Add support to extract viewer preference

fpdfsdk/src/fpdfview.cpp

Index: fpdfsdk/src/fpdfview.cpp
diff --git a/fpdfsdk/src/fpdfview.cpp b/fpdfsdk/src/fpdfview.cpp
index a5ba796158705184300e27a699a48ce64c4b02f6..7b2d51f99985d59a0ec14470b86c69dedef3bb39 100644
--- a/fpdfsdk/src/fpdfview.cpp
+++ b/fpdfsdk/src/fpdfview.cpp
@@ -866,6 +866,38 @@ DLLEXPORT FPDF_BOOL STDCALL FPDF_VIEWERREF_GetPrintScaling(FPDF_DOCUMENT documen
 	return viewRef.PrintScaling();
 }
 
+DLLEXPORT int STDCALL FPDF_VIEWERREF_GetNumCopies(FPDF_DOCUMENT document)
+{
+    CPDF_Document* pDoc = (CPDF_Document*)document;
+    if (!pDoc) return 1;
+    CPDF_ViewerPreferences viewRef(pDoc);
+    return viewRef.NumCopies();
+}
+
+DLLEXPORT FPDF_PAGERANGE STDCALL FPDF_VIEWERREF_GetPrintPageRange(FPDF_DOCUMENT document)
+{
+    CPDF_Document* pDoc = (CPDF_Document*)document;
+    if (!pDoc) return NULL;
+    CPDF_ViewerPreferences viewRef(pDoc);
+    return viewRef.PrintPageRange();
+}
+
+DLLEXPORT FPDF_DUPLEXTYPE STDCALL FPDF_VIEWERREF_GetDuplex(FPDF_DOCUMENT document)
+{
+    CPDF_Document* pDoc = (CPDF_Document*)document;
+    if (!pDoc) return DuplexUndefined;
+    CPDF_ViewerPreferences viewRef(pDoc);
+    CFX_ByteString duplex = viewRef.Duplex();
+    if (FX_BSTRC("None") == duplex)
+        return DuplexUndefined;
+    if (FX_BSTRC("Simplex") == duplex)
+        return Simplex;
+    if (FX_BSTRC("DuplexFlipShortEdge") == duplex)
+        return DuplexFlipShortEdge;
+    if (FX_BSTRC("DuplexFlipLongEdge") == duplex)
+        return DuplexFlipLongEdge;
+}

[Nikhil, 2014/07/11 06:58:42]

I just realized that this gives warning! Control may reach end of non-void
function. Do we worry about warnings? It can be removed by maintaining a local
variable, setting its value based on string comparisons, and then returning it.

[Vitaly Buka (NO REVIEWS), 2014/07/11 19:31:54]

Please just return DuplexUndefined; at the end of function.
and you can remove if (FX_BSTRC("None") == duplex) case

On 2014/07/11 06:58:42, Nikhil wrote:

[Nikhil, 2014/07/14 07:25:10]

Done.

+
 DLLEXPORT FPDF_DEST STDCALL FPDF_GetNamedDestByName(FPDF_DOCUMENT document,FPDF_BYTESTRING name)
 {
 	if (document == NULL)