Implement FPDF_VIEWERREF_GetName() API.chromium/2910

This is a generic API function to retrieve any viewer preference of type
name.

BUG=pdfium:414

Review-Url: https://codereview.chromium.org/2475923003

2 files changed, 21 insertions, 0 deletions

diff --git a/core/fpdfdoc/cpdf_viewerpreferences.cpp b/core/fpdfdoc/cpdf_viewerpreferences.cpp
index 799f2d5814..f1fc4b0347 100644
--- a/core/fpdfdoc/cpdf_viewerpreferences.cpp
+++ b/core/fpdfdoc/cpdf_viewerpreferences.cpp
@@ -7,6 +7,7 @@
 #include "core/fpdfdoc/cpdf_viewerpreferences.h"
 
 #include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_name.h"
 
 CPDF_ViewerPreferences::CPDF_ViewerPreferences(CPDF_Document* pDoc)
     : m_pDoc(pDoc) {}
@@ -38,6 +39,21 @@ CFX_ByteString CPDF_ViewerPreferences::Duplex() const {
   return pDict ? pDict->GetStringFor("Duplex") : CFX_ByteString("None");
 }
 
+bool CPDF_ViewerPreferences::GenericName(const CFX_ByteString& bsKey,
+                                         CFX_ByteString* bsVal) const {
+  ASSERT(bsVal);
+  CPDF_Dictionary* pDict = GetViewerPreferences();
+  if (!pDict)
+    return false;
+
+  const CPDF_Name* pName = ToName(pDict->GetObjectFor(bsKey));
+  if (!pName)
+    return false;
+
+  *bsVal = pName->GetString();
+  return true;
+}
+
 CPDF_Dictionary* CPDF_ViewerPreferences::GetViewerPreferences() const {
   CPDF_Dictionary* pDict = m_pDoc->GetRoot();
   return pDict ? pDict->GetDictFor("ViewerPreferences") : nullptr;
diff --git a/core/fpdfdoc/cpdf_viewerpreferences.h b/core/fpdfdoc/cpdf_viewerpreferences.h
index c64292d9f9..c7e9112380 100644
--- a/core/fpdfdoc/cpdf_viewerpreferences.h
+++ b/core/fpdfdoc/cpdf_viewerpreferences.h
@@ -25,6 +25,11 @@ class CPDF_ViewerPreferences {
   CPDF_Array* PrintPageRange() const;
   CFX_ByteString Duplex() const;
 
+  // Gets the entry for |bsKey|. If the entry exists and it is of type name,
+  // then this method writes the value into |bsVal| and returns true. Otherwise
+  // returns false and |bsVal| is untouched. |bsVal| must not be NULL.
+  bool GenericName(const CFX_ByteString& bsKey, CFX_ByteString* bsVal) const;
+
  private:
   CPDF_Dictionary* GetViewerPreferences() const;