qrcodejs/index.html at master · danielgjackson/qrcodejs · GitHub

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<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <link rel="icon" href="data:;base64,=">
  <title>QR Code JS</title>
  <style type="text/css">
  html, body {
    font-family: sans-serif;
  }
  .controls {
    margin: 1em 0;
  }
  textarea {
    resize: both;
    field-sizing: content;
    vertical-align: top;
    min-width: 80%;
  }
  summary {
    cursor: pointer;
  }
  li {
    margin-top: 0.25em;
    margin-bottom: 0.25em;
  }
  .hidden {
    display: none;
  }
  #text {
    width: 90%;
    border-radius: 0.5em;
  }
  #output_text {
    cursor: copy;
    font-family: monospace;
    -webkit-font-smoothing: none;
    font-smooth: never;
    text-rendering: optimizeSpeed;
    line-height: 1.1;
    white-space: nowrap;
  }
  /* Fix for monospace fonts where the space is not the same width as the block characters */
  #output_text span {
    display: inline-block;
    width: 1ch;
  }
  #output_img, #output_svg {
    cursor: copy;
  }
  #output_img img, #output_svg svg {
    width: 50vw;
    max-width: 75vmin;
  }
  #caution-input, #error {
    background: #ffffdd;
    border: 1px solid #cccc00;
    padding: 0.5em;
    margin: 1em 0;
    border-radius: 0.5em;
  }
  #error {
    background: #ffdddd;
    border: 1px solid #cc0000;
  }
  #caution-input::before {
    content: "⚠️ ";
  }
  #error::before {
    content: "❗ ";
  }
  </style>
</head>
<body>
<h1>QR Code JS</h1>

<ul>
  <li>Generate a QR Code for any input.</li>
  <li>Data stays only in your browser and is not sent anywhere else.</li>
  <li>Open source repository: <a href="https://github.com/danielgjackson/qrcodejs">github.com/danielgjackson/qrcodejs</a></li>
</ul>

<div class="controls">
  <label><input type="checkbox" id="rounded" checked>Rounded.</label>
  <label>Error correction level:
    <select id="ecl">
      <option value="L+" selected>Low, or better for same size (~7%+)</option>
      <option value="M+">Medium, or better for same size (~15%+)</option>
      <option value="Q+">Quartile, or better for same size (~25%+)</option>
      <option value="H">High (~30%)</option>
      <option value="Q">Quartile (~25%)</option>
      <option value="M">Medium (~15%)</option>
      <option value="L">Low (~7%)</option>
    </select>
  </label>
</div>

<div id="caution-input" class="hidden">
  <strong>Caution:</strong> Please double-check the input as it may unintentionally contain: multiple lines, or leading/trailing whitespace, or is an improperly formatted URL.
</div>

<div id="error" class="hidden">
  <strong>Error:</strong> <span id="error_message">-</span>
</div>

<div class="controls">
  <label>
    Text:
    <textarea type="text" id="text" wrap="soft" rows="4" autofocus placeholder="https://example.com"></textarea>
  </label>
</div>

<details name="qrcode" open>
<summary>Image &lt;svg&gt;</summary>
<div id="output_svg">
  <svg></svg>
</div>
</details>

<details name="qrcode">
<summary>Image &lt;img&gt;</summary>
<div id="output_img">
  <img src="" alt="">
</div>
</details>

<details name="qrcode">
<summary>Text</summary>
<div id="output_text">
-
</div>
</details>

<ul>
  <li>Simpler codes are easier to scan:
    <ul>
      <li>Keep the input as short as possible.</li>
      <li>If using a URL with a common top-level-domain (such as <code>.com</code>), some readers work without an initial <code>http://</code> or <code>https://</code>, but it's probably best not to rely on this.</li>
      <li>All upper-case alphanumeric (with some, e.g. URL, symbols allowed) is more compact than mixed-case, but be careful that any path part may be case sensitive, and some readers may not like the protocol in capital letters.</li>
      <li>Lower error correction levels can decrease complexity, but may be more susceptible to damage or occlusion.</li>
    </ul>
  </li>
  <li>Always include a written alternative for the URL.</li>
  <li>Always place the QR code on a 'quiet' area: light on a standard code (if the code is inverted, it should be placed on a dark background).</li>
  <li>For WiFi QR codes, use the format: <code>WIFI:S:my_ssid;T:WPA;P:my_passphrase;;</code></li>
</ul>

<!-- Don't use as a module here so that this demo page can work over the file: protocol -->
<script src="./qrcode.mjs"></script>
<script> <!-- type="module" -->
//import QrCode from './qrcode.mjs';

function renderHtml(matrix) {
  // '▀', '▄', '█' // '\u{0020}' space, '\u{2580}' upper half block, '\u{2584}' lower half block, '\u{2588}' block
  // Figure space: '\u{2007}'
  const renderOptions = {
    segments: ['<span>&nbsp;</span>', '<span>▀</span>', '<span>▄</span>', '<span>█</span>'],
    sep: '<br>',
  };
  return QrCode.render('medium', matrix, renderOptions);
}

function focus() {
  document.querySelector('#text').select();
}

function change() {
  let errorMessage = null;

  const input = document.querySelector('#text').value;
  //console.log('Input:', JSON.stringify(input));

