/**
* There are many "versions" of QR codes, which describes how many dots appear
* in the resulting image, thus limiting the amount of data that can be
* represented.
*
* The encoder used here allows for versions 1 - 10 (more dots for larger
* versions).
*
* It expects you to pick a version large enough to contain your message.  Here
* we search for the mimimum version based on the message length.
* @param string message
*        Text to encode
* @param string quality
*        Quality level: L, M, Q, H
* @return integer
*/
exports.findMinimumVersion = function (message, quality) {
  const msgLength = message.length;
  const qualityLevel = QRErrorCorrectLevel[quality];
  for (let version = 1; version <= 10; version++) {
    const rsBlocks = QRRSBlock.getRSBlocks(version, qualityLevel);
    let maxLength = rsBlocks.reduce((prev, block) => {
      return prev + block.dataCount;
    }, 0);
    // Remove two bytes to fit header info
    maxLength -= 2;
    if (msgLength <= maxLength) {
      return version;
    }
  }
  throw new Error("Message too large");
};

/**
* Simple wrapper around the underlying encoder's API.
* @param string  message
*        Text to encode
* @param string  quality (optional)
          Quality level: L, M, Q, H
* @param integer version (optional)
*        QR code "version" large enough to contain the message
* @return object with the following fields:
*   * src:    an image encoded a data URI
*   * height: image height
*   * width:  image width
*/
exports.encodeToDataURI = function (message, quality, version) {
  quality = quality || "H";
  version = version || exports.findMinimumVersion(message, quality);
  const encoder = new Encoder(version, quality);
  encoder.addData(message);
  encoder.make();
  return encoder.createImgData();
};

/**
* Simple wrapper around the underlying decoder's API.
* @param string URI
*        URI of an image of a QR code
* @return Promise
*         The promise will be resolved with a string, which is the data inside
*         the QR code.
*/
exports.decodeFromURI = function (URI) {
  if (!decoder) {
    return Promise.reject();
  }
  return new Promise((resolve, reject) => {
    decoder.decodeFromURI(URI, resolve, reject);
  });
};

/**
* Decode a QR code that has been drawn to a canvas element.
* @param Canvas canvas
*        <canvas> element to read from
* @return string
*         The data inside the QR code
*/
exports.decodeFromCanvas = function (canvas) {
  if (!decoder) {
    throw new Error("Decoder not available");
  }
  return decoder.decodeFromCanvas(canvas);
};

quality94%

¤ Dauer der Verarbeitung: 0.14 Sekunden (vorverarbeitet) ¤

Wurzel

Suchen

Beweissystem der NASA

Beweissystem Isabelle

NIST Cobol Testsuite

Cephes Mathematical Library

Wiener Entwicklungsmethode

Haftungshinweis

Die Informationen auf dieser Webseite wurden nach bestem Wissen sorgfältig zusammengestellt. Es wird jedoch weder Vollständigkeit, noch Richtigkeit, noch Qualität der bereit gestellten Informationen zugesichert.