Return unique_ptr<> from IPDF_StructTree

core/fpdfdoc/doc_tagged.cpp

Index: core/fpdfdoc/doc_tagged.cpp
diff --git a/core/fpdfdoc/doc_tagged.cpp b/core/fpdfdoc/doc_tagged.cpp
index 10c573b5cae576e1d7ab0eb6099abd48d76af3d7..39feaeef88c15168b5fdc16f1ad1226ac2bc23eb 100644
--- a/core/fpdfdoc/doc_tagged.cpp
+++ b/core/fpdfdoc/doc_tagged.cpp
@@ -5,6 +5,8 @@
 // Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
 
 #include <map>
+#include <memory>
+#include <utility>
 
 #include "core/fpdfapi/parser/cpdf_array.h"
 #include "core/fpdfapi/parser/cpdf_dictionary.h"
@@ -16,6 +18,7 @@
 #include "core/fpdfdoc/cpdf_numbertree.h"
 #include "core/fpdfdoc/fpdf_tagged.h"
 #include "core/fpdfdoc/tagged_int.h"
+#include "third_party/base/ptr_util.h"
 
 namespace {
 
@@ -30,24 +33,15 @@ bool IsTagged(const CPDF_Document* pDoc) {
 }  // namespace
 
 // static
-IPDF_StructTree* IPDF_StructTree::LoadPage(const CPDF_Document* pDoc,
-                                           const CPDF_Dictionary* pPageDict) {
+std::unique_ptr<IPDF_StructTree> IPDF_StructTree::LoadPage(
+    const CPDF_Document* pDoc,
+    const CPDF_Dictionary* pPageDict) {
   if (!IsTagged(pDoc))
     return nullptr;
 
-  CPDF_StructTreeImpl* pTree = new CPDF_StructTreeImpl(pDoc);
+  auto pTree = pdfium::MakeUnique<CPDF_StructTreeImpl>(pDoc);
   pTree->LoadPageTree(pPageDict);
-  return pTree;
-}
-
-// static.
-IPDF_StructTree* IPDF_StructTree::LoadDoc(const CPDF_Document* pDoc) {
-  if (!IsTagged(pDoc))
-    return nullptr;
-
-  CPDF_StructTreeImpl* pTree = new CPDF_StructTreeImpl(pDoc);
-  pTree->LoadDocTree();
-  return pTree;
+  return std::move(pTree);

[Wei Li, 2016/12/16 20:26:33]

Nit: move() is not needed here

[Tom Sepez, 2016/12/16 22:45:17]

Sadly, it is required, because the return type is an unique_ptr to a superclass
of the actual unique_ptr, and that breaks on android's old tool chain without
the move.

 }
 
 CPDF_StructTreeImpl::CPDF_StructTreeImpl(const CPDF_Document* pDoc)
@@ -65,31 +59,6 @@ IPDF_StructElement* CPDF_StructTreeImpl::GetTopElement(int i) const {
   return m_Kids[i].Get();
 }
 
-void CPDF_StructTreeImpl::LoadDocTree() {
-  m_pPage = nullptr;
-  if (!m_pTreeRoot)
-    return;
-
-  CPDF_Object* pKids = m_pTreeRoot->GetDirectObjectFor("K");
-  if (!pKids)
-    return;
-
-  if (CPDF_Dictionary* pDict = pKids->AsDictionary()) {
-    m_Kids.push_back(CFX_RetainPtr<CPDF_StructElementImpl>(
-        new CPDF_StructElementImpl(this, nullptr, pDict)));
-    return;
-  }
-
-  CPDF_Array* pArray = pKids->AsArray();
-  if (!pArray)
-    return;
-
-  for (size_t i = 0; i < pArray->GetCount(); i++) {
-    m_Kids.push_back(CFX_RetainPtr<CPDF_StructElementImpl>(
-        new CPDF_StructElementImpl(this, nullptr, pArray->GetDictAt(i))));
-  }
-}
-
 void CPDF_StructTreeImpl::LoadPageTree(const CPDF_Dictionary* pPageDict) {
   m_pPage = pPageDict;
   if (!m_pTreeRoot)