  // Check for possible ill-formed input
  const trimmedInput = input.trim();
  const whitespace = input.length != trimmedInput.length;
  const multipleLines = trimmedInput.includes('\n');
  const startsWithHttp = trimmedInput.toLowerCase().startsWith('http:') || trimmedInput.toLowerCase().startsWith('https:');
  const startsWithWiFi = trimmedInput.toUpperCase().startsWith('WIFI:');
  const nonUrlCharacters = trimmedInput.match(/[^a-zA-Z0-9\-._~:/?#[\]@!$&'()*+,;=%]/);
  let caution = (startsWithHttp || startsWithWiFi) && (whitespace || multipleLines);
  if (startsWithHttp && URL.canParse && !URL.canParse(trimmedInput)) {
    caution = true;
  }
  document.querySelector('#caution-input').classList.toggle('hidden', !caution);

  let text = '';
  let svg;
  try {
    const ecl = document.querySelector('#ecl').value;
    const qrOptions = {
      errorCorrectionLevel: QrCode.ErrorCorrectionLevel[ecl[0]],
      optimizeEcc: ecl.includes('+'),
    };
    const matrix = QrCode.generate(input, qrOptions);
    text = renderHtml(matrix);
    const renderOptions = {
      color: 'currentColor',
      moduleRound: null,      // 1.0 looks nice
      finderRound: null,      // 0.5 looks nice
      alignmentRound: null,
      white: false,    // Output an element for every module, not just black/dark ones but white/light ones too.
      moduleSize: 1,
    };

    if (document.querySelector('#rounded').checked) {
      renderOptions.moduleRound = 1.0;
      renderOptions.finderRound = 0.5;
    }

    svg = QrCode.render('svg', matrix, renderOptions);
  } catch (e) {
    let message = JSON.stringify(e);

    // Check for currently unsupported input
    const currentlyUnsupportedInput = [...input].some(c => c.charCodeAt(0) < 0x00 || c.charCodeAt(0) > 0xff);
    if (currentlyUnsupportedInput) {
      message += ' -- Note: the input contains characters outside the ISO-8859-1 (Latin-1) range (0x00-0xff), and this is currently unsupported.';
    }

    console.error('Error: ' + message);
    errorMessage = message;
  }
  const textElement = document.querySelector('#output_text');
  const imgElement = document.querySelector('#output_img img');
  const svgElement = document.querySelector('#output_svg svg');
  textElement.innerHTML = text;
  imgElement.src = 'data:image/svg+xml,' + encodeURIComponent(svg);
  imgElement.alt = input;
  svgElement.alt = input;
  if (svg) {
    svgElement.outerHTML = svg;
  } else {
    svgElement.innerHTML = svg;
  }

  if (errorMessage) {
    document.querySelector('#error').classList.remove('hidden');
    document.querySelector('#error_message').innerText = errorMessage;
  } else {
    document.querySelector('#error').classList.add('hidden');
    document.querySelector('#error_message').innerText = '-';
  }
}

function copyMultiLinePlainTextToClipboard(text) {
  const temp = document.createElement('textarea');
  temp.value = text;
  document.body.appendChild(temp);
  temp.select();
  document.execCommand('copy');
  document.body.removeChild(temp);
}

function safeFilename(text) {
  text = text.replace(/^https?:\/\//i, '');
  text = text.replaceAll(/[^a-zA-Z0-9_.-]/g, '_').toLowerCase();
  text = text.replaceAll(/\.+/g, '.');
  text = text.replaceAll(/_+/g, '_');
  return text;
}

async function dataUriToBlob(dataUri) {
  try {
    return await (await fetch(dataUri)).blob();
  } catch (e) {
    const protocolParts = dataUri.split(':');
    if (protocolParts[0] != 'data') throw new Error('Invalid data URI');
    const nonProtocol = protocolParts.slice(1).join(':');
    const dataParts = nonProtocol.split(',');
    const metaParts = dataParts[0].split(';');
    const type = metaParts[0];
    const encoding = metaParts[1];
    const rawData = dataParts.slice(1).join('');
    const data = encoding == 'base64' ? atob(rawData) : decodeURIComponent(rawData);
    const bytes = [];
    for (let i = 0; i < binary.length; i++) bytes.push(data.charCodeAt(i));
    return new Blob([new Uint8Array(bytes)], { type });
  }
}

async function rasterizeImageToBlob(src, type = 'image/png') {
  const img = new Image();
  const ctx = document.createElement('CANVAS').getContext('2d');
  img.crossOrigin = '';
  img.src = src;
  return new Promise(resolve => {
    img.onload = () => {
      ctx.canvas.width = img.naturalWidth;
      ctx.canvas.height = img.naturalHeight;
      ctx.drawImage(img, 0, 0);
      ctx.canvas.toBlob((blob) => resolve(blob), type);
    };
  });
}

