Merge pull request #7514 from Snuffleupagus/viewer-abort-rendering-on-close

Ensure that we cancel any pending rendering operations when the viewer is closed (issue 7274)

web/app.js

@@ -1583,6 +1583,19 @@ function webViewerPageRendered(e) {
   var pageIndex = pageNumber - 1;
   var pageView = PDFViewerApplication.pdfViewer.getPageView(pageIndex);
 
+  // If the page is still visible when it has finished rendering,
+  // ensure that the page number input loading indicator is hidden.
+  if (pageNumber === PDFViewerApplication.page) {
+    var pageNumberInput = PDFViewerApplication.appConfig.toolbar.pageNumber;
+    pageNumberInput.classList.remove(PAGE_NUMBER_LOADING_INDICATOR);
+  }
+
+  // Prevent errors in the edge-case where the PDF document is removed *before*
+  // the 'pagerendered' event handler is invoked.
+  if (!pageView) {
+    return;
+  }
+
   // Use the rendered page to set the corresponding thumbnail image.
   if (PDFViewerApplication.pdfSidebar.isThumbnailViewVisible) {
     var thumbnailView = PDFViewerApplication.pdfThumbnailViewer.
@@ -1599,13 +1612,6 @@ function webViewerPageRendered(e) {
       'An error occurred while rendering the page.'), pageView.error);
   }
 
-  // If the page is still visible when it has finished rendering,
-  // ensure that the page number input loading indicator is hidden.
-  if (pageNumber === PDFViewerApplication.page) {
-    var pageNumberInput = PDFViewerApplication.appConfig.toolbar.pageNumber;
-    pageNumberInput.classList.remove(PAGE_NUMBER_LOADING_INDICATOR);
-  }
-
 //#if !PRODUCTION
   if (true) {
     return;
@@ -1626,18 +1632,13 @@ function webViewerPageRendered(e) {
 }
 
 function webViewerTextLayerRendered(e) {
-  var pageIndex = e.pageNumber - 1;
-  var pageView = PDFViewerApplication.pdfViewer.getPageView(pageIndex);
-
 //#if !PRODUCTION
   if (true) {
     return;
   }
 //#endif
 //#if (FIREFOX || MOZCENTRAL)
-  if (pageView.textLayer && pageView.textLayer.textDivs &&
-      pageView.textLayer.textDivs.length > 0 &&
-      !PDFViewerApplication.supportsDocumentColors) {
+  if (e.numTextDivs > 0 && !PDFViewerApplication.supportsDocumentColors) {
     console.error(mozL10n.get('document_colors_not_allowed', null,
       'PDF documents are not allowed to use their own colors: ' +
       '\'Allow pages to choose their own colors\' ' +

web/pdf_page_view.js

@@ -92,6 +92,7 @@ var PDFPageView = (function PDFPageViewClosure() {
     this.textLayerFactory = textLayerFactory;
     this.annotationLayerFactory = annotationLayerFactory;
 
+    this.renderTask = null;
     this.renderingState = RenderingStates.INITIAL;
     this.resume = null;
 
@@ -135,11 +136,7 @@ var PDFPageView = (function PDFPageViewClosure() {
     },
 
     reset: function PDFPageView_reset(keepZoomLayer, keepAnnotations) {
-      if (this.renderTask) {
-        this.renderTask.cancel();
-      }
-      this.resume = null;
-      this.renderingState = RenderingStates.INITIAL;
+      this.cancelRendering();
 
       var div = this.div;
       div.style.width = Math.floor(this.viewport.width) + 'px';
@@ -225,6 +222,20 @@ var PDFPageView = (function PDFPageViewClosure() {
       this.reset(/* keepZoomLayer = */ true, /* keepAnnotations = */ true);
     },
 
