Compile print_preview, part 4: reduce down to 140 errors

chrome/browser/resources/print_preview/previewarea/preview_area.js

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+/**
+ * @typedef {{accessibility: Function,
+ *            documentLoadComplete: Function,
+ *            getHeight: Function,
+ *            getHorizontalScrollbarThickness: Function,
+ *            getPageLocationNormalized: Function,
+ *            getVerticalScrollbarThickness: Function,
+ *            getWidth: Function,
+ *            getZoomLevel: Function,
+ *            goToPage: Function,
+ *            grayscale: Function,
+ *            loadPreviewPage: Function,
+ *            onload: Function,
+ *            onPluginSizeChanged: Function,
+ *            onScroll: Function,
+ *            pageXOffset: Function,
+ *            pageYOffset: Function,
+ *            printPreviewPageCount: Function,
+ *            reload: Function,
+ *            removePrintButton: Function,
+ *            resetPrintPreviewUrl: Function,
+ *            sendKeyEvent: Function,
+ *            setPageNumbers: Function,
+ *            setPageXOffset: Function,
+ *            setPageYOffset: Function,
+ *            setZoomLevel: Function,
+ *            fitToHeight: Function,
+ *            fitToWidth: Function,
+ *            zoomIn: Function,
+ *            zoomOut: Function}}

[Dan Beam, 2014/09/29 22:10:06]

where is this code?  why not @externs?

[Vitaly Pavlenko, 2014/10/01 00:57:44]

These methods are dispatched by C++ code:

https://code.google.com/p/chromium/codesearch#chromium/src/pdf/instance.cc&sq...

For other places we used @typedef. Why do you think we need to use externs here?

[Dan Beam, 2014/10/01 01:11:31]

because this is basically a complex, static class

[Dan Beam, 2014/10/01 01:20:54]

in looking at the class, keeping @externs up to date would kind of suck.  choose
your poison.

+ */
+print_preview.PDFPlugin;
+
 cr.define('print_preview', function() {
   'use strict';
 
   /**
    * Creates a PreviewArea object. It represents the area where the preview
    * document is displayed.
    * @param {!print_preview.DestinationStore} destinationStore Used to get the
    *     currently selected destination.
    * @param {!print_preview.PrintTicketStore} printTicketStore Used to get
    *     information about how the preview should be displayed.
@@ skipping 39 matching lines @@
 
     /**
      * Used to read generated page previews.
      * @type {print_preview.PreviewGenerator}
      * @private
      */
     this.previewGenerator_ = null;
 
     /**
      * The embedded pdf plugin object. It's value is null if not yet loaded.
-     * @type {HTMLEmbedElement}
+     * @type {HTMLEmbedElement|print_preview.PDFPlugin}
      * @private
      */
     this.plugin_ = null;
 
     /**
      * Custom margins component superimposed on the preview plugin.
      * @type {!print_preview.MarginControlContainer}
      * @private
      */
     this.marginControlContainer_ = new print_preview.MarginControlContainer(
@@ skipping 113 matching lines @@
   PreviewArea.PluginType_ = {
     // TODO(raymes): Remove all references to the IN_PROCESS plugin once it is
     // removed.
     IN_PROCESS: 'in-process',
     OUT_OF_PROCESS: 'out-of-process',
     NONE: 'none'
   };
 
   /**
    * Maps message IDs to the CSS class that contains them.
-   * @type {object.<PreviewArea.MessageId_, string>}
+   * @type {Object.<print_preview.PreviewArea.MessageId_, string>}
    * @private
    */
   PreviewArea.MessageIdClassMap_ = {};
   PreviewArea.MessageIdClassMap_[PreviewArea.MessageId_.CUSTOM] =
       'preview-area-custom-message';
   PreviewArea.MessageIdClassMap_[PreviewArea.MessageId_.LOADING] =
       'preview-area-loading-message';
   PreviewArea.MessageIdClassMap_[PreviewArea.MessageId_.PREVIEW_FAILED] =
       'preview-area-preview-failed-message';
 
@@ skipping 64 matching lines @@
      * @param {string} message Custom message to show.
      */
     showCustomMessage: function(message) {
       this.showMessage_(PreviewArea.MessageId_.CUSTOM, message);
     },
 
