Fixes an issue with later pages in pdfs not rendering correctly

Author: KaneMorgan

web/index.js

@@ -17,10 +17,20 @@ PDFJS.workerSrc = './shared/pdf.worker.js';
 
 // Render stuff
 let NUM_PAGES = 0;
+let renderedPages = [];
+let okToRender = false;
 document.getElementById('content-wrapper').addEventListener('scroll', function (e) {
   let visiblePageNum = Math.round(e.target.scrollTop / PAGE_HEIGHT) + 1;
   let visiblePage = document.querySelector(`.page[data-page-number="${visiblePageNum}"][data-loaded="false"]`);
-  if (visiblePage) {
+
+  if (renderedPages.indexOf(visiblePageNum) == -1){
+    okToRender = true;
+    renderedPages.push(visiblePageNum);
+  } else {
+    okToRender = false;
+  }
+
+  if (visiblePage && okToRender) {
     setTimeout(function () {
       UI.renderPage(visiblePageNum, RENDER_OPTIONS);
     });