Merge to XFA: Introduce CPDFDocumentFromFPDFDocument().

fpdfsdk/src/fpdf_ext.cpp

 // Copyright 2014 PDFium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include "../../core/include/fxcrt/fx_xml.h"
 #include "../../public/fpdf_ext.h"
 #include "../include/fsdk_define.h"
 #include "../include/fpdfxfa/fpdfxfa_doc.h"
@@ skipping 159 matching lines @@
   }
 
   // SharedForm
   CPDF_Metadata metaData(pDoc);
   const CXML_Element* pElement = metaData.GetRoot();
   if (pElement)
     CheckSharedForm(pElement, "workflowType");
 }
 
 DLLEXPORT int FPDFDoc_GetPageMode(FPDF_DOCUMENT document) {
-  if (!document)
+  CPDF_Document* pDoc = CPDFDocumentFromFPDFDocument(document);
+  if (!pDoc)
     return PAGEMODE_UNKNOWN;
 
-  CPDF_Dictionary* pRoot =
-      (((CPDFXFA_Document*)document)->GetPDFDoc())->GetRoot();
+  CPDF_Dictionary* pRoot = pDoc->GetRoot();
   if (!pRoot)
     return PAGEMODE_UNKNOWN;
 
   CPDF_Object* pName = pRoot->GetElement("PageMode");
   if (!pName)
     return PAGEMODE_USENONE;
 
   CFX_ByteString strPageMode = pName->GetString();
   if (strPageMode.IsEmpty() || strPageMode.EqualNoCase("UseNone"))
     return PAGEMODE_USENONE;
   if (strPageMode.EqualNoCase("UseOutlines"))
     return PAGEMODE_USEOUTLINES;
   if (strPageMode.EqualNoCase("UseThumbs"))
     return PAGEMODE_USETHUMBS;
   if (strPageMode.EqualNoCase("FullScreen"))
     return PAGEMODE_FULLSCREEN;
   if (strPageMode.EqualNoCase("UseOC"))
     return PAGEMODE_USEOC;
   if (strPageMode.EqualNoCase("UseAttachments"))
     return PAGEMODE_USEATTACHMENTS;
 
   return PAGEMODE_UNKNOWN;
 }