     /** @override */
     enterDocument: function() {
       print_preview.Component.prototype.enterDocument.call(this);
       this.tracker.add(
-          this.openSystemDialogButton_,
+          assert(this.openSystemDialogButton_),
           'click',
           this.onOpenSystemDialogButtonClick_.bind(this));
 
       this.tracker.add(
           this.printTicketStore_,
           print_preview.PrintTicketStore.EventType.INITIALIZE,
           this.onTicketChange_.bind(this));
       this.tracker.add(
           this.printTicketStore_,
           print_preview.PrintTicketStore.EventType.TICKET_CHANGE,
@@ skipping 98 matching lines @@
      *     plugin for rendering the preview.
      *     PreviewArea.PluginType_.IN_PROCESS for an in-process plugin
      *     PreviewArea.PluginType_.OUT_OF_PROCESS for an out-of-process plugin
      *     PreviewArea.PluginType_.NONE if no plugin is available.
      * @private
      */
     getPluginType_: function() {
       // TODO(raymes): Remove the in-process check after we remove the
       // in-process plugin. Change this function back to
       // checkPluginCompatibility_().
+      /** @type {print_preview.PDFPlugin|Object} */

[Dan Beam, 2014/09/29 22:10:06]

why |Object?

[Vitaly Pavlenko, 2014/10/01 00:57:43]

Sorry, removed.

       var compatObj = this.getElement().getElementsByClassName(
           PreviewArea.Classes_.COMPATIBILITY_OBJECT)[0];
       var isCompatible =
           compatObj.onload &&
           compatObj.goToPage &&
           compatObj.removePrintButton &&
           compatObj.loadPreviewPage &&
           compatObj.printPreviewPageCount &&
           compatObj.resetPrintPreviewUrl &&
           compatObj.onPluginSizeChanged &&
@@ skipping 79 matching lines @@
      * @param {string} srcUrl Initial URL of the plugin.
      * @private
      */
     createPlugin_: function(srcUrl) {
       if (this.plugin_) {
         console.warn('Pdf preview plugin already created');
         return;
       }
 
       if (this.pluginType_ == PreviewArea.PluginType_.IN_PROCESS) {
-        this.plugin_ = document.createElement('embed');
+        this.plugin_ = assertInstanceof(document.createElement('embed'),
+                                        HTMLEmbedElement);
         this.plugin_.setAttribute(
             'type', 'application/x-google-chrome-print-preview-pdf');
         this.plugin_.setAttribute('src', srcUrl);
       } else {
-        this.plugin_ = PDFCreateOutOfProcessPlugin(srcUrl);
+        this.plugin_ = /** @type {print_preview.PDFPlugin} */(
+            PDFCreateOutOfProcessPlugin(srcUrl));
       }
 
       this.plugin_.setAttribute('class', 'preview-area-plugin');
       this.plugin_.setAttribute('aria-live', 'polite');
       this.plugin_.setAttribute('aria-atomic', 'true');
       // NOTE: The plugin's 'id' field must be set to 'pdf-viewer' since
       // chrome/renderer/printing/print_web_view_helper.cc actually references
       // it.
       this.plugin_.setAttribute('id', 'pdf-viewer');
       this.getChildElement('.preview-area-plugin-wrapper').
-          appendChild(this.plugin_);
+          appendChild(/** @type {Node} */(this.plugin_));
 
 
       if (this.pluginType_ == PreviewArea.PluginType_.OUT_OF_PROCESS) {
         var pageNumbers =
             this.printTicketStore_.pageRange.getPageNumberSet().asArray();
         var grayscale = !this.printTicketStore_.color.getValue();
         this.plugin_.setLoadCallback(this.onPluginLoad_.bind(this));
         this.plugin_.setViewportChangedCallback(
             this.onPreviewVisualStateChange_.bind(this));
         this.plugin_.resetPrintPreviewMode(srcUrl, grayscale, pageNumbers,
                                            this.documentInfo_.isModifiable);
       } else {
         global['onPreviewPluginLoad'] = this.onPluginLoad_.bind(this);
-        this.plugin_.onload('onPreviewPluginLoad()');
+        (/** @type {print_preview.PDFPlugin} */(this.plugin_)).
+            onload('onPreviewPluginLoad()');
 
         global['onPreviewPluginVisualStateChange'] =
             this.onPreviewVisualStateChange_.bind(this);
         this.plugin_.onScroll('onPreviewPluginVisualStateChange()');
         this.plugin_.onPluginSizeChanged('onPreviewPluginVisualStateChange()');
 
         this.plugin_.removePrintButton();
         this.plugin_.grayscale(!this.printTicketStore_.color.getValue());
       }
     },
@@ skipping 192 matching lines @@
             new print_preview.Size(viewportWidth, viewportHeight));
       }
     }
   };
 
   // Export
   return {
     PreviewArea: PreviewArea
   };
 });