Adding new errorback and code to display error messages.

src/core.js

@@ -63,6 +63,10 @@ var Page = (function pagePage() {
     };
     this.xref = xref;
     this.ref = ref;
+
+    this.ctx = null;
+    this.callback = null;
+    this.errorback = null;
   }
 
   constructor.prototype = {
@@ -165,8 +169,10 @@ var Page = (function pagePage() {
           try {
             self.display(gfx, self.callback);
           } catch (e) {
-            if (self.callback) self.callback(e.toString());
-            throw e;
+            if (self.errorback)
+              self.errorback(e);
+            else
+              throw e;
           }
         });
       };
@@ -303,9 +309,10 @@ var Page = (function pagePage() {
       }
       return links;
     },
-    startRendering: function pageStartRendering(ctx, callback)  {
+    startRendering: function pageStartRendering(ctx, callback, errorback)  {
       this.ctx = ctx;
       this.callback = callback;
+      this.errorback = errorback;
 
       this.startRenderingTime = Date.now();
       this.pdf.startRendering(this);
@@ -599,6 +606,14 @@ var PDFDoc = (function pdfDoc() {
         }
       }.bind(this));
 
+      messageHandler.on('page_error', function pdfDocError(data) {
+        var page = this.pageCache[data.pageNum];
+        if (page.errorback)
+          page.errorback(data.error)
+        else
+          throw data.error;
+      }, this);
+
       setTimeout(function pdfDocFontReadySetTimeout() {
         messageHandler.send('doc', this.data);
         this.workerReadyPromise.resolve(true);

src/worker.js

@@ -14,7 +14,6 @@ function MessageHandler(name, comObj) {
   ah['console_error'] = [function ahConsoleError(data) {
       console.error.apply(console, data);
   }];
-
   comObj.onmessage = function messageHandlerComObjOnMessage(event) {
     var data = event.data;
     if (data.action in ah) {
@@ -67,7 +66,6 @@ var WorkerMessageHandler = {
     handler.on('page_request', function wphSetupPageRequest(pageNum) {
       pageNum = parseInt(pageNum);
 
-      var page = pdfDoc.getPage(pageNum);
 
       // The following code does quite the same as
       // Page.prototype.startRendering, but stops at one point and sends the
@@ -77,9 +75,22 @@ var WorkerMessageHandler = {
       var start = Date.now();
 
       var dependency = [];
-
-      // Pre compile the pdf page and fetch the fonts/images.
-      var IRQueue = page.getIRQueue(handler, dependency);
+      try {
+        var page = pdfDoc.getPage(pageNum);
+        // Pre compile the pdf page and fetch the fonts/images.
+        var IRQueue = page.getIRQueue(handler, dependency);
+      } catch(e) {
+        // Turn the error into an obj that can be serialized
+        e = {
+          message: e.message,
+          stack: e.stack
+        };
+        handler.send('page_error', {
+          pageNum: pageNum,
+          error: e
+        });
+        return;
+      }
 
       console.log('page=%d - getIRQueue: time=%dms, len=%d', pageNum,
                                   Date.now() - start, IRQueue.fnArray.length);

test/driver.js

@@ -162,9 +162,11 @@ function nextPage(task, loadError) {
 
       page.startRendering(
         ctx,
-        function nextPageStartRendering(e) {
-          snapshotCurrentPage(task, (!failure && e) ?
-            ('render : ' + e) : failure);
+        function nextPageStartRendering() {
+          snapshotCurrentPage(task, false);
+        },
+        function errorNextPageStartRendering(e) {
+          snapshotCurrentPage(task, 'render : ' + e.message);
         }
       );
     } catch (e) {

web/viewer.css

@@ -252,6 +252,37 @@ canvas {
   display: none;
 }
 
+#errorWrapper {
+  background: none repeat scroll 0 0 #FF5555;
+  color: white;
+  left: 0;
+  position: fixed;
+  right: 0;
+  top: 30px;
+  z-index: 1000;
+  padding: 3px;
+}
+
+#errorMessageLeft {
+  float: left;
+}
+
+#errorMessageRight {
+  float: right;
+}
+
+#errorMoreInfo {
+  background-color: #FFFFFF;
+  color: black;
+  padding: 3px;
+  margin: 3px;
+  white-space: pre;
+}
+
+.clearBoth {
+  clear: both;
+}
+
 /* === Printed media overrides === */
 @media print {
   #sidebar {

web/viewer.html

@@ -97,6 +97,24 @@
 
       <span id="info">--</span>
     </div>
+    <div id="errorWrapper" hidden='true'>
+      <div id="errorMessageLeft">
+        <span id="errorMessage"></span>
+        <button id="errorShowMore" onclick="" oncontextmenu="return false;">
+          More Information
+        </button>
+        <button id="errorShowLess" onclick="" oncontextmenu="return false;" hidden='true'>
+          Less Information
+        </button>
+      </div>
+      <div id="errorMessageRight">
+        <button id="errorClose" oncontextmenu="return false;">
+          X
+        </button>
+      </div>
+      <div class="clearBoth"></div>
+      <div id="errorMoreInfo" hidden='true'></div>
+    </div>
 
     <div id="sidebar">
       <div id="sidebarBox">

web/viewer.js

@@ -181,9 +181,34 @@ var PDFView = {
     return '';
   },
 
-  error: function pdfViewError() {
-    var loadingIndicator = document.getElementById('loading');
-    loadingIndicator.innerHTML = 'Error';
+  error: function pdfViewError(message, error) {
+    var errorWrapper = document.getElementById('errorWrapper');
+    errorWrapper.removeAttribute('hidden');
+
+    var errorMessage = document.getElementById('errorMessage');
+    errorMessage.innerHTML = message;
+
+    if (error) {
+      var errorMoreInfo = document.getElementById('errorMoreInfo');
+      var moreInfoButton = document.getElementById('errorShowMore');
+      var lessInfoButton = document.getElementById('errorShowLess');
+      var closeButton = document.getElementById('errorClose');
+      moreInfoButton.onclick = function() {
+        errorMoreInfo.removeAttribute('hidden');
+        moreInfoButton.setAttribute('hidden', 'true');
+        lessInfoButton.removeAttribute('hidden');
+      };
+      lessInfoButton.onclick = function() {
+        errorMoreInfo.setAttribute('hidden', 'true');
+        moreInfoButton.removeAttribute('hidden');
+        lessInfoButton.setAttribute('hidden', 'true');
+      };
+      closeButton.onclick = function() {
+        errorWrapper.setAttribute('hidden', 'true');
+      };
+      moreInfoButton.removeAttribute('hidden');
+      errorMoreInfo.innerHTML = error.message + '\n' + error.stack;
+    }
   },
 
   progress: function pdfViewProgress(level) {
@@ -487,7 +512,9 @@ var PageView = function pageView(container, content, id, pageWidth, pageHeight,
     ctx.translate(-this.x * scale, -this.y * scale);
 
     stats.begin = Date.now();
-    this.content.startRendering(ctx, this.updateStats);
+    this.content.startRendering(ctx, this.updateStats, function(e) {
+      PDFView.error('An error occured while rendering the page.', e);
+    });
 
     setupLinks(this.content, this.scale);
     div.setAttribute('data-loaded', true);