synchronize the scrollbars of two iframes containing pdf

To synchronize the scrollbars of two iframes containing PDFs, you can use JavaScript to listen for scroll events on both iframes and then update the scroll position of the other iframe accordingly. Here's a step-by-step guide on how to achieve this:

HTML:

htmlCopy code
<iframe id="pdfIframe1" src="path_to_your_pdf_file.pdf"></iframe>
<iframe id="pdfIframe2" src="path_to_your_pdf_file.pdf"></iframe>

JavaScript:

javascriptCopy code
const iframe1 = document.getElementById('pdfIframe1');
const iframe2 = document.getElementById('pdfIframe2');

function syncScroll(event) {
  // Get the scroll position of the first iframe
  const scrollPosition = event.target.scrollTop;

  // Update the scroll position of the second iframe
  iframe2.contentWindow.scrollTo(0, scrollPosition);
}

// Add scroll event listeners to both iframes
iframe1.addEventListener('scroll', syncScroll);
iframe2.addEventListener('scroll', syncScroll);

In this example, we have two iframes with IDs pdfIframe1 and pdfIframe2, each containing the same PDF file. We then define the syncScroll function, which updates the scroll position of the second iframe to match the scroll position of the first iframe whenever either of the iframes is scrolled.

By adding scroll event listeners to both iframes, we can call the syncScroll function whenever a scroll event is triggered. The syncScroll function then updates the scroll position of the second iframe to match the scroll position of the first iframe.

Keep in mind that the two iframes should have the same height to ensure that the synchronization works correctly. If the iframes have different heights, you may need to adjust the scroll position calculation accordingly.

Additionally, if you're working with PDFs hosted on different domains, you may encounter cross-origin restrictions when trying to access the contentWindow property. In such cases, you'll need to ensure that the two PDFs are hosted on the same domain or have appropriate CORS settings to allow access to their contentWindow properties.

Please note that synchronizing scrollbars between two iframes can be complex, especially when dealing with different PDF documents and various browser and PDF viewer configurations. Depending on your specific use case, you may encounter additional challenges and considerations.