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>
diff --git a/BUILD.gn b/BUILD.gn
index 008ac77..132f3c2 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -481,6 +481,8 @@
"core/fpdfapi/edit/cpdf_flateencoder.h",
"core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp",
"core/fpdfapi/edit/cpdf_pagecontentgenerator.h",
+ "core/fpdfapi/edit/cpdf_pagecontentmanager.cpp",
+ "core/fpdfapi/edit/cpdf_pagecontentmanager.h",
"core/fpdfapi/font/cfx_cttgsubtable.cpp",
"core/fpdfapi/font/cfx_cttgsubtable.h",
"core/fpdfapi/font/cfx_stockfontarray.cpp",
diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
index 3365b5f..e3a8674 100644
--- a/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
+++ b/core/fpdfapi/edit/cpdf_pagecontentgenerator.cpp
@@ -9,6 +9,7 @@
#include <tuple>
#include <utility>
+#include "core/fpdfapi/edit/cpdf_pagecontentmanager.h"
#include "core/fpdfapi/font/cpdf_font.h"
#include "core/fpdfapi/page/cpdf_docpagedata.h"
#include "core/fpdfapi/page/cpdf_image.h"
@@ -64,60 +65,67 @@
void CPDF_PageContentGenerator::GenerateContent() {
ASSERT(m_pObjHolder->IsPage());
- CPDF_Document* pDoc = m_pDocument.Get();
- std::ostringstream buf;
+ std::map<int32_t, std::unique_ptr<std::ostringstream>> stream =
+ GenerateModifiedStreams();
+ UpdateContentStreams(&stream);
+}
+
+std::map<int32_t, std::unique_ptr<std::ostringstream>>
+CPDF_PageContentGenerator::GenerateModifiedStreams() {
+ auto buf = pdfium::MakeUnique<std::ostringstream>();
+
+ std::map<int32_t, std::unique_ptr<std::ostringstream>> streams;
+ if (GenerateStreamWithNewObjects(buf.get()))
+ streams[CPDF_PageObject::kNoContentStream] = std::move(buf);
+
+ // TODO(pdfium:1051): Generate other streams and add to |streams|.
+
+ return streams;
+}
+
+bool CPDF_PageContentGenerator::GenerateStreamWithNewObjects(
+ std::ostringstream* buf) {
// Set the default graphic state values
- buf << "q\n";
+ *buf << "q\n";
if (!m_pObjHolder->GetLastCTM().IsIdentity())
- buf << m_pObjHolder->GetLastCTM().GetInverse() << " cm\n";
- ProcessDefaultGraphics(&buf);
+ *buf << m_pObjHolder->GetLastCTM().GetInverse() << " cm\n";
+ ProcessDefaultGraphics(buf);
// Process the page objects
- if (!ProcessPageObjects(&buf))
- return;
+ if (!ProcessPageObjects(buf))
+ return false;
// Return graphics to original state
- buf << "Q\n";
+ *buf << "Q\n";
- // Add buffer to a stream in page's 'Contents'
- CPDF_Dictionary* pPageDict = m_pObjHolder->GetDict();
- if (!pPageDict)
+ return true;
+}
+
+void CPDF_PageContentGenerator::UpdateContentStreams(
+ std::map<int32_t, std::unique_ptr<std::ostringstream>>* new_stream_data) {
+ // If no streams were regenerated or removed, nothing to do here.
