Merge pull request #5586 from fkaelberer/updateThumbnailClassesOnlyWhenVisible

Update thumbnails only when they are visible (to improve scrolling through large documents)

web/pdf_thumbnail_viewer.js

@@ -76,7 +76,9 @@ var PDFThumbnailViewer = (function PDFThumbnailViewerClosure() {
         selected.classList.remove('selected');
       }
       var thumbnail = document.getElementById('thumbnailContainer' + page);
+      if (thumbnail) {
         thumbnail.classList.add('selected');
+      }
       var visibleThumbs = this._getVisibleThumbs();
       var numVisibleThumbs = visibleThumbs.views.length;
 

web/viewer.js

@@ -1157,6 +1157,23 @@ var PDFViewerApplication = {
     }
   },
 
+  refreshThumbnailViewer: function pdfViewRefreshThumbnailViewer() {
+    var pdfViewer = this.pdfViewer;
+    var thumbnailViewer = this.pdfThumbnailViewer;
+
+    // set thumbnail images of rendered pages
+    var pagesCount = pdfViewer.pagesCount;
+    for (var pageIndex = 0; pageIndex < pagesCount; pageIndex++) {
+      var pageView = pdfViewer.getPageView(pageIndex);
+      if (pageView && pageView.renderingState === RenderingStates.FINISHED) {
+        var thumbnailView = thumbnailViewer.getThumbnail(pageIndex);
+        thumbnailView.setImage(pageView);
+      }
+    }
+
+    thumbnailViewer.scrollThumbnailIntoView(this.page);
+  },
+
   switchSidebarView: function pdfViewSwitchSidebarView(view, openSidebar) {
     if (openSidebar && !this.sidebarOpen) {
       document.getElementById('sidebarToggle').click();
@@ -1551,6 +1568,9 @@ function webViewerInitialized() {
       outerContainer.classList.toggle('sidebarOpen');
       PDFViewerApplication.sidebarOpen =
         outerContainer.classList.contains('sidebarOpen');
+      if (PDFViewerApplication.sidebarOpen) {
+        PDFViewerApplication.refreshThumbnailViewer();
+      }
       PDFViewerApplication.forceRendering();
     });
 
@@ -1665,9 +1685,12 @@ document.addEventListener('pagerendered', function (e) {
   var pageNumber = e.detail.pageNumber;
   var pageIndex = pageNumber - 1;
   var pageView = PDFViewerApplication.pdfViewer.getPageView(pageIndex);
+
+  if (PDFViewerApplication.sidebarOpen) {
     var thumbnailView = PDFViewerApplication.pdfThumbnailViewer.
                         getThumbnail(pageIndex);
     thumbnailView.setImage(pageView);
+  }
 
   if (PDFJS.pdfBug && Stats.enabled && pageView.stats) {
     Stats.add(pageNumber, pageView.stats);
@@ -1897,8 +1920,10 @@ window.addEventListener('pagechange', function pagechange(evt) {
   var page = evt.pageNumber;
   if (evt.previousPageNumber !== page) {
     document.getElementById('pageNumber').value = page;
+    if (PDFViewerApplication.sidebarOpen) {
       PDFViewerApplication.pdfThumbnailViewer.scrollThumbnailIntoView(page);
     }
+  }
   var numPages = PDFViewerApplication.pagesCount;
 
   document.getElementById('previous').disabled = (page <= 1);