Add support to extract viewer preference

core/src/fpdfdoc/doc_viewerPreferences.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 "../../include/fpdfdoc/fpdf_doc.h"
 CPDF_ViewerPreferences::CPDF_ViewerPreferences(CPDF_Document *pDoc): m_pDoc(pDoc)
 {
 }
@@ skipping 11 matching lines @@
 }
 FX_BOOL CPDF_ViewerPreferences::PrintScaling() const
 {
     CPDF_Dictionary *pDict = m_pDoc->GetRoot();
     pDict = pDict->GetDict(FX_BSTRC("ViewerPreferences"));
     if (!pDict) {
         return TRUE;
     }
     return FX_BSTRC("None") != pDict->GetString(FX_BSTRC("PrintScaling"));
 }
+FX_INT32 CPDF_ViewerPreferences::NumCopies() const
+{
+    CPDF_Dictionary *pDict = m_pDoc->GetRoot();
+    pDict = pDict->GetDict(FX_BSTRC("ViewerPreferences"));
+    if (!pDict) {
+        return TRUE;

[Bo Xu, 2014/07/07 18:11:19]

As the return type is FX_INT32, we should do "return 1;" explicitly here.

[Nikhil, 2014/07/08 07:54:37]

Done.

+    }
+    return pDict->GetInteger(FX_BSTRC("NumCopies"));
+}
+CPDF_Array* CPDF_ViewerPreferences::PrintPageRange() const
+{
+    CPDF_Dictionary *pDict = m_pDoc->GetRoot();
+    CPDF_Array *pRange = NULL;
+    pDict = pDict->GetDict(FX_BSTRC("ViewerPreferences"));
+    if (!pDict) {
+        return pRange;
+    }
+    pRange = pDict->GetArray(FX_BSTRC("PrintPageRange"));
+    return pRange;
+}
+CFX_ByteString CPDF_ViewerPreferences::Duplex() const
+{
+    CPDF_Dictionary *pDict = m_pDoc->GetRoot();
+    pDict = pDict->GetDict(FX_BSTRC("ViewerPreferences"));
+    if (!pDict) {
+        return FX_BSTRC("None");
+    }
+    return pDict->GetString(FX_BSTRC("Duplex"));
+}