+ if (new_stream_data->empty())
return;
- CPDF_Object* pContent = pPageDict->GetObjectFor("Contents");
- CPDF_Stream* pStream = pDoc->NewIndirect<CPDF_Stream>();
- pStream->SetData(&buf);
- if (pContent) {
- CPDF_Array* pArray = ToArray(pContent);
- if (pArray) {
- pArray->Add(pStream->MakeReference(pDoc));
- return;
+ CPDF_PageContentManager page_content_manager(m_pObjHolder.Get());
+
+ for (auto& pair : *new_stream_data) {
+ int32_t stream_index = pair.first;
+ std::ostringstream* buf = pair.second.get();
+
+ if (stream_index == CPDF_PageObject::kNoContentStream) {
+ int new_stream_index = page_content_manager.AddStream(buf);
+ UpdateStreamlessPageObjects(new_stream_index);
+ continue;
}
- CPDF_Reference* pReference = ToReference(pContent);
- if (!pReference) {
- pPageDict->SetFor("Contents", pStream->MakeReference(pDoc));
- return;
- }
- CPDF_Object* pDirectObj = pReference->GetDirect();
- if (!pDirectObj) {
- pPageDict->SetFor("Contents", pStream->MakeReference(pDoc));
- return;
- }
- CPDF_Array* pObjArray = pDirectObj->AsArray();
- if (pObjArray) {
- pObjArray->Add(pStream->MakeReference(pDoc));
- return;
- }
- if (pDirectObj->IsStream()) {
- CPDF_Array* pContentArray = pDoc->NewIndirect<CPDF_Array>();
- pContentArray->Add(pDirectObj->MakeReference(pDoc));
- pContentArray->Add(pStream->MakeReference(pDoc));
- pPageDict->SetFor("Contents", pContentArray->MakeReference(pDoc));
- return;
- }
+
+ CPDF_Stream* old_stream =
+ page_content_manager.GetStreamByIndex(stream_index);
+ ASSERT(old_stream);
+
+ old_stream->SetData(buf);
}
- pPageDict->SetFor("Contents", pStream->MakeReference(pDoc));
}
ByteString CPDF_PageContentGenerator::RealizeResource(
@@ -165,6 +173,12 @@
return bDirty;
}
+void CPDF_PageContentGenerator::UpdateStreamlessPageObjects(
+ int new_content_stream_index) {
+ // TODO(pdfium:1051): Mark page objects that did not have a content stream
+ // with the new content stream index.
+}
+
void CPDF_PageContentGenerator::ProcessImage(std::ostringstream* buf,
CPDF_ImageObject* pImageObj) {
if ((pImageObj->matrix().a == 0 && pImageObj->matrix().b == 0) ||
diff --git a/core/fpdfapi/edit/cpdf_pagecontentgenerator.h b/core/fpdfapi/edit/cpdf_pagecontentgenerator.h
index a6cf215..677d292 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 @@
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;
diff --git a/core/fpdfapi/edit/cpdf_pagecontentmanager.cpp b/core/fpdfapi/edit/cpdf_pagecontentmanager.cpp
new file mode 100644
index 0000000..e9ade27
--- /dev/null
+++ b/core/fpdfapi/edit/cpdf_pagecontentmanager.cpp
@@ -0,0 +1,87 @@
+// Copyright 2018 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "core/fpdfapi/edit/cpdf_pagecontentmanager.h"
+
+#include "core/fpdfapi/parser/cpdf_array.h"
+#include "core/fpdfapi/parser/cpdf_dictionary.h"
+#include "core/fpdfapi/parser/cpdf_document.h"
+#include "core/fpdfapi/parser/cpdf_reference.h"
+#include "core/fpdfapi/parser/cpdf_stream.h"
+
+CPDF_PageContentManager::CPDF_PageContentManager(
+ CPDF_PageObjectHolder* obj_holder)
+ : obj_holder_(obj_holder), doc_(obj_holder_->GetDocument()) {
+ CPDF_Dictionary* page_dict = obj_holder_->GetDict();
+ CPDF_Object* contents_obj = page_dict->GetObjectFor("Contents");
+ CPDF_Array* contents_array = ToArray(contents_obj);
+ if (contents_array) {
+ contents_array_ = contents_array;
+ return;
+ }
+
+ CPDF_Reference* contents_reference = ToReference(contents_obj);
+ if (contents_reference) {
+ CPDF_Object* indirect_obj = contents_reference->GetDirect();
+ if (!indirect_obj)
+ return;
+
+ contents_array = indirect_obj->AsArray();
+ if (contents_array)
+ contents_array_ = contents_array;
+ else if (indirect_obj->IsStream())
+ contents_stream_ = indirect_obj->AsStream();
+ }
+}
+
+CPDF_PageContentManager::~CPDF_PageContentManager() = default;
+
+CPDF_Stream* CPDF_PageContentManager::GetStreamByIndex(size_t stream_index) {
+ if (contents_stream_)
+ return stream_index == 0 ? contents_stream_.Get() : nullptr;
+
+ if (contents_array_) {
+ CPDF_Reference* stream_reference =
+ ToReference(contents_array_->GetObjectAt(stream_index));
+ if (!stream_reference)
+ return nullptr;
+
+ return stream_reference->GetDirect()->AsStream();
+ }
+
+ return nullptr;
+}
+
+size_t CPDF_PageContentManager::AddStream(std::ostringstream* buf) {
+ CPDF_Stream* new_stream = doc_->NewIndirect<CPDF_Stream>();
+ new_stream->SetData(buf);
+
+ // If there is one Content stream (not in an array), now there will be two, so
+ // create an array with the old and the new one. The new one's index is 1.
