Add support to extract viewer preference

fpdfsdk/include/fpdfview.h

 // 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
 
 
 #ifndef _FPDFVIEW_H_
 #define _FPDFVIEW_H_
 
@@ skipping 16 matching lines @@
 typedef void*   FPDF_TEXTPAGE;
 typedef void*   FPDF_SCHHANDLE;
 typedef void*   FPDF_PAGELINK;
 typedef void*   FPDF_HMODULE;
 typedef void*   FPDF_DOCSCHHANDLE;
 
 typedef void*   FPDF_BOOKMARK;
 typedef void*   FPDF_DEST;
 typedef void*   FPDF_ACTION;
 typedef void*   FPDF_LINK;
+typedef void*   FPDF_PAGERANGE;
 
 // Basic data types
 typedef int                             FPDF_BOOL;
 typedef int                             FPDF_ERROR;     
 typedef unsigned long   FPDF_DWORD;
 
 typedef float                   FS_FLOAT;
 
+// Duplex types
+typedef enum _FPDF_DUPLEXTYPE_ {
+    DuplexUndefined = 0,
+    Simplex,
+    DuplexFlipShortEdge,
+    DuplexFlipLongEdge
+} FPDF_DUPLEXTYPE;
+
 // String types
 typedef unsigned short                  FPDF_WCHAR;
 typedef unsigned char const*    FPDF_LPCBYTE;
 
 // FPDFSDK may use three types of strings: byte string, wide string (UTF-16LE encoded), and platform dependent string
 typedef const char*                             FPDF_BYTESTRING;
 
 typedef const unsigned short*   FPDF_WIDESTRING;                // Foxit PDF SDK always use UTF-16LE encoding wide string,
                                                                                                                 // each character use 2 bytes (except surrogation), with low byte first.
 
@@ skipping 494 matching lines @@
 
 // Function: FPDF_VIEWERREF_GetPrintScaling
 //                      Whether the PDF document prefers to be scaled or not.
 // Parameters: 
 //                      document        -       Handle to the loaded document.
 // Return value:
 //                      None.
 //
 DLLEXPORT FPDF_BOOL STDCALL FPDF_VIEWERREF_GetPrintScaling(FPDF_DOCUMENT document);
 
+// Function: FPDF_VIEWERREF_GetNumCopies
+//                      Returns the number of copies to be printed.
+// Parameters:
+//                      document        -       Handle to the loaded document.
+// Return value:
+//          The number of copies to be printed.
+//
+DLLEXPORT int STDCALL FPDF_VIEWERREF_GetNumCopies(FPDF_DOCUMENT document);
+
+// Function: FPDF_VIEWERREF_GetPrintPageRange
+//                      Page numbers to initialize print dialog box when file is printed.
+// Parameters:
+//                      document        -       Handle to the loaded document.
+// Return value:
+//          The print page range to be used for printing.
+//
+DLLEXPORT FPDF_PAGERANGE STDCALL FPDF_VIEWERREF_GetPrintPageRange(FPDF_DOCUMENT document);
+
+// Function: FPDF_VIEWERREF_GetDuplex
+//                      Returns the paper handling option to be used when printing from print dialog.
+// Parameters:
+//                      document        -       Handle to the loaded document.
+// Return value:
+//          The paper handling option to be used when printing.
+//
+DLLEXPORT FPDF_DUPLEXTYPE STDCALL FPDF_VIEWERREF_GetDuplex(FPDF_DOCUMENT document);
+
 // Function: FPDF_GetNamedDestByName
 //                      get a special dest handle by the index.
 // Parameters: 
 //                      document        -       Handle to the loaded document.
 //                      name            -       The name of a special named dest.
 // Return value:
 //                      The handle of the dest.
 //
 DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDestByName(FPDF_DOCUMENT document,FPDF_BYTESTRING name);
 
 #ifdef __cplusplus
 };
 #endif
 
 #endif // _FPDFVIEW_H_