Add the |location| to the |updateviewarea| UI event

*This patch addresses an issue I stumbled upon while working on rewriting the history implementation.*

Currently the `updateviewarea` UI event doesn't include the `location`, and in the event handler in viewer.js we instead reach into `PDFViewer` to retrieve it. Not only does this seem conceptually wrong, it also makes the `updateviewarea` event less useful in general since it's currently only possible to access the `location` if you have a reference to the `PDFViewer`.

To me, this simply appears to be an oversight in the implementation, hence this patch which adds `location` to the `updateviewarea` event. It also changes `location` to be a "private" property of `PDFViewer`.

web/pdf_viewer.js

@@ -326,7 +326,7 @@ var PDFViewer = (function pdfViewer() {
       this._currentScale = UNKNOWN_SCALE;
       this._currentScaleValue = null;
       this._buffer = new PDFPageViewBuffer(DEFAULT_CACHE_SIZE);
-      this.location = null;
+      this._location = null;
       this._pagesRotation = 0;
       this._pagesRequests = [];
 
@@ -374,11 +374,11 @@ var PDFViewer = (function pdfViewer() {
 
       if (!noScroll) {
         var page = this._currentPageNumber, dest;
-        if (this.location && !IGNORE_CURRENT_POSITION_ON_ZOOM &&
+        if (this._location && !IGNORE_CURRENT_POSITION_ON_ZOOM &&
             !(this.isInPresentationMode || this.isChangingPresentationMode)) {
-          page = this.location.pageNumber;
+          page = this._location.pageNumber;
-          dest = [null, { name: 'XYZ' }, this.location.left,
+          dest = [null, { name: 'XYZ' }, this._location.left,
-            this.location.top, null];
+                  this._location.top, null];
         }
         this.scrollPageIntoView(page, dest);
       }
@@ -557,7 +557,7 @@ var PDFViewer = (function pdfViewer() {
       var intTop = Math.round(topLeft[1]);
       pdfOpenParams += ',' + intLeft + ',' + intTop;
 
-      this.location = {
+      this._location = {
         pageNumber: pageNumber,
         scale: normalizedScaleValue,
         top: intTop,
@@ -611,6 +611,7 @@ var PDFViewer = (function pdfViewer() {
 
       var event = document.createEvent('UIEvents');
       event.initUIEvent('updateviewarea', true, true, window, 0);
+      event.location = this._location;
       this.container.dispatchEvent(event);
     },
 

web/viewer.js

@@ -1753,12 +1753,11 @@ function updateViewarea() {
   PDFViewerApplication.pdfViewer.update();
 }
 
-window.addEventListener('updateviewarea', function () {
+window.addEventListener('updateviewarea', function (evt) {
   if (!PDFViewerApplication.initialized) {
     return;
   }
-
+  var location = evt.location;
-  var location = PDFViewerApplication.pdfViewer.location;
 
   PDFViewerApplication.store.initializedPromise.then(function() {
     PDFViewerApplication.store.setMultiple({