+ if (contents_stream_) {
+ CPDF_Array* new_contents_array = doc_->NewIndirect<CPDF_Array>();
+ new_contents_array->Add(contents_stream_->MakeReference(doc_.Get()));
+ new_contents_array->Add(new_stream->MakeReference(doc_.Get()));
+
+ CPDF_Dictionary* page_dict = obj_holder_->GetDict();
+ page_dict->SetFor("Contents",
+ new_contents_array->MakeReference(doc_.Get()));
+ contents_array_ = new_contents_array;
+ contents_stream_ = nullptr;
+ return 1;
+ }
+
+ // If there is an array, just add the new stream to it, at the last position.
+ if (contents_array_) {
+ contents_array_->Add(new_stream->MakeReference(doc_.Get()));
+ return contents_array_->GetCount() - 1;
+ }
+
+ // There were no Contents, so add the new stream as the single Content stream.
+ // Its index is 0.
+ CPDF_Dictionary* page_dict = obj_holder_->GetDict();
+ page_dict->SetFor("Contents", new_stream->MakeReference(doc_.Get()));
+ contents_stream_ = new_stream;
+ return 0;
+}
diff --git a/core/fpdfapi/edit/cpdf_pagecontentmanager.h b/core/fpdfapi/edit/cpdf_pagecontentmanager.h
new file mode 100644
index 0000000..384405b
--- /dev/null
+++ b/core/fpdfapi/edit/cpdf_pagecontentmanager.h
@@ -0,0 +1,38 @@
+// Copyright 2018 PDFium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTMANAGER_H_
+#define CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTMANAGER_H_
+
+#include <sstream>
+
+#include "core/fxcrt/unowned_ptr.h"
+
+class CPDF_Array;
+class CPDF_Document;
+class CPDF_Object;
+class CPDF_Stream;
+class CPDF_PageObjectHolder;
+
+class CPDF_PageContentManager {
+ public:
+ explicit CPDF_PageContentManager(CPDF_PageObjectHolder* pObjHolder);
+ ~CPDF_PageContentManager();
+
+ // Gets the Content stream at a given index. If Contents is a single stream
+ // rather than an array, it is considered to be at index 0.
+ CPDF_Stream* GetStreamByIndex(size_t stream_index);
+
+ // Adds a new Content stream. Its index in the array will be returned, or 0
+ // if Contents is not an array, but only a single stream.
+ size_t AddStream(std::ostringstream* buf);
+
+ private:
+ UnownedPtr<CPDF_PageObjectHolder> const obj_holder_;
+ UnownedPtr<CPDF_Document> const doc_;
+ UnownedPtr<CPDF_Array> contents_array_;
+ UnownedPtr<CPDF_Stream> contents_stream_;
+};
+
+#endif // CORE_FPDFAPI_EDIT_CPDF_PAGECONTENTMANAGER_H_