+    cancelRendering: function PDFPageView_cancelRendering() {
+      if (this.renderTask) {
+        this.renderTask.cancel();
+        this.renderTask = null;
+      }
+      this.renderingState = RenderingStates.INITIAL;
+      this.resume = null;
+
+      if (this.textLayer) {
+        this.textLayer.cancel();
+        this.textLayer = null;
+      }
+    },
+
     /**
      * Called when moved in the parent's container.
      */
@@ -320,6 +331,7 @@ var PDFPageView = (function PDFPageViewClosure() {
     draw: function PDFPageView_draw() {
       if (this.renderingState !== RenderingStates.INITIAL) {
         console.error('Must be in new state before drawing');
+        this.reset(); // Ensure that we reset all state to prevent issues.
       }
 
       this.renderingState = RenderingStates.RUNNING;

web/pdf_thumbnail_view.js

@@ -98,8 +98,9 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
     this.linkService = linkService;
     this.renderingQueue = renderingQueue;
 
-    this.resume = null;
+    this.renderTask = null;
     this.renderingState = RenderingStates.INITIAL;
+    this.resume = null;
     this.disableCanvasToImageConversion = disableCanvasToImageConversion;
 
     this.pageWidth = this.viewport.width;
@@ -151,11 +152,7 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
     },
 
     reset: function PDFThumbnailView_reset() {
-      if (this.renderTask) {
-        this.renderTask.cancel();
-      }
-      this.resume = null;
-      this.renderingState = RenderingStates.INITIAL;
+      this.cancelRendering();
 
       this.pageWidth = this.viewport.width;
       this.pageHeight = this.viewport.height;
@@ -199,6 +196,15 @@ var PDFThumbnailView = (function PDFThumbnailViewClosure() {
       this.reset();
     },
 
+    cancelRendering: function PDFThumbnailView_cancelRendering() {
+      if (this.renderTask) {
+        this.renderTask.cancel();
+        this.renderTask = null;
+      }
+      this.renderingState = RenderingStates.INITIAL;
+      this.resume = null;
+    },
+
     /**
      * @private
      */

web/pdf_thumbnail_viewer.js

@@ -135,15 +135,14 @@ var PDFThumbnailViewer = (function PDFThumbnailViewerClosure() {
       this.thumbnails = [];
       this._pagesRotation = 0;
       this._pagesRequests = [];
+
+      // Remove the thumbnails from the DOM.
+      this.container.textContent = '';
     },
 
     setDocument: function PDFThumbnailViewer_setDocument(pdfDocument) {
       if (this.pdfDocument) {
-        // cleanup of the elements and views
-        var thumbsView = this.container;
-        while (thumbsView.hasChildNodes()) {
-          thumbsView.removeChild(thumbsView.lastChild);
-        }
+        this._cancelRendering();
         this._resetView();
       }
 
@@ -169,6 +168,17 @@ var PDFThumbnailViewer = (function PDFThumbnailViewerClosure() {
       }.bind(this));
     },
 
+    /**
+     * @private
+     */
+    _cancelRendering: function PDFThumbnailViewer_cancelRendering() {
+      for (var i = 0, ii = this.thumbnails.length; i < ii; i++) {
+        if (this.thumbnails[i]) {
+          this.thumbnails[i].cancelRendering();
+        }
+      }
+    },
+
     /**
      * @param {PDFThumbnailView} thumbView
      * @returns {PDFPage}

web/pdf_viewer.js

@@ -299,6 +299,7 @@ var PDFViewer = (function pdfViewer() {
      */
     setDocument: function (pdfDocument) {
       if (this.pdfDocument) {
+        this._cancelRendering();
         this._resetView();
       }
 
@@ -424,10 +425,8 @@ var PDFViewer = (function pdfViewer() {
       this._pagesRequests = [];
       this._pageViewsReady = false;
 
-      var container = this.viewer;
-      while (container.hasChildNodes()) {
-        container.removeChild(container.lastChild);
-      }
+      // Remove the pages from the DOM.
+      this.viewer.textContent = '';
     },
 
     _scrollUpdate: function PDFViewer_scrollUpdate() {
@@ -802,6 +801,17 @@ var PDFViewer = (function pdfViewer() {
       }
     },
 
