Move SharedForm check to CPDF_Metadata class

This CL moves code related to shared form detection into the
CPDF_Metadata class. This allows us to hide the usage of CXML inside
CPDF_Metadata.

Change-Id: I547471a2bcc119221565c415a58211c1500cbb3c
Reviewed-on: https://pdfium-review.googlesource.com/30370
Reviewed-by: Henrique Nakashima <hnakashima@chromium.org>
Commit-Queue: dsinclair <dsinclair@chromium.org>

2 files changed, 90 insertions, 20 deletions

diff --git a/core/fpdfdoc/cpdf_metadata.cpp b/core/fpdfdoc/cpdf_metadata.cpp
index efe3c29dbf..11fde82036 100644
--- a/core/fpdfdoc/cpdf_metadata.cpp
+++ b/core/fpdfdoc/cpdf_metadata.cpp
@@ -6,27 +6,76 @@
 
 #include "core/fpdfdoc/cpdf_metadata.h"
 
-#include "core/fpdfapi/parser/cpdf_document.h"
 #include "core/fpdfapi/parser/cpdf_stream.h"
 #include "core/fpdfapi/parser/cpdf_stream_acc.h"
+#include "core/fxcrt/xml/cxml_content.h"
 #include "core/fxcrt/xml/cxml_element.h"
 
-CPDF_Metadata::CPDF_Metadata(const CPDF_Document* pDoc) {
-  const CPDF_Dictionary* pRoot = pDoc->GetRoot();
-  if (!pRoot)
-    return;
+namespace {
 
-  CPDF_Stream* pStream = pRoot->GetStreamFor("Metadata");
-  if (!pStream)
-    return;
+void CheckForSharedFormInternal(CXML_Element* element,
+                                std::vector<UnsupportedFeature>* unsupported) {
+  size_t count = element->CountAttrs();
+  for (size_t i = 0; i < count; ++i) {
+    ByteString space;
+    ByteString name;
+    WideString value;
+    element->GetAttrByIndex(i, &space, &name, &value);
+    if (space != "xmlns" || name != "adhocwf" ||
+        value != L"http://ns.adobe.com/AcrobatAdhocWorkflow/1.0/") {
+      continue;
+    }
 
-  auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(pStream);
-  pAcc->LoadAllDataFiltered();
-  m_pXmlElement = CXML_Element::Parse(pAcc->GetData(), pAcc->GetSize());
+    CXML_Element* pVersion = element->GetElement("adhocwf", "workflowType", 0);
+    if (!pVersion)
+      continue;
+
+    CXML_Content* pContent = ToContent(pVersion->GetChild(0));
+    if (!pContent)
+      continue;
+
+    switch (pContent->m_Content.GetInteger()) {
+      case 0:
+        unsupported->push_back(UnsupportedFeature::kDocumentSharedFormEmail);
+        break;
+      case 1:
+        unsupported->push_back(UnsupportedFeature::kDocumentSharedFormAcrobat);
+        break;
+      case 2:
+        unsupported->push_back(
+            UnsupportedFeature::kDocumentSharedFormFilesystem);
+        break;
+    }
+  }
+
+  count = element->CountChildren();
+  for (size_t i = 0; i < count; ++i) {
+    CXML_Element* child = ToElement(element->GetChild(i));
+    if (!child)
+      continue;
+
+    CheckForSharedFormInternal(child, unsupported);
+  }
 }
 
-CPDF_Metadata::~CPDF_Metadata() {}
+}  // namespace
+
+CPDF_Metadata::CPDF_Metadata(const CPDF_Stream* pStream) : stream_(pStream) {
+  ASSERT(pStream);
+}
+
+CPDF_Metadata::~CPDF_Metadata() = default;
+
+std::vector<UnsupportedFeature> CPDF_Metadata::CheckForSharedForm() const {
+  auto pAcc = pdfium::MakeRetain<CPDF_StreamAcc>(stream_.Get());
+  pAcc->LoadAllDataFiltered();
+
+  std::unique_ptr<CXML_Element> xml_root =
+      CXML_Element::Parse(pAcc->GetData(), pAcc->GetSize());
+  if (!xml_root)
+    return {};
 
-const CXML_Element* CPDF_Metadata::GetRoot() const {
-  return m_pXmlElement.get();
+  std::vector<UnsupportedFeature> unsupported;
+  CheckForSharedFormInternal(xml_root.get(), &unsupported);
+  return unsupported;
 }
diff --git a/core/fpdfdoc/cpdf_metadata.h b/core/fpdfdoc/cpdf_metadata.h
index fa958153fc..edf1938c4e 100644
--- a/core/fpdfdoc/cpdf_metadata.h
+++ b/core/fpdfdoc/cpdf_metadata.h
@@ -8,19 +8,40 @@
 #define CORE_FPDFDOC_CPDF_METADATA_H_
 
 #include <memory>
-
-class CPDF_Document;
-class CXML_Element;
+#include <vector>
+
+#include "core/fxcrt/unowned_ptr.h"
+
+class CPDF_Stream;
+
+enum class UnsupportedFeature : uint8_t {
+  kDocumentXFAForm = 1,
+  kDocumentPortableCollection = 2,
+  kDocumentAttachment = 3,
+  kDocumentSecurity = 4,
+  kDocumentSharedReview = 5,
+  kDocumentSharedFormAcrobat = 6,
+  kDocumentSharedFormFilesystem = 7,
+  kDocumentSharedFormEmail = 8,
+
+  kAnnotation3d = 11,
+  kAnnotationMovie = 12,
+  kAnnotationSound = 13,
+  kAnnotationScreenMedia = 14,
+  kAnnotationScreenRichMedia = 15,
+  kAnnotationAttachment = 16,
+  kAnnotationSignature = 17
+};
 
 class CPDF_Metadata {
  public:
-  explicit CPDF_Metadata(const CPDF_Document* pDoc);
+  explicit CPDF_Metadata(const CPDF_Stream* pStream);
   ~CPDF_Metadata();
 
-  const CXML_Element* GetRoot() const;
+  std::vector<UnsupportedFeature> CheckForSharedForm() const;
 
  private:
-  std::unique_ptr<CXML_Element> m_pXmlElement;
+  UnownedPtr<const CPDF_Stream> stream_;
 };
 
 #endif  // CORE_FPDFDOC_CPDF_METADATA_H_