Add support to extract viewer preference

fpdfsdk/include/fpdfview.h

Index: fpdfsdk/include/fpdfview.h
diff --git a/fpdfsdk/include/fpdfview.h b/fpdfsdk/include/fpdfview.h
index a563762613aad02d340f3cbdfed8323c711b2374..5ef4779da775fd6c82d1ff35c1a95250fbf1d10d 100644
--- a/fpdfsdk/include/fpdfview.h
+++ b/fpdfsdk/include/fpdfview.h
@@ -34,6 +34,7 @@ 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;
@@ -561,6 +562,33 @@ DLLEXPORT void STDCALL FPDFBitmap_Destroy(FPDF_BITMAP bitmap);
 //
 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:
+//			None.
+//
+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:
+//			None.
+//
+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:
+//			None.
+//
+DLLEXPORT FPDF_BYTESTRING STDCALL FPDF_VIEWERREF_GetDuplex(FPDF_DOCUMENT document);
+
 // Function: FPDF_GetNamedDestByName
 //			get a special dest handle by the index.
 // Parameters: