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PDF Viewer Embedder

Embeds PDFs directly in the page instead of downloading, with fallback and cleanup

  1. // ==UserScript==
  2. // @name         PDF Viewer Embedder
  3. // @namespace    *
  4. // @version      1.7
  5. // @author       zinchaiku
  6. // @description  Embeds PDFs directly in the page instead of downloading, with fallback and cleanup
  7. // @match        *://*/*
  8. // @grant        none
  9. // @license      MIT
  10. // ==/UserScript==
  11.  
  12. (function () {
  13.     'use strict';
  14.  
  15.     let currentBlobUrl = null;
  16.  
  17.     function showPDF(srcUrl, isBlob = false) {
  18.         const existing = document.getElementById('tampermonkey-pdf-viewer');
  19.         if (existing) existing.remove();
  20.  
  21.         const overlay = document.createElement('div');
  22.         overlay.id = 'tampermonkey-pdf-viewer';
  23.         overlay.style.position = 'fixed';
  24.         overlay.style.top = 0;
  25.         overlay.style.left = 0;
  26.         overlay.style.width = '100vw';
  27.         overlay.style.height = '100vh';
  28.         overlay.style.background = 'rgba(0,0,0,0.8)';
  29.         overlay.style.zIndex = 99999;
  30.         overlay.style.display = 'flex';
  31.         overlay.style.alignItems = 'center';
  32.         overlay.style.justifyContent = 'center';
  33.  
  34.         const iframe = document.createElement('iframe');
  35.         iframe.src = srcUrl;
  36.         iframe.style.width = '80vw';
  37.         iframe.style.height = '90vh';
  38.         iframe.style.border = 'none';
  39.         iframe.style.background = '#fff';
  40.         overlay.appendChild(iframe);
  41.  
  42.         // Fallback if iframe fails to load (e.g. X-Frame-Options)
  43.         iframe.onerror = () => {
  44.             overlay.remove();
  45.             if (isBlob && currentBlobUrl) {
  46.                 URL.revokeObjectURL(currentBlobUrl);
  47.                 currentBlobUrl = null;
  48.             }
  49.             window.open(srcUrl, '_blank');
  50.         };
  51.  
  52.         // Close button
  53.         const closeBtn = document.createElement('button');
  54.         closeBtn.textContent = 'Close PDF';
  55.         closeBtn.style.position = 'absolute';
  56.         closeBtn.style.top = '20px';
  57.         closeBtn.style.right = '200px';
  58.         closeBtn.style.zIndex = 100000;
  59.         closeBtn.style.padding = '2px 6px';
  60.         closeBtn.style.fontSize = '1.2em';
  61.         closeBtn.onclick = () => {
  62.             overlay.remove();
  63.             if (isBlob && currentBlobUrl) {
  64.                 URL.revokeObjectURL(currentBlobUrl);
  65.                 currentBlobUrl = null;
  66.             }
  67.         };
  68.         overlay.appendChild(closeBtn);
  69.  
  70.         // "Open in New Tab" button
  71.         const newTabBtn = document.createElement('button');
  72.         newTabBtn.textContent = 'Open in New Tab';
  73.         newTabBtn.style.position = 'absolute';
  74.         newTabBtn.style.top = '20px';
  75.         newTabBtn.style.right = '40px';
  76.         newTabBtn.style.zIndex = 100000;
  77.         newTabBtn.style.padding = '2px 6px';
  78.         newTabBtn.style.fontSize = '1.2em';
  79.         newTabBtn.onclick = () => {
  80.             window.open(srcUrl, '_blank');
  81.         };
  82.         overlay.appendChild(newTabBtn);
  83.  
  84.         document.body.appendChild(overlay);
  85.  
  86.         // Track for cleanup
  87.         if (isBlob) {
  88.             currentBlobUrl = srcUrl;
  89.         } else {
  90.             currentBlobUrl = null;
  91.         }
  92.     }
  93.  
  94.     function isPDFLink(href) {
  95.         try {
  96.             const url = new URL(href, window.location.href);
  97.             return url.pathname.toLowerCase().endsWith('.pdf');
  98.         } catch {
  99.             return false;
  100.         }
  101.     }
  102.  
  103.     function attachPDFInterceptors() {
  104.         document.querySelectorAll('a[href]').forEach(link => {
  105.             const href = link.getAttribute('href');
  106.             if (!href || link.dataset.tmPdfBound) return;
  107.  
  108.             const isWrapper = href.includes('_download.html');
  109.             const isDirectPDF = isPDFLink(href);
  110.  
  111.             if (isWrapper || isDirectPDF) {
  112.                 link.dataset.tmPdfBound = "1";
  113.  
  114.                 link.addEventListener('click', function (e) {
  115.                     e.preventDefault();
  116.  
  117.                     if (isDirectPDF) {
  118.                         showPDF(link.href);
  119.                     } else {
  120.                         fetch(link.href, { credentials: 'include' })
  121.                             .then(res => {
  122.                                 const contentType = res.headers.get('Content-Type') || '';
  123.                                 if (contentType.includes('pdf')) {
  124.                                     return res.blob().then(blob => {
  125.                                         const blobUrl = URL.createObjectURL(blob);
  126.                                         showPDF(blobUrl, true);
  127.                                     });
  128.                                 } else {
  129.                                     window.location.href = link.href;
  130.                                 }
  131.                             })
  132.                             .catch(err => {
  133.                                 alert("Could not open PDF: " + err);
  134.                                 window.location.href = link.href;
  135.                             });
  136.                     }
  137.                 });
  138.             }
  139.         });
  140.     }
  141.  
  142.     window.addEventListener('keydown', (e) => {
  143.         if (e.key === 'Escape') {
  144.             const viewer = document.getElementById('tampermonkey-pdf-viewer');
  145.             if (viewer) {
  146.                 viewer.remove();
  147.                 if (currentBlobUrl) {
  148.                     URL.revokeObjectURL(currentBlobUrl);
  149.                     currentBlobUrl = null;
  150.                 }
  151.             }
  152.         }
  153.     });
  154.  
  155.     attachPDFInterceptors();
  156.     const observer = new MutationObserver(attachPDFInterceptors);
  157.     observer.observe(document.body, { childList: true, subtree: true });
  158. })();