+    /**
+     * @private
+     */
+    _cancelRendering: function PDFViewer_cancelRendering() {
+      for (var i = 0, ii = this._pages.length; i < ii; i++) {
+        if (this._pages[i]) {
+          this._pages[i].cancelRendering();
+        }
+      }
+    },
+
     /**
      * @param {PDFPageView} pageView
      * @returns {PDFPage}

web/text_layer_builder.js

@@ -18,8 +18,7 @@
 (function (root, factory) {
   if (typeof define === 'function' && define.amd) {
     define('pdfjs-web/text_layer_builder', ['exports', 'pdfjs-web/dom_events',
-        'pdfjs-web/pdfjs'],
-      factory);
+        'pdfjs-web/pdfjs'], factory);
   } else if (typeof exports !== 'undefined') {
     factory(exports, require('./dom_events.js'), require('./pdfjs.js'));
   } else {
@@ -52,8 +51,8 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
   function TextLayerBuilder(options) {
     this.textLayerDiv = options.textLayerDiv;
     this.eventBus = options.eventBus || domEvents.getGlobalEventBus();
+    this.textContent = null;
     this.renderingDone = false;
-    this.divContentDone = false;
     this.pageIdx = options.pageIndex;
     this.pageNumber = this.pageIdx + 1;
     this.matches = [];
@@ -66,6 +65,9 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
   }
 
   TextLayerBuilder.prototype = {
+    /**
+     * @private
+     */
     _finishRendering: function TextLayerBuilder_finishRendering() {
       this.renderingDone = true;
 
@@ -77,7 +79,8 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
 
       this.eventBus.dispatch('textlayerrendered', {
         source: this,
-        pageNumber: this.pageNumber
+        pageNumber: this.pageNumber,
+        numTextDivs: this.textDivs.length,
       });
     },
 
@@ -87,14 +90,10 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
      *   for specified amount of ms.
      */
     render: function TextLayerBuilder_render(timeout) {
-      if (!this.divContentDone || this.renderingDone) {
+      if (!this.textContent || this.renderingDone) {
         return;
       }
-
-      if (this.textLayerRenderTask) {
-        this.textLayerRenderTask.cancel();
-        this.textLayerRenderTask = null;
-      }
+      this.cancel();
 
       this.textDivs = [];
       var textLayerFrag = document.createDocumentFragment();
@@ -111,17 +110,23 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
         this._finishRendering();
         this.updateMatches();
       }.bind(this), function (reason) {
-        // canceled or failed to render text layer -- skipping errors
+        // cancelled or failed to render text layer -- skipping errors
       });
     },
 
-    setTextContent: function TextLayerBuilder_setTextContent(textContent) {
+    /**
+     * Cancels rendering of the text layer.
+     */
+    cancel: function TextLayerBuilder_cancel() {
       if (this.textLayerRenderTask) {
         this.textLayerRenderTask.cancel();
         this.textLayerRenderTask = null;
       }
+    },
+
+    setTextContent: function TextLayerBuilder_setTextContent(textContent) {
+      this.cancel();
       this.textContent = textContent;
-      this.divContentDone = true;
     },
 
     convertMatches: function TextLayerBuilder_convertMatches(matches,
@@ -324,6 +329,7 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
       var div = this.textLayerDiv;
       var self = this;
       var expandDivsTimer = null;
+
       div.addEventListener('mousedown', function (e) {
         if (self.enhanceTextSelection && self.textLayerRenderTask) {
           self.textLayerRenderTask.expandTextDivs(true);
@@ -357,11 +363,14 @@ var TextLayerBuilder = (function TextLayerBuilderClosure() {
 //#endif
         end.classList.add('active');
       });
+
       div.addEventListener('mouseup', function (e) {
         if (self.enhanceTextSelection && self.textLayerRenderTask) {
 //#if !(MOZCENTRAL || FIREFOX)
           expandDivsTimer = setTimeout(function() {
-            self.textLayerRenderTask.expandTextDivs(false);
+            if (self.textLayerRenderTask) {
+              self.textLayerRenderTask.expandTextDivs(false);
+            }
             expandDivsTimer = null;
           }, EXPAND_DIVS_TIMEOUT);
 //#else