Print Preview: Finish removing global Javascript functions.

chrome/test/data/webui/print_preview/native_layer_stub.js

 // Copyright 2017 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.
 
 cr.define('print_preview', function() {
   /**
   * Test version of the native layer.
   * @constructor
   * @extends {TestBrowserProxy}
   */
   function NativeLayerStub() {
     TestBrowserProxy.call(this, [
         'getInitialSettings',
         'getPrinters',
         'getExtensionPrinters',
         'getPreview',
         'getPrivetPrinters',
         'getPrinterCapabilities',
         'print',
         'setupPrinter'
       ]);
 
     /**
-     * @private {!cr.EventTarget} The event target used for dispatching and
-     *     receiving events.
-     */
-    this.eventTarget_ = new cr.EventTarget();
-
-    /**
      * @private {!print_preview.NativeInitialSettings} The initial settings
      *     to be used for the response to a |getInitialSettings| call.
      */
     this.initialSettings_ = null;
 
     /**
      *
      * @private {!Array<!print_preview.LocalDestinationInfo>} Local destination
      *     list to be used for the response to |getPrinters|.
      */
@@ skipping 48 matching lines @@
     /** @override */
     getPreview: function(
         destination, printTicketStore, documentInfo, generateDraft, requestId) {
       this.methodCalled('getPreview', {
         destination: destination,
         printTicketStore: printTicketStore,
         documentInfo: documentInfo,
         generateDraft: generateDraft,
         requestId: requestId,
       });
-      var rejectString = print_preview.PreviewArea.EventType.SETTINGS_INVALID;
-      rejectString = rejectString.substring(
-          rejectString.lastIndexOf(".") + 1, rejectString.length);
-      return destination.id == this.badPrinterId_ ?
-          Promise.reject(rejectString) :
-          Promise.resolve(requestId);
+      if (destination.id == this.badPrinterId_) {
+        var rejectString = print_preview.PreviewArea.EventType.SETTINGS_INVALID;
+        rejectString = rejectString.substring(
+            rejectString.lastIndexOf('.') + 1, rejectString.length);
+        return Promise.reject(rejectString);
+      }
+      var pageRanges = printTicketStore.pageRange.getDocumentPageRanges();
+      if (pageRanges.length == 0) {  // assume full length document, 1 page.
+        cr.webUIListenerCallback('page-count-ready', 1, requestId, 100);
+        cr.webUIListenerCallback('page-preview-ready', 0, 0, requestId);
+      } else {
+        var pages = [];
+        var totalPages = 0;
+        pageRanges.forEach(function(range) {

[dpapad, 2017/07/08 00:40:03]

Nit: This logic can be simplified.
1) Use Array#push() to grow the array instead of keeping track of |totalPages|
2) Use Array#reduce()

var pages = pageRanges.reduce(function(soFar, range) {
  for (var page = range.from; page <= range.to; page++) {
     soFar.push(page);
  }
  return soFar;
}, []);

[rbpotter, 2017/07/08 03:10:52]

Done.

+          for (var page = range.from; page <= range.to; page++) {
+            pages[totalPages] = page;
+            totalPages++;
+          }
+        });
+        cr.webUIListenerCallback(
+            'page-count-ready', totalPages, requestId, 100);
+        pages.forEach(function(page) {
+          cr.webUIListenerCallback(
+              'page-preview-ready', page - 1, 0, requestId);
+        });
+      }
+      return Promise.resolve(requestId);
     },
 
     /** @override */
     getPrivetPrinters: function() {
       this.methodCalled('getPrivetPrinters');
       return Promise.resolve(true);
     },
 
     /** @override */
     getPrinterCapabilities: function(printerId) {
@@ skipping 15 matching lines @@
 
     /** @override */
     setupPrinter: function(printerId) {
       this.methodCalled('setupPrinter', printerId);
       return this.shouldRejectPrinterSetup_ ?
           Promise.reject(this.setupPrinterResponse_) :
           Promise.resolve(this.setupPrinterResponse_);
     },
 
     /** Stubs for |print_preview.NativeLayer| methods that call C++ handlers. */
-    previewReadyForTest: function() {},
     startHideDialog: function () {},
 
-    /** @return {!cr.EventTarget} The native layer event target. */
-    getEventTarget: function() { return this.eventTarget_; },
-
-    /** @param {!cr.EventTarget} eventTarget The event target to use. */
-    setEventTarget: function(eventTarget) {
-      this.eventTarget_ = eventTarget;
-    },
-
     /**
      * @param {!print_preview.NativeInitialSettings} settings The settings
      *     to return as a response to |getInitialSettings|.
      */
     setInitialSettings: function(settings) {
       this.initialSettings_ = settings;
     },
 
     /**
      * @param {!Array<!print_preview.LocalDestinationInfo>} localDestinations
@@ skipping 32 matching lines @@
      */
     setInvalidPrinterId: function(id) {
       this.badPrinterId_ = id;
     },
   };
 
   return {
     NativeLayerStub: NativeLayerStub,
   };
 });