PDF.js Previous/Next example

by pdfjs

HTML

<script src="//mozilla.github.io/pdf.js/build/pdf.mjs" type="module"></script>

<script type="module">
  // If absolute URL from the remote server is provided, configure the CORS
  // header on that server.
  var url = 'https://raw.githubusercontent.com/mozilla/pdf.js/ba2edeae/web/compressed.tracemonkey-pldi-09.pdf';

  // Loaded via <script> tag, create shortcut to access PDF.js exports.
  var { pdfjsLib } = globalThis;

  // The workerSrc property shall be specified.
  pdfjsLib.GlobalWorkerOptions.workerSrc = '//mozilla.github.io/pdf.js/build/pdf.worker.mjs';

  var pdfDoc = null,
      pageNum = 1,
      pageRendering = false,
      pageNumPending = null,
      scale = 0.8,
      canvas = document.getElementById('the-canvas'),
      ctx = canvas.getContext('2d');

  /**
   * Get page info from document, resize canvas accordingly, and render page.
   * @param num Page number.
   */
  function renderPage(num) {
    pageRendering = true;
    // Using promise to fetch the page
    pdfDoc.getPage(num).then(function(page) {
      var viewport = page.getViewport({scale: scale});
      canvas.height = viewport.height;
      canvas.width = viewport.width;

      // Render PDF page into canvas context
      var renderContext = {
        canvasContext: ctx,
        viewport: viewport
      };
      var renderTask = page.render(renderContext);

      // Wait for rendering to finish
      renderTask.promise.then(function() {
        pageRendering = false;
        if (pageNumPending !== null) {
          // New page rendering is pending
          renderPage(pageNumPending);
          pageNumPending = null;
        }
      });
    });

    // Update page counters
    document.getElementById('page_num').textContent = num;
  }

  /**
   * If another page rendering in progress, waits until the rendering is
   * finised. Otherwise, executes rendering immediately.
   */
  function queueRenderPage(num) {
    if...

CSS

#the-canvas {
  border: 1px solid black;
  direction: ltr;
}