function svgToBlob(svg, type = 'image/svg+xml') {
  return new Blob([svg], { type });
}

function copyBlobToClipboard(blob) {
  const itemSrc = {};
  itemSrc[blob.type] = blob;
  const item = new ClipboardItem(itemSrc);
  return navigator.clipboard.write([item]);
}

function downloadBlob(blob, filename = null, type = null) { // 'application/octet-stream'
  if (!(blob instanceof Blob)) { blob = new Blob([blob], type ? { type } : undefined); }
  const elem = window.document.createElement('A');
  elem.href = window.URL.createObjectURL(blob);
  if (filename) elem.download = filename;
  if (type) elem.type = type;
  document.body.appendChild(elem);
  elem.click();
  document.body.removeChild(elem);
}

async function copySvgToClipboard(svg, imgSrc, element) {
  // Try to copy the SVG as an image to the clipboard
  try {
    if ('write' in navigator.clipboard && navigator.permissions) {
      const permissionResult = await navigator.permissions.query({ name: 'clipboard-write' });
      if (permissionResult.state === 'granted') {
        const svgBlob = svgToBlob(svg);
        const pngBlob = await rasterizeImageToBlob(imgSrc);
        const htmlBlob = svgToBlob(svg, 'text/html');
        const textBlob = svgToBlob(svg, 'text/plain');

        console.log('COPY: clipboard.write(ClipboardItem) -- SVG')
        try {
          const item = new ClipboardItem({
            'image/svg+xml': svgBlob,
            //'image/png': pngBlob,
            //'text/html': htmlBlob,
            //'text/plain': textBlob,
          });
          await navigator.clipboard.write([item]);
          return true;
        } catch (e) {
          console.error(e.name, e.message);
        }

        console.log('COPY: clipboard.write(ClipboardItem) -- PNG')
        try {
          const item = new ClipboardItem({
            //'image/svg+xml': svgBlob,
            'image/png': pngBlob,
            //'text/html': htmlBlob,
            //'text/plain': textBlob,
          });
          await navigator.clipboard.write([item]);
          return true;
        } catch (e) {
          console.error(e.name, e.message);
        }

        console.log('COPY: clipboard.write(ClipboardItem) -- HTML')
        try {
          const item = new ClipboardItem({
            //'image/svg+xml': svgBlob,
            //'image/png': pngBlob,
            'text/html': htmlBlob,
            'text/plain': textBlob,
          });
          await navigator.clipboard.write([item]);
          return true;
        } catch (e) {
          console.error(e.name, e.message);
        }

      }
    }
  } catch (e) {
    console.error(e.name, e.message);
  }

  try {
    // Fallback: this tries to copy the selected range around the image as HTML
    console.log('COPY: execCommand(copy) range')
    window.getSelection().removeAllRanges();
    const range = document.createRange();
    range.selectNode(element);
    window.getSelection().addRange(range);
    document.execCommand('copy');
    window.getSelection().removeAllRanges();
    return true;
  } catch (e) {
    console.error(e.name, e.message);
  }

  // Fall back to copying source
  try {
    console.log('COPY: writeText source')
    await navigator.clipboard.writeText(svg);
    return true;
  } catch (e) {
    console.error(e.name, e.message);
  }

  return false;
}

function click_text() {
  const text = document.querySelector('#output_text').innerText;
  copyMultiLinePlainTextToClipboard(text);
  document.querySelector('#text').focus();
}

async function click_img() {
  const element = document.querySelector('#output_img img');
  const svg = decodeURIComponent(element.src.split(',').slice(1).join(''));
  //const imgSrc = element.src;
  //copySvgToClipboard(svg, imgSrc, element);
  downloadBlob(svgToBlob(svg), safeFilename(document.querySelector('#text').value) + '.svg');
}

function click_svg() {
  const element = document.querySelector('#output_svg svg');
  const svg = element.outerHTML;
  //const imgSrc = 'data:image/svg+xml,' + encodeURIComponent(svg);
  //copySvgToClipboard(svg, imgSrc, element);
  downloadBlob(svgToBlob(svg), safeFilename(document.querySelector('#text').value) + '.svg');
}

function start() {
  document.querySelector('#text').addEventListener('focus', focus);
  document.querySelector('#text').addEventListener('input', change);
  document.querySelector('#ecl').addEventListener('change', change);
  document.querySelector('#rounded').addEventListener('change', change);
  document.querySelector('#output_text').addEventListener('click', click_text);
  document.querySelector('#output_img img').addEventListener('click', click_img);
  document.querySelector('#output_svg').addEventListener('click', click_svg);
  document.querySelector('#text').focus();
  change();
}

window.addEventListener('DOMContentLoaded', start);

</script>
</body>
</html>