Move getPage, on the worker side, from Catalog and into PDFDocument instead

Addresses an existing TODO, and avoids having to pass in a `pageFactory` when creating `Catalog` instances.

src/core/document.js

@@ -355,6 +355,7 @@ var PDFDocument = (function PDFDocumentClosure() {
       xref: this.xref,
       isEvalSupported: evaluatorOptions.isEvalSupported,
     });
+    this._pagePromises = [];
   }
 
   function find(stream, needle, limit, backwards) {
@@ -520,21 +521,7 @@ var PDFDocument = (function PDFDocumentClosure() {
     },
     setup: function PDFDocument_setup(recoveryMode) {
       this.xref.parse(recoveryMode);
-      var pageFactory = {
+      this.catalog = new Catalog(this.pdfManager, this.xref);
-        createPage: (pageIndex, dict, ref, fontCache, builtInCMapCache) => {
-          return new Page({
-            pdfManager: this.pdfManager,
-            xref: this.xref,
-            pageIndex,
-            pageDict: dict,
-            ref,
-            fontCache,
-            builtInCMapCache,
-            pdfFunctionFactory: this.pdfFunctionFactory,
-          });
-        },
-      };
-      this.catalog = new Catalog(this.pdfManager, this.xref, pageFactory);
     },
     get numPages() {
       var linearization = this.linearization;
@@ -599,8 +586,25 @@ var PDFDocument = (function PDFDocumentClosure() {
       return shadow(this, 'fingerprint', fileID);
     },
 
-    getPage: function PDFDocument_getPage(pageIndex) {
+    getPage(pageIndex) {
-      return this.catalog.getPage(pageIndex);
+      if (this._pagePromises[pageIndex] !== undefined) {
+        return this._pagePromises[pageIndex];
+      }
+      const catalog = this.catalog;
+
+      return this._pagePromises[pageIndex] =
+        catalog.getPageDict(pageIndex).then(([pageDict, ref]) => {
+          return new Page({
+            pdfManager: this.pdfManager,
+            xref: this.xref,
+            pageIndex,
+            pageDict,
+            ref,
+            fontCache: catalog.fontCache,
+            builtInCMapCache: catalog.builtInCMapCache,
+            pdfFunctionFactory: this.pdfFunctionFactory,
+          });
+        });
     },
 
     cleanup: function PDFDocument_cleanup() {

src/core/obj.js

@@ -29,7 +29,7 @@ import { CipherTransformFactory } from './crypto';
 import { ColorSpace } from './colorspace';
 
 var Catalog = (function CatalogClosure() {
-  function Catalog(pdfManager, xref, pageFactory) {
+  function Catalog(pdfManager, xref) {
     this.pdfManager = pdfManager;
     this.xref = xref;
     this.catDict = xref.getCatalogObj();
@@ -40,9 +40,6 @@ var Catalog = (function CatalogClosure() {
     this.fontCache = new RefSetCache();
     this.builtInCMapCache = Object.create(null);
     this.pageKidsCountCache = new RefSetCache();
-    // TODO refactor to move getPage() to the PDFDocument.
-    this.pageFactory = pageFactory;
-    this.pagePromises = [];
   }
 
   Catalog.prototype = {
@@ -453,18 +450,6 @@ var Catalog = (function CatalogClosure() {
       });
     },
 
-    getPage: function Catalog_getPage(pageIndex) {
-      if (!(pageIndex in this.pagePromises)) {
-        this.pagePromises[pageIndex] = this.getPageDict(pageIndex).then(
-            ([dict, ref]) => {
-          return this.pageFactory.createPage(pageIndex, dict, ref,
-                                             this.fontCache,
-                                             this.builtInCMapCache);
-        });
-      }
-      return this.pagePromises[pageIndex];
-    },
-
     getPageDict: function Catalog_getPageDict(pageIndex) {
       var capability = createPromiseCapability();
       var nodesToVisit = [this.catDict.getRaw('Pages')];