Refactor modification of Contents in CPDF_PageContentGenerator.

This is a pure refactor, there should be no change in behavior. It
prepares for the next CL, which will allow modification of content
streams.

Bug: pdfium:1051
Change-Id: I01ca3e897efe423e89df75e1f31cd67539cc3d08
Reviewed-on: https://pdfium-review.googlesource.com/34470
Commit-Queue: Henrique Nakashima <hnakashima@chromium.org>
Reviewed-by: dsinclair <dsinclair@chromium.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.h b/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
index a6cf215734..677d29267b 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
@@ -7,6 +7,8 @@
 #ifndef CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTGENERATOR_H_
 #define CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTGENERATOR_H_
 
+#include <map>
+#include <memory>
 #include <sstream>
 #include <vector>
 
@@ -41,6 +43,23 @@ class CPDF_PageContentGenerator {
   ByteString RealizeResource(const CPDF_Object* pResource,
                              const ByteString& bsType);
 
+  // Returns a map from content stream index to new stream data. Unmodified
+  // streams are not touched.
+  std::map<int32_t, std::unique_ptr<std::ostringstream>>
+  GenerateModifiedStreams();
+
+  // Generate new stream data with all dirty page objects.
+  bool GenerateStreamWithNewObjects(std::ostringstream* buf);
+
+  // Add buffer as a stream in page's 'Contents'
+  void UpdateContentStreams(
+      std::map<int32_t, std::unique_ptr<std::ostringstream>>* buf);
+
+  // Set the stream index of all page objects with stream index ==
+  // |CPDF_PageObject::kNoContentStream|. These are new objects that had not
+  // been parsed from or written to any content stream yet.
+  void UpdateStreamlessPageObjects(int new_content_stream_index);
+
   UnownedPtr<CPDF_PageObjectHolder> const m_pObjHolder;
   UnownedPtr<CPDF_Document> const m_pDocument;
   std::vector<UnownedPtr<CPDF_PageObject>> m_pageObjects;